Bleeding circuit and power supply system

Abstract

The utility model provides a bleeder circuit and a power supply system. The bleeder circuit comprises a trigger unit and a bleeder loop. The trigger unit is electrically connected with an energy storage capacitor and a discharge loop in the power supply system, and is used for controlling the discharge loop to be conducted when the voltage of the energy storage capacitor is lower than a preset voltage; and the discharge loop is also electrically connected with the energy storage capacitor and is used for discharging energy on the energy storage capacitor when the discharge loop is switched on. After the input end of the power supply system is disconnected, the energy on the energy storage capacitor can be quickly discharged along with the output load and the like, and the energy can be continuously and quickly discharged through the discharge loop as long as the voltage of the energy storage capacitor is lower than the preset voltage, so that the discharge speed is improved.

Description

Technical Field

[0001] This application relates to the field of power supply technology, specifically to a discharge circuit and a power supply system. Background Technology

[0002] In a power supply, an energy storage capacitor is a component used to store electrical energy. It is typically placed at the output terminal of the power supply to smooth the output voltage and provide transient response. When the input terminal of the power supply is disconnected, the energy storage capacitor still contains a large amount of stored energy, which can easily lead to related safety hazards, so it needs to be discharged.

[0003] Existing technologies include solutions for releasing the energy stored in energy storage capacitors, but the release effect of existing solutions is poor. Utility Model Content

[0004] In view of the shortcomings of the prior art, this application provides a discharge circuit and a power supply system.

[0005] In one embodiment, this application provides a discharge circuit, comprising:

[0006] Triggering unit and discharge circuit;

[0007] The trigger unit is electrically connected to the energy storage capacitor and the discharge circuit in the power supply system, respectively, and is used to control the discharge circuit to conduct when the voltage on the energy storage capacitor is lower than the preset voltage; the preset voltage is lower than the output voltage of the power supply system.

[0008] The discharge circuit is also electrically connected to the energy storage capacitor to discharge energy from the energy storage capacitor when it is conducting.

[0009] In one embodiment, the triggering unit includes a first Zener diode, a first resistor, and a level-flipping unit;

[0010] The first Zener diode includes a cathode electrically connected to the first terminal of the energy storage capacitor and the first access terminal of the discharge circuit, and an anode electrically connected to the first terminal of the first resistor and the input terminal of the level switching unit. The level switching unit also includes an output terminal electrically connected to the controlled terminal of the discharge circuit. The second terminal of the first resistor, the second terminal of the energy storage capacitor and the second access terminal of the discharge circuit are respectively grounded.

[0011] The level-flipping unit is used to flip the levels of its input and output terminals; the bleeder circuit is used to conduct when a high level is applied to its controlled terminal;

[0012] When the voltage on the energy storage capacitor is lower than the preset voltage, the input terminal of the level flipping unit is connected to a low level, the output terminal of the level flipping unit is at a high level, and the controlled terminal of the discharge circuit is connected to a high level and turned on.

[0013] The voltage amplitude of a high-level voltage is higher than that of a low-level voltage. In one embodiment, the level-flipping unit includes a first switching transistor and a second resistor;

[0014] The first switching transistor includes a controlled terminal electrically connected to the anode of the first Zener diode and the first terminal of the first resistor, a first access terminal electrically connected to the controlled terminal of the discharge circuit and the second terminal of the second resistor, and a grounded second access terminal. The second resistor also includes a first terminal electrically connected to the first terminal of the energy storage capacitor, the cathode of the first Zener diode, and the first access terminal of the discharge circuit.

[0015] The first switching transistor is used to turn on when a high level is applied to its controlled terminal;

[0016] When the voltage on the energy storage capacitor is lower than the preset voltage, the controlled terminal of the first switching transistor is connected to a low level, the level of the first access terminal of the first switching transistor is a high level, and the controlled terminal of the discharge circuit is connected to a high level and turned on.

[0017] In one embodiment, the triggering unit further includes a first capacitor;

[0018] The first capacitor includes a first terminal electrically connected to the anode of the first Zener diode, the first terminal of the first resistor, and the controlled terminal of the first switching transistor, and a second terminal grounded.

[0019] In one embodiment, the discharge circuit includes a dummy load resistor and a second switch.

