JP2002171784A - Motor for radiating fan having revolution controlled by pulse operation frequency - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motor for a radiation fan having a revolution controlled by a pulse operation frequency which can gently change the resolution of the radiation fan, without making the pulse frequency change. SOLUTION: There are provided two rectifying circuits, one voltage comparator circuit, and one differential amplifier. A pulse is inputted to the first rectifying circuit 60, a signal of an actual revolution detected by a radiation fan is inputted to the second rectifying circuit 60'. Then, after the voltage of the pulse signal and the voltage of the revolution signal have been compared with each other by the voltage comparator circuit 70, the difference voltage is inputted to the negative terminal of the differential amplifier, while the partial voltage of a power supply voltage Vcc is inputted to the positive terminal of the differential amplifier. The differential amplifier calculates the difference between the two inputted voltages and then outputs a drive voltage Vf. The revolution of the radiation fan is simultaneous changed when the value of the drive voltage Vf is changed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor for a radiating fan having a pulse work cycle control rotation speed, and more particularly to a motor for a radiator fan by changing a pulse work cycle without changing a frequency of an input pulse signal. In addition to controlling the rotation speed, the heat dissipation fan can obtain smooth rotation in the process of increasing or decreasing the speed, which can extend the service life of the heat dissipation fan. It is related.

[0002]

2. Description of the Related Art Conventionally, this type is as follows.

FIG. 1 is a circuit diagram of a speed control type radiator fan disclosed in US Pat. No. 5,197,858 "Temperature Speed Control Type DC Brushless Radiator Fan". FIG. 2 is an output waveform diagram of the speed control type circuit. Referring to FIG. 1, Patent No. 5,
In the circuit diagram of the speed control type heat radiating fan disclosed in Japanese Patent No. 197,858, after the power supply is turned on, it is applied to the circuit and the brushless motor of the heat radiating fan via the reverse pressure protection diode D1, and the winding coil and the annular permanent magnet are provided. Can be induced to start rotating the blades of the radiating fan by mutual action. At this time, the resistors R2 and R3 can be driven by the Hall effect induction integrated circuit IC1, which is an operation point of the direction change of the DC motor. With the predetermined current and DC level provided by the radiator, a radio wave of a magnetic field change between the winding coil of the heat dissipation fan and the annular permanent magnet can be induced. The Hall effect induction integrated circuit IC1 has a positive voltage V +
And a negative voltage V- are output to the driving integrated circuit IC2, and the driving integrated circuit IC2 performs a comparison shaping process on the above-mentioned two waveforms by the internal voltage, and the F.I. G. FIG.
The same waveforms can be obtained, and the radio waves output from the semiconductor switches A1 and A2 can be controlled by the radio waves having the same phase as shown in FIGS. 2B and 2C. Using the radio waves output from the semiconductor switches A1 and A2, the winding coils L1, L2, L
3 and L4 control the operation of the direction change caused by the annular permanent magnet. The capacitor C1 provides the driving integrated circuit IC2 itself with electric energy from when the blade stops and completely restarts, and is constituted by the Hall effect induction integrated circuit IC1 and the driving integrated circuit IC2. The drive system alone can rotate the blades of the heat radiating fan, and can periodically generate a pulse signal for detection. IC3 (not shown)
Inside are three operational amplifiers IC31, IC32 and IC3
3 and the IC 31 includes resistors R4, R5, R
6, R7, R8, R9, R10 and the temperature-controlled speed-changing inductor Rth, together with the temperature-controlled speed-changing rotation speed and temperature gradient control circuit of the radiating fan,
Due to the characteristic that the resistance value also changes at different temperatures of h, the voltage Va formed by the temperature-controlled shift inductor Rth and the resistor R4 also changes according to the change in temperature, and the temperature-controlled shift inductor Rth and the resistors R9 and R10 change. After the formed reference voltage Vref is calculated by the operational amplifier IC31,
Since the voltage Vb is formed so as to change, when the transistor TR2 is turned on and the current also changes, the rotation speed of the heat radiating fan changes, thereby achieving the purpose of shifting the temperature control heat radiating fan. It is configured as follows.

