CN216056318U

CN216056318U - Multifunctional protection circuit for semiconductor pump solid laser

Info

Publication number: CN216056318U
Application number: CN202121492524.9U
Authority: CN
Inventors: 郭俊超; 韩耀锋; 李刚; 王亮; 李龙骧; 陈胜石; 张佳; 张晓辉; 刘芳; 穆让修; 侯风乾; 马世伟; 雷俊杰; 李军芳; 李永锋; 陈文建; 周根东; 龙井宇; 毕博瑞; 王诚
Original assignee: Xian institute of Applied Optics
Current assignee: Xian institute of Applied Optics
Priority date: 2021-07-02
Filing date: 2021-07-02
Publication date: 2022-03-15
Anticipated expiration: 2031-07-02

Abstract

The utility model discloses a multifunctional protection circuit for a semiconductor pumping solid laser, wherein a transient suppression circuit absorbs voltage surge in external direct current voltage and transmits the processed direct current voltage to an anti-reverse connection and slow start circuit; the reverse connection prevention and slow start circuit is used for blocking the direct current voltage with the wrong polarity and outputting the direct current voltage with the correct polarity to the under-overvoltage and overcurrent protection circuit and the power-on control circuit; the power-on control circuit determines the level of an enable signal output to the under-overvoltage and overcurrent protection circuit according to the level of the power-on control signal; the undervoltage and overcurrent protection circuit monitors the DC voltage and the output current, when there is no fault, the DC voltage is transmitted to the output end, when the DC voltage undervoltage, overvoltage or output overcurrent fault occurs, it will block the DC voltage to output to the backward stage. The circuit has the advantages of simple structure, small volume, low cost and complete functions.

Description

Multifunctional protection circuit for semiconductor pump solid laser

Technical Field

The utility model belongs to the technical field of laser, relates to a laser protection circuit, and particularly relates to a multifunctional protection circuit for a semiconductor pumping solid laser.

Background

In recent years, a semiconductor Pumped Solid State Laser (DPSSL) is widely used in the fields of Laser ranging, Laser pressing, semi-active Laser guidance, and the like. The DPSSL electrical component generally includes a semiconductor Laser Diode Array (LDA) driver board, a Q-regulator board, an LDA temperature controller board, a communication controller board, and a power board. In order to ensure the normal operation and the service life of the DPSSL, each circuit board should operate in a safe and reliable environment.

In practical use, DPSSL externally supplied with dc voltage (voltage range 18V to 36V) generally faces several threat sources: (1) the DPSSL circuit boards and the LDA are irreversibly damaged by the power-on instantaneous overshoot voltage of external power supply and external environment electrostatic discharge; (2) the overvoltage and undervoltage of external power supply can cause each circuit board to work abnormally and even be damaged; (3) when the output current of the DPSSL internal circuit board exceeds a safety threshold or a short-circuit fault occurs, if the external power supply cannot be cut off in time, the circuit board can be damaged, and even more serious faults are caused; (4) when the DPSSL operator connects the positive and negative polarities of the external power supply in a reverse direction carelessly, the reliability and the service life of the circuit board are seriously influenced, or the circuit board is directly burnt. In addition, the current photoelectric integrated system generally requires that the DPSSL single body has a power-on control function.

In order to ensure safe and reliable work of DPSSL and meet the actual use requirements of a system, the research on a protection circuit which is used for a semiconductor pumping solid laser and has multiple functions of surge suppression, reverse connection prevention, slow start, overvoltage protection, undervoltage protection, overcurrent protection, electrification control and the like is of great significance.

The protection circuit that china utility model patent 201720104686.8 provided does not have slow start and goes up electric control function, and its prevents that reverse connection circuit adopts the mode of concatenating the diode, and the diode volume is great when passing through the electric current great, and needs extra heat sink. Chinese utility model patent 201620295591.4 proposes a multifunctional protection circuit comprising an input overvoltage overcurrent module, an input undervoltage module, an output current-limiting module, etc., and this scheme has few functions and a complex structure.

SUMMERY OF THE UTILITY MODEL

Objects of the utility model

The purpose of the utility model is: the multifunctional protection circuit for the semiconductor pumping solid laser ensures safe and reliable work of DPSSL and meets the actual use requirements of a system.

