CN108317786B - A control circuit for a Stirling refrigerator - Google Patents

Abstract

The control circuit of the Stirling refrigerator provided by the present invention, the DC power conversion circuit is connected with the main drive circuit, the temperature setting circuit, the filtering and reverse connection protection circuit, the temperature measurement feedback circuit, the Hall power supply circuit and the feedback comparison circuit; The drive circuit is connected with the feedback comparison circuit, the power bridge drive circuit and the filtering and reverse connection protection circuit; the temperature setting circuit is connected with the feedback comparison circuit, the Hall power supply circuit and the temperature measurement feedback circuit; the temperature measurement feedback circuit is connected with the feedback comparison circuit; The Hall feedback filter circuit is connected with the main drive circuit, the DC power conversion circuit and the Hall sensor of the Stirling refrigerator; the Hall power supply circuit is connected with the Hall sensor of the Stirling refrigerator; the overcurrent protection circuit is connected with the power bridge drive The circuit, the main driving circuit and the filtering and reverse connection protection circuit are connected; the power bridge driving circuit is connected with the three-phase winding of the Stirling refrigerator.

Description

A control circuit for a Stirling refrigerator

technical field

The invention relates to the field of infrared detectors, in particular to a control circuit of a Stirling refrigerator.

Background technique

A large area array infrared detector is a semiconductor imaging device that is highly sensitive to temperature. It usually needs to work in a stable low temperature environment provided by a Stirling refrigerator in order to achieve the best infrared imaging effect and obtain high-quality infrared imaging. infrared image.

The control circuit of the existing Stirling refrigerator can output less power for the power output circuit that drives the operation of the refrigerator, so that the cooling capacity generated by the Stirling refrigerator cannot be provided for the stable operation of the large area array infrared detector. Suitable working environment, and in the control circuit of the existing Stirling refrigerator, the power conversion circuit mostly uses a low-dropout linear regulator LDO for DC conversion, and the heat dissipation of the circuit is large, which leads to low efficiency of the power conversion circuit. high, thus affecting the efficiency of the entire control circuit.

SUMMARY OF THE INVENTION

The invention provides a control circuit for a Stirling refrigerator, which is used to solve the following problems in the prior art: the control circuit of the existing Stirling refrigerator is not suitable for controlling a large area array infrared detector to work stably Stirling refrigerators that provide the required cooling capacity.

In order to solve the above technical problems, the present invention provides a control circuit for a Stirling refrigerator, including: a Hall power supply circuit, a filter and reverse connection protection circuit, a DC power conversion circuit, a temperature setting circuit, a temperature measurement feedback circuit, a Hall Hall feedback filter circuit, feedback comparison circuit, main drive circuit, overcurrent protection circuit, power bridge drive circuit; wherein, the Hall power supply circuit, the DC power conversion circuit and the Hall sensor of the Stirling refrigerator connection; the filtering and reverse connection protection circuit is connected with the DC power conversion circuit and the main drive circuit; the DC power conversion circuit is connected with the main drive circuit, the temperature setting circuit, and the temperature measurement feedback circuit and the feedback comparison circuit; the main drive circuit is connected with the feedback comparison circuit and the power bridge drive circuit; the temperature setting circuit is connected with the feedback comparison circuit, the Hall power supply circuit and the The temperature measurement feedback circuit is connected to the temperature measurement feedback circuit; the temperature measurement feedback circuit is connected to the feedback comparison circuit; the Hall feedback filter circuit is connected to the main drive circuit, the DC power conversion circuit and the Stirling refrigerator. Hall sensor connection; the overcurrent protection circuit is connected with the power bridge drive circuit, the main drive circuit and the filtering and reverse connection protection circuit; the power bridge drive circuit is connected with the Stirling refrigerator Three-phase winding connection.

Optionally, the DC power conversion circuit includes: a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a first capacitor, a second capacitor, a third capacitor, a fourth resistor capacitor, fifth capacitor, first switch tube, first predetermined chip and transformer; wherein, one end of the first resistor is connected to one end of the first capacitor, and the other end of the first resistor is connected to the first predetermined chip. The first port is connected, the other end of the first capacitor is connected to one end of the second capacitor, the other end of the second capacitor is connected to the second port of the first predetermined chip, and the third capacitor is One end is connected to one end of the second resistor, one end of the second resistor is grounded, the other end of the third capacitor is connected to the third port of the first predetermined chip, and the other end of the second resistor is connected to The fourth port of the first predetermined chip is connected; one end of the third resistor is connected to the fifth port of the first predetermined chip, and the other end of the third resistor is connected to the sixth port of the first predetermined chip connection, the gate of the first switch tube is connected to the seventh port of the first predetermined chip, the source of the first switch tube is connected to one end of the fourth resistor and the seventh port of the first predetermined chip Eight-port connection, the other end of the fourth resistor is connected to the ninth port of the first predetermined chip, the ninth port is grounded, the drain of the switch tube is connected to one end of the primary side of the transformer, so the other end of the primary side of the transformer is connected to the tenth port of the first predetermined chip; the first end of the secondary side of the transformer is connected to one end of the fifth capacitor, the input end of the main drive circuit and the The input end of the power supply circuit is connected, the other end of the fifth capacitor is grounded, the second end of the secondary side of the transformer is connected to one end of the fourth capacitor, one end of the fifth resistor, and the temperature setting circuit The input end of the temperature measurement feedback circuit and the input end of the feedback comparison circuit are connected, the other end of the fourth capacitor is grounded, and the other end of the fifth resistor is connected to one end of the sixth resistor connected, the other end of the sixth resistor is connected to the third end of the secondary side of the transformer, and the third end is grounded.

Optionally, the main drive circuit includes: a seventh resistor, an eighth resistor, a ninth resistor, a tenth resistor, an eleventh resistor, a twelfth resistor, a thirteenth resistor, a fourteenth resistor, and a fifteenth resistor a resistor, a sixteenth resistor, a sixth capacitor, a seventh capacitor, an eighth capacitor, a ninth capacitor, a tenth capacitor, a first diode, and a second predetermined chip; wherein the cathode of the first diode is connected to the The output end of the feedback comparison circuit is connected, the anode of the first diode is connected to one end of the seventh resistor, one end of the tenth capacitor and the first port of the second predetermined chip, the The other end of the seventh resistor is connected to one end of the eighth resistor and the second port of the second predetermined chip, and the other end of the eighth resistor is connected to the third port of the second predetermined chip and the second port of the second predetermined chip. One end of the ninth capacitor is connected to one end of the tenth resistor, the other end of the tenth resistor is connected to one end of the eleventh resistor, one end of the eleventh resistor is grounded, and the other end of the eleventh resistor is connected to the ground. The other end is connected to the fourth port of the second predetermined chip and one end of the ninth resistor, and the other end of the ninth resistor is connected to one end of the eighth capacitor and the fifth port of the second predetermined chip connected, the other end of the eighth capacitor, the other end of the ninth capacitor and the other end of the tenth capacitor are grounded, and one end of the twelfth resistor is connected to the sixth port of the second predetermined chip , the other end of the twelfth resistor is grounded, one end of the thirteenth resistor is connected to the seventh port of the second predetermined chip, the other end of the thirteenth resistor is grounded, and one end of the sixth capacitor connected to the eighth port of the second predetermined chip, the other end of the sixth capacitor is grounded, one end of the fourteenth resistor is connected to one end of the sixteenth resistor, one end of the seventh capacitor and the The ninth port of the second predetermined chip is connected, the other end of the fourteenth resistor is grounded, the other end of the sixteenth resistor is connected to one end of the fifteenth resistor, the other end of the seventh capacitor and The tenth port of the second predetermined chip is connected, and the other end of the fifteenth resistor is grounded.