[0020] The dummy load resistor includes a first terminal electrically connected to the first terminal of the energy storage capacitor and the cathode of the first Zener diode, and a second terminal electrically connected to the first access terminal of the second switching transistor. The second switching transistor also includes a controlled terminal electrically connected to the output terminal of the level flipping unit and a grounded second access terminal.

[0021] Alternatively, the second switching transistor includes a first access terminal electrically connected to the first terminal of the energy storage capacitor and the cathode of the first Zener diode, a second access terminal electrically connected to the first terminal of the dummy load resistor, and a controlled terminal electrically connected to the output terminal of the level flipping unit. The dummy load resistor also includes a second terminal grounded.

[0022] The second switch is used to turn on when a high level is applied to its controlled terminal.

[0023] In one embodiment, the discharge circuit further includes a second Zener diode;

[0024] The second Zener diode includes a cathode electrically connected to the output terminal of the level-flipping unit and the controlled terminal of the second switch, and an anode electrically connected to the second access terminal of the second switch.

[0025] In one embodiment, the discharge circuit further includes a second capacitor;

[0026] The second capacitor includes a first end electrically connected to the output terminal of the level-flipping unit and the controlled terminal of the second switching transistor, and a second end electrically connected to the second access terminal of the second switching transistor.

[0027] In one embodiment, the triggering unit includes a first Zener diode and a first resistor;

[0028] The first Zener diode includes a cathode electrically connected to a first terminal of an energy storage capacitor and a first access terminal of a discharge circuit, and an anode electrically connected to a first terminal of a first resistor and a controlled terminal of the discharge circuit, respectively. The second terminal of the first resistor, the second terminal of the energy storage capacitor, and the second access terminal of the discharge circuit are respectively grounded.

[0029] The bleed circuit is used to conduct when a low level is applied to its controlled terminal and a high level is applied to its first input terminal.

[0030] The voltage amplitude of a high-level voltage is higher than that of a low-level voltage.

[0031] In one embodiment, the triggering unit includes a first Zener diode and a first resistor;

[0032] The first resistor includes a first terminal electrically connected to the first terminal of the energy storage capacitor and the first access terminal of the discharge circuit, and a second terminal electrically connected to the cathode of the first Zener diode and the controlled terminal of the discharge circuit, respectively. The anode of the first Zener diode, the second terminal of the energy storage capacitor and the second access terminal of the discharge circuit are respectively grounded.

[0033] The bleeder circuit is used to turn on when a high level is applied to its controlled terminal;

[0034] The voltage amplitude of the high-level circuit is higher than the input level of the second input terminal of the discharge circuit. Secondly, in one embodiment, this invention provides a power supply system including a filter circuit, a surge protection circuit, an energy storage capacitor, and the discharge circuit described in any of the above embodiments.

[0035] The filter circuit, surge protection circuit, energy storage capacitor, and discharge circuit are connected in sequence.

[0036] With the above-mentioned discharge circuit and power system, a trigger unit and a discharge circuit are set up. Under the control of the trigger unit, the discharge circuit is only turned on when the voltage on the energy storage capacitor is lower than the preset voltage. After the energy storage capacitor is disconnected at the input terminal of the power system, it will also be quickly discharged along with the output load, etc. As long as its voltage is lower than the preset voltage, it can continue to be quickly discharged through the discharge circuit. This utility model improves the discharge speed. Attached Figure Description

[0037] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0038] Figure 1 This is a schematic diagram of a discharge circuit provided in one embodiment of this application;

[0039] Figure 2 A schematic diagram of a discharge circuit including a specific structure of a trigger unit, provided in one embodiment of this application;

[0040] Figure 3 A schematic diagram of a discharge circuit including a specific structure of a level-flipping unit, provided in one embodiment of this application;

[0041] Figure 4 A schematic diagram of a discharge circuit including a specific structure of a discharge loop is provided for one embodiment of this application;

[0042] Figure 5 A schematic diagram of a discharge circuit including a specific structure of a trigger unit is provided for another embodiment of this application;

[0043] Figure 6 A schematic diagram of the discharge circuit after the positions of the first Zener diode and the first resistor are replaced according to an embodiment of this application;

[0044] Figure 7 This is a schematic diagram of the power supply system provided in one embodiment of this application;

