Solid laser energy storage capacitor charging and slow start system

Abstract

The application provides a solid laser energy storage capacitor charging and slow starting system, which comprises a switch, a charging resistor, a working resistor, an energy storage capacitor and a delay switching circuit, the charging resistor and the working resistor are connected in parallel, one end of the charging resistor and the working resistor is connected with the energy storage capacitor, the other end of the charging resistor and the working resistor is connected with the switch, the delay switching circuit is connected with the charging resistor and controls the switch to selectively connect the charging resistor or the working resistor. By switching the series resistor with different resistance values, the energy storage capacitor is slowly charged when the laser is powered on, the over-current protection of the power supply is avoided, the resistance loss is small during the light emitting process of the laser, the energy storage capacitor can be charged in time, and the voltage and the electric quantity of the energy storage capacitor are ensured.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of solid-state laser, and particularly relates to a charging and slow starting system based on a solid-state laser energy storage capacitor. BACKGROUND

[0002] In the field of solid-state laser, a power supply is needed to charge the energy storage capacitor. Due to the output overcurrent protection mechanism of the power supply itself, the capacitive load capacity cannot be designed to be very high. When the power supply charges the energy storage capacitor, the output overcurrent protection function of the power supply is easily triggered, resulting in repeated starting of the power supply, especially for the power supply with a relatively high output voltage. In view of the problem, a slow starting circuit is designed between the output of the power supply and the input of the energy storage capacitor to avoid triggering the output overcurrent protection of the power supply in a large capacitive load working environment, and to improve the working stability of the solid-state laser circuit system.

[0003] The capacitor charging and slow starting is generally realized by a series resistor. However, when the power supply charges the capacitor through the series resistor, the resistor value is small, although the capacitor charging speed is fast, the output overcurrent protection function of the power supply is still triggered, resulting in power voltage drop or repeated starting. When the series resistor is increased, the energy storage capacitor cannot be fully charged in time during continuous light emission of the laser, which affects the light emission state of the laser, and the resistor loss is large. SUMMARY

[0004] The present application provides a charging and slow starting system based on a solid-state laser energy storage capacitor to solve the technical problems in the prior art. Different resistance values of the series resistor are switched to slowly charge the energy storage capacitor when the laser is powered on, to avoid triggering the overcurrent protection of the power supply, and to reduce the resistor loss during the light emission working process of the laser, and to ensure the voltage and capacity of the energy storage capacitor.

[0005] The technical scheme adopted by the present application is as follows: a charging and slow starting system based on a solid-state laser energy storage capacitor, comprising a switch, a charging resistor, a working resistor, an energy storage capacitor and a delay switching circuit, the charging resistor and the working resistor are connected in parallel, one end of the charging resistor and the working resistor is connected with the energy storage capacitor, and the other end is connected with the switch, the delay switching circuit is connected with the charging resistor and controls the switch to selectively connect the charging resistor or the working resistor.

[0006] Preferably, the resistance value of the charging resistor is greater than that of the working resistor.

[0007] Preferably, the switch is a relay, one end of the winding of the relay is connected with a power supply, the other end of the winding is connected with the delay switching circuit, the main contact of the relay is connected with a laser charging voltage, the normally closed contact is connected with the charging resistor, and the normally open contact is connected with the working resistor.

[0008] As preferred, the time-delay switching circuit collects the voltage on the charging resistor to drive the optocoupler, and controls the relay by the conduction of the transistor.

[0009] As preferred, the time-delay switching circuit comprises a voltage collecting sub-circuit, a time-delay sub-circuit and a switching sub-circuit, the voltage collecting sub-circuit is connected with the charging resistor and the time-delay sub-circuit, and the switching sub-circuit is connected with the time-delay sub-circuit and the switch.

[0010] As preferred, the circuit structure of the voltage collecting sub-circuit is that the resistor R1, the diode D1 and the resistor R2 are connected in series and then connected in parallel with the charging resistor, and the input end of the optocoupler is connected in parallel with the resistor R2.

[0011] As preferred, the circuit structure of the time-delay sub-circuit is that the e pole of the output end of the optocoupler is connected with the positive pole of the diode D3, the c pole of the output end of the optocoupler is connected with one end of the capacitor C1, the negative pole of the diode D4 and VCC, the positive pole of the diode D4 is connected with the e pole of the transistor Q1, the b pole of the transistor Q1 is connected with one end of the capacitor C2, one end of the resistor R3, the other end of the capacitor C1 and the negative pole of the diode D3, the c pole of the transistor Q1 is connected with one end of the resistor R6, the other end of R6 is connected with one end of the resistor R7, one end of the capacitor C4 and the negative pole of the diode D5, the positive pole of the diode D5 is connected with the b pole of the transistor Q2, the e pole of the transistor Q2, the other end of the capacitor C4, the other end of the resistor R7, the other end of the capacitor C2, the other end of the resistor R3 are all connected with the ground.