Optionally, the temperature setting circuit includes: a voltage reference source, a predetermined resistance network, a potentiometer, an eleventh capacitor and a first predetermined operational amplifier; wherein the input end of the voltage reference source is converted with the DC power supply The second end of the transformer secondary side of the circuit is connected, the output end of the voltage reference source is connected to the first end of the predetermined resistance network, and the third end of the predetermined resistance network is connected to the ground of the voltage reference source terminal, the ground terminal of the voltage reference source is grounded, the second terminal of the predetermined resistor network is connected to the first terminal of the potentiometer, and the fourth terminal of the predetermined resistor network is connected to the second terminal of the potentiometer The third end of the potentiometer is connected to one end of the eleventh capacitor and the non-inverting input end of the first predetermined operational amplifier, the other end of the eleventh capacitor is grounded, and the first predetermined operation The inverting input terminal of the amplifier is connected to the output terminal of the first predetermined operational amplifier, and the positive power supply terminal of the first predetermined operational amplifier is connected to the second terminal of the secondary side of the transformer of the DC power conversion circuit, so The negative power supply terminal of the first predetermined operational amplifier is grounded.

Optionally, the filtering and reverse connection protection circuit includes: a second diode, a first inductor, a second inductor, a twelfth capacitor, a thirteenth capacitor, a fourteenth capacitor, a fifteenth capacitor, a tenth capacitor Six capacitors and magnetic beads; wherein, positive voltage is applied to the anode of the second diode, the cathode of the second diode is connected to one end of the first inductor, and the other end of the first inductor is connected to the One end of the twelfth capacitor is connected to the first end of the second inductor, the other end of the twelfth capacitor is applied with a negative voltage, and the other end of the twelfth capacitor is connected to the second end of the second inductor connected, the third end of the second inductor is connected to one end of the thirteenth capacitor, one end of the fourteenth capacitor, one end of the fifteenth capacitor and one end of the magnetic bead, and the first The fourth end of the second inductor is connected to the other end of the thirteenth capacitor, the other end of the thirteenth capacitor, the other end of the fourteenth capacitor, and the other end of the fifteenth capacitor are grounded, so The other end of the magnetic bead is connected to one end of the sixteenth capacitor, the first predetermined chip of the DC power conversion circuit and the input end of the main drive circuit, and the other end of the sixteenth capacitor is grounded .

Optionally, the power bridge drive circuit includes: a third predetermined chip, a fourth predetermined chip, a fifth predetermined chip, a seventeenth capacitor, an eighteenth capacitor, a nineteenth capacitor, a seventeenth resistor, an eighteenth capacitor Resistor, nineteenth resistor, twentieth resistor, twenty-first resistor, twenty-second resistor, second switch tube, third switch tube, fourth switch tube, fifth switch tube, sixth switch tube, first switch tube seven switches, a third diode, a fourth diode and a fifth diode; wherein the third predetermined chip is connected to the first predetermined chip of the main drive circuit, and the seventeenth One end of the capacitor is connected to the first port of the third predetermined chip, and the other end of the seventeenth capacitor is connected to the second port of the third predetermined chip, the source of the second switch tube, and the first port of the third predetermined chip. The drain of the three-switch tube is connected to the input end of the third diode, one end of the seventeenth resistor is connected to the third port of the third predetermined chip, and the other end of the seventeenth resistor is connected to the third port of the third predetermined chip. The gate of the second switch tube is connected, the drain of the second switch tube is voltage-applied, one end of the eighteenth resistor is connected to the fourth port of the third predetermined chip, and the eighteenth resistor is connected to the fourth port of the third predetermined chip. The other end is connected to the gate of the third switch tube, and the source of the third switch tube is grounded; the fourth predetermined chip is connected to the first predetermined chip of the main drive circuit, and the tenth predetermined chip is connected to the first predetermined chip of the main drive circuit. One end of the eighteenth capacitor is connected to the first port of the fourth predetermined chip, and the other end of the eighteenth capacitor is connected to the second port of the fourth predetermined chip, the source of the fourth switch tube, the The drain of the fifth switch tube is connected to the input end of the fourth diode, one end of the nineteenth resistor is connected to the third port of the third predetermined chip, and the other end of the nineteenth resistor is connected connected to the gate of the fourth switch tube, the drain of the fourth switch tube is voltage applied, one end of the twentieth resistor is connected to the fourth port of the fourth predetermined chip, and the twentieth resistor The other end of the switch is connected to the gate of the fifth switch tube, and the source of the fifth switch tube is grounded;

The fifth predetermined chip is connected to the first predetermined chip of the main drive circuit, one end of the nineteenth capacitor is connected to the first port of the fifth predetermined chip, and the other end of the nineteenth capacitor is connected to the first port of the fifth predetermined chip. One end is connected to the second port of the fifth predetermined chip, the source of the sixth switch tube, the drain of the seventh switch tube and the input end of the fifth diode, the twentieth One end of a resistor is connected to the third port of the fifth predetermined chip, the other end of the twenty-first resistor is connected to the gate of the sixth switch tube, and the drain of the sixth switch tube is voltage-applied , one end of the 22nd resistor is connected to the fourth port of the fifth predetermined chip, the other end of the 22nd resistor is connected to the gate of the seventh switch tube, the seventh switch tube The source is grounded.

Optionally, the temperature measurement feedback circuit includes: a predetermined temperature measurement element, a third inductance, a twenty-third resistor, a twenty-fourth resistor, a twenty-fifth resistor, a twenty-sixth resistor, and a twenty-seventh resistor , the twentieth capacitor, the twenty-first capacitor, the twenty-second capacitor, and a second predetermined operational amplifier; wherein, the positive electrode of the predetermined temperature measuring element is connected to the first end of the third inductor, and the predetermined temperature measuring element is connected to the first end of the third inductor. The negative electrode of the temperature element is connected to the second end of the third inductor, one end of the twenty-third resistor is connected to the second end of the secondary side of the transformer, and the other end of the twenty-third resistor is connected to the second end of the transformer secondary side. The third end of the third inductor, one end of the twentieth capacitor, and one end of the twenty-fifth resistor are connected, and the other end of the twentieth capacitor is connected to the fourth end of the third inductor, the One end of the twenty-fourth resistor is connected to one end of the twenty-sixth resistor, the other end of the twenty-fourth resistor is grounded, and the other end of the twenty-fifth resistor is connected to the twenty-first capacitor. One end is connected to the first end of the second predetermined operational amplifier, the other end of the twenty-sixth resistor is connected to one end of the twenty-second capacitor and the second end of the second predetermined operational amplifier, so The other end of the twenty-first capacitor is connected to the other end of the twenty-second capacitor, the third end of the second predetermined operational amplifier, and the fourth end of the second predetermined operational amplifier, and the second The third terminal of the predetermined operational amplifier is grounded, one end of the twenty-seventh resistor is connected to the fifth terminal of the second predetermined operational amplifier, and the other end of the twenty-seventh resistor is connected to the second predetermined operational amplifier The sixth terminal of the amplifier is connected to the input terminal of the feedback comparison circuit, and the seventh terminal of the second predetermined operational amplifier is connected to the second terminal of the secondary side of the transformer.

Optionally, the feedback comparison circuit includes: the twenty-eighth resistor, the twenty-ninth resistor, the thirtieth resistor, the thirty-first resistor, the thirty-second resistor, the thirty-third resistor, the twenty-third resistor capacitor, the twenty-fourth capacitor, the twenty-fifth capacitor, the third predetermined operational amplifier, the fourth predetermined operational amplifier and the sixth predetermined chip; wherein, one end of the twenty-eighth resistor is connected to the temperature setting circuit. the output end is connected, and the other end of the twenty-eighth resistor is connected to one end of the twenty-ninth resistor and the non-inverting input end of the third predetermined operational amplifier, and the inverting input end of the third predetermined operational amplifier is connected to the sixth end of the second predetermined operational amplifier of the temperature measurement feedback circuit, and the other end of the twenty-ninth resistor is connected to the output end of the third predetermined operational amplifier and the sixth predetermined chip , one end of the thirtieth resistor is connected to the output end of the first predetermined operational amplifier of the temperature setting circuit, and the other end of the thirtieth resistor is connected to one end of the twenty-third capacitor and the The non-inverting input end of the fourth operational amplifier is connected, the other end of the twenty-third capacitor is grounded, one end of the thirty-first resistor is connected to the sixth predetermined chip, and the other end of the thirty-first resistor is connected to the ground. One end is connected to one end of the twenty-fourth capacitor and one end of the thirty-third resistor, and one end of the thirty-second resistor is connected to the sixth end of the second predetermined operational amplifier of the temperature measurement feedback circuit. The other end of the thirty-second resistor is connected to the inverting input end of the fourth predetermined operational amplifier, the other end of the thirty-third resistor, and one end of the twenty-fifth capacitor, so The output end of the fourth predetermined operational amplifier is connected to the other end of the twenty-fourth capacitor, the other end of the twenty-fifth capacitor, and the sixth predetermined chip.

