Capacitor discharge circuit and power supply system

Abstract

The utility model relates to the technical field of power supplies, and provides a capacitor discharge circuit and a power supply system, the capacitor discharge circuit comprises a control module, an acceleration module and a discharge module; the control module is respectively connected with the port capacitor and the acceleration module, the acceleration module is connected with the port capacitor, and the discharge module is connected with the acceleration module in parallel. The discharge module is used for discharging the capacitor voltage of the port capacitor; the control module is used for storing the capacitor voltage of the port capacitor when the port capacitor discharges, and controlling the acceleration module to work when the difference between the stored capacitor voltage and the current capacitor voltage of the port capacitor is greater than a voltage threshold. And the acceleration module and the discharge module discharge the voltage of the port capacitor at the same time, so that the discharge speed is accelerated, and the discharge efficiency of the capacitor is improved. And the port capacitor is discharged through a pure analog circuit, so that the cost is reduced, and the reliability of the circuit is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of power supplies, and particularly to a capacitor discharge circuit and a power supply system.

Background Art

[0002] The capacitor voltage discharge circuit at both ends of a capacitor is widely used in DC power supplies. Currently, there are mainly two widely used capacitor voltage discharge methods.

[0003] One is to control the power switch in series with a resistor through an IC such as an MCU. This solution has the advantage of high power supply efficiency. However, using an IC such as an MCU has the disadvantages of high cost, complex circuit structure, and poor anti-interference ability. The other is to use a fixed resistor discharge method, which realizes the purpose of rapid discharge by connecting a resistor in parallel at the capacitor terminal. Since a resistor is added at the capacitor terminal, it causes serious power supply heating and low efficiency.

Content of the Utility Model

[0004] The embodiments of the utility model provide a capacitor discharge circuit and a power supply system, aiming to solve the technical problems of high cost, low efficiency, and low reliability in capacitor discharge in the prior art.

[0005] To solve the above technical problems, a technical solution adopted in the embodiments of the utility model is: providing a capacitor discharge circuit, the capacitor discharge circuit includes a control module, an acceleration module, and a discharge module;

[0006] The control module is respectively connected to a port capacitor and the acceleration module, the acceleration module is connected to the port capacitor, and the discharge module is connected in parallel with the acceleration module;

[0007] The discharge module is used to discharge the capacitor voltage of the port capacitor;

[0008] The control module is used to store the capacitor voltage of the port capacitor when the port capacitor discharges, and when the difference between the stored capacitor voltage and the current capacitor voltage of the port capacitor is greater than a voltage threshold, control the acceleration module to work, so that the acceleration module and the discharge module discharge the voltage of the port capacitor simultaneously.

[0009] Optionally, the control module includes an energy storage unit and a control unit;

[0010] The energy storage unit is connected to the port capacitor, the energy storage unit is also connected to the control unit, and the control unit is respectively connected to the port capacitor and the acceleration module;

[0011] The energy storage unit is used to store the capacitor voltage of the port capacitor when the port capacitor discharges;

[0012] The control unit is configured to output a control signal to the acceleration module to control the operation of the acceleration module when the difference between the voltage stored in the energy storage unit and the current capacitor voltage is greater than a voltage threshold.

[0013] Optionally, the energy storage unit includes a resistor R2 and a capacitor C2;

[0014] The resistor R2 is respectively connected to the port capacitor and the capacitor C2. The capacitor C2 is connected to the control unit and is also grounded.

[0015] Optionally, the control unit includes a zener diode D2, a resistor R3, and a switching transistor Q2;

[0016] The anode of the zener diode D2 is connected to the port capacitor. The cathode of the zener diode D2 is connected to the control terminal of the switching transistor Q2 through the resistor R3. The first terminal of the switching transistor Q2 is connected to the capacitor C2, and the second terminal of the switching transistor Q2 is connected to the acceleration module.

[0017] Optionally, the acceleration module includes a resistor R4, a resistor R1, and a switching transistor Q1;

[0018] The control terminal of the switching transistor Q1 is connected to the control module through the resistor R4. The first terminal of the switching transistor Q1 is connected to the port capacitor through the resistor R1, and the second terminal of the switching transistor Q1 is grounded.