[0012] As preferred, the circuit structure of the switching sub-circuit is that the diode D2 is connected in parallel with the relay, the positive pole of the diode D2 is connected with the b pole of the transistor Q2, the e pole of the transistor Q1 and the ground, and the negative pole of the diode D2 is connected with VCC.

[0013] Compared with the prior art, the application has the beneficial effects that: the application adopts the charging resistor with large resistance value and the working resistor with small resistance value which are connected in series with the energy storage capacitor respectively, the charging resistor is used to charge the energy storage capacitor when the laser is powered on, and the over-current protection of the power supply is avoided; whether the energy storage capacitor is full is judged by collecting the voltage of the charging resistor, and the working resistor with small resistance value is switched to after the energy storage capacitor is full, and the laser light is avoided, and the over-current protection of the power supply is avoided during the charging and discharging process of the energy storage capacitor; the delay circuit is designed, and the relay is avoided to be switched in advance due to the power-on time sequence. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 The figure is the structural schematic diagram of the embodiment of the application; Figure 2 The figure is the circuit diagram of the voltage collecting sub-circuit of the embodiment of the application; Figure 3 The figure is the circuit diagram of the time-delay sub-circuit of the embodiment of the application; Figure 4This is a circuit diagram of the switching sub-circuit according to an embodiment of the present invention.

[0015] In the diagram, 1 is the voltage acquisition sub-circuit, 2 is the delay sub-circuit, 3 is the switching sub-circuit, C3 is the energy storage capacitor, R5 is the charging resistor, R4 is the working resistor, and K1 is the switch. Detailed Implementation

[0016] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0017] Embodiments of the present invention provide a charging soft-start system based on a solid-state laser energy storage capacitor, such as... Figure 1 As shown, it includes a switch K1, a charging resistor R5, a working resistor R4, an energy storage capacitor C3, and a delay switching circuit. The charging resistor R5 and the working resistor R4 are connected in parallel. One end of both the charging resistor R5 and the working resistor R4 is connected to the energy storage capacitor C3, and the other end of both is connected to the switch K1. The delay switching circuit is connected to the charging resistor R5 and controls the switch K1 to selectively connect either the charging resistor R5 or the working resistor R4. The resistance of the charging resistor R5 is greater than the resistance of the working resistor R4. The switch K1 is a relay. One end of the relay winding is connected to the power supply, and the other end of the winding is connected to the delay switching circuit. The main contacts of the relay are connected to the laser charging voltage, the normally closed contacts are connected to the charging resistor R5, and the normally open contacts are connected to the working resistor R4. The delay switching circuit collects the voltage across the charging resistor R5 to drive the optocoupler N1, and uses the conduction of a transistor to control the relay.

[0018] The delay switching circuit includes a voltage acquisition subcircuit 1, a delay subcircuit 2, and a switching subcircuit 3. The voltage acquisition subcircuit 1 is connected to the charging resistor R5 and the delay subcircuit 2. The switching subcircuit 3 is connected to the delay subcircuit 2 and the switch K1. The circuit structure of the voltage acquisition subcircuit 1 is as follows: Figure 2 As shown, resistor R1, diode D1, and resistor R2 are connected in series and then in parallel with charging resistor R5. The input terminal of optocoupler N1 is connected in parallel with resistor R2. The circuit structure of the delay sub-circuit is as follows: Figure 3As shown, the emitter (e) of the output terminal of optocoupler N1 is connected to the anode of diode D3. The collector (c) of the output terminal of optocoupler N1 is connected to one end of capacitor C1, the cathode of diode D4, and VCC. The anode of diode D4 is connected to the emitter (e) of transistor Q1. The base (b) of transistor Q1 is connected to one end of capacitor C2, one end of resistor R3, the other end of capacitor C1, and the cathode of diode D3. The collector (c) of transistor Q1 is connected to one end of resistor R6. The other end of R6 is connected to one end of resistor R7, one end of capacitor C4, and the cathode of diode D5. The anode of diode D5 is connected to the base (b) of transistor Q2. The emitter (e) of transistor Q2, the other end of capacitor C4, the other end of resistor R7, the other end of capacitor C2, and the other end of resistor R3 are all grounded. The circuit structure of the switching sub-circuit 3 is as follows: Figure 4 As shown, diode D2 is connected in parallel with the relay. The positive terminal of diode D2 is connected to the base (b) and emitter (e) of transistor Q2 and ground, while the negative terminal of diode D2 is connected to VCC.

