808 laser power switch circuit

Abstract

In order to solve the existing technical problem, the utility model provides an 808 laser power switch circuit, which comprises a resistor R1, a resistor R2, a resistor R3, a resistor R4, a triode Q1, a triode Q2, a diode D1, a TVS (Transient Voltage Suppressor) D2 and a field effect transistor G1, the 808 laser power switch circuit adopts the field effect transistor as a control switch for 808 power output, has no mechanical contact, is high in switching frequency, and greatly improves the service life and the safety of the switch; in addition, the circuit controls on and off of the field effect transistor through PWM, and stepless adjustment of output power is achieved.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of laser power supply, in particular to an 808 laser power supply switching circuit. BACKGROUND

[0002] 808nm laser is mainly used for medical cosmetic laser hair removal, and the 808 power supply is a special power supply for driving the 808nm laser, and the output current is dozens of amperes to hundreds of amperes, and the laser needs to be cooled when working, and the current of the current cooling mainly adopts TEC refrigeration, and the refrigeration current is also dozens of amperes to dozens of amperes. At present, the switching control of these power outputs mainly adopts two ways: 1, relay control; and 2, contactor control.

[0003] The two control modes mainly have the following shortcomings:

[0004] 1, large size: the larger the current borne by the relay and the contactor, the larger the size, which seriously affects the miniaturization design of the equipment.

[0005] 2, large on-off: the current exists electric arc, and electromagnetic interference and safety hazards are generated.

[0006] 3, short service life of frequent switching of contacts: the service life of the relay and the contactor has on-off times, and the service life is generally 100,000-1,000,000 times, and the switching life of the power control is short.

[0007] 4, low switching frequency: the relay and the contactor adopt attraction to control the contact, and the switching frequency is less than 100Hz. SUMMARY

[0008] In order to solve the technical problems of the prior art, the utility model provides an 808 laser power supply switching circuit, which comprises resistance R1, resistance R2, resistance R3, resistance R4, triode Q1, triode Q2, diode D1, TVS tube D2 and field effect tube G1, the utility model adopts the field effect tube as the control switch of the 808 power supply power output, has no mechanical contact, the switching frequency is high, and the service life and safety of the switch are greatly improved, in addition, the circuit controls the conduction and turn-off of the field effect tube through PWM, and realizes stepless adjustment of the output power.

[0009] The field effect tube G1 serves as a switching device.

[0010] The resistance R1, the resistance R2, the resistance R4 and the triode Q2 constitute a conduction circuit of the field effect tube G1.

[0011] The resistance R3, the resistance R4, the diode D1 and the triode Q2 constitute an off circuit of the field effect tube G1.

[0012] The diode D1 and the TVS tube D2 serve as overvoltage protection devices.

[0013] Beneficial effects: the utility model discloses the field effect transistor as 808 power supply power output's control switch, no mechanical contact, switching frequency is high, has improved the life and security of switch greatly, in addition, this drive circuit response speed is fast, can realize stepless adjustment of output power. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 It is circuit structural drawing for the utility model. DETAILED DESCRIPTION

[0015] The utility model discloses an embodiment will be described in detail below:

[0016] The utility model discloses a 808 laser power switch circuit, including resistance R1, resistance R2, resistance R3, resistance R4, triode Q1, triode Q2, diode D1, TVS pipe D2, field effect transistor G1, the utility model discloses the field effect transistor as 808 power supply power output's control switch, no mechanical contact, switching frequency is high, has improved the life and security of switch greatly, in addition, this circuit passes through PWM control field effect transistor's conduction and shutdown, realizes stepless adjustment of output power.

[0017] The field effect transistor G1 is used as a switching device.

[0018] The resistance R1, the resistance R2, the resistance R4 and the triode Q2 constitute a conduction circuit of the field effect transistor G1.

[0019] The resistance R3, the resistance R4, the diode D1 and the triode Q2 constitute a shutdown circuit of the field effect transistor G1.

[0020] The diode D1 and the TVS pipe D2 are used as overvoltage protection devices.

[0021] Embodiment 1:

[0022] Referring to the accompanying drawings Figure 1 Embodiment 1 of the utility model is divided into two stages:

[0023] The PWM setting stage: determine the duty ratio R of the critical PWM wave of the conduction and shutdown of the circuit.

[0024] The conduction stage: at this time, the input duty ratio is greater than R, when G1 is converted from the cut-off state to the conduction, the initial gate voltage of the field effect transistor is low, the voltage on the driving resistor R2 is high, and the gate voltage rises quickly; as the gate voltage of the field effect transistor rises, the voltage on R2 gradually decreases, the driving current decreases, and when the gate voltage exceeds the threshold value and approaches the driving voltage, the gate voltage rises slowly, which reduces the oscillation of the field effect transistor and realizes a fast conduction circuit.

[0025] Off stage: at this time the input duty cycle is less than R, after Q1 is turned on, the gate voltage of the field effect tube is discharged to below the threshold voltage of the field effect tube through R3 and D1, and the remaining voltage is discharged through R4, so that the fast-off circuit is realized.

[0026] The above is the preferred embodiment of the present application, but the present application should not be limited to the embodiments and the contents disclosed in the drawings. Therefore, any equivalent or modification made without departing from the spirit of the present application falls within the scope of the present application.

Claims

1. An 808 laser power supply switching circuit, characterized by, It includes resistance R1, resistance R2, resistance R3, resistance R4, triode Q1, triode Q2, diode D1, TVS tube D2, field effect tube G1, the field effect tube G1 as switching device, the resistance R1, resistance R2, resistance R4, triode Q2 constitute the on circuit of field effect tube G1, the resistance R3, resistance R4, diode D1, triode Q2 constitute the off circuit of field effect tube G1, diode D1, TVS tube D2 as overvoltage protection device.

Images