[0019] Optionally, the capacitor discharge circuit further includes a clamping module;

[0020] The clamping module is connected to the acceleration module.

[0021] Optionally, the clamping module is a zener diode D3;

[0022] The cathode of the zener diode D3 is connected to the control terminal of the switching transistor Q1, and the anode of the zener diode D3 is grounded.

[0023] Optionally, the discharging module is a resistor R5;

[0024] The first terminal of the resistor R5 is connected to the port capacitor, and the second terminal of the resistor R5 is grounded.

[0025] Optionally, the capacitor discharge circuit further includes an anti-backflow module;

[0026] The anti-backflow module is respectively connected to the port capacitor and the energy storage unit;

[0027] The anti-backflow module is configured to prevent the current on the energy storage unit from flowing to the port capacitor.

[0028] To solve the above technical problems, another technical solution adopted in the embodiments of the present utility model is: to provide a power supply system, the power supply system includes:

[0029] Port capacitance;

[0030] Power supply; and

[0031] The capacitance discharge circuit as described above, wherein the port capacitance is respectively connected to the power supply and the capacitance discharge circuit.

[0032] Different from the related art, the present utility model provides a capacitance discharge circuit and a power supply system. The capacitance discharge circuit includes a control module, an acceleration module and a discharge module; the control module is respectively connected to the port capacitance and the acceleration module, the acceleration module is connected to the port capacitance, and the discharge module is connected in parallel with the acceleration module. The discharge module is used to discharge the capacitance voltage of the port capacitance; the control module is used to store the capacitance voltage of the port capacitance when the port capacitance discharges, and when the difference between the stored capacitance voltage and the current capacitance voltage of the port capacitance is greater than the voltage threshold, control the acceleration module to work, so that the acceleration module and the discharge module discharge the voltage of the port capacitance at the same time, thereby accelerating the discharge speed and further improving the efficiency of capacitance discharge. And by discharging the port capacitance through a pure analog circuit, not only the cost is reduced, but also the reliability of the circuit is improved.

Description of the Drawings

[0033] One or more embodiments are exemplarily illustrated by corresponding drawings. These exemplary illustrations do not limit the embodiments. Elements with the same reference numerals in the drawings represent similar elements. Unless otherwise stated, the drawings in the figures do not constitute a proportional limitation.

[0034] Figure 1 is a structural block diagram of a power supply system provided by an embodiment of the present utility model;

[0035] Figure 2 is a structural block diagram of a capacitance discharge circuit provided by an embodiment of the present utility model;

[0036] Figure 3 is a circuit diagram of a capacitance discharge circuit provided by an embodiment of the present utility model.

Detailed Embodiments

[0037] In order to make the purpose, technical solutions and advantages of the present utility model clearer, the present utility model will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present utility model and are not used to limit the present utility model.

[0038] In each of the embodiments of the present application described below, the technical features involved do not conflict with each other and can be combined with each other.

[0039] When an element is expressed as "connected" to another element, it can be directly connected to the other element, or there can be one or more intermediate elements therebetween.

[0040] Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by those of ordinary skill in the technical field to which this utility model belongs. The terms used in the specification of this utility model are only for the purpose of describing specific embodiments and are not intended to limit this utility model. The term "and / or" used in this specification includes any and all combinations of one or more of the related listed items.

[0041] Please refer to Figure 1 , Figure 1 which is a structural block diagram of a power supply system provided by an embodiment of this utility model. As shown in Figure 1 , the power supply system 100 includes a power supply 10, a port capacitor C1, and a capacitor discharge circuit 20; the port capacitor C1 is respectively connected to the power supply 10 and the capacitor discharge circuit 20. When the power supply 10 is working, the port capacitor C1 stores the output voltage of the power supply 10, and when the power supply 10 loses power, it is necessary to quickly discharge the voltage stored in the port capacitor C1 to ensure that the power supply circuit can be restarted normally.