FIG. 3 shows another conventional heat dissipation fan structure disclosed in U.S. Pat. No. 5,942,866 entitled "Control Circuit for Adjusting Wave Width of DC Brushless Heat Dissipation Fan". FIG. 4 is an output waveform diagram of the control switch. Referring to FIG. 3, the rectifier circuit 10 of the heat dissipation fan disclosed in the publication number 5,942,866 constitutes a high-pass filter circuit with a capacitor 11 and a resistor 14, and has two diodes 12, Thirteen
Since the rectifying filter is formed by the filter capacitor 15, the received square wave signal can be converted into a DC voltage signal. Further, by adding a high-pass filter circuit, the output voltage is directly proportional to the frequency according to the frequency. Can be changed. As described above, the rotation speed of the heat radiating fan 50 can be measured by the output voltage of the rectifier circuit 10, and the reference voltage supplied to the voltage comparator 20 includes the heat resistor 40 and the voltage dividing resistor having a minus temperature coefficient. Since the reference voltage can be obtained from the voltage dividing end, the design of the thermal resistor 40 can also serve as a temperature compensation effect, that is, when the environmental temperature rises, Since the resistance of the resistor 40 relatively decreases, the reference voltage input to the voltage comparator 20 is increased (increases the reference value of the rotation speed). Can be maintained. On the other hand, if the ambient temperature drops below the standard value, the reference value of the rotation speed also drops relatively, that is, the radiation fan 50
At a relatively low rotational speed. The output waveform of the control switch is formed in a rotational speed control circuit whose wave width can be adjusted, as shown in FIG.

[0005]

In the above-mentioned U.S. Pat. No. 5,197,858 "Temperature Speed Control Type DC Brushless Heat Dissipating Fan", the drive integrated circuit IC2 switches the winding coils L1, L2, L3 and L4. The output waveform is a square wave as shown in 2B and 2C in FIG. 2. In addition, a change in the Vb voltage output in accordance with the environmental temperature via the operational amplifier IC31 causes the transistor TR2 to conduct to cause a change in current. However, the transistor TR2 also outputs a square wave. Square wave wound coil L
1, L2, L3 and L4, the heat radiation fan rapidly increases or decelerates according to the square wave. At this time, the rotational speed of the heat radiation fan is rattled by a rapid change. There is a problem that the service life of the device is shortened.

[0006] The aforementioned U.S. Publication No. 5,942,
No. 866, "Control Circuit for Adjusting Wave Width of DC Brushless Heat Dissipating Fan", the waveform of the output driving voltage V + is a square wave that opens and closes intermittently, and the rotation of heat radiating fan 50 is a square wave or control switch 30. The rapid opening or closing causes rapid acceleration or deceleration. At this time, the rotational speed of the heat radiating fan is rattled by a rapid change, so that the service life of the heat radiating fan is shortened.

In view of the above problems, the present invention controls the rotation speed of a motor of a heat radiating fan by using a work cycle of a pulse, and mainly inputs a pulse to a first rectifier circuit before a voltage comparator. It is connected to the circuit, and the signal of the actual rotation speed detected by the heat dissipation fan is input to the second rectifier circuit, and then connected to the voltage comparator circuit, which compares the two voltages and outputs the comparison voltage Then, the divided voltage of the comparison voltage and the power supply voltage Vcc is adjusted by adjusting the voltage by a differential amplifier, and then the driving voltage Vf is output. The output driving voltage Vf is used to output to the radiating fan. Since Vf is formed in a linear and flat waveform, the rotation speed of the heat dissipation fan can be gently increased or decreased, and the speed of the heat dissipation fan can be rapidly increased or decreased. By being able to avoid the occurrence, it can be extended service life of the cooling fan.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to compare an input pulse with a detected signal of a rotation speed of a radiating fan to obtain a pulse. The rotation speed is controlled by changing the work cycle without changing the frequency of the fan, and a voltage having a flat waveform is output, so that the rotation speed of the radiation fan is gradually increased or decreased. The purpose of the present invention is to provide a radiation fan motor with a pulse work cycle control rotation speed, which can prolong the service life of the radiation fan by avoiding the sudden increase or rapid deceleration of the radiation fan. is there.