(II) technical scheme

In order to solve the technical problem, the utility model provides a multifunctional protection circuit for a semiconductor pumping solid laser, which comprises a transient suppression circuit 1, an anti-reverse connection and slow start circuit 2, an under-overvoltage and overcurrent protection circuit 3 and an electrifying control circuit 4, wherein the transient suppression circuit comprises a first control circuit, a second control circuit and a third control circuit; the transient suppression circuit 1 absorbs voltage surge in the external direct current voltage VIN and transmits the processed direct current voltage to the reverse connection prevention and slow start circuit 2; the reverse connection prevention slow start circuit 2 blocks the direct current voltage with the wrong polarity, and the direct current voltage with the correct polarity is respectively output to the under-overvoltage and overcurrent protection circuit 3 and the power-on control circuit 4; the power-on control circuit 4 determines the level of an enable signal output to the under-overvoltage and overcurrent protection circuit 3 according to the level of a power-on control signal CTRL; the undervoltage and overvoltage and overcurrent protection circuit 3 monitors the direct-current voltage and the output current, when no fault exists, the direct-current voltage is transmitted to the output terminal VOUT, and when the direct-current voltage is undervoltage, overvoltage or overcurrent fault is output, the direct-current voltage is blocked to be output to the backward stage.

The transient suppression circuit 1 comprises a diode R10, one end of a diode R10 is connected with an external direct-current voltage VIN input end, the drain of a field-effect transistor Q1 in the reverse-connection prevention slow-start circuit 2, and the other end of the diode R10 is grounded.

The reverse connection prevention and slow start circuit 2 comprises a field effect transistor Q1, a resistor R1, a resistor R2 and a capacitor C1; the source electrode of the field-effect transistor Q1 is connected with one end of a resistor R1 and one end of a capacitor C1, the grid electrode of the field-effect transistor Q1 is connected with the other end of a resistor R1, the other end of a capacitor C1 and one end of a resistor R2, and the other end of the resistor R2 is grounded; the source electrode of the field effect transistor Q1 is also connected with an under-overvoltage and overcurrent protection circuit 3.

The under-overvoltage and over-current protection circuit 3 comprises a resistor R5, a resistor R6, a resistor R7, a resistor R8, a resistor R9, a capacitor C2, a capacitor C3, a capacitor C4, a field effect transistor Q2 and an integrated circuit module K1; one end of the resistor R5 is connected with the source electrode of the field effect transistor Q1, and the other end of the resistor R5 is connected with the input pin UV of the undervoltage comparator of the integrated circuit module K1 and one end of the resistor R6; the other end of the resistor R6 is connected with an input pin OV of an overvoltage comparator of an integrated circuit module K1 and one end of a resistor R7; the other end of the resistor R7 is connected with a ground pin GND of the integrated circuit module K1 and is grounded; one end of the resistor R8 is connected with a GATE drive output pin GATE of the integrated circuit module K1 and a GATE of the field effect transistor Q2, and the other end of the resistor R8 is connected with one end of the capacitor C2; the other end of the capacitor C2 is grounded; one end of the resistor R9 is connected with a source electrode of a field effect transistor Q2 and an overcurrent detection input pin SENSE of the integrated circuit module K1, the other end of the resistor R9 is connected with an output voltage detection pin VOUT of the integrated circuit module K1, one end of the capacitor C4 and a voltage output end VOUT, and the other end of the capacitor C4 is grounded; one end of the capacitor C3 is connected with the locking selection pin RETRY of the integrated circuit module K1, and the other end of the capacitor C3 is grounded.

The power-on control circuit 4 comprises a resistor R3, a resistor R4 and a photoelectric coupler Q3; one end of the resistor R3 is connected with the cathode of the photoelectric coupler Q3, and the other end of the resistor R3 is grounded; one end of the resistor R4 and an integrated circuit module K1 turn-off control pin in the emitter of the photoelectric coupler Q3, under-overvoltage and overcurrent protection circuit

The other end of the resistor R4 is grounded; the positive pole of a photoelectric coupler Q3 is connected with a power-on control signal CTRL, and the collector of a pin Q3 of the photoelectric coupler is connected with the source of a field effect tube Q1 in the anti-reverse connection and slow start circuit and the drain of a field effect tube Q1 in the under-overvoltage and overcurrent protection circuit; when the power-on control signal CTRL is at a high level and no other faults exist, the output of the voltage output end VOUT is normal; when the power-up control signal CTRL is low and there are no other faults, the voltage output VOUT output is turned off.