[0042] Specifically, when the power supply 10 loses power, the capacitor discharge circuit 20 detects the capacitance voltage of the port capacitor C1, and when there is residual electricity on the port capacitor C1, discharges the capacitance voltage on the port capacitor C1 to ensure that the power supply circuit can be restarted. It should be noted that in some scenarios where the power supply needs to be switched on and off quickly and repeatedly, when the switch of the power supply 10 is turned off, due to the existence of the port capacitor C1, the voltage on the load circuit will drop slowly. And if power is reapplied when the port capacitor C1 has not completely lost power, it may cause the power supply circuit to not be able to reset and start normally, and then situations such as the computer freezing during startup may occur. Therefore, by setting the capacitor discharge circuit 20, the residual electricity in the port capacitor C1 can be quickly discharged, thereby ensuring that the power supply circuit can be restarted normally.

[0043] Further, please refer to Figure 2 , Figure 2 which is a structural block diagram of a capacitor discharge circuit provided by an embodiment of this utility model. As shown in Figure 2 , the capacitor discharge circuit 20 includes a control module 21, an acceleration module 22, and a discharge module 23;

[0044] The control module 21 is respectively connected to the port capacitor C1 and the acceleration module 22. The acceleration module 22 is connected to the port capacitor C1, and the discharge module 23 is connected in parallel with the acceleration module 22;

[0045] The discharge module 23 is used to discharge the capacitance voltage of the port capacitor C1;

[0046] The control module 21 is used to store the capacitance voltage of the port capacitor C1 when the port capacitor C1 discharges, and when the difference between the stored capacitance voltage and the current capacitance voltage of the port capacitor C1 is greater than the voltage threshold, control the acceleration module 22 to work, so that the acceleration module 22 and the discharge module 23 discharge the voltage of the port capacitor C1 at the same time.

[0047] Specifically, when the power supply 10 loses power, the port capacitor C1 starts to discharge the remaining power through the capacitor discharge circuit 20. At this time, the port capacitor C1 will discharge through the discharge module 23. At the same time, the capacitance voltage of the port capacitor C1 will also be input to the control module 21, so that the control module 21 stores the capacitance voltage. During the process of the port capacitor C1 discharging through the discharge module 23, the capacitance voltage of the port capacitor C1 gradually decreases. At this time, the control module 21 will determine the difference between the current capacitance voltage of the port capacitor C1 and the stored voltage. If the difference between the current capacitance voltage of the port capacitor C1 and the capacitance voltage stored in the control module 21 is greater than the voltage threshold, the control module 21 will output a control signal to the acceleration module 22, so that the acceleration module 22 starts to work. When the acceleration module 22 starts to work, the acceleration module 22 and the discharge module 23 will discharge the capacitance voltage on the port capacitor C1 at the same time, thereby accelerating the discharge speed of the port capacitor C1 and improving the discharge efficiency of the port capacitor C1.

[0048] In some embodiments, as Figure 2 shown, the control module 21 includes an energy storage unit 211 and a control unit 212;

[0049] The energy storage unit 211 is connected to the port capacitor C1, the energy storage unit 211 is also connected to the control unit 212, and the control unit 212 is respectively connected to the port capacitor C1 and the acceleration module 22;

[0050] The energy storage unit 211 is used to store the capacitance voltage of the port capacitor C1 when the port capacitor C1 discharges;

[0051] The control unit 212 is configured to output a control signal to the acceleration module 22 to control the operation of the acceleration module 22 when the difference between the voltage stored in the energy storage unit 211 and the current capacitor voltage is greater than a voltage threshold.

[0052] In another embodiment, please refer to Figure 3 , Figure 3 which is a circuit diagram of a capacitor discharge circuit provided by an embodiment of the present invention. As Figure 3 shown, the energy storage unit 211 includes a resistor R2 and a capacitor C2; the control unit 212 includes a zener diode D2, a resistor R3, and a switching transistor Q2;

[0053] The resistor R2 is respectively connected to the port capacitor C1 and the capacitor C2. The capacitor C2 is connected to the control unit 212, and the capacitor C2 is also grounded.

