Access control circuit of filter circuit and discharge resistor

Abstract

The utility model provides a filter circuit and an access control circuit of a discharge resistor. The access control circuit of the discharge resistor comprises a state determination unit and an on-off control unit connected with the state determination unit, the on-off control unit and the discharge resistor form a resistor access loop; the state determination unit outputs a turn-off signal when the circuit to which the discharge resistor belongs is in a standby state, and outputs a turn-on signal when the circuit to which the discharge resistor belongs is in a power-off state; the on-off control unit disconnects itself to disconnect the resistor access loop when the state determination unit outputs the turn-off signal, and conducts itself to connect the resistor access loop when the state determination unit outputs the turn-on signal, so that the standby power consumption of the circuit to which the discharge resistor belongs can be reduced, and the time consumed for discharging to the safe voltage after the circuit is powered off is shortened; the problems of long time consumption and high standby power of discharging to safe voltage after power failure of an existing circuit are solved.

Description

Technical Field

[0001] The present application relates to the field of electronic power technology, and in particular to a filter circuit and a discharge resistor access control circuit. Background Art

[0002] When connected to a power source and in standby mode, household appliances must meet regulatory requirements and consume less than 0.48W of power. Furthermore, when the power is disconnected, the power must be discharged to a safe voltage below 34V within 1 second to prevent electric shock.

[0003] like Figure 1 As shown, the existing circuit primarily consists of X-capacitors C106 and C107, a common-mode inductor L101, and discharge resistors R107, R108, and R109. When the live input terminal L_IN and the neutral input terminal N_IN are powered, the X-capacitors C106 and C107 charge. When these terminals are powered off, the discharge resistors R107, R108, and R109 form a loop with the X-capacitors C106 and C107, discharging the capacitors. When the live input terminal L_IN and the neutral input terminal N_IN are powered on and in standby mode, the discharge resistors R107, R108, and R109 continue to consume power. When the power is off, the power supply must drop below 34V within 1 second.

[0004] The inventors have found that since the power supply must be reduced to a safe voltage within 1 second when the power is cut off, the discharge resistors R107, R108, and R109 cannot be selected too large, nor can they be selected too small, which will affect the standby power. As a result, the existing circuit takes a long time to discharge to a safe voltage after power is cut off and the standby power is high. Utility Model Content

[0005] In this regard, the present application provides a filter circuit and a discharge resistor access control circuit to solve the problem that the existing circuit takes a long time to discharge to a safe voltage after power failure and has high standby power.

[0006] To achieve the above objectives, the present invention provides the following technical solutions:

[0007] In a first aspect, the present application discloses a discharge resistor access control circuit, comprising: a state determination unit and an on-off control unit connected to the state determination unit;

[0008] The on-off control unit and the discharge resistor form a resistance access loop;

[0009] The state determination unit outputs an off signal when the circuit to which the discharge resistor belongs is in a standby state, and outputs an on signal when the circuit to which the discharge resistor belongs is in a power-off state;

[0010] The on-off control unit disconnects itself to disconnect the resistor access loop when the state determination unit outputs an off signal, and turns itself on to connect the resistor access loop when the state determination unit outputs an on signal.

[0011] Optionally, in the above-mentioned discharge resistor access control circuit, a first terminal of the state determination unit is connected to one terminal of the discharge resistor, and a connection point is connected to a live wire input terminal of a circuit to which the discharge resistor belongs;

[0012] The second end of the state determination unit is connected to the first end of the on-off control unit;

[0013] The third terminal of the state determination unit is connected to the second terminal of the on-off control unit;

[0014] The fourth terminal of the state determination unit is connected to the third terminal of the on-off control unit, and the connection point is connected to the zero line input terminal of the circuit to which the discharge resistor belongs;

[0015] The fourth end of the on-off control unit is connected to the other end of the discharge resistor.

