CN209516621U - Under-voltage protecting circuit and cell apparatus - Google Patents

Abstract

A kind of under-voltage protecting circuit and cell apparatus, by the control module that the switch module and control switch module on-off that are connected between battery and load is added, so that when cell voltage threshold values critical lower than battery undervoltage, control module exports cut-off signals to the control terminal of switch module and when cell voltage threshold values critical higher than battery undervoltage, control module exports open signal to the control terminal of switch module, that is realize the battery when cell voltage is normal normally power to the load and when battery undervoltage battery stopping power to the load, it solves present in traditional technical solution in battery undervoltage, battery is also in discharge condition, the problem of causing battery capacity to exhaust and then cannot be charged and be used again.

Description

Undervoltage protection circuit and battery device

technical field

The utility model belongs to the technical field of undervoltage protection, in particular to an undervoltage protection circuit and a battery device.

Background technique

At present, the positive electrode of the traditional battery is generally directly output to supply power to the load, or to provide power to the load by adding a fuse for overcurrent protection, but this battery is still in discharge when the battery voltage is lower than the rated voltage ( That is, to supply power to the load) state, resulting in the depletion of battery capacity and can no longer be charged and used.

Therefore, there is a problem in the traditional technical solution that when the battery is undervoltage, the battery is still in the state of discharging (that is, supplying power to the load), resulting in the exhaustion of the battery capacity and the problem that it can no longer be charged and used.

Utility model content

In view of this, the embodiment of the utility model provides an undervoltage protection circuit and a battery device, aiming to solve the problem in the traditional technical solution that the battery is still in the state of discharging (that is, supplying power to the load) when the battery is undervoltage. A problem that causes the battery capacity to be depleted so that it can no longer be charged and used.

The first aspect of the embodiment of the utility model provides an undervoltage protection circuit connected to the battery and the load, including:

a switch module, the switch module is connected between the battery and the load;

A control module, the first end of the control module is connected to the positive pole of the battery, the second end of the control module is connected to a reference voltage, the output end of the control module is connected to the control end of the switch module, and the control module The module is configured to turn off the switching module when the battery voltage is lower than a threshold and to turn on the switching module when the battery voltage is higher than a threshold.

In one embodiment, the control module includes:

A comparison unit, the first terminal of the comparison unit is the first terminal of the control module, the second terminal of the comparison unit is connected to the reference voltage, and the comparison unit is configured to compare the battery voltage with the valve Value and output high level signal or low level signal;

A switch unit, the switch unit is connected between the control terminal of the switch module and the ground, the control terminal of the switch unit is connected to the output terminal of the comparison unit, and the switch unit is configured to The level signal is turned on or off, and then the switch module is turned on or off.

In one embodiment, the comparison unit includes a voltage detection chip.

In one embodiment, the comparison unit includes a voltage comparator, the positive phase input terminal of the voltage comparator is connected to the positive pole of the battery, the negative phase input terminal of the voltage comparator is connected to a reference voltage, the The output terminal of the voltage comparator is connected with the control terminal of the switch unit.

In one embodiment, the switch unit includes a first switch tube, the control terminal of the first switch tube is connected to the output terminal of the comparison unit, and the input terminal of the first switch tube is connected to the control terminal of the switch module. connected, and the output terminal of the first switching tube is grounded.

In one embodiment, the switch module includes a second switch tube and a first resistor, the input end of the second switch tube and the first end of the first resistor are commonly connected to the positive pole of the battery, and the The control terminal of the second switch tube is connected to the output terminal of the control module in common with the second terminal of the first resistor, and the output terminal of the second switch tube is connected to the load.

In one embodiment, the above-mentioned undervoltage protection circuit further includes at least one filter module, each of the filter modules is respectively connected between the undervoltage protection circuit and the ground, and each of the filter modules is used to filter out impurities wave interference.

In one embodiment, each of the filter modules includes a first capacitor, a first end of the first capacitor is connected to the undervoltage protection circuit, and a second end of the first capacitor is grounded.

The second aspect of the embodiment of the present invention provides a battery device, including the above-mentioned undervoltage protection circuit, an overcurrent protection module, and a battery, and the undervoltage protection circuit is connected to the battery through the overcurrent protection module.

In one embodiment, the overcurrent protection module includes a first fuse.

