High-voltage auxiliary power supply starting circuit

Abstract

The power supply starting circuit has the characteristics of extremely low standby power consumption, perfect circuit protection function, safe and controllable electric energy transmission, complete and reliable starting logic and the like. The invention provides a novel high-voltage auxiliary power supply starting circuit. The novel high-voltage auxiliary power supply starting circuit comprises a starting logic processing unit, a power energy storage unit and a charge release unit, the input end of the power supply starting circuit is connected with an external input voltage, a temperature detection signal and a maintaining voltage after starting, and the output end is connected with an external power supply master control circuit to provide auxiliary power supply starting energy and a protection shutdown signal. The novel high-voltage auxiliary power supply starting circuit is extremely low in standby power consumption, complete in protection function, safe, reliable and complete in starting logic. The problems that a traditional power supply starting circuit is large in standby power consumption, incomplete in protection circuit, incomplete in starting logic and the like are solved.

Description

Technical Field

[0001] The invention belongs to the field of electrical engineering, and in particular relates to a high-voltage auxiliary power supply starting circuit. Background Art

[0002] In order to meet the growing demand for energy conservation and environmental protection, the increasingly stringent power density requirements, and the increasingly concerned safety needs, power supply technology continues to develop in the direction of high efficiency, low standby power consumption, high integration, green and safety. At the same time, the further increase in power density has caused the concentration of heat sources and the difficulty of heat dissipation design, further affecting the reliability of the product. Therefore, each functional circuit of the power supply needs to be designed with low power consumption and safety.

[0003] The power startup circuit is an important part of the power supply product. It is responsible for the power startup logic processing and the PWM control device startup energy supply. At the same time, the power startup circuit is also the first line of defense for power safety. Therefore, the power startup circuit should have extremely low standby power consumption, perfect circuit protection function, safe and controllable power transmission, complete and reliable startup logic and other characteristics. Summary of the invention

[0004] To this end, the present invention proposes a new type of high-voltage auxiliary power supply startup circuit, which has extremely low standby power consumption, perfect protection function, safety and reliability, and complete startup logic. It solves the problems of high standby power consumption, imperfect protection circuit, and incomplete startup logic of traditional power supply startup circuits.

[0005] The present invention discloses a high voltage auxiliary power supply starting circuit structure, such as Figure 1 As shown, the circuit component unit includes a startup logic processing unit, a power storage unit and a charge release unit. The input end of the power startup circuit is connected to the external input voltage, the temperature detection signal and the maintenance voltage after the startup is completed, and the output end is connected to the external power main control circuit to provide auxiliary power startup energy and protection shutdown signal.

[0006] The power-on logic processing unit includes a hysteresis voltage start-up circuit and an overvoltage, undervoltage and overtemperature protection circuit. The circuit structure diagram is shown in Figure 2As shown, the hysteresis voltage start-up circuit includes an operational amplifier N1A, 7 resistors R1-R7, and a triode or MOSFET power tube Q1. R5 and R6 constitute an input voltage divider conditioning circuit, and the midpoint is connected to the inverting input of the operational amplifier. R1, R2, R4, and N1A constitute the upper and lower limits of the hysteresis voltage comparison (hysteresis voltage upper limit Vh, hysteresis voltage lower limit Vl). R1 ​​and R2 divide the reference voltage provided by the charge release unit and the midpoint is connected to the non-inverting input of the operational amplifier; one end of R4 is connected to the non-inverting input of N1A, and the other end is connected to the output of N1A. R3, R7, and Q1 constitute a power-on output control circuit, one end of R7 is connected to the output of N1A, and the other end is connected to the base or gate of Q1; one end of R3 is connected to the reference voltage provided by the charge release unit, and the other end is connected to the collector or drain of Q1. The overvoltage, undervoltage and overtemperature protection circuit includes an operational amplifier N1B, three resistors R8-R10, two triodes or MOS tubes Q2 and Q7, and a diode D1. The non-inverting input of N1B is connected to the inverting input of N1A, R8 and R9 form a reference voltage divider circuit connected to the inverting input of N1B (to set the overvoltage value Vov), and the anode of D1 is connected to the inverting input of N1B; one end of R10 is connected to the output of N1B, and the other end is connected to the base or gate of Q2, and the collector or drain of Q2 is sent out as a shutdown control signal. The base or gate of Q7 is connected to the base or gate of Q1, and the collector or drain of Q7 is connected to the collector or drain of Q2. The main functions of the power-on logic processing unit are as follows: when the input voltage reaches the interval [Vh, Vov] for the first time, after the voltage rises to the upper limit of the hysteresis voltage Vh, the voltage is allowed to fluctuate within the range above the lower limit of the hysteresis voltage Vl, that is, when it is in the interval [Vl, Vov], the power-on control signal output is high. When the input voltage is at [0, Vh] when the power supply is not started, the power-on control signal output is low. When the input voltage is at [0, Vl] after the power supply is started, the shutdown control signal output is low, that is, the undervoltage protection is started. When the voltage exceeds Vov or the temperature exceeds the set value (the temperature signal is low), it is identified as a fault mode and the shutdown control output is low.