[0016] Optionally, in the above-mentioned discharge resistor access control circuit, the state determination unit includes: a first diode, a second diode, a first resistor, a second resistor, a third resistor, a fourth resistor, a photocoupler, a first transistor, a second transistor, and a pulse-to-high-level unit;

[0017] The anode of the first diode serves as the first terminal of the state determining unit; the cathode of the first diode is connected to the cathode of the second diode and the anode of the photoelectric coupler respectively; the anode of the second diode is connected to the cathode of the photoelectric coupler and one end of the first resistor respectively; the other end of the first resistor serves as the fourth terminal of the state determining unit;

[0018] The collector of the photoelectric coupler is connected to one end of the second resistor; the emitter of the photoelectric coupler is connected to one end of the third resistor and one end of the pulse-to-high level unit respectively;

[0019] The other end of the second resistor is connected to one end of the fourth resistor, and the connection point receives the power supply voltage and serves as the second end of the state determination unit;

[0020] The other end of the fourth resistor is connected to the collector of the first transistor and the base of the second transistor respectively; the emitter of the second transistor is connected to the emitter of the first transistor and the other end of the third resistor respectively, and the connection point is grounded;

[0021] The base of the first transistor is connected to the other end of the pulse-to-high-level unit; the collector of the second transistor serves as the third end of the state determination unit.

[0022] Optionally, in the above-mentioned discharge resistor access control circuit, the first resistor and the fourth resistor are current limiting resistors, the second resistor is a pull-up resistor, the third resistor is a pull-down resistor, and the pulse-to-high-level unit includes an RC circuit.

[0023] Optionally, in the above-mentioned discharge resistor access control circuit, the on-off control unit includes at least: a relay;

[0024] The first coil terminal of the relay serves as the first end of the on-off control unit;

[0025] The second coil terminal of the relay serves as the second end of the on-off control unit;

[0026] The first contact terminal of the relay serves as the third terminal of the on-off control unit;

[0027] The second contact terminal of the relay serves as the fourth end of the on-off control unit.

[0028] A second aspect of the present application discloses a filter circuit, comprising: a first capacitor, a second capacitor, a discharge resistor, a common-mode inductor, and an access control circuit for the discharge resistor as described in any one of the items disclosed in the first aspect;

[0029] One end of the first capacitor, one end of the discharge resistor, the positive input end of the common-mode inductor, and the first end of the access control circuit are connected to the live wire input end of the filter circuit; the other end of the discharge resistor is connected to the second end of the access control circuit;

[0030] The other end of the first capacitor, the negative input end of the common-mode inductor, the third end of the access control circuit, and the fourth end of the access control circuit are connected to the neutral line input end of the filter circuit;

[0031] The positive output end of the common-mode inductor and one end of the second capacitor are connected to the live line output end of the filter circuit; the negative output end of the common-mode inductor and the other end of the second capacitor are connected to the neutral line output end of the filter circuit.

[0032] Optionally, in the above-mentioned filter circuit, it further includes: a third capacitor and a fourth capacitor;

[0033] One end of the third capacitor is connected to the live wire output end of the filter circuit;

[0034] The other end of the third capacitor is connected to one end of the fourth capacitor, and the connection point is grounded;

[0035] The other end of the fourth capacitor is connected to the neutral line output end of the filter circuit.

[0036] Optionally, in the above-mentioned filter circuit, it further includes: a varistor;

[0037] One end of the varistor is connected to the live wire input end of the filter circuit, and the other end of the varistor is connected to the neutral wire input end of the filter circuit.

[0038] Optionally, the above-mentioned filter circuit further includes: a power supply voltage unit, which includes at least: a switching power supply, a fifth capacitor and a sixth capacitor; the positive output terminal of the switching power supply, one end of the fifth capacitor and the first end of the sixth capacitor are connected, and the connection point outputs the power supply voltage; the negative output terminal of the switching power supply, the other end of the fifth capacitor and the other end of the sixth capacitor are connected, and the connection point is grounded.