[0045] Figure 8 This is a schematic diagram of the specific circuit structure of a power supply system provided in one embodiment of this application. Detailed Implementation

[0046] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0047] In the description of this application, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of this application, "a plurality of" means two or more, unless otherwise expressly defined as an example. In this application, the term "exemplary" is used to mean "used as an example, illustration, or description." Any embodiment described as "exemplary" in this application is not necessarily to be construed as being more preferred or advantageous than other embodiments. To enable any person skilled in the art to implement and use this application, the following description is provided. In this description, details are set forth for purposes of explanation. It should be understood that those skilled in the art will recognize that this application can be implemented without using these specific details. In other instances, well-known structures and processes will not be described in detail to avoid obscuring the description of this application with unnecessary detail. Therefore, this application is not intended to be limited to the embodiments shown, but is consistent with the broadest scope of the principles and features disclosed in this application.

[0048] Firstly, such as Figure 1 As shown, in one embodiment, this application provides a discharge circuit, including a triggering unit and a discharge circuit.

[0049] exist Figure 1 In the middle, the trigger unit is electrically connected to the energy storage capacitor and the discharge circuit in the power supply system respectively, and is used to control the discharge circuit to conduct when the voltage on the energy storage capacitor is lower than the preset voltage; the preset voltage is lower than the output voltage V_Bulk of the power supply system.

[0050] The triggering condition of the triggering unit depends on the output voltage V_Bulk of the power supply system, or in other words, it depends on the undervoltage threshold voltage of the power supply system. The undervoltage threshold voltage is lower than the output voltage V_Bulk of the power supply system, which is the lowest voltage at which the output load is turned off. For example, if the output voltage V_Bulk of the power supply system is 60V and the corresponding undervoltage threshold voltage is 40V, then the corresponding preset voltage can be set to 40V. When the input terminal of the power supply system is disconnected, the voltage on the energy storage capacitor drops below 40V through the discharge of the output load, and the triggering unit outputs a trigger signal indicating conduction to the discharge circuit, thus turning on the discharge circuit. Conversely, when the power supply system is outputting normally, the voltage on the energy storage capacitor is basically stable at 60V, and the triggering unit cannot output a trigger signal indicating conduction to the discharge circuit, thus turning off the discharge circuit.

[0051] exist Figure 1 In the circuit, the discharge circuit is also electrically connected to the energy storage capacitor, and is used to discharge the energy on the energy storage capacitor when it is conducting.

[0052] When the discharge circuit is open, the two ends of the energy storage capacitor are connected, allowing the stored energy to be released quickly. Conversely, when the discharge circuit is closed, the two ends of the energy storage capacitor are not connected, and the stored energy will not be released, thereby reducing the power consumption of the power system and ensuring the efficiency of the power system during normal output.

[0053] When the preset voltage is set to the undervoltage threshold corresponding to the power system output voltage V_Bulk, the energy on the energy storage capacitor can be seamlessly connected between the output load and the discharge circuit, that is, it is first discharged through the output load and then discharged through the discharge circuit.

[0054] By using the aforementioned discharge circuit, a trigger unit and a discharge circuit are configured. Under the control of the trigger unit, the discharge circuit only conducts when the voltage on the energy storage capacitor is lower than a preset voltage. Since the preset voltage is lower than the output voltage V_Bulk of the power supply system, the discharge circuit will not conduct when the power supply system is outputting normally, thereby greatly reducing power consumption. In addition, the energy on the energy storage capacitor will also be rapidly discharged along with the output load after the power supply system input is disconnected. As long as its voltage is lower than the preset voltage, it can continue to be rapidly discharged through the discharge circuit. In summary, this utility model takes into account both discharge speed and discharge power consumption, and has a good discharge effect.

[0055] like Figure 2 As shown, in one embodiment, the triggering unit includes a first Zener diode (including Zener diodes ZD12 and ZD13), a first resistor (including resistor R153), and a level switching unit.

[0056] exist Figure 2 In this embodiment, the Zener diode ZD12 includes a cathode electrically connected to the first terminal of the energy storage capacitor (including the first terminals of capacitors C1 and C2) and the first access terminal of the discharge circuit, and an anode electrically connected to the first terminal of resistor R153 and the input terminal of the level-flipping unit via Zener diode ZD13 and resistor R152, respectively. The level-flipping unit also includes an output terminal electrically connected to the controlled terminal of the discharge circuit. The second terminal of resistor R153, the second terminal of capacitor C1, the second terminal of capacitor C2, and the second access terminal of the discharge circuit are respectively grounded. In other embodiments, resistor R152 can be omitted, in which case the first Zener diode is directly electrically connected to the first resistor.