The above-mentioned undervoltage protection circuit is connected to the battery and the load. By adding a switch module connected between the battery and the load and a control module that controls the on-off of the switch module, when the battery voltage is lower than the battery undervoltage critical threshold, the control module outputs Turn off the signal to the control terminal of the switch module and when the battery voltage is higher than the critical threshold of battery undervoltage, the control module outputs the turn-on signal to the control terminal of the switch module, that is to say, the battery supplies power to the load normally when the battery voltage is normal And when the battery is undervoltage, the battery stops supplying power to the load, which solves the problem in the traditional technical solution that when the battery is undervoltage, the battery is still in the discharge state, resulting in the exhaustion of the battery capacity and the problem that it can no longer be charged and used.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the utility model, the following will briefly introduce the accompanying drawings that are required in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only the practical For some novel embodiments, those skilled in the art can also obtain other drawings based on these drawings without any creative work.

Fig. 1 is a schematic circuit diagram of an undervoltage protection circuit provided by an embodiment of the present invention;

FIG. 2 is an example circuit schematic diagram of a control module in the undervoltage protection circuit shown in FIG. 1;

Fig. 3 is an example circuit schematic diagram of a comparison unit in the control module shown in Fig. 2;

Fig. 4 is another example circuit principle diagram of the comparison unit in the control module shown in Fig. 2;

Fig. 5 is an example circuit schematic diagram of a switch unit in the control module shown in Fig. 2;

FIG. 6 is an example circuit schematic diagram of a switch module in the undervoltage protection circuit shown in FIG. 1;

FIG. 7 is a circuit schematic diagram of an undervoltage protection circuit provided by an embodiment of the present invention;

FIG. 8 is a schematic circuit diagram of an undervoltage protection circuit provided by another embodiment of the present invention;

FIG. 9 is an example circuit schematic diagram of a filter module in the undervoltage protection circuit shown in FIG. 8;

Fig. 10 is a schematic circuit diagram of a battery device provided by an embodiment of the present invention;

FIG. 11 is a schematic circuit diagram of an example of an overcurrent protection module in the battery device shown in FIG. 10 .

Detailed ways

In order to make the purpose, technical solution and advantages of the utility model clearer, the utility model will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the utility model, and are not intended to limit the utility model.

Please refer to Fig. 1, the schematic circuit diagram of the undervoltage protection circuit provided by the first embodiment of the present invention. For the convenience of explanation, only the parts related to this embodiment are shown, and the details are as follows:

The undervoltage protection circuit in this embodiment is connected to the battery 100 and the load 200, including: a switch module 300 and a control module 400, the switch module 300 is configured to control the on-off of the power supply circuit between the battery 100 and the load 200, the switch module 300 It can be composed of a device or chip that is turned on or off according to a control signal, such as a switch tube, a switch chip, or a relay; the control module 400 is configured to turn off the switch module 300 and the battery when the voltage of the battery 100 is lower than the threshold When the 100 voltage is higher than the threshold, the switch module 300 is turned on. The control module 400 can be composed of a device or chip that judges the magnitude of two voltages and outputs a corresponding level signal, such as a voltage detection chip, a comparator, or a microprocessor.

The switch module 300 is connected between the battery 100 and the load 200. It can be understood that the input terminal of the switch module 300 is connected with the positive pole of the battery 100, the output terminal of the switch module 300 is connected with the load 200, and the control terminal of the switch module 300 is connected with the control module 400. connection, the first terminal of the control module 400 is connected to the positive pole of the battery 100 , the second terminal of the control module 400 is connected to the reference voltage Uref, and the output terminal of the control module 400 is connected to the control terminal of the switch module 300 .

It should be understood that the threshold described in this embodiment is the critical threshold of the battery undervoltage, and the critical threshold of the battery undervoltage should be equal to or configured according to the value of the reference voltage Uref.

The undervoltage protection circuit in this embodiment is connected with the battery 100 and the load 200, by adding a switch module 300 connected between the battery 100 and the load 200 and a control module 400 for controlling the on-off of the switch module 300, so that when the voltage of the battery 100 is lower than When the battery undervoltage threshold is critical, the control module 400 outputs a shutdown signal to the control terminal of the switch module 300 and when the voltage of the battery 100 is higher than the battery undervoltage critical threshold, the control module 400 outputs a turn-on signal to the control terminal of the switch module 300 That is to say, when the voltage of the battery 100 is normal, the battery 100 supplies power to the load 200 normally and when the battery 100 is undervoltage, the battery 100 stops supplying power to the load 200, which solves the problem in the traditional technical solution that when the battery 100 is undervoltage, The battery 100 is still in the state of discharging (that is, supplying power to the load 200 ), which leads to the problem that the capacity of the battery 100 is depleted and cannot be charged and used any more.