[0039] Optionally, in the above-mentioned filtering circuit, the first end of the state determination unit in the access control circuit serves as the first end of the access control circuit; the fourth end of the on-off control unit in the access control circuit serves as the second end of the access control circuit; the third end of the on-off control unit serves as the third end of the access control circuit; and the fourth end of the state determination unit serves as the fourth end of the access control circuit.

[0040] The discharge resistor access control circuit provided in the present application includes: a state determination unit and an on-off control unit connected to the state determination unit; the on-off control unit and the discharge resistor form a resistor access loop; the state determination unit outputs an off signal when the circuit to which the discharge resistor belongs is in a standby state, and outputs a on signal when the circuit to which the discharge resistor belongs is in a power-off state; the on-off control unit disconnects itself to disconnect the resistor access loop when the state determination unit outputs the off signal, and turns itself on to connect the resistor access loop when the state determination unit outputs the on signal, thereby reducing the standby power consumption of the circuit to which the discharge resistor belongs and shortening the time taken for the circuit to discharge to a safe voltage after power failure, thereby solving the problems of a long time taken for the existing circuit to discharge to a safe voltage after power failure and high standby power. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without any creative work.

[0042] Figure 1An existing filter circuit diagram provided for this application;

[0043] Figure 2 A schematic diagram of a discharge resistor access control circuit according to an embodiment of the present application;

[0044] Figure 3 A circuit diagram of a discharge resistor access control circuit provided in an embodiment of the present application;

[0045] Figure 4 A circuit diagram of a power supply voltage unit provided in an embodiment of the present application;

[0046] Figure 5 A circuit diagram of a filter circuit provided in an embodiment of the present application;

[0047] Figure 6 A schematic diagram of the off-state voltage drop test results of a filter circuit at a positive peak value provided by an embodiment of the present application;

[0048] Figure 7 A schematic diagram of the off-state voltage drop test results of a filter circuit at a negative peak value provided in an embodiment of the present application. DETAILED DESCRIPTION

[0049] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0050] The embodiments of the present application provide a filter circuit and a discharge resistor access control circuit to solve the problems of a long time taken to discharge to a safe voltage and high standby power in existing circuits after power failure.

[0051] See Figure 2 The access control circuit of the discharge resistor mainly includes: a state determination unit 101 and an on-off control unit 102 connected to the state determination unit 101.

[0052] The on-off control unit 102 and the discharge resistor R form a resistance access loop.

[0053] The state determining unit 101 outputs an off signal when the circuit to which the discharge resistor R belongs is in a standby state, and outputs an on signal when the circuit to which the discharge resistor R belongs is in a power-off state.

[0054] The on-off control unit 102 disconnects itself to disconnect the resistor access loop when the state determination unit 101 outputs an off signal, and connects itself to connect the resistor access loop when the state determination unit 101 outputs an on signal.

[0055] In practical applications, the discharge resistor R may be a discharge resistor in a filter circuit; wherein the filter circuit may be a circuit in various electrical devices, and may be used to filter the connected power supply.

[0056] In some embodiments, as Figure 3 As shown, the connection relationship between the discharge resistor R, the state determination unit 101 and the on-off control unit 102 in the discharge resistor access control circuit is as follows:

[0057] A first end of the state determination unit 101 is connected to one end of the discharge resistor R, and a connection point is connected to the live wire input terminal L_IN of the circuit to which the discharge resistor R belongs; a second end of the state determination unit 101 is connected to a first end of the on-off control unit 102; a third end of the state determination unit 101 is connected to a second end of the on-off control unit 102; a fourth end of the state determination unit 101 is connected to a third end of the on-off control unit 102, and a connection point is connected to the neutral wire input terminal N_IN of the circuit to which the discharge resistor R belongs; and a fourth end of the on-off control unit 102 is connected to the other end of the discharge resistor R.