[0057] The discharge circuit is used to conduct when a high level is applied to its controlled terminal.

[0058] The use of Zener diodes ZD12 and ZD13 in series increases reliability and withstand voltage. The overall breakdown voltage of Zener diodes ZD12 and ZD13 can be understood as the preset voltage.

[0059] Specifically, when the voltage across capacitors C1 and C2 is lower than the overall breakdown voltage of Zener diodes ZD12 and ZD13, Zener diodes ZD12 and ZD13 are not broken down. Due to the presence of resistor R153, the input terminal of the level-flipping unit is connected to a low level. Utilizing the level-flipping function, the level-flipping unit flips the levels of its input and output terminals, thereby making the output terminal of the level-flipping unit high. This allows the controlled terminal of the discharge circuit to be connected to a high level, enabling the discharge circuit to conduct and allowing the energy on capacitors C1 and C2 to be discharged quickly. Conversely, when the voltage across capacitors C1 and C2 is higher than the overall breakdown voltage of Zener diodes ZD12 and ZD13, Zener diodes ZD12 and ZD13 break down. Due to the presence of resistor R153, the input of the level-flipping unit is connected to a high level. Utilizing the level-flipping function, the level-flipping unit outputs a low level, causing the controlled terminal of the discharge circuit to be connected to a low level. The discharge circuit is not conducting, and the energy in capacitors C1 and C2 is not discharged.

[0060] In this embodiment, the level-flipping unit can be a monostable trigger.

[0061] The voltage amplitude of the high-level voltage is higher than that of the low-level voltage.

[0062] like Figure 3 As shown, in one embodiment, the level-flipping unit includes a first switching transistor (including an npn transistor Q36) and a second resistor (including resistor R150 and resistor R151).

[0063] exist Figure 3 In the transistor Q36, the base is electrically connected to the anode of the Zener diode ZD13 via resistor R152, the collector is electrically connected to the controlled terminal of the discharge circuit and the second terminal of resistor R151, and the emitter is grounded. The base of the NPN transistor Q36 is also electrically connected to the first terminal of resistor R153. Resistor R151 also includes a first terminal electrically connected to the second terminal of resistor R150. Resistor R150 also includes a first terminal electrically connected to the first terminal of capacitor C1, the first terminal of capacitor C2, the cathode of Zener diode ZD12, and the first access terminal of the discharge circuit.

[0064] In other embodiments, an NMOS transistor or similar device can be used instead of the npn transistor Q36, as long as it can achieve the purpose of turning on when a high level is applied to the controlled terminal.

[0065] Specifically, when the voltage across capacitors C1 and C2 is lower than the overall breakdown voltage of Zener diodes ZD12 and ZD13, Zener diodes ZD12 and ZD13 are not broken down. Due to the presence of resistor R153, the base of npn transistor Q36 is connected to a low level, and npn transistor Q36 is not conducting. Due to the presence of resistors R150 and R151, the collector of npn transistor Q36 is at a high level, so that the controlled terminal of the discharge circuit is connected to a high level, the discharge circuit is conducting, and the energy on capacitors C1 and C2 can be quickly discharged. Conversely, when the voltage across capacitors C1 and C2 is higher than the overall breakdown voltage of Zener diodes ZD12 and ZD13, Zener diodes ZD12 and ZD13 break down. Due to the presence of resistor R153, the base of npn transistor Q36 is connected to a high level, and npn transistor Q36 is turned on. Due to the presence of resistors R150 and R151, the collector of npn transistor Q36 is at a low level, so that the controlled terminal of the discharge circuit is connected to a low level, the discharge circuit is not turned on, and the energy in capacitors C1 and C2 is not discharged.

[0066] like Figure 3 As shown, in one embodiment, the triggering unit further includes a first capacitor (including capacitor C27).

[0067] exist Figure 3 In the capacitor C27, there is a first terminal that is electrically connected to the anode of the Zener diode ZD13, the first terminal of the resistor R153 and the base of the npn transistor, and a second terminal that is grounded.