[0054] The anode of the zener diode D2 is connected to the port capacitor C1. The cathode of the zener diode D2 is connected to the control terminal of the switching transistor Q2 through the resistor R3. The first end of the switching transistor Q2 is connected to the capacitor C2, and the second end of the switching transistor Q2 is connected to the acceleration module 22.

[0055] In some embodiments, the switching transistor Q2 is a P-channel field effect transistor. That is, the control terminal of the switching transistor Q2 is the gate, the first end of the switching transistor Q2 is the source, and the second end of the switching transistor Q2 is the drain. When the GS voltage of the switching transistor Q2 is less than a certain value (that is, the gate voltage is less than the source voltage by a certain value), it is considered that the switching transistor Q2 is turned on.

[0056] Specifically, when the port capacitor C1 discharges through the discharge module 23, the capacitor voltage of the port capacitor C1 will also charge the capacitor C2 through the resistor R2. During the charging process of the capacitor C2, since the voltage across the switching transistor Q2 does not meet the conduction condition (there is no voltage difference between GS), the switching transistor Q2 is in the cut-off state. At this time, the port capacitor C1 only discharges through the discharge module 23. It should be noted that after the port capacitor C1 charges the capacitor C2, since the switching transistor Q2 is in the cut-off state, there is no discharge path for the capacitor C2. Therefore, during the discharge process of the port capacitor C1, the voltage of the port capacitor C1 will gradually decrease, but the capacitor voltage across the capacitor C2 remains unchanged.

[0057] When the capacitance voltage stored in the port capacitor C1 gradually decreases, the gate voltage of the switching transistor Q2 also gradually decreases. When the difference between the voltage of the port capacitor C1 and the voltage of the capacitor C2 is less than a preset threshold, the capacitor C2, the switching transistor Q2, the voltage stabilizing diode D2, and the capacitor C1 form a loop, and the switching transistor Q2 conducts, thereby outputting a control signal to the acceleration module 22. It should be noted that the preset threshold is determined according to the voltage stabilizing value of the voltage stabilizing diode D2 and the conduction threshold (GS voltage) of the switching transistor Q2; only when the current capacitance voltage of the port capacitor C1 plus the voltage stabilizing value of the voltage stabilizing diode D2 and the voltage value after the conduction threshold of the switching transistor Q2 is less than the voltage value stored in the capacitor C2, the capacitor C2, the switching transistor Q2, the voltage stabilizing diode D2, and the capacitor C1 will form a loop, the voltage stabilizing diode D2 will be broken down, and the switching transistor Q2 will be in a conducting state. For example, the voltage of the port capacitor C1 is 24V, the conduction threshold of the switching transistor Q2 is 3V, and the voltage stabilizing value of the voltage stabilizing diode D2 is 3.3V; when the power supply 10 loses power, the port capacitor C1 starts to discharge through the discharge module 23 and charges the capacitor C2 at the same time. At this time, the capacitance voltage on the capacitor C2 is the capacitance voltage of the port capacitor C1 (that is, 24V). When the capacitance voltage of the port capacitor C1 discharges to 17V, the voltage difference between the capacitor C2 and the port capacitor C1 is greater than the preset threshold (that is, 3V + 3.3V). At this time, the capacitor C2, the switching transistor Q2, the voltage stabilizing diode D2, and the capacitor C1 form a loop, the switching transistor Q2 conducts, the voltage stabilizing diode D2 is broken down, and the switching transistor Q2 outputs a control signal to the acceleration module 22.

[0058] It can be known that by introducing the voltage stabilizing diode D2 to increase the preset threshold, the conduction time of the acceleration module 22 is delayed, the situation of rapid discharge when the capacitance voltage of the port capacitor C1 is particularly large is avoided, and further, the safety accident caused by the release of huge energy by the port capacitor C1 in a very short time is avoided.