Please refer to FIG. 2 , in one embodiment, the control module 400 includes: a comparison unit 410 and a switch unit 420, the comparison unit 410 is configured to compare the voltage of the battery 100 with a threshold and output a high level signal or a low level signal, for comparison The unit 410 can be composed of a device or chip that judges the magnitude of two voltages and outputs a corresponding level signal, such as a voltage detection chip, a comparator; the switch unit 420 is configured to be turned on or off according to the level signal of the comparison unit 410 , and then turn on or off the switch module 300 , the switch unit 420 may be composed of switch tubes, such as NMOS tubes, PMOS tubes, IGBT thyristors, NPN transistors, and PNP transistors.

The first terminal of the comparison unit 410 is connected to the positive pole of the battery 100, the second terminal of the comparison unit 410 is connected to the reference voltage Uref, the output terminal of the comparison unit 410 is connected to the control terminal of the switch unit 420, and the switch unit 420 is connected to the switch module 300 and between.

Please refer to Fig. 3. In one embodiment, the comparison unit 410 includes a voltage detection chip. In this embodiment, the voltage detection chip adopts the XC61JC3002ML low voltage detection chip. In other embodiments, it can also be selected depending on the specific threshold value. The corresponding voltage detection chip.

Please refer to FIG. 4, in one embodiment, the comparison unit 410 includes a voltage comparator U1, the first terminal of the voltage comparator U1 is connected to the positive pole of the battery 100, the second terminal of the voltage comparator U1 is connected to a reference voltage, and the voltage comparison The output terminal of the comparator U1 is connected to the control terminal of the switch unit 420. It should be understood that the battery undervoltage critical threshold here should be equal to or configured according to the value of the reference voltage Uref. In this embodiment, the first terminal of the voltage comparator U1 is The positive phase input terminal, the second terminal of the voltage comparator U1 is a negative phase input terminal, in other embodiments, it is also possible: the first terminal of the voltage comparator U1 is a negative phase input terminal, the second terminal of the voltage comparator U1 For positive input.

Please refer to FIG. 5. In one embodiment, the switch unit 420 includes a first switch tube Q1, the control terminal of the first switch tube Q1 is connected to the output terminal of the comparison unit 410, and the input terminal of the first switch tube Q1 is connected to the switch module 300. The control end of the first switch tube Q1 is connected to the ground.

It should be understood that the first switching transistor Q1 in this embodiment is an NMOS transistor, and in other embodiments, the first switching transistor Q1 may also be other switching transistors, such as PMOS transistors, NPN transistors, PNP transistors or IGBT thyristors, etc. .

It should be understood that the diode D1 in this embodiment is the body diode D1 of the first switching transistor Q1.

Please refer to FIG. 6 , in one embodiment, the switch module 300 includes a second switch tube Q2 and a first resistor R1, the input end of the second switch tube Q2 and the first end of the first resistor R1 are connected to the positive pole of the battery 100 , the control terminal of the second switching transistor Q2 and the second terminal of the first resistor R1 are jointly connected to the output terminal of the control module 400 , and the output terminal of the second switching transistor Q2 is connected to the load 200 .

In this embodiment, the second switching transistor Q2 is a PMOS transistor. In other embodiments, the second switching transistor Q2 may also be an NMOS transistor, an NPN transistor, a PNP transistor, or an IGBT thyristor.

Please refer to Fig. 7, in order to facilitate the understanding of the present invention, the working principle of the undervoltage protection circuit is illustrated with one of the embodiments:

When the output voltage of the battery 100 is greater than the battery undervoltage critical threshold, the low-voltage detection chip 411 outputs a high level to the gate of the first switching tube Q1. At this time, the first switching tube Q1 is turned on, and the second switching tube Q2 is turned on, and the battery 100 supplies power to the load 200 normally;

When the output voltage of the battery 100 is less than the battery undervoltage critical threshold, the low voltage detection chip 411 outputs a low level to the gate of the first switching tube Q1, at this time, the first switching tube Q1 is turned off, and the second switching tube Q2 When off, the battery 100 stops supplying power to the load 200 .