[0007] The schematic diagram of the power storage unit circuit structure is as follows Figure 3As shown, it includes two MOSFET power devices Q3-Q4, five resistors R11-R15, two voltage regulators D2-D3 and two capacitors C1-C2. The input voltage charges the energy storage capacitor C2 through the power devices Q3-Q4 and the resistor R15. The drain of the power device Q3 is connected to the input voltage, and the source of Q3 is connected to the drain of Q4; one end of the charging resistor R15 is connected to the source of Q4, and the other end is connected to the positive end of C2. Resistors R11-R14 and D2-D3 constitute the drive circuit of Q3 and Q4. R13 is connected in parallel with D2, the cathode of D2 is connected to the gate of Q3, and the anode of D2 is connected to the source of Q3. The voltage regulator clamps the gate-source drive voltage of Q3. One end of R14 is connected to the gate of Q4, and the other end is connected to the source of Q4. The voltage across R14 is the drive voltage value, and R11 and R12 are connected in series to the input voltage to provide voltage for the drive of the power device. The function of capacitor C1 is to store energy in advance and control the opening of Q4 through the voltage difference between it and C2. D3 is to clamp the voltage across capacitor C1, thereby achieving the purpose of controlling the charging voltage amplitude Vcc of C2. The main function of the power energy storage unit is: during the establishment of the input voltage, the conduction of Q3 and Q4 is controlled by the resistor voltage divider to charge the energy storage capacitor C2.

[0008] The schematic diagram of the charge release unit structure is shown in Figure 4 As shown, it includes a reference generation circuit and an energy storage discharge circuit. The reference generation circuit includes a resistor R19, a voltage regulator D4 and a filter capacitor C3, wherein one end of R19 is connected to the power supply port output by the power storage unit, and the other end is connected to the cathode of the voltage regulator D4. C3 and D4 are connected in parallel, and the reference generation circuit generates a voltage reference to power the startup logic processing unit. The energy storage discharge circuit includes three resistors R16-R18, an NPN transistor or MOSFET power tube Q5, a PNP transistor Q6 and a diode D5. Among them, R16, Q5, and R17 constitute the discharge circuit of the power storage unit capacitor C1. One end of R16 is connected to the startup control signal and the base or gate of Q5, and the other end is connected to the emitter or source of Q5. One end of R17 is connected to the collector or drain of Q5, and the other end is connected to the positive electrode of the energy storage capacitor C1. When the power-on signal sent by the logic processing unit is high, Q5 is turned on, and the capacitor C1 is discharged through R17 and Q5, and the voltage drops to 0. R18, Q6, and D5 form the discharge circuit of the energy storage capacitor C2 (C2 provides auxiliary power startup energy). One end of R18 is connected to the positive electrode of the energy storage capacitor C1, and the other end is connected to the base of Q6; the emitter of Q6 is connected to the positive electrode of the energy storage capacitor C2, and the collector of Q6 is connected to the startup power supply end (that is, the final output of the startup circuit); the anode of D5 is connected to the maintenance power supply port, and the cathode is connected to the positive electrode of the energy storage capacitor C2. When the external power supply is started, the external power supply output maintains the power supply.

[0009] The beneficial effects of the present invention are

[0010] 1. The startup process has an input voltage hysteresis loop, and the hysteresis loop width can be set, which can reduce the risk of logical misjudgment caused by input voltage fluctuations.

[0011] 2. The power on voltage and off voltage can be set independently. When the input voltage is higher than the on voltage, the power is turned on. When the input voltage is lower than the off voltage, the power is turned off.

[0012] 3. It has complete protection functions, including input undervoltage protection, input overvoltage protection and over-temperature protection.

[0013] 4. The power start-up circuit is instantaneous power supply start-up. After starting, the power storage unit stops working, and the standby power consumption of the power start-up circuit is extremely low. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a schematic diagram of the power startup circuit structure.