[0009]

In order to achieve the above-mentioned object, a motor for a radiating fan having a pulse operation cycle control rotation speed according to the present invention is as follows. That is, the motor of the heat dissipation fan having the pulse work cycle control rotation speed according to the present invention includes the heat dissipation fan, the pulse input terminal, the voltage comparator circuit, and the differential amplifier. The heat radiating fan can detect a rotation speed signal of the heat radiating fan and convert the signal into a voltage. The pulse input terminal can input a frequency-invariant pulse and convert it to a voltage. The voltage comparator circuit may compare the voltage converted from the signal detected by the heat radiation fan and the voltage converted from the input pulse, and then output the comparison voltage. The differential amplifier is connected between the heat dissipation fan and the voltage comparator circuit. While the power supply voltage is input to the positive terminal of the differential amplifier, the comparison voltage is input to the negative terminal, and the positive terminal and the negative terminal of the differential amplifier are connected. The drive voltage for outputting to the heat dissipation fan can be changed according to the voltage difference input to the end. When the working period of the pulse is reduced, the voltage of the pulse can be reduced, and when the voltage of the pulse is gradually reduced, the voltage comparator circuit outputs a gradually higher voltage to the minus terminal of the differential amplifier. Since the driving voltage for the output of the differential amplifier is formed so as to gradually decrease gradually, the heat radiation fan can be gradually decelerated. Also, when the working period of the pulse is increased, the voltage of the pulse can be increased,
When the pulse voltage is gradually increased, the voltage comparator circuit can output a gradually decreasing voltage to the minus terminal of the differential amplifier, so that the driving voltage for the differential amplifier to output gradually decreases. Since it is formed so as to rise, the speed of the heat dissipation fan can be increased gradually.

Further, the motor of the radiating fan of the pulse work cycle control rotation speed of the present invention may be configured as follows. 1. The pulse is a square wave. 2. The pulse is a triangular wave. 3. A first rectifier circuit and a second rectifier circuit are included, wherein the first rectifier circuit is connected between the voltage comparator circuit and the pulse input terminal and can convert a pulse to a voltage, while the second rectifier circuit Is connected between the voltage comparator circuit and the signal end detected by the heat dissipation fan, and can convert the signal detected by the heat dissipation fan into a voltage. 4. The voltage comparator circuit is composed of two resistors, one capacitor, and one operational amplifier.

[0011]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 5 is a circuit diagram of a square wave working cycle control according to an embodiment of the present invention. The present invention mainly comprises a first rectifier circuit 60, a second rectifier circuit 60 ', a voltage comparator circuit 70 and a differential amplifier 80. Be composed. The first rectifier circuit 60 includes a voltage comparator circuit 70 and a pulse input terminal Pulse.
The first rectifier circuit 60 includes one operational amplifier OP1, two resistors R1, R2, and a diode D1.
And the voltage comparator circuit 70 includes two resistors R5 and R6, one capacitor C and one operational amplifier OP3. The pulse input terminal Pulse can input a pulse such as a square wave or a triangular wave whose frequency is invariable and whose work cycle is variable. The pulse is first rectified through the first rectifier circuit 60, and then the operational amplifier OP3 of the voltage comparator 70. Voltage is output to the minus end of. The second rectifier circuit 60 'includes a voltage comparator circuit 7
0 and the signal terminal FG detected by the heat radiating fan 90, and the second rectifier circuit 60 'includes one operational amplifier OP.
2, a rotation speed signal FG detected by the heat dissipation fan 90, including two resistors R3, R4 and a diode D2.
Is rectified through the second rectifier circuit 60 ', and then a voltage is output to the positive terminal of the operational amplifier OP3 of the voltage comparator 70. The voltage comparator circuit 70 compares the rectified pulse voltage with the voltage of the rotation speed signal, outputs a comparison voltage, and is connected to the minus terminal of the differential amplifier 80 via the resistor R7. Is divided by the resistor R9 and connected to the positive terminal of the differential amplifier 80. The differential amplifier 80 adjusts the positive terminal power supply voltage Vcc and the negative terminal comparison voltage, and then drives the driving voltage Vf.
And the drive voltage Vf can control the rotation speed of the heat radiating fan 90. When a change occurs in the operation cycle of the input pulse, the comparison voltage compared by the voltage comparator circuit 70 also changes at the same time, so the changed comparison voltage is again divided by the power supply voltage Vcc and the differential amplifier 8.
If the values are adjusted by 0, the drive voltage Vf for output also changes. The change (increase or decrease) of the pulse operation cycle causes the voltage comparator circuit 7
Since the comparison voltage for outputting 0 can gradually decrease or increase, the driving voltage Vf for outputting the differential amplifier 80 is also formed to increase or decrease gently. Further, since the rotation speed of the radiating fan 90 is also formed so as to gradually increase or decrease, the use life of the radiating fan 90 can be reduced by avoiding the occurrence of the rapid increase or the rapid deceleration of the radiating fan 90. Can be stretched