[0058] Since the first terminal of the state determination unit 101 is connected to the live input terminal L_IN of the circuit to which the discharge resistor R belongs, and the fourth terminal of the state determination unit 101 is connected to the neutral input terminal N_IN of the circuit to which the discharge resistor R belongs, the signal generated by the second terminal of the state determination unit 101 and the third terminal of the state determination unit 101 in cooperation with each other can be determined as an on signal or an off signal based on the voltage across the live input terminal L_IN and the neutral input terminal N_IN of the circuit to which the discharge resistor R belongs. When the voltage between the second terminal of the state determination unit 101 and the third terminal of the state determination unit 101 is equal, that is, when no current flows through the first terminal and the second terminal of the on-off control unit 102, the state determination unit 101 is considered to have outputted an off signal; when the voltage between the second terminal of the state determination unit 101 and the third terminal of the state determination unit 101 is not equal, that is, when current flows through the first terminal and the second terminal of the on-off control unit 102, the state determination unit 101 is considered to have outputted an on signal.

[0059] Likewise Figure 3 As shown, in some embodiments, the state determination unit 101 may include: a first diode D1, a second diode D2, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a photocoupler IC1, a first transistor Q1, a second transistor Q2 and a pulse to high level unit IC2.

[0060] The anode of the first diode D1 serves as the first terminal of the state determination unit 101; the cathode of the first diode D1 is connected to the cathode of the second diode D2 and the anode of the photocoupler IC1 respectively; the anode of the second diode D2 is connected to the cathode of the photocoupler IC1 and one end of the first resistor R1 respectively; the other end of the first resistor R1 serves as the fourth terminal of the state determination unit 101; the collector of the photocoupler IC1 is connected to one end of the second resistor R2; the emitter of the photocoupler IC1 is connected to one end of the third resistor R3 and one end of the pulse high level unit IC2 respectively. The other end of the second resistor R2 is connected to one end of the fourth resistor R4, the connection point receives the power supply voltage and serves as the second end of the state determination unit 101; the other end of the fourth resistor R4 is respectively connected to the collector of the first transistor Q1 and the base of the second transistor Q2; the emitter of the second transistor Q2 is respectively connected to the emitter of the first transistor Q1 and the other end of the third resistor R3, and the connection point is grounded; the base of the first transistor Q1 is connected to the other end of the pulse to high level unit IC2; the collector of the second transistor Q2 serves as the third end of the state determination unit 101.

[0061] In practical applications, the first diode D1 can be used to prevent the anode and cathode of the photocoupler IC1 from being connected to a reverse voltage; the second diode D2 can provide a reverse voltage path to prevent the reverse voltage from being applied to the anode and cathode of the photocoupler IC1; the first resistor R1 can be used as a current-limiting resistor for the cathode of the photocoupler IC1; the second resistor R2 can be used as a pull-up resistor for the collector of the photocoupler IC1; the third resistor R3 can be used as a pull-down resistor for the pulse-to-high-level unit IC2, which can prevent the pulse-to-high-level unit IC2 from inputting an unstable floating signal, resulting in an abnormal signal input to the base of the first transistor Q1, thereby avoiding mis-conduction of the first transistor Q1; the fourth resistor R4 can be used as a current-limiting resistor for the collector of the first transistor Q1 and the base of the second transistor Q2.

[0062] It can be understood that the types of the resistors in the state determination unit 101 are specifically: the first resistor R1 and the fourth resistor R4 are current limiting resistors, the second resistor R2 is a pull-up resistor, and the third resistor R3 is a pull-down resistor.

[0063] In practical applications, the pulse-to-high-level unit IC2 may be an RC circuit; of course, it is not limited thereto, and may also be determined by the application environment and user needs, all within the scope of protection of this application.

[0064] It should be noted that the power supply voltage received by the second end of the state determining unit 101 can be 12V, which can be supplied by the power supply voltage unit; of course, it is not limited to this, and the specific value of the power supply voltage can also be determined according to the application environment and user demand, which is within the protection scope of the present application.