[0068] Among them, capacitor C27 is used for filtering to improve anti-interference capability.

[0069] like Figure 4As shown, in one embodiment, the discharge circuit includes a dummy load resistor (including resistors R144, R145, R146, R147, R148, and R149) and a second switch (including an NMOS transistor Q35).

[0070] exist Figure 4 In the circuit, resistors R144, R145, and R146 each have a first terminal electrically connected to the first terminal of capacitor C1, the first terminal of capacitor C2, and the cathode of Zener diode ZD12, respectively, and a second terminal electrically connected to the first terminal of resistors R147, R148, and R149, respectively. Resistors R147, R148, and R149 each also have a second terminal electrically connected to the drain of NMOS transistor Q35. NMOS transistor Q35 also includes a gate electrically connected to the output terminal of a level-flipping unit (such as the collector of an NPN transistor Q36) and a grounded source.

[0071] When the voltages of capacitors C1 and C2 are lower than the preset voltage, Zener diodes ZD12 and ZD13 are not broken down, the base of the npn transistor is connected to a low level and the npn transistor is not turned on, the gate of NMOS transistor Q35 is connected to a high level and the NMOS transistor Q35 is turned on, and capacitors C1 and C2 are discharged through resistors R144, R145, R146, R147, R148 and R149. Conversely, when the voltage across capacitors C1 and C2 is higher than the preset voltage, Zener diodes ZD12 and ZD13 are broken down, the base of the NPN transistor is connected to a high level, the NPN transistor is turned on, the gate of NMOS transistor Q35 is connected to a low level, the NMOS transistor Q35 is not turned on, and capacitors C1 and C2 are not discharged through resistors R144, R145, R146, R147, R148, and R149.

[0072] In other embodiments, the positions of the dummy load resistor and NMOS transistor Q35 can be interchanged without affecting the circuit function. For example, NMOS transistor Q35 includes a drain electrically connected to the first terminal of capacitor C1, the first terminal of capacitor C2, and the cathode of Zener diode ZD12; a source electrically connected to the first terminals of resistors R144, R145, and R146; and a controlled terminal electrically connected to the output terminal of the level-flipping unit (such as the collector of NPN transistor Q36). Resistors R147, R148, and R149 also each include a grounded second terminal.

[0073] like Figure 4 As shown, in one embodiment, the discharge circuit further includes a second Zener diode (including Zener diode ZD14).

[0074] exist Figure 4 In the Zener diode ZD14, there are a cathode that is electrically connected to the output terminal of the level-flipping unit (such as the collector of the npn transistor Q36) and the gate of the NMOS transistor Q35, and an anode that is electrically connected to the source of the NMOS transistor Q35.

[0075] Among them, the Zener diode ZD14 is used to prevent the voltage difference between the gate and source of the NMOS transistor Q35 from being too large, thereby achieving the purpose of overvoltage protection.

[0076] like Figure 4 As shown, in one embodiment, the discharge circuit further includes a second capacitor (including capacitor C29).

[0077] exist Figure 4 In the capacitor C29, there is a first terminal that is electrically connected to the output terminal of the level-flipping unit (such as the collector of the npn transistor Q36) and the gate of the NMOS transistor Q35, and a second terminal that is electrically connected to the source of the NMOS transistor Q35.

[0078] Among them, capacitor C29 is used for filtering to improve anti-interference capability.

[0079] like Figure 5 As shown, in one embodiment, the triggering unit includes a first Zener diode (including Zener diodes ZD12 and ZD13) and a first resistor (including resistor R153).

[0080] exist Figure 5 In this embodiment, the Zener diode ZD12 includes a cathode electrically connected to a first terminal of the energy storage capacitor (including the first terminals of capacitors C1 and C2) and a first access terminal of the discharge circuit, and an anode electrically connected to a first terminal of resistor R153 and a controlled terminal of the discharge circuit via Zener diode ZD13 and resistor R152, respectively. The second terminal of resistor R153, the second terminal of capacitor C1, the second terminal of capacitor C2, and the second access terminal of the discharge circuit are grounded. In other embodiments, resistor R152 can be omitted, in which case the first Zener diode is directly electrically connected to the first resistor.