[0015] Figure 2 This is a schematic diagram of the circuit structure of the startup logic processing unit.

[0016] Figure 3 Schematic diagram of the circuit structure of the power storage unit.

[0017] Figure 4 Schematic diagram of the circuit structure of the charge release unit.

[0018] Figure 5 This is the application environment diagram of the power startup circuit. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] Example:

[0021] A practical application diagram of a power startup circuit embodiment is shown in FIG. Figure 5 As shown, the power startup circuit includes a startup logic processing unit, a power storage unit and a charge release unit. The input end of the power startup circuit is connected to the external input voltage, the temperature detection signal and the maintenance voltage after the startup is completed, and the output end is connected to the external power main control circuit to provide the initial startup power supply energy and shutdown control signal for the external power main control circuit.

[0022] The working process of the power startup circuit is as follows: first, the power storage unit transmits and stores electric energy through the input voltage, and after the storage is completed, the electric energy supply is generated and sent to the charge release unit; the charge release unit converts the electric energy supply of the power storage unit into a reference voltage and sends it to the startup logic processing unit; the startup logic processing unit judges the external conditions, and when the startup conditions are met, the startup logic processing unit generates a startup control signal and sends it to the charge release unit; after the charge release unit receives the startup control signal, a discharge loop is formed to send the energy stored in the power storage unit to the startup power supply of the main control chip in the form of instantaneous discharge; the main control chip is turned on and a PWM control signal is generated, the switching power supply in the example is started, and the secondary side of the transformer generates power output and maintains the power supply output; the maintenance power supply output is connected to the charge release unit, and continues to generate the reference voltage required by the startup logic processing unit, and continuously protects and controls the input voltage, temperature and other information.

[0023] The power-on logic processing unit includes a hysteresis voltage start-up circuit and an overvoltage, undervoltage and overtemperature protection circuit. The circuit structure diagram is shown in Figure 2 As shown, the hysteresis voltage start-up circuit includes an operational amplifier N1A, 7 resistors R1-R7, and a triode or MOSFET power tube Q1. R5 and R6 constitute an input voltage divider conditioning circuit, and the midpoint is connected to the inverting input of the operational amplifier. R1, R2, R4, and N1A constitute the upper and lower limits of the hysteresis voltage comparison (hysteresis voltage upper limit Vh, hysteresis voltage lower limit Vl). R1 ​​and R2 divide the reference voltage provided by the charge release unit and the midpoint is connected to the non-inverting input of the operational amplifier; one end of R4 is connected to the non-inverting input of N1A, and the other end is connected to the output of N1A. R3, R7, and Q1 constitute a power-on output control circuit, one end of R7 is connected to the output of N1A, and the other end is connected to the base or gate of Q1; one end of R3 is connected to the reference voltage provided by the charge release unit, and the other end is connected to the collector or drain of Q1. The overvoltage, undervoltage and overtemperature protection circuit includes an operational amplifier N1B, three resistors R8-R10, two triodes or MOSFET power tubes Q2 and Q7, and a diode D1. The non-inverting input of N1B is connected to the inverting input of N1A, R8 and R9 form a reference voltage divider circuit connected to the inverting input of N1B (to set the overvoltage value Vov), and the anode of D1 is connected to the inverting input of N1B; one end of R10 is connected to the output of N1B, and the other end is connected to the base or gate of Q2, and the collector or drain of Q2 is sent out as a shutdown control signal. The base or gate of Q7 is connected to the base or gate of Q1, and the collector of Q7 is connected to the collector of Q2.

[0024] The main functions of the power-on logic processing unit are as follows: when the input voltage reaches the interval [Vh, Vov] for the first time, after the voltage rises to the upper limit Vh of the hysteresis voltage, the voltage is allowed to fluctuate within the range above the lower limit Vl of the hysteresis voltage, that is, when it is in the interval [Vl, Vov], the power-on control signal output is a high level. When the input voltage is at [0, Vh] when the power supply is not started, the power-on control signal output is a low level. When the input voltage is at [0, Vl] after the power supply is started, the shutdown control signal output is a low level, that is, the undervoltage protection is started. When the voltage exceeds Vov or the temperature exceeds the set value (the temperature signal is low), it is identified as a fault mode and the shutdown control output is a low level.