The control circuit of the Stirling refrigerator provided by the present invention, the DC power conversion circuit is connected with the main drive circuit, the temperature setting circuit, the filtering and reverse connection protection circuit, the temperature measurement feedback circuit, the Hall power supply circuit and the feedback comparison circuit; The drive circuit is connected with the feedback comparison circuit, the power bridge drive circuit and the filtering and reverse connection protection circuit; the temperature setting circuit is connected with the feedback comparison circuit, the Hall power supply circuit and the temperature measurement feedback circuit; the temperature measurement feedback circuit is connected with the feedback comparison circuit; The Hall feedback filter circuit is connected with the main drive circuit, the DC power conversion circuit and the Hall sensor of the Stirling refrigerator; the Hall power supply circuit is connected with the Hall sensor of the Stirling refrigerator; the overcurrent protection circuit is connected with the power bridge drive The circuit, the main drive circuit and the filtering and reverse connection protection circuit are connected; the power bridge drive circuit is connected with the three-phase winding of the Stirling refrigerator.

In this circuit, the external power supply supplies power to the filtering and reverse connection protection circuit. The output of this circuit is used as the input of the DC power conversion circuit and the main drive circuit. The output of the DC power conversion circuit is used as the input of the Hall power supply circuit. The output provides a suitable working voltage to the Hall sensor of the Stirling refrigerator. When the voltage value measured by the temperature measuring element in the temperature measurement feedback circuit is less than the set level value, the Stirling refrigerator works at full speed and rapidly cools down; When the voltage value measured by the temperature measurement feedback circuit is close to the set level value, the voltage value set by the temperature control setting circuit is compared with the voltage value obtained by the temperature measurement feedback circuit, and is output as the control voltage through the feedback comparison circuit. The level is input to the main drive circuit and compared with the triangular wave generated by it, so that the main drive circuit outputs a pulse width modulated PWM wave. The PWM wave is used as the input of the power bridge drive circuit, and the power is output to the Stirling refrigerator through the power bridge drive circuit. The three-phase winding of the Stirling refrigerator is used to control the speed of the Stirling refrigerator, thereby controlling the output power of the Stirling refrigerator. The following problems in the prior art are solved: the control circuit of the existing Stirling refrigerator is not suitable for controlling the Stirling refrigerator capable of providing the cooling capacity required for the stable operation of the large area array infrared detector.

Description of drawings

1 is a schematic structural diagram of a control circuit of a Stirling refrigerator in an embodiment of the present invention;

2 is a circuit diagram of a DC power conversion circuit in an embodiment of the present invention;

3 is a circuit diagram of a main drive circuit in an embodiment of the present invention;

4 is a circuit diagram of a temperature setting circuit in an embodiment of the present invention;

5 is a circuit diagram of a filtering and reverse connection protection circuit in an embodiment of the present invention;

Fig. 6 is the electromagnetic compatibility performance test chart of RE102 of the existing filter and reverse connection protection circuit;

Fig. 7 is the CE102 electromagnetic compatibility performance test diagram of the existing filter and reverse protection circuit;

Fig. 8 is the RE102 electromagnetic compatibility performance test diagram of the filtering and reverse connection protection circuit in the embodiment of the present invention;

Fig. 9 is the CE102 electromagnetic compatibility performance test diagram of the filtering and reverse connection protection circuit in the present embodiment in the embodiment of the present invention;

10 is a circuit diagram of a power bridge drive circuit in an embodiment of the present invention;

11 is a circuit diagram of a temperature measurement feedback circuit in an embodiment of the present invention;

12 is a circuit diagram of a feedback comparison circuit in an embodiment of the present invention;

13 is a circuit diagram of an overcurrent protection circuit in an embodiment of the present invention;

14 is a circuit diagram of a Hall power supply circuit in an embodiment of the present invention;

FIG. 15 is a circuit diagram of a Hall feedback filter circuit in an embodiment of the present invention.

Detailed ways

In order to solve the following problems in the prior art: the control circuit of the existing Stirling refrigerator is not suitable for controlling the Stirling refrigerator capable of providing the cooling capacity required for the stable operation of the large area array infrared detector. This embodiment provides a control circuit for a Stirling refrigerator. The schematic structural diagram of the circuit is shown in Figure 1, including: a Hall power supply circuit, a filtering and reverse connection protection circuit, a DC power conversion circuit, and a temperature setting circuit , Temperature measurement feedback circuit, Hall feedback filter circuit, feedback comparison circuit, main drive circuit, overcurrent protection circuit, power bridge drive circuit.

Among them, the Hall power supply circuit is connected with the DC power conversion circuit and the Hall sensor of the Stirling refrigerator; the filter and reverse connection protection circuit is connected with the DC power conversion circuit and the main drive circuit; the DC power conversion circuit is connected with the main drive circuit, temperature The setting circuit, the temperature measurement feedback circuit and the feedback comparison circuit are connected; the main drive circuit is connected with the feedback comparison circuit and the power bridge drive circuit; the temperature setting circuit is connected with the feedback comparison circuit, the Hall power supply circuit and the temperature measurement feedback circuit; temperature measurement The feedback circuit is connected with the feedback comparison circuit; the Hall feedback filter circuit is connected with the main drive circuit, the DC power conversion circuit and the Hall sensor of the Stirling refrigerator; the overcurrent protection circuit is connected with the power bridge drive circuit, the main drive circuit and the filter and The reverse protection circuit is connected; the power bridge drive circuit is connected with the three-phase winding of the Stirling refrigerator.

The circuit diagram of the DC power conversion circuit is shown in Figure 2. The circuit includes: a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, and a first capacitor C6 , a second capacitor C7, a third capacitor C8, a fourth capacitor C9, a fifth capacitor C10, a first switch tube Q11, a first predetermined chip U1 and a transformer T1.

In this embodiment, the specific connection method of the DC power conversion circuit is as follows: one end of the first resistor is connected to one end of the first capacitor, the other end of the first resistor is connected to the first port (COMP) of the first predetermined chip, and the first capacitor is connected to the first port (COMP) of the first predetermined chip. The other end of the capacitor is connected to one end of the second capacitor, the other end of the second capacitor is connected to the second port (FB) of the first predetermined chip, one end of the third capacitor is connected to one end of the second resistor, and one end of the second resistor is grounded , the other end of the third capacitor is connected to the third port (VREF) of the first predetermined chip, and the other end of the second resistor is connected to the fourth port (BIAS) of the first predetermined chip;

One end of the third resistor is connected to the fifth port (OSCOUT) of the first predetermined chip, the other end of the third resistor is connected to the sixth port (OSCIN) of the first predetermined chip, and the gate of the first switch tube is connected to the first predetermined chip The seventh port (OUTPUT) of the first switch tube is connected to one end of the fourth resistor and the eighth port (SENSE) of the first predetermined chip, and the other end of the fourth resistor is connected to the ninth port of the first predetermined chip. The port (DISCHARGE) is connected, the ninth port is grounded, the drain of the switch tube is connected to one end of the primary side of the transformer, and the other end of the primary side of the transformer is connected to the tenth port (+VIN) of the first predetermined chip;

The first end of the secondary side of the transformer is connected to one end of the fifth capacitor, the input end of the main drive circuit and the input end of the Hall power supply circuit, the other end of the fifth capacitor is grounded, and the second end of the secondary side of the transformer is connected to the end of the fourth capacitor. One end, one end of the fifth resistor, the input end of the temperature setting circuit, the input end of the temperature measurement feedback circuit and the input end of the feedback comparison circuit are connected, the other end of the fourth capacitor is grounded, and the other end of the fifth resistor is connected to the sixth resistor One end of the sixth resistor is connected to the third end of the secondary side of the transformer, and the third end of the secondary side of the transformer is grounded.