The minimum value of the breakdown voltage of the diode R10 is 33.3V, and the maximum peak pulse power is 600W.

In the undervoltage and overvoltage and overcurrent protection circuit 3, the capacitor C4 is a single or multiple parallel high-capacity capacitors with a capacitance value range of 22 muF-1000 muF, and the rated voltage is 50V-100V; the capacitance value range of the capacitor C3 is 1 nF-10 muF, the rated voltage is 50V-100V, and the capacitor C3 is used for determining the time from fault generation to output turn-off, the larger the capacitance value is, the longer the time is, otherwise, the shorter the time is; a voltage division network consisting of the resistor R5, the resistor R6 and the resistor R7 jointly determines an undervoltage threshold value and an overvoltage threshold value; the resistor R9 has a value range of 2m omega-20 m omega, the rated power is more than or equal to 0.5W, and the resistor R9 is used for determining an overcurrent threshold; the field effect transistor Q2 is an N-channel high-current MOS transistor, the limit drain-source voltage value is not lower than 50V, the limit gate-source voltage absolute value is not lower than 15V, the limit continuous drain current value is not lower than 70A, and the maximum gate-source threshold voltage value is not higher than 3.0V.

Preferably, the capacitor C4 is formed by connecting two 33 muF/50V tantalum electrolytic capacitors in parallel, the capacitor C3 is a 1 muF/50V ceramic capacitor, the capacitor C2 is a 3.3nF/100V ceramic capacitor, the resistor R5 is an E96 series 1.26MΩ/0.1W metal film resistor, the R6 is an E96 series 11.5kΩ/0.1W metal film resistor, the resistor R7 is an E96 series 20kΩ/0.1W metal film resistor, the resistor R8 is an E96 series 22kΩ/0.1W metal film resistor, and the resistor R9 is formed by connecting one 5mΩ/0.8W metal film resistor and one 10mΩ/0.8W metal film resistor in parallel.

In the reverse connection prevention and slow start circuit, the capacitance value of a capacitor C1 is determined according to slow start time, the longer the slow start time is, the larger the capacitance value is, and otherwise, the smaller the capacitance value is, the capacitance value range is 1 nF-100 muF, the rated voltage value of a capacitor C1 is related to an external direct current voltage VIN, the resistance value of a resistor R1 and the resistance value of a resistor R2, and the voltage range is 50V-100V; the field effect transistor Q1 is a P-channel high-current MOS transistor, the absolute value of the limit drain-source voltage is not lower than 50V, the absolute value of the limit gate-source voltage is not lower than 15V, the absolute value of the limit continuous leakage current is not lower than 70A, and the absolute value of the maximum gate-source threshold voltage is not higher than 3.0V.

The maximum forward current of the photoelectric coupler Q3 is not less than 20mA, the maximum collector-emitter voltage is not less than 50V, the maximum reverse voltage is not less than 5V, the forward voltage is not more than 2.5V, the current transfer ratio is not less than 50%, and the saturation voltage drop is not more than 0.25V.

(III) advantageous effects

According to the multifunctional protection circuit for the semiconductor pumping solid laser, the anti-reverse connection and slow start circuit adopts a mode of combining the PMOS tube and the capacitor, the circuit structure is simple, the slow start speed is adjustable, and the maximum allowable current is large; the power-on control circuit adopts an optical coupling isolation technology, so that the photoelectric integrated system can realize isolated control on the DPSSL, and can play a better protection role on the DPSSL; the under-overvoltage and overcurrent protection circuit adopts the technical scheme of an integrated control chip, and has a simple structure and flexible and variable voltage and current protection ranges; the multifunctional protection circuit is applied to the DPSSL power supply front end, can realize multiple functions of surge suppression, reverse connection prevention, slow start, overvoltage protection, undervoltage protection, overcurrent protection, power-on control and the like, has a simple structure, a small size, low cost and complete functions, can effectively ensure safe and reliable work of the DPSSL, and meets the actual use requirements of the system.

Drawings

Fig. 1 is a circuit diagram of a multifunctional protection circuit for a semiconductor pumped solid state laser according to the present invention.

In the figure: the circuit comprises a 1-transient suppression circuit, a 2-reverse connection prevention and slow start circuit, a 3-under-overvoltage and overcurrent protection circuit and a 4-power-on control circuit.