[0065] As shown in Figure 4 , the power supply voltage unit can at least include: a switching power supply SMPS, a fifth capacitor C5 and a sixth capacitor C6; the positive output end of the switching power supply SMPS, one end of the fifth capacitor C5 and the first end of the sixth capacitor C6 are connected, and the connection point outputs the power supply voltage; the negative output end of the switching power supply SMPS, the other end of the fifth capacitor C5 and the other end of the sixth capacitor C6 are connected, and the connection point is grounded. Among them, the sixth capacitor C6 can be a parallel plate capacitor; of course, it is not limited to this, and can also be determined according to the application environment and user demand, which is within the protection scope of the present application.

[0066] It should be noted that the power supply voltage unit can provide stable power supply voltage for the access control circuit of the discharge resistor, so that the access control circuit of the discharge resistor realizes access control in standby state and off state.

[0067] As shown in Figure 3 , in some embodiments, the on-off control unit 102 at least includes: a relay RL101.

[0068] The first coil terminal 1 of the relay RL101 serves as the first end of the on-off control unit 102; the second coil terminal 2 of the relay RL101 serves as the second end of the on-off control unit 102; the first contact terminal 3 of the relay RL101 serves as the third end of the on-off control unit 102; the second contact terminal 4 of the relay RL101 serves as the fourth end of the on-off control unit 102.

[0069] It should be noted that in combination Figure 3 , when the circuit to which the discharge resistor R belongs is in standby state, because the live input end L_IN and the neutral input end N_IN receive power input reaching the opening threshold of the optocoupler IC1, the optocoupler IC1 is turned on, and the optocoupler IC1 outputs a pulse signal, which is connected to the first transistor Q1 through the pulse-to-high-level unit IC2. At this time, the first transistor Q1 is turned on, the base of the second transistor Q2 is low, and the second transistor Q2 is in the cut-off state, that is, there is no pressure difference between the second end of the state determining unit 101 and the third end of the state determining unit 101, the output off signal, the first coil terminal of the relay RL101 and the second coil terminal of the relay RL101 have no current flowing through, the relay RL101 is in the off state, the discharge resistor R is disconnected from the circuit, and the standby state power consumption is 0.

[0070] When the circuit to which the discharge resistor R belongs is in the off state, the open threshold of the optocoupler IC1 is not reached by the power input received by the live input terminal L_IN and the neutral input terminal N_IN, the optocoupler IC1 is cut off, at this time, the base of the first transistor Q1 is at a low level, the first transistor Q1 is cut off, and the base of the second transistor Q2 is connected to the power supply voltage through the fourth resistor R4. At this time, the second transistor Q2 is turned on, that is, there is a voltage difference between the second end of the state determination unit 101 and the third end of the state determination unit 101, an output on signal is output, the first coil terminal of the relay RL101 and the second coil terminal of the relay RL101 have current flowing therethrough, and the relay RL101 is in the on state. The discharge resistor R is connected to the circuit to which the discharge resistor R belongs and can form a circuit with the X capacitor to quickly discharge the X capacitor.

[0071] It should be further noted that, assuming that the power supply voltage provided by the power supply voltage unit is 12V, the energy storage 12V slowly decreases to 0V when the power is off, which can last for more than 2-5s. Among them, the relay will be disconnected when the voltage drops to about 10% of the rated voltage after being attracted and turned on. In the above circuit, the discharge resistor R can be selected to have a relatively small resistance value; when the circuit to which the discharge resistor R belongs is not connected to the power supply, the relay will be attracted and turned on for about 2-3s, and the quick discharge of the X capacitor can be completely realized.

[0072] It can be understood that the access control circuit of the discharge resistor provided by the present application can cut off the connection circuit of the discharge resistor R in the standby state of the circuit to which the discharge resistor R belongs, so that it does not consume additional power; when the circuit to which the discharge resistor R belongs is in the off state, the connection circuit of the discharge resistor R is turned on, so that the X capacitor is quickly discharged through the discharge resistor R.