In this embodiment, when the DC power conversion circuit is powered on, the voltage VCC generated at the first end of the secondary side of the transformer can supply power to the circuit itself, and can be used as the input of the Hall power supply circuit and the main drive circuit. The other output voltage VS of the second end of the secondary side of the transformer is the tap of the secondary side of the transformer in specific implementation, and VS can be used as the input of the temperature setting circuit, the temperature measurement feedback circuit and the feedback comparison circuit. The DC power conversion circuit in this embodiment adopts a high-efficiency DC conversion chip, and adopts the method of arranging a transformer on the circuit board, which can significantly improve the efficiency of DC power conversion.

The circuit diagram of the main driving circuit in this embodiment is shown in FIG. 3, including: a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, a tenth resistor R10, an eleventh resistor R11, a twelfth resistor R12, The thirteenth resistor R13, the fourteenth resistor R14, the fifteenth resistor R15, the sixteenth resistor R161, the sixth capacitor C11, the seventh capacitor C12, the eighth capacitor C13, the ninth capacitor C14, the tenth capacitor C15, the sixth capacitor a diode D2 and a second predetermined chip U10;

The specific connection method of the main drive circuit is as follows: the cathode of the first diode is connected to the output end of the feedback comparison circuit, the anode of the first diode is connected to one end of the seventh resistor, one end of the tenth capacitor and the second predetermined chip. The first port (PWM_I) is connected, the other end of the seventh resistor is connected to one end of the eighth resistor and the second port (VREF) of the second predetermined chip, and the other end of the eighth resistor is connected to the third port (VREF) of the second predetermined chip. OC_REF), one end of the ninth capacitor and one end of the tenth resistor are connected, the other end of the tenth resistor is connected to one end of the eleventh resistor, one end of the eleventh resistor is grounded, and the other end of the eleventh resistor is connected to the second predetermined resistor. The fourth port (PWM_NI) of the chip is connected to one end of the ninth resistor, and the other end of the ninth resistor is connected to one end of the eighth capacitor and the fifth port (CT) of the second predetermined chip. The other end of the ninth capacitor and the other end of the tenth capacitor are grounded, one end of the twelfth resistor is connected to the sixth port (BRAKE) of the second predetermined chip, the other end of the twelfth resistor is grounded, and one end of the thirteenth resistor is connected to the sixth port (BRAKE) of the second predetermined chip. The seventh port (R_TACH) of the second predetermined chip is connected, the other end of the thirteenth resistor is grounded, one end of the sixth capacitor is connected to the eighth port (C_TACH) of the second predetermined chip, the other end of the sixth capacitor is grounded, and the tenth capacitor is connected to the ground. One end of the fourth resistor is connected to one end of the sixteenth resistor, one end of the seventh capacitor and the ninth port (SNS_NI) of the second predetermined chip, the other end of the fourteenth resistor is grounded, and the other end of the sixteenth resistor is connected to the tenth One end of the fifth resistor, the other end of the seventh capacitor and the tenth port (SNS_I) of the second predetermined chip are connected, and the other end of the fifteenth resistor is grounded.

In addition, the HALLA port, HALLB port and HALLC port in U10 are connected to the output of the Hall feedback filter circuit, the VDD port is connected to the VCC terminal of the transformer secondary output of the DC power conversion circuit, AHI port, ALO port, BHI port, BLOW The port, CHI port, and CLOW port are respectively connected with the corresponding input terminals of the power bridge output circuit. R14, R15, R161, C12 together with the overcurrent protection circuit constitute a current sampling circuit. When the operating current exceeds the design value, the U10 will stop. work to protect the circuit.

In this implementation, the circuit diagram of the temperature setting circuit is shown in FIG. 4 , including: a voltage reference source A1, a predetermined resistance network Z, a potentiometer VR1, an eleventh capacitor C21 and a first predetermined operational amplifier A2A;

The specific connection method of the temperature setting circuit is as follows: the input end of the voltage reference source is connected to the second end of the transformer secondary output voltage VS of the DC power conversion circuit, and the output end of the voltage reference source is connected to the first end of the predetermined resistance network. connection, the third end of the predetermined resistance network is connected to the grounding end of the voltage reference source, the grounding end of the voltage reference source is grounded, the second end of the predetermined resistance network is connected to the first end of the potentiometer, and the fourth end of the predetermined resistance network is connected to the potential The second end of the potentiometer is connected to the second end of the potentiometer, the third end of the potentiometer is connected to one end of the eleventh capacitor and the non-inverting input end of the first predetermined operational amplifier, the other end of the eleventh capacitor is grounded, and the inverting input of the first predetermined operational amplifier The terminal is connected to the output terminal of the first predetermined operational amplifier, the positive power terminal of the first predetermined operational amplifier is connected to the second terminal of the secondary side of the transformer of the DC power conversion circuit, and the negative power terminal of the first predetermined operational amplifier is grounded.

The temperature setting circuit takes the VS voltage provided by the DC power conversion circuit as the input, the voltage reference source is converted, and is adjusted by the passive resistance network Z and the potentiometer VR1, and the VIN2 output by the output end of the first predetermined operational amplifier is connected to Feedback comparison circuit, the temperature setting circuit of this embodiment adopts a high-precision voltage reference source, so that it can output a voltage with better stability and accuracy, so that the voltage value output by the circuit has a higher accuracy and better sensitivity This makes the setting of the working temperature of the Stirling refrigerator more precise.

The circuit diagram of the filtering and reverse connection protection circuit in this embodiment is shown in FIG. 5, including: a second diode D1, a first inductor L2, a second inductor L1, a twelfth capacitor C1, a thirteenth capacitor C2, The fourteenth capacitor C3, the fifteenth capacitor C4, the sixteenth capacitor C5 and the magnetic bead L3;

The specific connection method of the filtering and reverse connection protection circuit is as follows: the anode of the second diode is applied with a positive voltage, the cathode of the second diode is connected to one end of the first inductor, and the other end of the first inductor is connected to one end of the twelfth capacitor. And the first end of the second inductor is connected, the other end of the twelfth capacitor is connected with a negative voltage, the other end of the twelfth capacitor is connected to the second end of the second inductor, and the third end of the second inductor is connected to the thirteenth capacitor. One end of the fourteenth capacitor, one end of the fifteenth capacitor and one end of the magnetic bead are connected, the fourth end of the second inductor is connected to the other end of the thirteenth capacitor, the other end of the thirteenth capacitor, the tenth The other end of the four capacitors and the other end of the fifteenth capacitor are grounded, and the other end of the magnetic bead is connected to one end of the sixteenth capacitor, the first predetermined chip of the DC power conversion circuit and the input end of the main drive circuit. The sixteenth capacitor the other end is grounded.