Detailed Description

In order to make the objects, contents and advantages of the present invention clearer, the following detailed description of the embodiments of the present invention will be made in conjunction with the accompanying drawings and examples.

In this embodiment, the nominal voltage of the external dc voltage VIN is 28V, the undervoltage protection threshold is 20V, the overvoltage protection threshold is 32V, the load current is 14A, and the overcurrent protection threshold is 15A. The signal of the power-on control end is 5V-CMOS level, the high level is more than or equal to 4.5V, and the low level is less than or equal to 0.5V. The transient voltage of the external direct-current voltage input end is 150V, and the decay time constant is 200 ms.

The multifunctional protection circuit for the semiconductor pump solid laser mainly comprises a transient suppression circuit, an anti-reverse connection and slow start circuit, an electrifying control circuit, an under-overvoltage and over-current protection circuit and the like, as shown in fig. 1.

The transient suppression circuit is comprised of a diode R10. One end of R10 is connected with an external direct-current voltage input end VIN and the drain electrode of a field effect tube Q1 in the reverse connection prevention and slow start circuit, and the other end of R10 is grounded. The model of the diode R10 is SMAJxxCA series or SMBJXXCA series TVS tube (xx in the model represents a numerical value, such as 36) of Yongguan photoelectron Co., Ltd.

In the embodiment, the model of the diode R10 is SMBJ30CA of Yongphotoelectron GmbH, Zhenhua group, China, and the minimum value of the breakdown voltage is 33.3V, and the maximum peak pulse power is 600W.

Powering upThe control circuit consists of a resistor R3, a resistor R4 and a photoelectric coupler Q3. One end of the resistor R3 is connected with the cathode of the photoelectric coupler Q3, and the other end of the resistor R3 is grounded. One end of a resistor R4 is connected with an emitter of a photoelectric coupler Q3 and a pin of an integrated circuit module K1 in the undervoltage and overvoltage protection circuit

The other end of the resistor R4 is connected to ground. An anode of an optocoupler Q3 is connected with an electrifying control signal CTRL, and a collector of a pin Q3 of a photoelectric coupler is connected with a source electrode of a field effect tube Q1 in the reverse connection prevention and slow start circuit and a drain electrode of a field effect tube Q1 in the undervoltage and overcurrent protection circuit. When the power-on control signal CTRL is at a high level and has no other faults (TTL or CMOS level standard), the output of the voltage output end VOUT is normal; when the power-up control signal CTRL is low and there are no other faults, the voltage output VOUT output is turned off. The maximum forward current of the photoelectric coupler Q3 is not less than 20mA, the maximum collector-emitter voltage is not less than 50V, the maximum reverse voltage is not less than 5V, the forward voltage is not more than 2.5V (when the forward current is 10 mA), the current transmission ratio (when the forward current is 10 mA) is not less than 50%, and the saturation voltage drop (when the forward current is 10 mA) is not more than 0.25V.

In this embodiment, when the power-on control signal CTRL is at a high level (greater than or equal to 4.5V) of 5V-CMOS and there is no other fault, the output of the voltage output terminal VOUT is normal; when the power-on control signal CTRL is at a low level (less than or equal to 0.5V) of the 5V-CMOS and no other faults exist, the output of the voltage output end VOUT is turned off. The resistance R3 is a 330 Ω/0.1W metal film resistance, and the resistance R4 is a 100k Ω/0.1W metal film resistance. The photoelectric coupler Q3 is model YGS521-1 of Yongguan photoelectron GmbH of Shanhua group in China, and its maximum forward current is 70 mA.

The anti-reverse connection and slow start circuit is composed of a field effect transistor Q1, a resistor R1, a resistor R2 and a capacitor C1. The source of the field effect transistor Q1 is connected with one end of a resistor R1 and one end of a capacitor C1, and the grid of the field effect transistor Q1 is connected with the other end of a resistor R1, the other end of a capacitor C1 and one end of a resistor R2. The other end of the resistor R2 is grounded. The capacitance value of the capacitor C1 is determined according to the slow start time, the longer the slow start time is, the larger the capacitance value is, otherwise, the smaller the capacitance value is, the capacitance value range is 1 nF-100 muF, the rated voltage value of the capacitor C1 is related to the external direct-current voltage VIN, the resistance value of the resistor R1 and the resistance value of the resistor R2, and the voltage range is 50V-100V. The field effect transistor Q1 is a P-channel high-current MOS transistor, the absolute value of the limit drain-source voltage is not lower than 50V, the absolute value of the limit gate-source voltage is not lower than 15V, the absolute value of the limit continuous leakage current is not lower than 70A, and the absolute value of the maximum gate-source threshold voltage is not higher than 3.0V.