[0025] The schematic diagram of the power storage unit circuit structure is as follows Figure 3 As shown, it includes two MOSFET power devices Q3-Q4, five resistors R11-R15, two voltage regulators D2-D3 and two capacitors C1-C2. The input voltage charges the energy storage capacitor C2 through the power devices Q3-Q4 and the resistor R15. The drain of the power device Q3 is connected to the input voltage, and the source of Q3 is connected to the drain of Q4; one end of the charging resistor R15 is connected to the source of Q4, and the other end is connected to the positive end of C2. Resistors R11-R14 and D2-D3 constitute the driving circuit of Q3 and Q4. R13 is connected in parallel with D2, the cathode of D2 is connected to the gate of Q3, and the anode of D2 is connected to the source of Q3. The voltage regulator clamps the gate-source driving voltage of Q3. One end of R14 is connected to the gate of Q4, and the other end is connected to the source of Q4. The voltage across R14 is the driving voltage value, and R11 and R12 are connected in series to the input voltage to provide voltage for the driving of the power tube. The function of capacitor C1 is to store energy in advance and control the opening of Q4 through the voltage difference between it and C2. The function of D3 is to clamp the voltage across capacitor C1, thereby achieving the purpose of controlling the charging voltage amplitude Vcc of C2.

[0026] The main function of the power energy storage unit is: as the input voltage is established, the conduction of Q3 and Q4 is controlled by resistor voltage division to charge the energy storage capacitor C2.

[0027] The schematic diagram of the charge release unit structure is shown in Figure 4As shown, it includes a reference generation circuit and an energy storage discharge circuit. The reference generation circuit includes a resistor R19, a voltage regulator D4 and a filter capacitor C3, wherein one end of R19 is connected to the power supply pin output by the power storage unit, and the other end is connected to the cathode of the voltage regulator D4. C3 and D4 are connected in parallel, and the reference generation circuit generates a voltage reference to power the startup logic processing unit. The energy storage discharge circuit includes three resistors R16-R18, an NPN transistor or MOS transistor Q5, a PNP transistor Q6 and a diode D5. Among them, R16, Q5, and R17 constitute the discharge circuit of the power storage unit capacitor C1. One end of R16 is connected to the startup control signal and the base or gate of Q5, and the other end is connected to the emitter or source of Q5. One end of R17 is connected to the collector or drain of Q5, and the other end is connected to the positive electrode of the energy storage capacitor C1. When the power-on signal sent by the logic processing unit is high, Q5 is turned on, and the capacitor C1 is discharged through R17 and Q5, and the voltage drops to 0. R18, Q6, and D5 form the discharge circuit of the energy storage capacitor C2 (C2 provides power startup energy). One end of R18 is connected to the positive electrode of the energy storage capacitor C1, and the other end is connected to the base of Q6; the emitter of Q6 is connected to the positive electrode of the energy storage capacitor C2, and the collector of Q6 is connected to the startup power supply end (that is, the final output of the startup circuit); the anode of D5 is connected to the maintenance power supply port, and the cathode is connected to the positive electrode of the energy storage capacitor C2. When the external power supply is started, the external power supply output maintains the power supply.

[0028] The application environment of power supply startup circuit includes startup power supply of various PWM control chips, power supply startup power supply, etc. Figure 5 This is a schematic diagram of a case applied to a PWM control device. In this application, the power supply topology adopts a switch flyback topology, and the transformer includes a primary winding, which is greater than or equal to two secondary windings. One set of secondary windings generates a maintenance power supply, which is used to maintain the power supply of the PWM control device after the power supply is started, and the other set of secondary windings generates the power supply output voltage. Temperature detection can use a temperature switch value converted by a temperature relay or a temperature sampling resistor. The shutdown control signal is connected to the COMP comparison output terminal or the fault control terminal of the PWM control device to shut down the output of the PWM control device.

[0029] The present invention is not limited to the above specific implementations, and the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made to the above implementations based on the technical essence of the present invention shall be included in the protection scope of the present invention.

Claims

1. A high voltage auxiliary power supply starting circuit, characterized in that: It includes a power-on logic processing unit, a power storage unit and a charge release unit; The power-on logic processing unit is connected to the external power main circuit input voltage, the power temperature detection signal, and the main control circuit protection shutdown signal, and is internally connected to the power-on signal terminal and the reference voltage terminal of the charge release unit; and is used to determine the power-on condition and fault protection information; The power energy storage unit is externally connected to the input voltage of the external power main circuit and internally connected to the power supply end of the charge release unit, and is used to obtain the startup energy from the input voltage of the external power main circuit and store it in the energy storage capacitor; The charge release unit receives the maintenance voltage established after the external power supply is successfully turned on and sends a startup power supply signal to the external power supply main control circuit. It is internally connected to the power supply end of the power storage unit and the startup signal end and reference voltage end of the startup logic processing unit; the power energy stored in the power storage unit is transmitted to the external power supply main control circuit through the startup signal of the startup logic processing unit to start the power supply.