[0059] Further, in another embodiment, as Figure 2 shown, the capacitor discharge circuit 20 further includes a backflow prevention module 25; the backflow prevention module 25 is respectively connected to the port capacitor C1 and the energy storage unit 211.

[0060] The backflow prevention module 25 is used to prevent the current on the energy storage unit 211 from flowing to the port capacitor C1.

[0061] Among them, as Figure 3 shown, the backflow prevention module 25 is a diode D1;

[0062] The anode of the diode D1 is connected to the port capacitor C1, and the cathode of the diode D1 is connected to the resistor R2. Specifically, by utilizing the unidirectional conductivity of the diode, the current on the capacitor C2 is prevented from flowing into the port capacitor C1.

[0063] In another embodiment, as Figure 3 shown, the discharging module 23 is a resistor R5; the first end of the resistor R5 is connected to the port capacitor C1, and the second end of the resistor R5 is used for grounding. Specifically, the resistor R5 is a fixed discharging resistor. When the power supply 10 loses power, the resistor R5 and the port capacitor C1 form a discharging circuit, thereby discharging the capacitor voltage on the port capacitor C1.

[0064] In some embodiments, as Figure 3 shown, the accelerating module 22 includes a resistor R4, a resistor R1, and a switching transistor Q1;

[0065] The control end of the switching transistor Q1 is connected to the control module 21 through the resistor R4, the first end of the switching transistor Q1 is connected to the port capacitor C1 through the resistor R1, and the second end of the switching transistor Q1 is used for grounding.

[0066] Specifically, when the switching transistor Q2 is turned on, the switching transistor Q1 will receive a control signal and turn on based on the control signal. When the switching transistor Q1 is turned on, the capacitor voltage of the port capacitor C1 will also be discharged through the resistor R1, thereby accelerating the discharging speed of the port capacitor C1. It should be noted that when the switching transistor Q1 is turned on, the resistor R1 is in parallel with the resistor R5. At this time, since the resistance value of the resistors will become smaller when they are connected in parallel, the discharging resistance is reduced, and the smaller the resistance, the faster the discharging speed. Based on this, the discharging speed of the port capacitor C1 can be accelerated. Through the cooperation between the resistor and the switching transistor, avoiding the use of devices such as digital switches can enable the remaining electricity to be quickly discharged after the power supply loses power, thereby reducing the cost of capacitor discharging.

[0067] Further, in another embodiment, as Figure 2 shown, the capacitor discharging circuit 20 further includes a clamping module 24; the clamping module 24 is connected to the accelerating module 22.

[0068] Among them, as Figure 3 shown, the clamping module 24 is a voltage stabilizing diode D3;

[0069] The cathode of the voltage stabilizing diode D3 is connected to the control terminal of the switching transistor Q1, and the anode of the voltage stabilizing diode D3 is grounded. Specifically, the voltage stabilizing diode D3 is mainly used to protect the switching transistor Q1 from being damaged when the capacitance voltage of the port capacitor C1 is too large. Specifically, after the switching transistor Q2 is turned on, the capacitance voltage of the port capacitor C1 is input to the control terminal of the switching transistor Q1 through the voltage stabilizing diode D2, the resistor R3 and the switching transistor Q2. At this time, if the capacitance voltage is too large, that is, the capacitance voltage is greater than the regulated value of the voltage stabilizing diode D3, the voltage stabilizing diode D3 will be broken down, thereby limiting the voltage between the control terminal and the second terminal of the switching transistor Q1 to the regulated value of the voltage stabilizing diode D3, avoiding a large voltage being directly input to the control terminal of the switching transistor Q1, and further protecting the switching transistor Q1.

[0070] An embodiment of the present invention provides a capacitor discharge circuit, which includes a control module, an acceleration module and a discharge module; the control module is respectively connected to a port capacitor and the acceleration module, the acceleration module is connected to the port capacitor, and the discharge module is connected in parallel with the acceleration module. The discharge module is used to discharge the capacitance voltage of the port capacitor; the control module is used to store the capacitance voltage of the port capacitor when the port capacitor discharges, and when the difference between the stored capacitance voltage and the current capacitance voltage of the port capacitor is greater than a voltage threshold, control the acceleration module to work, so that the acceleration module and the discharge module discharge the voltage of the port capacitor at the same time, thereby accelerating the discharge speed, and further improving the efficiency of capacitor discharge. And by using a pure analog circuit to discharge the port capacitor, not only the cost is reduced, but also the reliability of the circuit is improved.