In this embodiment, the capacitor C1 is a 100nF/50V ceramic capacitor, the resistor R1 is a 220k Ω/0.1W metal film resistor, and the resistor R2 is a 330k Ω/0.1W metal film resistor. The model of the field-effect tube Q1 is SUM110P06-08L of VISIHAY company, USA, the ultimate drain-source voltage of the field-effect tube Q1 is-60V, the ultimate gate-source voltage is +/-20V, the ultimate continuous leakage current is 75A, and the maximum gate-source threshold voltage is-3.0V, so that the field-effect tube Q1 is suitable for the application scene of the implementation mode and meets the requirements of a safe working area.

The under-overvoltage and over-current protection circuit consists of a resistor R5, a resistor R6, a resistor R7, a resistor R8, a resistor R9, a capacitor C2, a capacitor C3, a capacitor C4, a field effect transistor Q2 and an integrated circuit module K1. One end of the resistor R5 is connected with the source electrode of the field effect transistor Q1, and the other end of the resistor R5 is connected with the pin UV of the integrated circuit module K1 and one end of the resistor R6. The other end of the resistor R6 is connected with the integrated circuit module K1 pin OV and one end of the resistor R7. The other end of the resistor R7 is connected with a pin GND of the integrated circuit module K1 and is grounded. One end of the resistor R8 is connected with a GATE pin of the integrated circuit module K1 and a grid electrode of the field effect transistor Q2, and the other end of the resistor R8 is connected with one end of the capacitor C2. The other end of the capacitor C2 is grounded. One end of the resistor R9 is connected with a source electrode of the field effect transistor Q2 and a SENSE pin of the integrated circuit module K1, the other end of the resistor R9 is connected with a VOUT pin of the integrated circuit module K1, one end of the capacitor C4 and a voltage output end VOUT, and the other end of the capacitor C4 is grounded. One end of the capacitor C3 is connected with a RETRY pin of the integrated circuit module K1, and the other end of the capacitor C3 is grounded. The capacitor C4 is a single or a plurality of parallel high-capacity capacitors, the capacitance range is 22 muF-1000 muF, and the rated voltage is 50V-100V. The capacitor C3 is used for determining the time from fault generation to output turn-off, the larger the capacitance value is, the longer the time is, otherwise, the shorter the time is, the capacitance value range is 1 nF-10 muF, and the rated voltage is 50V-100V. A voltage division network consisting of the resistor R5, the resistor R6 and the resistor R7 jointly determines an undervoltage threshold value and an overvoltage threshold value. The resistor R9 determines the overcurrent threshold value, the value range is 2m omega-20 m omega, and the rated power is more than or equal to 0.5W. The field effect transistor Q2 is an N-channel high-current MOS transistor, the limit drain-source voltage value is not lower than 50V, the limit gate-source voltage absolute value is not lower than 15V, the limit continuous drain current value is not lower than 70A, and the maximum gate-source threshold voltage value is not higher than 3.0V. The integrated circuit module K1 is model number ADI LTC4368 series.

In this embodiment, the capacitor C4 is formed by connecting two 33 μ F/50V tantalum electrolytic capacitors in parallel, the capacitor C3 is a 1 μ F/50V ceramic capacitor, the capacitor C2 is a 3.3nF/100V ceramic capacitor, the resistor R5 is an E96 series 1.26M Ω/0.1W metal film resistor, the resistor R6 is an E96 series 11.5k Ω/0.1W metal film resistor, the resistor R7 is an E96 series 20k Ω/0.1W metal film resistor, the resistor R8 is an E96 series 22k Ω/0.1W metal film resistor, and the resistor R9 is formed by connecting one 5M Ω/0.8W metal film resistor and one 10M Ω/0.8W metal film resistor in parallel. The model of the field-effect tube Q2 is SUM50020EL of VISIY company, USA, the limit drain-source voltage value of the field-effect tube Q2 is 60V, the limit gate-source voltage is +/-20V, the limit continuous drain current value is 120A, and the maximum gate-source threshold voltage value is 2.5V, so that the field-effect tube Q2 is suitable for the application scene of the embodiment and meets the requirement of a safe working area. The integrated circuit module K1 is model number ADI LTC4368HDD-2# PBF.