[0073] Based on the above principle, the access control circuit of the discharge resistor provided by the present embodiment includes: a state determination unit 101 and a on-off control unit 102 connected to the state determination unit 101; the on-off control unit 102 and the discharge resistor R form a resistance access circuit; the state determination unit 101 outputs an off signal when the circuit to which the discharge resistor R belongs is in the standby state, and outputs an on signal when the circuit to which the discharge resistor R belongs is in the off state; the on-off control unit 102 is disconnected when the state determination unit 101 outputs the off signal, so that the resistance access circuit is disconnected, and the on-off control unit 102 is turned on when the state determination unit 101 outputs the on signal, so that the resistance access circuit is turned on, which can reduce the standby power consumption of the circuit to which the discharge resistor R belongs and shorten the time consumed for discharging to a safe voltage after the circuit is powered off, thereby solving the problems of long time consumed for discharging to a safe voltage after the circuit is powered off and high standby power in the prior art.

[0074] Based on the above, optionally, another embodiment of the present application further provides a filter circuit, as Figure 5As shown, it includes: a first capacitor C1, a second capacitor C2, a discharge resistor R, a common-mode inductor L1, and an access control circuit for the discharge resistor as described in any of the above embodiments;

[0075] One end of the first capacitor C1, one end of the discharge resistor R, the positive input end of the common-mode inductor L1, and the first end of the access control circuit are connected to the live wire input end L_IN of the filter circuit; the other end of the discharge resistor R is connected to the second end of the access control circuit; the other end of the first capacitor C1, the negative input end of the common-mode inductor L1, the third end of the access control circuit, and the fourth end of the access control circuit are connected to the neutral wire input end N_IN of the filter circuit; the positive output end of the common-mode inductor L1 and one end of the second capacitor C2 are connected to the live wire output end L_OUT of the filter circuit; the negative output end of the common-mode inductor L1 and the other end of the second capacitor C2 are connected to the neutral wire output end N_OUT of the filter circuit.

[0076] In practical applications, the first capacitor C1 and the second capacitor C2 can be X capacitors; when the filter circuit is in the standby state, the discharge resistor access control circuit controls the discharge resistor R not to be connected to the circuit; when the filter circuit is in the disconnected state, the discharge resistor access control circuit controls the discharge resistor R to be connected to the circuit.

[0077] It should be noted that, combined with Figure 3 or Figure 5 , the first end of the state determination unit 101 in the access control circuit serves as the first end of the access control circuit; the fourth end of the on-off control unit 102 in the access control circuit serves as the second end of the access control circuit; the third end of the on-off control unit 102 serves as the third end of the access control circuit; and the fourth end of the state determination unit 101 serves as the fourth end of the access control circuit.

[0078] In some embodiments, Figure 5 As shown, the filter circuit further includes: a third capacitor C3 and a fourth capacitor C4.

[0079] One end of the third capacitor C3 is connected to the live output terminal L_OUT of the filter circuit; the other end of the third capacitor C3 is connected to one end of the fourth capacitor C4, and the connection point is grounded; the other end of the fourth capacitor C4 is connected to the neutral output terminal N_OUT of the filter circuit.

[0080] In practical applications, the third capacitor C3 and the fourth capacitor C4 are Y capacitors, which can eliminate common-mode interference and further improve the stability of the filter circuit.

[0081] In some embodiments, Figure 5 As shown, the filter circuit further includes: a varistor VA1; one end of the varistor VA1 is connected to the live input terminal L_IN of the filter circuit, and the other end of the varistor VA1 is connected to the neutral input terminal N_IN of the filter circuit.

[0082] In practical applications, the varistor VA1 is arranged in the front stage of the first capacitor C1, the common mode inductor L1 and the second capacitor C2, so as to realize overvoltage protection in each period of the rear stage.

[0083] In some embodiments, Figure 4 As shown, the filter circuit also includes: a power supply voltage unit, which includes at least: a switching power supply SMPS, a fifth capacitor C5, and a sixth capacitor C6; the positive output terminal of the switching power supply SMPS, one end of the fifth capacitor C5, and the first end of the sixth capacitor C6 are connected, and the connection point outputs the power supply voltage (+12V in the figure); the negative output terminal of the switching power supply SMPS, the other end of the fifth capacitor C5, and the other end of the sixth capacitor C6 are connected, and the connection point is grounded.