Please refer to FIG. 8. In one embodiment, the undervoltage protection circuit further includes at least one filter module, and each filter module is respectively connected between the undervoltage protection circuit and the ground, and each filter module is used to filter out clutter interference, In this embodiment, the undervoltage protection circuit includes two filter modules (the first filter module 510 and the second filter module 520), and in other embodiments, it may also include one or more than two. The first filter module of this embodiment The filter module 510 is connected between the input terminal of the control module 400 and the ground, and the second filter module 520 is connected between the input terminal of the switch module 300 and the ground.

Referring to FIG. 9 , in one embodiment, each filter module includes a first capacitor C1 , the first end of the first capacitor C1 is connected to the undervoltage protection circuit, and the second end of the first capacitor C1 is grounded.

Please refer to FIG. 10 , the second embodiment of the present utility model provides a battery 100 device, including the above-mentioned undervoltage protection circuit, an overcurrent protection module 600 and a battery 100 , and the undervoltage protection circuit is connected to the battery 100 through the overcurrent protection module 600 .

Referring to FIG. 11 , in one embodiment, the overcurrent protection module 600 includes a first fuse F1 .

The above descriptions are only preferred embodiments of the present utility model, and are not intended to limit the present utility model. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present utility model shall be included in this utility model. within the scope of protection of utility models.

Claims (10)

1. A kind of undervoltage protection circuit, is connected with battery and load, is characterized in that, comprises: a switch module, the switch module is connected between the battery and the load; A control module, the first end of the control module is connected to the positive pole of the battery, the second end of the control module is connected to a reference voltage, the output end of the control module is connected to the control end of the switch module, and the control module The module is configured to turn off the switching module when the battery voltage is lower than a threshold and to turn on the switching module when the battery voltage is higher than a threshold. 2. The undervoltage protection circuit according to claim 1, wherein the control module comprises: A comparison unit, the first terminal of the comparison unit is the first terminal of the control module, the second terminal of the comparison unit is connected to the reference voltage, and the comparison unit is configured to compare the battery voltage with the valve Value and output high level signal or low level signal; A switch unit, the switch unit is connected between the control terminal of the switch module and the ground, the control terminal of the switch unit is connected to the output terminal of the comparison unit, and the switch unit is configured to The level signal is turned on or off, and then the switch module is turned on or off. 3. The undervoltage protection circuit according to claim 2, wherein the comparison unit comprises a voltage detection chip. 4. The undervoltage protection circuit according to claim 2, wherein the comparison unit comprises a voltage comparator, the positive phase input terminal of the voltage comparator is connected to the positive pole of the battery, and the voltage comparator The inverting input terminal of the voltage comparator is connected to the reference voltage, and the output terminal of the voltage comparator is connected to the control terminal of the switch unit. 5. The undervoltage protection circuit according to claim 2, wherein the switch unit comprises a first switch tube, the control terminal of the first switch tube is connected to the output terminal of the comparison unit, and the first switch tube is connected to the output terminal of the comparison unit. The input terminal of a switch tube is connected to the control terminal of the switch module, and the output terminal of the first switch tube is grounded. 6. The undervoltage protection circuit according to any one of claims 1-5, wherein the switch module includes a second switch tube and a first resistor, and the input terminal of the second switch tube is connected to the first resistor The first terminal of a resistor is commonly connected to the positive pole of the battery, the control terminal of the second switch tube and the second terminal of the first resistor are commonly connected to the output terminal of the control module, and the second switch The output of the tube is connected to the load. 7. The undervoltage protection circuit according to claim 6, further comprising at least one filter module, each of the filter modules is respectively connected between the undervoltage protection circuit and ground, and each of the filter modules Used to filter out clutter interference. 8. The undervoltage protection circuit according to claim 7, wherein each of the filter modules includes a first capacitor, the first terminal of the first capacitor is connected to the undervoltage protection circuit, and the first capacitor is connected to the undervoltage protection circuit. The second end of a capacitor is grounded. 9. A battery device, characterized in that it comprises the undervoltage protection circuit according to any one of claims 1-8, an overcurrent protection module and a battery, and the undervoltage protection circuit communicates with the overcurrent protection module through the overcurrent protection module. battery connection described above. 10. The battery device according to claim 9, wherein the overcurrent protection module comprises a first fuse.