Test results show that the implementation mode can well realize multiple functions of surge suppression, reverse connection prevention, slow start, overvoltage protection, undervoltage protection, overcurrent protection, power-on control and the like, has a simple structure, a small size, low cost and complete functions, can effectively ensure safe and reliable work of DPSSL, meets the actual use requirements of the system, and has great use and popularization values.

The above description is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, several modifications and variations can be made without departing from the technical principle of the present invention, and these modifications and variations should also be regarded as the protection scope of the present invention.

Claims

1. A multifunctional protection circuit for a semiconductor pumping solid laser is characterized by comprising a transient suppression circuit (1), an anti-reverse connection and slow start circuit (2), an under-overvoltage and overcurrent protection circuit (3) and a power-on control circuit (4); the transient suppression circuit (1) absorbs voltage surge in an external direct-current voltage VIN and transmits the processed direct-current voltage to the reverse connection prevention and slow start circuit (2); the reverse connection prevention and slow start circuit (2) blocks the direct current voltage with wrong polarity, and the direct current voltage with correct polarity is respectively output to the under-overvoltage and overcurrent protection circuit (3) and the power-on control circuit (4); the power-on control circuit (4) determines the level of an enable signal output to the under-overvoltage and overcurrent protection circuit (3) according to the level of a power-on control signal CTRL; the under-overvoltage and overcurrent protection circuit (3) monitors direct-current voltage and output current, when no fault exists, the direct-current voltage is transmitted to the output end VOUT, and when the direct-current voltage is under-voltage, over-voltage or output overcurrent fault occurs, the direct-current voltage is blocked to be output to the backward stage.

2. The multifunctional protection circuit for a semiconductor pumped solid state laser as claimed in claim 1, wherein said transient suppression circuit (1) comprises a diode R10, one end of the diode R10 is connected with the external direct voltage VIN input terminal, the drain of the field effect transistor Q1 in the reverse-connection prevention and slow start circuit (2), and the other end is grounded.

3. The multifunctional protection circuit for a semiconductor pumped solid state laser according to claim 2, wherein the reverse connection prevention and slow start circuit (2) comprises a field effect transistor Q1, a resistor R1, a resistor R2 and a capacitor C1; the source electrode of the field-effect transistor Q1 is connected with one end of a resistor R1 and one end of a capacitor C1, the grid electrode of the field-effect transistor Q1 is connected with the other end of a resistor R1, the other end of a capacitor C1 and one end of a resistor R2, and the other end of the resistor R2 is grounded; the source electrode of the field effect transistor Q1 is also connected with an under-overvoltage and overcurrent protection circuit (3).

4. A multifunctional protection circuit for a semiconductor pumped solid state laser according to claim 3, characterized in that the under-overvoltage and overcurrent protection circuit (3) comprises a resistor R5, a resistor R6, a resistor R7, a resistor R8, a resistor R9, a capacitor C2, a capacitor C3, a capacitor C4, a field effect transistor Q2 and an integrated circuit module K1; one end of the resistor R5 is connected with the source electrode of the field effect transistor Q1, and the other end of the resistor R5 is connected with the input pin UV of the undervoltage comparator of the integrated circuit module K1 and one end of the resistor R6; the other end of the resistor R6 is connected with an input pin OV of an overvoltage comparator of an integrated circuit module K1 and one end of a resistor R7; the other end of the resistor R7 is connected with a ground pin GND of the integrated circuit module K1 and is grounded; one end of the resistor R8 is connected with a GATE drive output pin GATE of the integrated circuit module K1 and a GATE of the field effect transistor Q2, and the other end of the resistor R8 is connected with one end of the capacitor C2; the other end of the capacitor C2 is grounded; one end of the resistor R9 is connected with a source electrode of a field effect transistor Q2 and an overcurrent detection input pin SENSE of the integrated circuit module K1, the other end of the resistor R9 is connected with an output voltage detection pin VOUT of the integrated circuit module K1, one end of the capacitor C4 and a voltage output end VOUT, and the other end of the capacitor C4 is grounded; one end of the capacitor C3 is connected with the locking selection pin RETRY of the integrated circuit module K1, and the other end of the capacitor C3 is grounded.