[0081] The discharge circuit is used to conduct when a low level is applied to its controlled terminal.

[0082] in, Figure 5 and Figure 2 The difference is that, Figure 5 The level shifting unit has been removed, which means that to achieve the same function, the discharge circuit must be activated when a low level is applied. (See reference...) Figure 4 can Figure 4The NMOS transistor Q35 in the discharge circuit is replaced with a PMOS transistor, which is then used as the discharge circuit in this embodiment.

[0083] like Figure 6 As shown, in one embodiment, the triggering unit includes a first Zener diode (including Zener diodes ZD12 and ZD13) and a first resistor (including resistor R153).

[0084] exist Figure 6 In this embodiment, resistor R153 includes a first end electrically connected to the first terminals of capacitors C1 and C2, and the first access terminal of the discharge circuit, respectively; and a second end electrically connected to the cathode of Zener diode ZD12 and the controlled terminal of the discharge circuit, respectively, via resistor R152. The anode of Zener diode ZD13, the second terminals of capacitors C1 and C2, and the second access terminal of the discharge circuit are grounded. In other embodiments, resistor R152 can be omitted, in which case the first Zener diode is directly electrically connected to the first resistor.

[0085] The discharge circuit is used to conduct when a high level is applied to its controlled terminal.

[0086] As mentioned in the previous embodiments, the corresponding level-flipping unit can be removed by making the discharge circuit conduct when connected to a low level. In this embodiment, it can also be achieved by changing the positions of Zener diodes ZD12 and ZD13 and resistor R153. In this embodiment, when the voltage of capacitors C1 and C2 is lower than the preset voltage, Zener diodes ZD12 and ZD13 are not broken down, and the controlled terminal of the discharge circuit is connected to a high level, enabling rapid discharge. Conversely, when the voltage of capacitors C1 and C2 is higher than the preset voltage, Zener diodes ZD12 and ZD13 are broken down, the controlled terminal of the discharge circuit is connected to a low level, the discharge circuit does not conduct, and no energy is discharged from capacitors C1 and C2. Therefore, changing the positions still achieves the function of discharge control.

[0087] Secondly, such as Figure 7 As shown, in one embodiment, the present invention provides a power supply system including a filter circuit, a surge protection circuit, an energy storage capacitor, and a discharge circuit as described in any of the above embodiments.

[0088] exist Figure 7 In the middle, the filter circuit, surge protection circuit, energy storage capacitor and discharge circuit are electrically connected in sequence.

[0089] By configuring a trigger unit and a discharge circuit in the aforementioned power system, the discharge circuit, under the control of the trigger unit, only conducts when the voltage on the energy storage capacitor is lower than a preset voltage. Since the preset voltage is not higher than the power system's output voltage V_Bulk, the discharge circuit will not conduct during normal power system output, thus significantly reducing power consumption. Furthermore, the energy on the energy storage capacitor will also be rapidly discharged along with the output load after the power system input is disconnected. As long as its voltage drops below the preset voltage, it can continue to be rapidly discharged through the discharge circuit. In summary, this invention balances discharge speed and discharge power consumption, achieving a good discharge effect.

[0090] like Figure 8 As shown, in one embodiment, the filter circuit includes capacitor C5, capacitor CY1, capacitor CY4 and inductor CLF1.

[0091] Specifically, the first terminal of capacitor C5 is electrically connected to the first input terminal of inductor CLF1, the second terminal of capacitor C5 is electrically connected to the second terminal of fuse F1 and the second input terminal of inductor CLF1, the first output terminal of inductor CLF1 is electrically connected to the first terminal of capacitor CY1, the second output terminal of inductor CLF1 is electrically connected to the second terminal of capacitor CY4, and the second terminal of capacitor CY1 and the first terminal of capacitor CY4 are grounded.

[0092] like Figure 8 As shown, in one embodiment, the surge protection circuit includes resistors R1, R2, R8, R9, R10, R11, Zener diode ZD2, transistor Q3, diode D2, capacitor C10, thermistor NTC1, NMOS transistor Q30, and NMOS transistor Q31.

[0093] When the energy in capacitors C1 and C2 is not discharged, it is discharged through resistors R1 and R2, thereby driving NMOS transistor Q30 to conduct and the thermistor NTC1 to be short-circuited. When power is restored, the power supply passes directly through NMOS transistor Q30, generating a large inrush current.