2. A high voltage auxiliary power supply starting circuit according to claim 1, characterized in that: The power-on logic processing unit includes a hysteresis voltage start-up circuit and an overvoltage, undervoltage and overtemperature protection circuit; The hysteresis voltage start-up circuit comprises an operational amplifier N1A, 7 resistors R1-R7, and a MOSFET power tube Q1; wherein, after R5 and R6 are connected in series, the midpoint is connected to the inverting input terminal of the operational amplifier, after R1 and R2 are connected in series, the midpoint is connected to the non-inverting input terminal of N1A, one end of R4 is connected to the non-inverting input terminal of N1A, and the other end is connected to the output terminal of N1A, R3, R7, and Q1 constitute a start-up output control circuit, one end of R7 is connected to the output terminal of N1A, and the other end is connected to the base of Q1, one end of R3 is connected to the reference voltage terminal of the charge release unit, and the other end is connected to the collector of Q1; The overvoltage, undervoltage and overtemperature protection circuit comprises an operational amplifier N1B, three resistors R8-R10, two MOSFET power tubes Q2 and Q7, and a diode D1; wherein, the non-inverting input terminal of N1B is connected to the inverting input terminal of N1A, R8 and R9 constitute a reference voltage divider circuit connected to the inverting input terminal of N1B, the anode of D1 is connected to the inverting input terminal of N1B, one end of R10 is connected to the output terminal of N1B, and the other end is connected to the base of Q2, the collector of Q2 sends out a shutdown control signal, the base of Q7 is connected to the base of Q1, and the collector of Q7 is connected to the collector of Q2.

3. A high voltage auxiliary power supply starting circuit according to claim 2, characterized in that: The power storage unit comprises two MOSFET power devices Q3-Q4, five resistors R11-R15, two voltage regulators D2-D3 and two capacitors C1-C2; the drain of Q3 is connected to the input voltage, the source of Q3 is connected to the drain of Q4, one end of R15 is connected to the source of Q4, and the other end is connected to the positive end of C2; the resistors R11-R14 and D2-D3 constitute a driving circuit for Q3 and Q4; wherein R13 is connected in parallel with D2, and the cathode of D2 is connected to the positive end of C2. The anode of D2 is connected to the gate of Q3, the anode of D2 is connected to the source of Q3, D2 clamps the gate-source driving voltage of Q3, one end of R14 is connected to the gate of Q4, and the other end is connected to the source of Q4, the voltage across R14 is the driving voltage value, R11 and R12 are connected in series to the input voltage to provide voltage for the drive of Q4, C1 stores energy in advance, and controls Q4 to be turned on through the voltage difference between it and C2, and D3 acts as the voltage across the clamping capacitor C1, thereby achieving the purpose of controlling the charging voltage amplitude of C2.

4. A high voltage auxiliary power supply starting circuit according to claim 3, characterized in that: The charge release unit includes a reference generation circuit and an energy storage discharge circuit; The reference generation circuit includes a resistor R19, a voltage regulator D4 and a filter capacitor C3; wherein one end of R19 is connected to the power supply pin output by the power storage unit, and the other end is connected to the cathode of the voltage regulator D4, C3 and D4 are connected in parallel, and the reference generation circuit generates a reference voltage to power the startup logic processing unit; The energy storage discharge circuit includes three resistors R16-R18, one NPN transistor Q5, one PNP transistor Q6 and one diode D5; wherein R16, Q5 and R17 constitute a discharge loop of the power storage unit capacitor C1, one end of R16 is connected to the start-up control end and the base of Q5, and the other end is connected to the emitter of Q5, one end of R17 is connected to the collector of Q5, and the other end is connected to the positive electrode of C1, one end of R18 is connected to the positive electrode of C1, and the other end is connected to the base of Q6, the emitter of Q6 is connected to the positive electrode of C2, the collector of Q6 is connected to the starting power supply end, the anode of D5 is connected to the maintenance power supply end, and the cathode is connected to the positive electrode of the energy storage capacitor C2.

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