[0071] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; under the idea of the present invention, the technical features in the above embodiments or different embodiments can also be combined, and the steps can be implemented in any order, and there are many other changes in different aspects of the present invention as described above. For the sake of brevity, they are not provided in detail; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the various embodiments of the present application.

Claims

1. A capacitor discharge circuit, characterized in that, The capacitor discharge circuit includes a control module, an acceleration module, and a discharge module; The control module is respectively connected to the port capacitor and the acceleration module, the acceleration module is connected to the port capacitor, and the discharge module is connected in parallel with the acceleration module; The discharge module is used to discharge the capacitance voltage of the port capacitor; The control module is used to store the capacitance voltage of the port capacitor when the port capacitor discharges, and when the difference between the stored capacitance voltage and the current capacitance voltage of the port capacitor is greater than the voltage threshold, control the acceleration module to work so that the acceleration module and the discharge module discharge the voltage of the port capacitor simultaneously.

2. The capacitor discharge circuit according to claim 1, wherein The control module includes an energy storage unit and a control unit; The energy storage unit is connected to the port capacitor, the energy storage unit is also connected to the control unit, and the control unit is respectively connected to the port capacitor and the acceleration module; The energy storage unit is used to store the capacitance voltage of the port capacitor when the port capacitor discharges; The control unit is used to output a control signal to the acceleration module to control the acceleration module to work when the difference between the voltage stored in the energy storage unit and the current capacitance voltage is greater than the voltage threshold.

3. The capacitor discharge circuit according to claim 2, wherein, The energy storage unit includes a resistor R2 and a capacitor C2; The resistor R2 is respectively connected to the port capacitor and the capacitor C2, the capacitor C2 is connected to the control unit, and the capacitor C2 is also used for grounding.

4. The capacitor discharge circuit according to claim 3, wherein The control unit includes a zener diode D2, a resistor R3, and a switching transistor Q2; The anode of the zener diode D2 is connected to the port capacitor, the cathode of the zener diode D2 is connected to the control terminal of the switching transistor Q2 through the resistor R3, the first end of the switching transistor Q2 is connected to the capacitor C2, and the second end of the switching transistor Q2 is connected to the acceleration module.

5. The capacitive discharge circuit according to claim 1, wherein The acceleration module includes a resistor R4, a resistor R1, and a switching transistor Q1; The control terminal of the switching transistor Q1 is connected to the control module through the resistor R4, the first end of the switching transistor Q1 is connected to the port capacitor through the resistor R1, and the second end of the switching transistor Q1 is used for grounding.

6. The capacitor discharge circuit according to claim 5, wherein The capacitor discharge circuit further includes a clamping module; The clamping module is connected to the acceleration module.

7. The capacitor discharge circuit according to claim 6, wherein The clamping module is a zener diode D3; The cathode of the zener diode D3 is connected to the control terminal of the switching transistor Q1, and the anode of the zener diode D3 is used for grounding.

8. The capacitor discharge circuit according to any one of claims 1-7, characterized in that, The discharge module is a resistor R5; The first end of the resistor R5 is connected to the port capacitor, and the second end of the resistor R5 is used for grounding.

9. The capacitive discharge circuit according to claim 2, wherein The capacitor discharge circuit further includes an anti-backflow module; The anti-backflow module is respectively connected to the port capacitor and the energy storage unit; The anti-backflow module is used to prevent the current on the energy storage unit from flowing to the port capacitor.

10. A power supply system, characterized in that, The power supply system includes: A port capacitor; A power supply; and The capacitor discharge circuit according to any one of claims 1-9, wherein the port capacitor is respectively connected to the power supply and the capacitor discharge circuit.

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