5. The multifunctional protection circuit for a semiconductor-pumped solid state laser according to claim 4, characterized in that the power-on control circuit (4) comprises a resistor R3, a resistor R4 and a photocoupler Q3; one end of the resistor R3 is connected with the cathode of the photoelectric coupler Q3, and the other end of the resistor R3 is grounded; one end of the resistor R4 and an integrated circuit module K1 turn-off control pin in the emitter of the photoelectric coupler Q3, under-overvoltage and overcurrent protection circuit

The other end of the resistor R4 is grounded; the positive pole of a photoelectric coupler Q3 is connected with a power-on control signal CTRL, and the collector of a pin Q3 of the photoelectric coupler is connected with the source of a field effect tube Q1 in the anti-reverse connection and slow start circuit and the drain of a field effect tube Q1 in the under-overvoltage and overcurrent protection circuit; when the power-on control signal CTRL is at a high level and has no fault, the output of the voltage output end VOUT is normal; when the power-up control signal CTRL is low and there is no fault, the voltage output VOUT output is turned off.

6. The multifunctional protection circuit for a semiconductor pumped solid state laser as claimed in claim 5, wherein said diode R10 has a breakdown voltage minimum of 33.3V and a maximum peak pulse power of 600W.

7. The multifunctional protection circuit for a semiconductor pumped solid state laser as claimed in claim 6, wherein in the undervoltage and overcurrent protection circuit (3), the capacitor C4 is a single or multiple parallel high-capacity capacitors with a capacitance value range of 22 μ F-1000 μ F, and the rated voltage is 50V-100V; the capacitance value range of the capacitor C3 is 1 nF-10 muF, the rated voltage is 50V-100V, and the capacitor C3 is used for determining the time from fault generation to output turn-off, and the larger the capacitance value is, the longer the time is, the smaller the capacitance value is, and the shorter the time is; a voltage division network consisting of the resistor R5, the resistor R6 and the resistor R7 jointly determines an undervoltage threshold value and an overvoltage threshold value; the resistor R9 has a value range of 2m omega-20 m omega, the rated power is more than or equal to 0.5W, and the resistor R9 is used for determining an overcurrent threshold; the field effect transistor Q2 is an N-channel high-current MOS transistor, the limit drain-source voltage value is not lower than 50V, the limit gate-source voltage absolute value is not lower than 15V, the limit continuous drain current value is not lower than 70A, and the maximum gate-source threshold voltage value is not higher than 3.0V.

8. The multifunctional protection circuit for a semiconductor-pumped solid state laser as claimed in claim 7, wherein the capacitor C4 is formed by connecting two 33 μ F/50V tantalum electrolytic capacitors in parallel, the capacitor C3 is a 1 μ F/50V ceramic capacitor, the capacitor C2 is a 3.3nF/100V ceramic capacitor, the resistor R5 is an E96 series 1.26M Ω/0.1W metal film resistor, the resistor R6 is an E96 series 11.5k Ω/0.1W metal film resistor, the resistor R7 is an E96 series 20k Ω/0.1W metal film resistor, the resistor R8 is an E96 series 22k Ω/0.1W metal film resistor, and the resistor R9 is formed by connecting a 5M Ω/0.8W metal film resistor and a 10M/0.8W metal film resistor in parallel.

9. The multifunctional protection circuit for a semiconductor pumped solid state laser as claimed in claim 7, wherein in the reverse connection preventing and slow start circuit (2), the capacitance value of the capacitor C1 is determined according to the slow start time, the longer the slow start time is, the larger the capacitance value is, the shorter the slow start time is, the smaller the capacitance value is, the capacitance value range is 1 nF-100 μ F, and the rated voltage value range of the capacitor C1 is 50V-100V; the field effect transistor Q1 is a P-channel high-current MOS transistor, the absolute value of the limit drain-source voltage is not lower than 50V, the absolute value of the limit gate-source voltage is not lower than 15V, the absolute value of the limit continuous leakage current is not lower than 70A, and the absolute value of the maximum gate-source threshold voltage is not higher than 3.0V.

10. The multifunctional protection circuit for a semiconductor pumped solid state laser as claimed in claim 9, wherein said photocoupler Q3 has a maximum forward current of not less than 20mA, a maximum collector-emitter voltage of not less than 50V, a maximum reverse voltage of not less than 5V, a forward voltage of not more than 2.5V, a current transfer ratio of not less than 50%, and a saturation voltage drop of not more than 0.25V.