[0084] It should be noted that the description of the access control circuit of the power supply voltage unit and the discharge resistor can be found in the above embodiments and will not be repeated here. The description of the filter circuit can also be found in the prior art and will not be repeated in this application.

[0085] Based on the above, the filter circuit provided in this embodiment can control the access of the discharge resistor R through the access control circuit. When the filter circuit is in the standby state, the access control circuit of the discharge resistor controls the discharge resistor R to not be connected to the circuit, thereby reducing standby power consumption. When the filter circuit is in the disconnected state, the access control circuit of the discharge resistor controls the discharge resistor R to be connected to the circuit, thereby realizing rapid discharge of the X capacitor in the filter circuit.

[0086] In summary, combined with Figure 5 Assuming that the value of the first diode D1 and the second diode D2 is 1G7, the model of the first transistor Q1 and the second transistor Q2 is DRC2123, the resistance of the discharge resistor R is 39kΩ, the resistance of the first resistor R1 is 150kΩ, the resistance of the second resistor R2 and the third resistor R3 is 47kΩ, the capacitance of the first capacitor C1 and the second capacitor C2 is 2.32μF, the model of the optocoupler IC1 is LTV817, the model of the relay RL101 is G5NB (12V), and the pulse-to-high-level unit IC2 is an RC circuit, the filter circuit is tested and verified, and it can be seen that the standby power test value of the filter circuit is 0.045W; when the power is off, the voltage across the power supply drops to 0 within 0.5s. Among them, the off-voltage drop test result of the filter circuit at the positive peak is as follows Figure 6 As shown in the figure, the off-state voltage drop test results of the filter circuit at the negative peak are as follows: Figure 7 shown.

[0087] It should be noted that the above is only a test example for testing and verification of the present application to illustrate the better standby power consumption and discharge time that can be obtained by the present application, and does not limit the scope of protection of the present application. As long as the principle is the same as that of the present application, it is within the scope of protection of the present application.

[0088] The features described in the various embodiments of this specification can be replaced or combined with each other. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on the differences from other embodiments. In particular, for system or system embodiments, since they are basically similar to method embodiments, the description is relatively simple. For relevant parts, refer to the partial description of the method embodiment. The system and system embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment. A person of ordinary skill in the art can understand and implement it without expending creative work.

[0089] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present application. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application is not limited to the embodiments shown herein, but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

[0090] It should also be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article, or device comprising the element.

Claims

1. A discharge resistor access control circuit, characterized in that: include: A state determination unit and an on-off control unit connected to the state determination unit; The on-off control unit and the discharge resistor form a resistance access loop; The state determination unit outputs an off signal when the circuit to which the discharge resistor belongs is in a standby state, and outputs an on signal when the circuit to which the discharge resistor belongs is in a power-off state; The on-off control unit disconnects itself to disconnect the resistor access loop when the state determination unit outputs an off signal, and turns itself on to connect the resistor access loop when the state determination unit outputs an on signal.

2. The discharge resistor access control circuit according to claim 1, characterized in that: A first end of the state determination unit is connected to one end of the discharge resistor, and a connection point is connected to a live wire input end of a circuit to which the discharge resistor belongs; The second end of the state determination unit is connected to the first end of the on-off control unit; The third terminal of the state determination unit is connected to the second terminal of the on-off control unit; The fourth terminal of the state determination unit is connected to the third terminal of the on-off control unit, and the connection point is connected to the zero line input terminal of the circuit to which the discharge resistor belongs; The fourth end of the on-off control unit is connected to the other end of the discharge resistor.