Referring to FIG. 6, a square wave is input from a pulse input terminal according to an embodiment of the present invention, and the square wave is designed to be invariable in frequency and to change only the working period, and to apply a high voltage (working voltage). Stretched on the time axis and labeled Hi, while low voltage was stretched on the time axis and labeled Lo, and on the time axis, Hi = 3Lo, H
Set i = Lo section and Hi = 9Lo section. When the square wave is formed in the Hi = 3Lo section, the voltage at which the square wave is output to the minus end of the voltage comparator circuit 70 via the first rectifier circuit 60 is the rotation speed signal FG detected by the radiating fan 90. Since the voltage is higher than the voltage output to the plus terminal of the voltage comparator circuit 70 via the second rectifier circuit 60 ', the voltage comparator circuit 70
The differential amplifier 80 is formed so as to output a relatively high drive voltage Vf in order to output to the minus end of 0. When the working period of the square wave is dropped from the Hi = 3Lo section to the Hi = Lo section, the frequency is unchanged, and the voltage of the square wave output to the minus terminal of the voltage comparator circuit 70 via the first rectifier circuit 60 is Since the voltage becomes gradually lower than the original voltage, the voltage comparator circuit 70 outputs the gradually higher voltage to the minus terminal of the differential amplifier 80,
The drive voltage Vf output from the differential amplifier 80 is formed so as to gradually decrease. When the square wave is formed in the Hi = Lo section, the frequency of the rotation speed signal FG detected by the heat radiating fan 90 to be input to the second rectifier circuit 60 'is reduced, so that the positive terminal of the voltage comparator circuit 70 is reduced. Is formed so as to be higher than the negative terminal, and the voltage comparator circuit 70 outputs the high voltage to the differential amplifier 8.
The differential amplifier 80 is formed so as to output a relatively low drive voltage Vf because it can be output to the minus end of 0. The work cycle width is widened and the square wave is Hi = L
When the frequency is increased from the section o to the section Hi = 9Lo, the frequency is unchanged, and the voltage at which the square wave is output to the minus terminal of the voltage comparator circuit 70 via the first rectifier circuit 60 gradually becomes smaller than the original voltage. Since the voltage becomes higher, the voltage comparator circuit 70 outputs a gradually lowering voltage to the minus end of the differential amplifier 80, so that the drive voltage Vf output from the differential amplifier 80 is formed so as to gradually increase. . When the square wave is formed in the Hi = 9Lo section, the voltage at which the square wave is output to the minus end of the voltage comparator circuit 70 via the first rectifier circuit 60 is the rotation speed signal FG detected by the heat dissipation fan 90. Since the voltage is higher than the voltage output to the positive terminal of the voltage comparator circuit 70 via the second rectifier circuit 60 ', the voltage comparator circuit 70 outputs a low voltage to the negative terminal of the differential amplifier 80. It is formed so as to output an extremely high drive voltage Vf. The present invention can control the rotation speed of the heat dissipation fan 90 to be maintained at a preset rotation speed by changing only the work cycle while keeping the frequency of the pulse unchanged. When the speed is increased, decelerated, or controlled, the rotation speed of the heat radiation fan 90 can be gradually increased or reduced by gradually increasing or decreasing the drive voltage Vf.

Referring to FIGS. 2, 4 and 6, in the above-mentioned U.S. Pat. No. 5,197,858 and U.S. Pat. No. 5,942,866, the driving voltage is formed into a square wave. As a result, the rotational speed of the radiating fan rapidly increases or decreases, so that the radiating fan 5
A rotational speed of 0 causes rattling due to a rapid change.
On the other hand, in the present invention, the pulse and the rotation speed signal input by the voltage comparator circuit are compared, and the compared voltage is input to the minus terminal of the differential amplifier, and the power supply voltage Vcc is divided to obtain the difference. Input to the positive terminal of the dynamic amplifier, and by adjusting the two voltages by a differential amplifier, output a gradual drive voltage Vf.
The rotation speed of the heat radiating fan can be gradually increased or decreased.

[0015]

According to the motor of the radiating fan of the present invention, the pulse is input to the first rectifier circuit and then connected to the voltage comparator circuit. The speed signal is input to the second rectifier circuit and then connected to the voltage comparator circuit. The voltage comparator circuit compares the two voltages and then outputs the comparison voltage. The divided voltage of the comparison voltage and the power supply voltage Vcc is differential. Drive voltage V after adjusting the voltage with an amplifier
f, and the output drive voltage Vf is used to output to the heat dissipation fan, and the drive voltage Vf is formed in a linear and flat waveform, so that the rotation speed of the heat dissipation fan is gradually increased. It is possible to reduce the speed of the heat radiation fan and to prevent the heat radiation fan from rapidly increasing or decelerating, thereby providing an advantage that the service life of the heat radiation fan can be extended.