In the above circuit, the voltage provided by the external DC stabilized power supply is filtered by the above circuit to output a voltage V+ with less fluctuation. V+ is used as the input voltage of the DC power conversion circuit and the main drive circuit. In this embodiment, D1 is a Schottky power diode with low conduction value, L2 is a differential mode power inductor, L1 is a common mode power inductor, C1 and C2 are tantalum capacitors with low equivalent resistance value, and C3, C4, and C5 are magnetic Dielectric capacitor, L3 is a power magnetic bead, L3 is equivalent to an inductor in the circuit of this embodiment, and can filter out high-frequency harmonics in the voltage, so the circuit symbol is the same as that of L2. When the power supply is connected correctly, the input power VIN1 is filtered through L2 differential mode power inductor, L1 common mode power inductor, C1, C2 tantalum capacitors, C3, C4, C5 magnetic dielectric capacitors and L3 power magnetic beads to suppress power supply. Voltage ripple, filtering out high-frequency noise, common mode and differential mode noise, which can significantly reduce the noise interference of the main drive circuit. After the above filtering design and processing, the filtering and reverse connection protection circuit in this embodiment has passed the GJB151B-CE102\RE102 electromagnetic compatibility test standard. The electromagnetic compatibility performance test diagram of RE102 of the existing filter and reverse connection protection circuit is shown in Figure 6, and the electromagnetic compatibility performance test diagram of CE102 of the existing filter and reverse connection protection circuit is shown in Figure 7. The electromagnetic compatibility performance test diagram of RE102 of the reverse connection protection circuit is shown in FIG. 8 , and the electromagnetic compatibility performance test diagram of CE102 of the filter and reverse connection protection circuit in this embodiment is shown in FIG. 9 . It can be seen from the above four figures that as the operating frequency increases, the noise of the filtering and reverse connection protection circuit in this embodiment is significantly lower than that of the existing circuit. In addition, if the power supply wrongly connects the positive and negative poles, the circuit will not be energized due to the unidirectional conduction characteristic of D1, which can protect the main drive circuit from being damaged due to the power connection.

The circuit diagram of the power bridge driving circuit in this embodiment is shown in FIG. 10 , including: a third predetermined chip U11 , a fourth predetermined chip U12 , a fifth predetermined chip U13 , a seventeenth capacitor C16 , an eighteenth capacitor C17 , and a fifth predetermined chip U13 . The nineteenth capacitor C18, the seventeenth resistor R16, the eighteenth resistor R17, the nineteenth resistor R18, the twentieth resistor R19, the twenty-first resistor R20, the twenty-second resistor R21, the second switch tube Q1, the Three switch transistors Q2, fourth switch transistor Q3, fifth switch transistor Q4, sixth switch transistor Q5, seventh switch transistor Q6, third diode D3, fourth diode D4 and fifth diode D5;

The specific connection method of the above circuit is as follows: the third predetermined chip is connected to the first predetermined chip of the main drive circuit, one end of the seventeenth capacitor is connected to the first port of the third predetermined chip, and the other end of the seventeenth capacitor is connected to the third predetermined chip. The second port of the predetermined chip, the source of the second switch tube, the drain of the third switch tube and the input end of the third diode are connected, and one end of the seventeenth resistor is connected to the third port of the third predetermined chip, The other end of the seventeenth resistor is connected to the gate of the second switch tube, the drain of the second switch tube is voltage-applied, one end of the eighteenth resistor is connected to the fourth port of the third predetermined chip, and the other end of the eighteenth resistor connected to the gate of the third switch tube, and the source of the third switch tube is grounded;

The fourth predetermined chip is connected to the first predetermined chip of the main drive circuit, one end of the eighteenth capacitor is connected to the first port of the fourth predetermined chip, and the other end of the eighteenth capacitor is connected to the second port and the first port of the fourth predetermined chip. The source of the four switch tubes, the drain of the fifth switch tube and the input end of the fourth diode are connected. One end of the nineteenth resistor is connected to the third port of the third predetermined chip, and the other end of the nineteenth resistor is connected to the third port of the third predetermined chip. The gate of the fourth switch tube is connected, the drain of the fourth switch tube is voltage-applied, one end of the twentieth resistor is connected to the fourth port of the fourth predetermined chip, and the other end of the twentieth resistor is connected to the gate of the fifth switch tube connected, the source of the fifth switch is grounded;

The fifth predetermined chip is connected to the first predetermined chip of the main drive circuit, one end of the nineteenth capacitor is connected to the first port of the fifth predetermined chip, and the other end of the nineteenth capacitor is connected to the second port and the first port of the fifth predetermined chip. The source of the six switch tubes, the drain of the seventh switch tube and the input end of the fifth diode are connected, one end of the twenty-first resistor is connected to the third port of the fifth predetermined chip, and the other end of the twenty-first resistor is connected to the third port of the fifth predetermined chip. One end is connected to the gate of the sixth switch tube, the drain of the sixth switch tube is applied with voltage, one end of the twenty-second resistor is connected to the fourth port of the fifth predetermined chip, and the other end of the twenty-second resistor is connected to the seventh switch The gate of the tube is connected, and the source of the seventh switch tube is grounded.

The power bridge drive circuit of this embodiment uses a professional power bridge drive chip and a high-performance MOSFET power transistor to form a power output circuit, which can reduce the power output loss while reducing the heat generation and output power. The output power of the drive circuit is more than twice that of the previous similar design circuits. The total output power of the existing power bridge drive circuit is about 18W. The output power of the power bridge drive circuit in this embodiment can reach more than 48W, so It can meet the cooling requirements of high-power Stirling refrigerators.

The circuit diagram of the temperature measurement feedback circuit of this embodiment is shown in FIG. 11 , including: a predetermined temperature measurement element, a third inductance CM1 , a twenty-third resistor R24 , a twenty-fourth resistor R25 , a twenty-fifth resistor R26 , a Twenty-six resistors R27, twenty-seventh resistors R28, twentieth capacitors C25, twenty-first capacitors C26, twenty-second capacitors C27, and a second predetermined operational amplifier A4;

The specific connection method of the above circuit is: the positive electrode An of the predetermined temperature measuring element is connected to the first end of the third inductor (marked as 3 in the figure), and the negative electrode Cat of the predetermined temperature measuring element is connected to the second end of the third inductor (marked as 3 in the figure). 4) Connection, one end of the twenty-third resistor is connected to the second end of the secondary side of the transformer, the other end of the twenty-third resistor is connected to the third end of the third inductor (marked as 1 in the figure), and one end of the twentieth capacitor And one end of the twenty-fifth resistor is connected, the other end of the twentieth capacitor is connected to the fourth end of the third inductor (marked as 2 in the figure), one end of the twenty-fourth resistor and one end of the twenty-sixth resistor are connected, the first The other end of the twenty-four resistor is grounded, the other end of the twenty-fifth resistor is connected to one end of the twenty-first capacitor and the first end of the second predetermined operational amplifier (marked as 3 in the figure), and the other end of the twenty-sixth resistor is connected to the ground. One end is connected to one end of the twenty-second capacitor and the second end of the second predetermined operational amplifier (marked as 2 in the figure), and the other end of the twenty-first capacitor is connected to the other end of the twenty-second capacitor and the second predetermined operational amplifier. The third terminal of the second predetermined operational amplifier (marked as 4 in the figure) is connected to the fourth terminal of the second predetermined operational amplifier (marked as 5 in the figure), the third terminal of the second predetermined operational amplifier is grounded, and one end of the twenty-seventh resistor is connected to the second predetermined operational amplifier. The fifth end of the operational amplifier (marked as 8 in the figure) is connected, the other end of the twenty-seventh resistor is connected to the sixth terminal of the second predetermined operational amplifier (marked as 6 in the figure) and the input terminal of the feedback comparison circuit is connected, and the second The seventh terminal of the predetermined operational amplifier (marked as 7 in the figure) is connected to the second terminal of the secondary side of the transformer.

In the temperature measurement feedback circuit of this embodiment, CM1 is a surface-mounted common mode inductor, which can effectively suppress common mode interference. The operational amplifier A4 can be integrated in the chip during specific implementation. There are 7 terminals, and through the filter network composed of C25, C26, C27, R25, and R26, the differential mode interference of the feedback signal output by the temperature measuring element can be filtered out, so that the interference of the temperature measuring feedback circuit is significantly smaller. , The anti-interference ability is enhanced, thereby significantly improving the accuracy of temperature control.