3. The discharge resistor access control circuit according to claim 2, characterized in that: The state determination unit includes: a first diode, a second diode, a first resistor, a second resistor, a third resistor, a fourth resistor, a photoelectric coupler, a first transistor, a second transistor and a pulse-to-high level unit; The anode of the first diode serves as the first terminal of the state determining unit; the cathode of the first diode is connected to the cathode of the second diode and the anode of the photoelectric coupler respectively; the anode of the second diode is connected to the cathode of the photoelectric coupler and one end of the first resistor respectively; the other end of the first resistor serves as the fourth terminal of the state determining unit; The collector of the photoelectric coupler is connected to one end of the second resistor; the emitter of the photoelectric coupler is connected to one end of the third resistor and one end of the pulse-to-high level unit respectively; The other end of the second resistor is connected to one end of the fourth resistor, and the connection point receives the power supply voltage and serves as the second end of the state determination unit; The other end of the fourth resistor is connected to the collector of the first transistor and the base of the second transistor respectively; the emitter of the second transistor is connected to the emitter of the first transistor and the other end of the third resistor respectively, and the connection point is grounded; The base of the first transistor is connected to the other end of the pulse-to-high-level unit; the collector of the second transistor serves as the third end of the state determination unit.

4. The discharge resistor access control circuit according to claim 3, characterized in that: The first resistor and the fourth resistor are current-limiting resistors, the second resistor is a pull-up resistor, the third resistor is a pull-down resistor, and the pulse-to-high-level unit includes an RC circuit.

5. The discharge resistor access control circuit according to claim 2, characterized in that: The on-off control unit at least includes: a relay; The first coil terminal of the relay serves as the first end of the on-off control unit; The second coil terminal of the relay serves as the second end of the on-off control unit; The first contact terminal of the relay serves as the third terminal of the on-off control unit; The second contact terminal of the relay serves as the fourth end of the on-off control unit.

6. A filter circuit, characterized in that: include: A first capacitor, a second capacitor, a discharge resistor, a common-mode inductor, and an access control circuit for the discharge resistor according to any one of claims 1 to 5; One end of the first capacitor, one end of the discharge resistor, the positive input end of the common-mode inductor, and the first end of the access control circuit are connected to the live wire input end of the filter circuit; the other end of the discharge resistor is connected to the second end of the access control circuit; The other end of the first capacitor, the negative input end of the common-mode inductor, the third end of the access control circuit, and the fourth end of the access control circuit are connected to the neutral line input end of the filter circuit; The positive output end of the common-mode inductor and one end of the second capacitor are connected to the live line output end of the filter circuit; the negative output end of the common-mode inductor and the other end of the second capacitor are connected to the neutral line output end of the filter circuit.

7. The filter circuit according to claim 6, characterized in that: Also comprising: a third capacitor and a fourth capacitor; One end of the third capacitor is connected to the live wire output end of the filter circuit; The other end of the third capacitor is connected to one end of the fourth capacitor, and the connection point is grounded; The other end of the fourth capacitor is connected to the neutral line output end of the filter circuit.

8. The filter circuit according to claim 6, characterized in that: Also includes: Varistor; One end of the varistor is connected to the live wire input end of the filter circuit, and the other end of the varistor is connected to the neutral wire input end of the filter circuit.

9. The filter circuit according to claim 6, characterized in that: Also includes: A power supply voltage unit, the power supply voltage unit comprising at least: a switching power supply, a fifth capacitor, and a sixth capacitor; The positive output terminal of the switching power supply, one end of the fifth capacitor and the first end of the sixth capacitor are connected, and the connection point outputs the power supply voltage; the negative output terminal of the switching power supply, the other end of the fifth capacitor and the other end of the sixth capacitor are connected, and the connection point is grounded.

10. The filter circuit according to claim 6, characterized in that: The first end of the state determination unit in the access control circuit serves as the first end of the access control circuit; the fourth end of the on-off control unit in the access control circuit serves as the second end of the access control circuit; the third end of the on-off control unit serves as the third end of the access control circuit; and the fourth end of the state determination unit serves as the fourth end of the access control circuit.

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