[0094] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the detailed descriptions of other embodiments above, which will not be repeated here.

[0095] The above provides a detailed description of a discharge circuit and power supply system provided in this application. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

[0096] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

Claims

1. A bleed circuit, characterized by The application relates to a trigger unit and a discharge loop. The trigger unit is electrically connected with an energy storage capacitor in a power supply system and the discharge loop respectively, and is used for controlling the discharge loop to be conducted when the voltage on the energy storage capacitor is lower than a preset voltage. The discharge loop is also electrically connected with the energy storage capacitor, and is used for discharging the energy on the energy storage capacitor when the discharge loop is conducted. The trigger unit comprises a first voltage stabilizing diode, a first resistor and a level flip unit. The first voltage stabilizing diode comprises a cathode electrically connected with a first end of the energy storage capacitor and a first access end of the discharge loop respectively, and an anode electrically connected with a first end of the first resistor and an input end of the level flip unit respectively, the level flip unit further comprises an output end electrically connected with a controlled end of the discharge loop, and a second end of the first resistor, a second end of the energy storage capacitor and a second access end of the discharge loop are grounded respectively. The level flip unit is used for flipping the level of the input end and the output end, and the discharge loop is used for being conducted when the controlled end is accessed with a high level. When the voltage on the energy storage capacitor is lower than the preset voltage, the input end of the level flip unit is accessed with a low level, the level of the output end of the level flip unit is a high level, the controlled end of the discharge loop is accessed with a high level and is conducted. The voltage amplitude of the high level is higher than that of the low level. The discharge loop comprises a dummy load resistor and a second switch tube. The dummy load resistor comprises a first end electrically connected with the first end of the energy storage capacitor and the cathode of the first voltage stabilizing diode respectively, and a second end electrically connected with a first access end of the second switch tube, the second switch tube further comprises a controlled end electrically connected with the output end of the level flip unit and a second access end grounded; or the second switch tube comprises a first access end electrically connected with the first end of the energy storage capacitor and the cathode of the first voltage stabilizing diode respectively, a second access end electrically connected with the first end of the dummy load resistor and a controlled end electrically connected with the output end of the level flip unit, and the dummy load resistor further comprises a second end grounded. The second switch tube is used for being conducted when the controlled end is accessed with a high level. The level flip unit comprises a first switch tube and a second resistor.

2. The bleed circuit of claim 1, wherein, The first switch tube comprises a controlled end electrically connected with the anode of the first voltage stabilizing diode and a first end of the first resistor respectively, a first access end electrically connected with the controlled end of the discharge loop and a second end of the second resistor respectively and a second access end grounded, and the second resistor further comprises a first end electrically connected with the first end of the energy storage capacitor, the cathode of the first voltage stabilizing diode and a first access end of the discharge loop. The first switch tube is used for being conducted when the controlled end is accessed with a high level. When the voltage on the energy storage capacitor is lower than the preset voltage, the controlled end of the first switch tube is accessed with a low level, the level of the first access end of the first switch tube is a high level, and the controlled end of the discharge loop is accessed with a high level and is conducted. The trigger unit further comprises a first capacitor.

3. The bleed circuit of claim 2, wherein, ​ The first capacitor comprises a first end electrically connected with the anode of the first voltage stabilizing diode, the first end of the first resistor and the controlled end of the first switch tube respectively, and a second end grounded.

4. The bleed circuit of claim 1, wherein, The bleed circuit further comprises a second voltage stabilizing diode; The second voltage stabilizing diode comprises a cathode electrically connected with the output end of the level inversion unit and the controlled end of the second switch tube respectively, and an anode electrically connected with the second access end of the second switch tube.

5. The bleed circuit of claim 1, wherein, The bleed circuit further comprises a second capacitor; The second capacitor comprises a first end electrically connected with the output end of the level inversion unit and the controlled end of the second switch tube respectively, and a second end electrically connected with the second access end of the second switch tube.

6. A power supply system characterized by comprising: The filter circuit, the surge protection circuit, the energy storage capacitor and the bleed circuit of any one of claims 1 to 5 are electrically connected in sequence. The filter circuit, the surge protection circuit, the energy storage capacitor and the bleed circuit are electrically connected in sequence.

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