The circuit diagram of the feedback comparison circuit in this embodiment is shown in FIG. 12 , including: a twenty-eighth resistor R29, a twenty-ninth resistor R30, a thirty-first resistor R31, a thirty-first resistor R32, and a thirty-second resistor R33, the thirty-third resistor R34, the twenty-third capacitor C28, the twenty-fourth capacitor C29, the twenty-fifth capacitor C30, the third predetermined operational amplifier A2B, the fourth predetermined operational amplifier A7 and the sixth predetermined chip A4;

The specific connection method of the feedback comparison circuit is: one end of the twenty-eighth resistor is connected to the output end of the temperature setting circuit, and the other end of the twenty-eighth resistor is connected to one end of the twenty-ninth resistor and the in-phase of the third predetermined operational amplifier. The input terminal is connected, the inverting input terminal of the third predetermined operational amplifier is connected to the sixth terminal of the second predetermined operational amplifier of the temperature measurement feedback circuit, and the other end of the twenty-ninth resistor is connected to the output terminal of the third predetermined operational amplifier and the first Six predetermined chip connections, one end of the thirtieth resistor is connected to the output end of the first predetermined operational amplifier of the temperature setting circuit, the other end of the thirtieth resistor is connected to one end of the twenty-third capacitor and the non-inverting input of the fourth operational amplifier The other end of the twenty-third capacitor is connected to the ground, one end of the thirty-first resistor is connected to the sixth predetermined chip, and the other end of the thirty-first resistor is connected to one end of the twenty-fourth capacitor and one end of the thirty-third resistor. One end of the thirty-second resistor is connected to the sixth end of the second predetermined operational amplifier of the temperature measurement feedback circuit, and the other end of the thirty-second resistor is connected to the inverting input end of the fourth predetermined operational amplifier, the third The other end of the three resistors and one end of the twenty-fifth capacitor are connected, and the output end of the fourth predetermined operational amplifier is connected to the other end of the twenty-fourth capacitor, the other end of the twenty-fifth capacitor and the sixth predetermined chip.

The input terminal VIN1 of the above circuit is the output of the temperature measurement feedback circuit, and the input terminal VIN2 is the output of the temperature setting circuit. The output signal VE of the feedback comparison circuit is connected to the main drive circuit and used as a control signal for the main drive circuit to adjust the PWM pulse width modulation. The circuit uses A7 to compare the two input voltage values of VIN1 and VIN2, amplify the difference, and output VE. R33, R34, C29, C30, R32, A5, A2B, R29, R30 together form the amplification feedback circuit of A7. If the difference between VIN2 and VIN1 is too large, A2B will amplify the difference signal, so as to control A5 to disconnect R32. At this time, the amplification feedback circuit is composed of R34, R33, C29, and C30, which can enhance the filtering and feedback gain ability, suppress the The effect of spike disturbances on the stability of temperature control. When the difference between VIN1 and VIN2 is within a reasonable range, the amplifying feedback circuit is composed of R32, R34, R32, and C30, forming a normal feedback filtering and feedback gain working mode. Since the amplifying feedback circuit can change with different situations, the feedback comparison circuit in this embodiment can effectively suppress the sudden spike interference in the external environment, and the ability to suppress the sudden interference in the environment is significantly enhanced, thereby significantly increasing the Stirling The reliability of the refrigerator control circuit significantly enhances the performance of the infrared detector. Compared with the previous similar circuits, the grayscale change of the detector image caused by the sudden change of temperature caused by environmental interference is tested, and the grayscale change is reduced from more than 100 code values to 4 code values.

In addition, the control circuit of the Stirling refrigerator in this embodiment further includes: an overcurrent protection circuit. The circuit diagram of the circuit is shown in Figure 13. When the overcurrent protection circuit works, the power bridge drive circuits Q2, Q4, and Q6 are powered The current flowing through the GND3 connected to the pole is used as the input, which is sampled by the equivalent resistance value R _on after the Q7 element is turned on and converted into a voltage signal, which is sent to U10 in the main drive circuit to judge the performance of the Stirling refrigerator. Whether the control circuit is overloaded. When the current input by the overcurrent protection circuit exceeds the set value of the main drive circuit, the main drive circuit stops working, thereby protecting the control circuit of the Stirling refrigerator from being overloaded and damaged. One end of the resistor R34 is connected to one end of the zener tube D6, connected to the gate of Q7, the other end of the resistor R34 is connected to the output voltage of the filter and reverse protection circuit, the other end of the zener tube D6 is connected to the ground, and the drain of Q7 is connected to the power bridge drive GND3 in the circuit is connected to the SNS_NI port of the main control chip U10 through R14 of the main drive circuit, the source of Q7 is grounded, and is connected to the SNS_I port of U10 through R15 of the main drive circuit. The calculation formula of the current input by the overcurrent protection circuit For I _stator(max) = 0.1/R _on .

The control circuit of the Stirling refrigerator also includes: Hall power supply circuit. The circuit diagram of this circuit is shown in Figure 14. This circuit converts the voltage VCC output by the power supply through the DC power supply, and after the conversion by the LDO chip U14, it is Stirling refrigeration. The Hall sensor inside the machine provides the voltage value V _Hall required for normal operation. In the specific implementation, the internal Hall sensor of the brushless DC motor is connected to the lead wire. Pin 1 (IN) and pin 3 (SHDH) of U14 are connected to the voltage VCC output by the DC power conversion power supply, pin 2 (GND) of U14 is grounded, one end of R22 is connected to one end of the magnetic dielectric non-polar capacitor C19, one end of C20 and U16 pin 5 (OUT) is connected, the other end of R22 is connected to one end of R23 and U14 pin 4 (ADJ), the other end of R23 is connected to the other end of C19, the other end of C20 and U14 pin 2 (GND) ) connection, the other end of C19 and the other end of C20 are grounded. The Hall power supply circuit of this embodiment determines the output voltage value by calculating according to the formula V _Hall =1.22×(1+R19/R20), and after filtering through C19 and C20, it is connected to the Hall inside the Stirling refrigerator through the lead wire. er sensor, and provide it with a suitable working voltage.

The control circuit of the Stirling refrigerator in this embodiment further includes: a Hall feedback filter circuit, the circuit diagram of which is shown in FIG. 15 . This circuit processes the signal output by the Hall sensor inside the Stirling refrigerator to remove high-frequency interference, etc., and then inputs it to the main drive circuit. The purpose is to prevent the signal output by the Hall sensor from being interfered, resulting in the output of the main control circuit. The control signal to the power bridge drive circuit is disordered, and then the power bridge drive circuit is damaged. CP1 in the circuit is an 8-pin small package surface-mounted non-polar magnetic dielectric capacitor, RP2 and RP1 are surface-mounted 8-pin small package resistors, CP1's Pins 2, 3, and 4 are grounded, and pin 5 of CP1 is connected to pin 5 of the resistor row. The output of this channel in the figure is marked as HALLA, and is connected to the HALLA port of the main drive circuit U10; pin 6 of CP1 is connected to the resistor row. Pin 6, this output is marked as HALLB, connected to the HALLB port of the main drive circuit U10; the pin 7 of CP1 is connected to the pin 7 of the resistor RP2, this output is marked as HALLC, and connected to the HALLC of the main drive circuit U10 Port; pin 2 of RP2 is connected to pin 5 of RP1, marked as HS1, and is connected to phase A of the Hall sensor in the Stirling refrigerator through a lead wire, and pin 3 of RP2 is connected to pin 6 of RP1. Marked as HS2, it is connected to the B phase of the Hall sensor in the Stirling refrigerator through the lead wire. The pin 4 of RP2 is connected to the pin 7 of RP1, marked as HS3, and is connected to the Hall sensor in the Stirling refrigerator through the lead wire. C-phase of the sensor. The pins 2, 3, and 4 of the RP1 exclusion are connected to the VCC output by the secondary side of the transformer of the DC power conversion circuit.

The control circuit of the Stirling refrigerator provided in this embodiment, the DC power conversion circuit is connected with the main drive circuit, the temperature setting circuit, the filtering and reverse connection protection circuit, the temperature measurement feedback circuit, the Hall power supply circuit and the feedback comparison circuit; The main drive circuit is connected with the feedback comparison circuit, the power bridge drive circuit and the filter and reverse connection protection circuit; the temperature setting circuit is connected with the feedback comparison circuit, the Hall power supply circuit and the temperature measurement feedback circuit; the temperature measurement feedback circuit is connected with the feedback comparison circuit ;The Hall feedback filter circuit is connected with the main drive circuit, the DC power conversion circuit and the Hall sensor of the Stirling refrigerator; the Hall power supply circuit is connected with the Hall sensor of the Stirling refrigerator; the overcurrent protection circuit is connected with the power bridge The drive circuit, the main drive circuit and the filter and reverse connection protection circuit are connected; the power bridge drive circuit is connected with the three-phase winding of the Stirling refrigerator.