The present invention may be embodied in other ways without departing from its spirit and essential characteristics. Accordingly, the preferred embodiments described herein are illustrative and not limiting.

[Brief description of the drawings]

FIG. 1 shows a conventional U.S. Pat. No. 5,197,858.
FIG. 3 is a circuit diagram of speed control by a heat radiating fan of FIG.

FIG. 2 shows a conventional US Patent No. 5,197,858.
FIG. 4 is an output waveform diagram of the heat radiation fan of FIG.

FIG. 3 shows a conventional U.S. Pat. No. 5,942,866.
FIG. 3 is a circuit diagram of speed control by a heat radiating fan of FIG.

FIG. 4 shows a conventional US Patent No. 5,942,866.
FIG. 4 is an output waveform diagram of the heat radiation fan of FIG.

FIG. 5 is a circuit diagram of square wave working cycle control according to an embodiment of the present invention.

FIG. 6 is a waveform diagram of a square wave control signal, a heat radiation fan detection signal FG, and a voltage Vf output to the heat radiation fan according to an embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 Rectifier circuit 11 Capacitor 12 Diode 13 Diode 14 Resistor 15 Filtering capacitor 20 Voltage comparator 30 Control switch 40 Thermal resistor 50 Heat dissipation fan 60 First rectifier circuit 60 'Second rectifier circuit 70 Voltage comparator circuit 80 Differential amplifier 90 Heat dissipation fan

Claims (5)

[Claims] 1. A heat radiation fan (90), a pulse input terminal (P)
ulse), a motor of a radiating fan having a pulse operation cycle control rotational speed constituted by a voltage comparator circuit (70) and a differential amplifier (80), wherein the radiating fan (90) has a rotational speed of the radiating fan (90). A signal can be detected and converted to a voltage, and a pulse input terminal (Pul
In step (se), a frequency-invariant pulse can be input and converted to a voltage, and the voltage comparator circuit (70) can convert the voltage converted from the signal detected by the heat radiation fan (90) and the voltage converted from the input pulse. The comparison voltage can be output after the comparison, and the differential amplifier (80) is connected between the heat dissipation fan (90) and the voltage comparator circuit (70), and the power supply voltage is connected to the positive terminal of the differential amplifier (80). (Vcc) is inputted, while the comparison voltage is inputted to the minus end, and the drive for outputting to the heat radiation fan (90) by the voltage difference inputted to the plus and minus ends of the differential amplifier (80). Voltage (Vf) can be changed,
When the working period of the pulse is reduced, the voltage of the pulse can be reduced, and when the voltage of the pulse is gradually reduced, the voltage comparator circuit (70) outputs the gradually increased voltage to the differential amplifier (80). , The driving voltage (Vf) for output by the differential amplifier (80) is formed to gradually decrease, so that the radiation fan (90) gradually decelerates. And when the working cycle of the pulse is increased,
The voltage of the pulse can be increased, and when the voltage of the pulse is gradually increased, the voltage comparator circuit (70) can output a gradually decreased voltage to the minus terminal of the differential amplifier (80). , Differential amplifier (8
0) is formed so that the drive voltage (Vf) for output is gradually increased gradually.
The motor of the radiating fan of the pulse work cycle control rotation speed, characterized in that it is configured to be able to gradually increase the speed. 2. The motor of claim 1, wherein the pulse is a square wave. 3. The motor of claim 1, wherein the pulse is a triangular wave. 4. A first rectifier circuit (60) and a second rectifier circuit (60 ') are included, the first rectifier circuit (60) comprising a voltage comparator circuit (70) and a pulse input (Pul).
The second rectifier circuit (60 ') is connected to the voltage rectifier circuit (70') and the radiating fan (90) while being connected during the period (se) and converting the pulse to a voltage.
2. The motor of claim 1, wherein the motor is connected between the detected signal ends and can convert a signal detected by the radiating fan into a voltage. . 5. The voltage comparator circuit (70) comprises two resistors (R5, R6), one capacitor (C) and one operational amplifier (OP3). The pulse work cycle control the rotation speed of the radiator fan motor.