In this circuit, the external power supply supplies power to the filtering and reverse connection protection circuit. The output of this circuit is used as the input of the DC power conversion circuit and the main drive circuit. The output of the DC power conversion circuit is used as the input of the Hall power supply circuit. The output provides a suitable working voltage to the Hall sensor of the Stirling refrigerator. When the voltage value measured by the temperature measuring element in the temperature measurement feedback circuit is less than the set level value, the Stirling refrigerator works at full speed and rapidly cools down; When the voltage value measured by the temperature measurement feedback circuit is close to the set level value, the voltage value set by the temperature control setting circuit is compared with the voltage value obtained by the temperature measurement feedback circuit, and is output as the control voltage through the feedback comparison circuit. The level is input to the main drive circuit and compared with the triangular wave generated by it, so that the main drive circuit outputs a pulse width modulated PWM wave. The PWM wave is used as the input of the power bridge drive circuit, and the power is output to the Stirling refrigerator through the power bridge drive circuit. The three-phase winding of the Stirling refrigerator is used to control the speed of the Stirling refrigerator, thereby controlling the output power of the Stirling refrigerator. The following problems in the prior art are solved: the control circuit of the existing Stirling refrigerator is not suitable for controlling the Stirling refrigerator capable of providing the cooling capacity required for the stable operation of the large area array infrared detector.

The beneficial effects of the present invention are as follows:

The invention adopts a feedback comparison circuit with variable gain and variable filter network, which can effectively suppress large instantaneous interference in the external environment, and significantly improve the temperature control stability of the Stirling refrigerator control circuit; in the temperature setting circuit, Using a high-precision voltage reference source and a precision resistor network to set the temperature value improves the precision of temperature adjustment; at the same time, it reduces the area of the circuit board, which is conducive to miniaturization and integrated manufacturing, and a large number of surface-mounted integrated chips and peripheral tables are used. Components with small packages, compact circuit layout and strong anti-interference ability, thus ensuring precise control of Stirling refrigerators and providing stable and reliable large area array infrared detector components with large cooling capacity. Low temperature working environment.

Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, and therefore, the scope of the present invention should not be limited to the above-described embodiments.

Claims (7)

1. A control circuit for a stirling cooler, comprising:

the device comprises a Hall power supply circuit, a filtering and reverse connection protection circuit, a direct current power supply conversion circuit, a temperature setting circuit, a temperature measurement feedback circuit, a Hall feedback filter circuit, a feedback comparison circuit, a main drive circuit, an overcurrent protection circuit and a power bridge drive circuit;

the Hall power supply circuit is connected with the direct-current power supply conversion circuit and a Hall sensor of the Stirling refrigerator; the filtering and reverse connection protection circuit is connected with the direct-current power supply conversion circuit and the main driving circuit; the direct-current power supply conversion circuit is connected with the main drive circuit, the temperature setting circuit, the temperature measurement feedback circuit and the feedback comparison circuit; the main driving circuit is connected with the feedback comparison circuit and the power bridge driving circuit; the temperature setting circuit is connected with the feedback comparison circuit, the Hall power supply circuit and the temperature measurement feedback circuit; the temperature measurement feedback circuit is connected with the feedback comparison circuit; the Hall feedback filter circuit is connected with the main drive circuit, the direct-current power supply conversion circuit and a Hall sensor of the Stirling refrigerator; the overcurrent protection circuit is connected with the power bridge drive circuit, the main drive circuit and the filtering and reverse connection protection circuit; the power bridge driving circuit is connected with a three-phase winding of the Stirling refrigerator;

the DC power conversion circuit includes:

the circuit comprises a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a fifth capacitor, a first switching tube, a first preset chip and a transformer;

one end of the first resistor is connected with one end of the first capacitor, the other end of the first resistor is connected with the first port of the first predetermined chip, the other end of the first capacitor is connected with one end of the second capacitor, the other end of the second capacitor is connected with the second port of the first predetermined chip, one end of the third capacitor is connected with one end of the second resistor, one end of the second resistor is grounded, the other end of the third capacitor is connected with the third port of the first predetermined chip, and the other end of the second resistor is connected with the fourth port of the first predetermined chip;

one end of the third resistor is connected with the fifth port of the first preset chip, the other end of the third resistor is connected with the sixth port of the first preset chip, the grid electrode of the first switch tube is connected with the seventh port of the first preset chip, the source electrode of the first switch tube is connected with one end of the fourth resistor and the eighth port of the first preset chip, the other end of the fourth resistor is connected with the ninth port of the first preset chip, the ninth port is grounded, the drain electrode of the switch tube is connected with one end of the primary side of the transformer, and the other end of the primary side of the transformer is connected with the tenth port of the first preset chip;

the first end of the secondary side of the transformer is connected with one end of a fifth capacitor, the input end of the main driving circuit and the input end of the Hall power supply circuit, the other end of the fifth capacitor is grounded, the second end of the secondary side of the transformer is connected with one end of a fourth capacitor, one end of a fifth resistor, the input end of the temperature setting circuit, the input end of the temperature measurement feedback circuit and the input end of the feedback comparison circuit, the other end of the fourth capacitor is grounded, the other end of the fifth resistor is connected with one end of a sixth resistor, the other end of the sixth resistor is connected with the third end of the secondary side of the transformer, and the third end of the sixth resistor is grounded.

2. The control circuit of claim 1, wherein the main drive circuit comprises:

the circuit comprises a seventh resistor, an eighth resistor, a ninth resistor, a tenth resistor, an eleventh resistor, a twelfth resistor, a thirteenth resistor, a fourteenth resistor, a fifteenth resistor, a sixteenth resistor, a sixth capacitor, a seventh capacitor, an eighth capacitor, a ninth capacitor, a tenth capacitor, a first diode and a second predetermined chip;

wherein a cathode of the first diode is connected to an output terminal of the feedback comparison circuit, an anode of the first diode is connected to one end of the seventh resistor, one end of the tenth capacitor, and a first port of the second predetermined chip, the other end of the seventh resistor is connected to one end of the eighth resistor and a second port of the second predetermined chip, the other end of the eighth resistor is connected to a third port of the second predetermined chip, one end of the ninth capacitor, and one end of the tenth resistor, the other end of the tenth resistor is connected to one end of the eleventh resistor, one end of the eleventh resistor is grounded, the other end of the eleventh resistor is connected to a fourth port of the second predetermined chip and one end of the ninth resistor, and the other end of the ninth resistor is connected to one end of the eighth capacitor and a fifth port of the second predetermined chip, the other end of the eighth capacitor, the other end of the ninth capacitor and the other end of the tenth capacitor are grounded, one end of the twelfth resistor is connected to the sixth port of the second predetermined chip, the other end of the twelfth resistor is grounded, one end of the thirteenth resistor is connected to the seventh port of the second predetermined chip, the other end of the thirteenth resistor is grounded, one end of the sixth capacitor is connected to the eighth port of the second predetermined chip, the other end of the sixth capacitor is grounded, one end of the fourteenth resistor is connected to one end of the sixteenth resistor, one end of the seventh capacitor and the ninth port of the second predetermined chip, the other end of the fourteenth resistor is grounded, and the other end of the sixteenth resistor is connected to one end of the fifteenth resistor, the other end of the seventh capacitor and the tenth port of the second predetermined chip, the other end of the fifteenth resistor is grounded.

3. The control circuit of claim 1, wherein the temperature setting circuit comprises:

the voltage reference source, the predetermined resistance network, the potentiometer, the eleventh capacitor and the first predetermined operational amplifier;

an input end of the voltage reference source is connected to a second end of the secondary side of the transformer of the dc power conversion circuit, an output end of the voltage reference source is connected to a first end of the predetermined resistor network, a third end of the predetermined resistor network is connected to a ground end of the voltage reference source, the ground end of the voltage reference source is grounded, a second end of the predetermined resistor network is connected to a first end of the potentiometer, a fourth end of the predetermined resistor network is connected to a second end of the potentiometer, a third end of the potentiometer is connected to one end of the eleventh capacitor and a non-inverting input end of the first predetermined operational amplifier, another end of the eleventh capacitor is grounded, an inverting input end of the first predetermined operational amplifier is connected to an output end of the first predetermined operational amplifier, and a positive power source end of the first predetermined operational amplifier is connected to a second end of the secondary side of the transformer of the dc power conversion circuit And then, the negative power supply end of the first predetermined operational amplifier is grounded.

4. The control circuit of any of claims 1-2, wherein the filtering and reverse-connection protection circuit comprises:

the second diode, the first inductor, the second inductor, the twelfth capacitor, the thirteenth capacitor, the fourteenth capacitor, the fifteenth capacitor, the sixteenth capacitor and the magnetic bead;

the anode of the second diode is positively charged, the cathode of the second diode is connected to one end of the first inductor, the other end of the first inductor is connected to one end of the twelfth capacitor and the first end of the second inductor, the other end of the twelfth capacitor is negatively charged, the other end of the twelfth capacitor is connected to the second end of the second inductor, the third end of the second inductor is connected to one end of the thirteenth capacitor, one end of the fourteenth capacitor, one end of the fifteenth capacitor and one end of the magnetic bead, the fourth end of the second inductor is connected to the other end of the thirteenth capacitor, the other end of the fourteenth capacitor and the other end of the fifteenth capacitor are grounded, and the other end of the magnetic bead is connected to one end of the sixteenth capacitor, the first predetermined chip of the dc power conversion circuit and the input end of the main driving circuit And the other end of the sixteenth capacitor is grounded.

5. The control circuit of claim 1, wherein the power bridge drive circuit comprises:

a third predetermined chip, a fourth predetermined chip, a fifth predetermined chip, a seventeenth capacitor, an eighteenth capacitor, a nineteenth capacitor, a seventeenth resistor, an eighteenth resistor, a nineteenth resistor, a twentieth resistor, a twenty-first resistor, a twenty-second resistor, a second switching tube, a third switching tube, a fourth switching tube, a fifth switching tube, a sixth switching tube, a seventh switching tube, a third diode, a fourth diode and a fifth diode;

the third preset chip is connected with the first preset chip of the main driving circuit, one end of a seventeenth capacitor is connected with a first port of the third preset chip, the other end of the seventeenth capacitor is connected with a second port of the third preset chip, a source electrode of the second switching tube, a drain electrode of the third switching tube and an input end of the third diode, one end of a seventeenth resistor is connected with a third port of the third preset chip, the other end of the seventeenth resistor is connected with a grid electrode of the second switching tube, the drain electrode of the second switching tube is applied with voltage, one end of an eighteenth resistor is connected with a fourth port of the third preset chip, the other end of the eighteenth resistor is connected with the grid electrode of the third switching tube, and the source electrode of the third switching tube is grounded;

the fourth preset chip is connected with the first preset chip of the main driving circuit, one end of an eighteenth capacitor is connected with a first port of the fourth preset chip, the other end of the eighteenth capacitor is connected with a second port of the fourth preset chip, a source electrode of the fourth switching tube, a drain electrode of the fifth switching tube and an input end of the fourth diode, one end of a nineteenth resistor is connected with a third port of the third preset chip, the other end of the nineteenth resistor is connected with a grid electrode of the fourth switching tube, the drain electrode of the fourth switching tube is applied with voltage, one end of a twentieth resistor is connected with a fourth port of the fourth preset chip, the other end of the twentieth resistor is connected with the grid electrode of the fifth switching tube, and the source electrode of the fifth switching tube is grounded;

the fifth preset chip is connected with the first preset chip of the main driving circuit, one end of a nineteenth capacitor is connected with a first port of the fifth preset chip, the other end of the nineteenth capacitor is connected with a second port of the fifth preset chip, a source electrode of the sixth switching tube, a drain electrode of the seventh switching tube and an input end of a fifth diode, one end of a twenty-first resistor is connected with a third port of the fifth preset chip, the other end of the twenty-first resistor is connected with a grid electrode of the sixth switching tube, the drain electrode of the sixth switching tube is applied with voltage, one end of a twenty-second resistor is connected with a fourth port of the fifth preset chip, the other end of the twenty-second resistor is connected with the grid electrode of the seventh switching tube, and the source electrode of the seventh switching tube is grounded.

6. The control circuit of claim 1, wherein the thermometry feedback circuit comprises:

the temperature measuring circuit comprises a preset temperature measuring element, a third inductor, a twenty-third resistor, a twenty-fourth resistor, a twenty-fifth resistor, a twenty-sixth resistor, a twenty-seventh resistor, a twentieth capacitor, a twenty-first capacitor, a twenty-second capacitor and a second preset operational amplifier;

wherein the positive electrode of the predetermined temperature measuring element is connected with the first end of the third inductor, the negative electrode of the predetermined temperature measuring element is connected with the second end of the third inductor, one end of the twenty-third resistor is connected with the second end of the secondary side of the transformer, the other end of the twenty-third resistor is connected with the third end of the third inductor, one end of the twentieth capacitor and one end of the twenty-fifth resistor, the other end of the twentieth capacitor is connected with the fourth end of the third inductor, one end of the twenty-fourth resistor and one end of the twenty-sixth resistor, the other end of the twenty-fourth resistor is grounded, the other end of the twenty-fifth resistor is connected with one end of the twenty-first capacitor and the first end of the second predetermined operational amplifier, the other end of the twenty-sixth resistor is connected with one end of the twenty-second capacitor and the second end of the second predetermined operational amplifier, the other end of the twenty-first capacitor is connected with the other end of the twenty-second capacitor, the third end of the second preset operational amplifier and the fourth end of the second preset operational amplifier, the third end of the second preset operational amplifier is grounded, one end of the twenty-seventh resistor is connected with the fifth end of the second preset operational amplifier, the other end of the twenty-seventh resistor is connected with the sixth end of the second preset operational amplifier and the input end of the feedback comparison circuit, and the seventh end of the second preset operational amplifier is connected with the second end of the secondary side of the transformer.

7. The control circuit of claim 6, wherein the feedback comparison circuit comprises:

a twenty-eighth resistor, a twenty-ninth resistor, a thirty-sixth resistor, a thirty-eleventh resistor, a thirty-second resistor, a thirty-third resistor, a twenty-third capacitor, a twenty-fourth capacitor, a twenty-fifth capacitor, a third predetermined operational amplifier, a fourth predetermined operational amplifier and a sixth predetermined chip;

wherein one end of the twenty-eighth resistor is connected to the output end of the temperature setting circuit, the other end of the twenty-eighth resistor is connected to one end of the twenty-ninth resistor and the non-inverting input end of the third predetermined operational amplifier, the inverting input end of the third predetermined operational amplifier is connected to the sixth end of the second predetermined operational amplifier of the temperature measurement feedback circuit, the other end of the twenty-ninth resistor is connected to the output end of the third predetermined operational amplifier and the sixth predetermined chip, one end of the thirty resistor is connected to the output end of the first predetermined operational amplifier of the temperature setting circuit, the other end of the thirty resistor is connected to one end of the twenty-third capacitor and the non-inverting input end of the fourth predetermined operational amplifier, and the other end of the twenty-third capacitor is grounded, one end of the thirty-first resistor is connected with the sixth preset chip, the other end of the thirty-first resistor is connected with one end of the twenty-fourth capacitor and one end of the thirty-third resistor, one end of the thirty-second resistor is connected with the sixth end of the second preset operational amplifier of the temperature measurement feedback circuit, the other end of the thirty-second resistor is connected with the inverting input end of the fourth preset operational amplifier, the other end of the thirty-third resistor and one end of the twenty-fifth capacitor, and the output end of the fourth preset operational amplifier is connected with the other end of the twenty-fourth capacitor, the other end of the twenty-fifth capacitor and the sixth preset chip.

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