[0019] After power-on, the laser's internal power supply output voltage connects to charging resistor R5, charging the subsequent energy storage capacitor C3. During charging, a voltage drop occurs across charging resistor R5. The voltage across resistor R2 is then switched on via optocoupler N1, causing the optocoupler to conduct. During capacitor charging, indicator LED D1 illuminates. As the capacitor charging voltage increases, the charging current decreases, and the voltage drop across charging resistor R5 decreases. Once charging is complete, there is no voltage drop across charging resistor R5, and indicator LED D1 turns off, indicating charging is finished. The maximum output current of the power supply is calculated using voltage VC and charging resistor R5, ensuring that this current does not exceed the power supply's overcurrent protection point to prevent overcurrent protection of the power supply module.

[0020] During capacitor charging, the secondary winding of optocoupler N1 conducts, the base of transistor Q1 is at a high level and not conducting, and transistor Q2 cannot conduct due to the pull-down resistor R7. Simultaneously, the collector of transistor Q2 sends a high level (soft-start control signal) to the main control unit, controlling the light-emitting unit to not operate. As the voltage across energy storage capacitor C3 increases, the current through charging resistor R5 decreases, and the voltage across charging resistor R5 also decreases, causing optocoupler N1 to turn off. The pull-down resistor R3 causes transistor Q1 to change from off to on. The VCC voltage charges capacitor C4 through resistor R6. When the voltage across capacitor C4 rises to the sum of the breakdown voltage of diode D5 and the Vbe voltage of transistor Q2, transistor Q2 conducts, completing capacitor charging. The delay time of resistor R6 and capacitor C4 can be adjusted according to the VCC and +144V power supply timing to avoid premature VCC power-on, which would cause transistor Q2 to conduct prematurely.

[0021] When the laser is powered on, after the energy storage capacitor C3 has finished charging, diode D2 conducts. Relay K1 activates, switching from a normally closed contact to a normally open contact, and the charging resistor R5 of the capacitor switches to the working resistor R4. During laser output, the energy storage capacitor C3 discharges to provide energy, and its voltage drops. The voltage drop of the energy storage capacitor C3 was calculated and designed based on the laser's output power to ensure that the charging current across the working resistor R4 does not exceed the maximum output current of the power supply during solid-state laser operation, thus ensuring stable laser power supply operation.

[0022] The present invention has been described in detail above through embodiments, but the content described is only an exemplary embodiment of the present invention and should not be considered as limiting the scope of the present invention. The scope of protection of the present invention is defined by the claims. Any technical solutions designed by those skilled in the art using the technical solutions described in the present invention, or designed by those skilled in the art under the inspiration of the technical solutions of the present invention, within the substance and protection scope of the present invention, to achieve the above-mentioned technical effects, or any equivalent changes and improvements made to the scope of the application, should still fall within the patent protection scope of the present invention.

Claims

1. A soft-start system based on a solid-state laser energy storage capacitor, characterized in that: It includes a switch, a charging resistor, a working resistor, an energy storage capacitor, and a delay switching circuit. The charging resistor and the working resistor are connected in parallel. One end of the charging resistor and the working resistor are both connected to the energy storage capacitor, and the other end of the working resistor is connected to the switch. The delay switching circuit is connected to the charging resistor and controls the switch to selectively connect the charging resistor or the working resistor. The switch is a relay. One end of the relay winding is connected to the power supply, and the other end of the winding is connected to the delay switching circuit. The main contact of the relay is connected to the laser charging voltage, the normally closed contact is connected to the charging resistor, and the normally open contact is connected to the working resistor. The delay switching circuit collects the voltage on the charging resistor to drive the optocoupler, and uses the conduction of the transistor to control the relay. The delay switching circuit includes a voltage acquisition sub-circuit, a delay sub-circuit, and a switching sub-circuit. The voltage acquisition sub-circuit is connected to the charging resistor and the delay sub-circuit, and the switching sub-circuit is connected to the delay sub-circuit and the switch. The circuit structure of the voltage acquisition sub-circuit is as follows: resistor R1, diode D1 and resistor R2 are connected in series and then connected in parallel with the charging resistor; the input terminal of the optocoupler is connected in parallel with resistor R2. The circuit structure of the delay sub-circuit is as follows: the emitter of the optocoupler output is connected to the positive terminal of diode D3; the collector of the optocoupler output is connected to one end of capacitor C1, the negative terminal of diode D4, and VCC; the positive terminal of diode D4 is connected to the emitter of transistor Q1; the base of transistor Q1 is connected to one end of capacitor C2, one end of resistor R3, the other end of capacitor C1, and the negative terminal of diode D3; the collector of transistor Q1 is connected to one end of resistor R6; the other end of R6 is connected to one end of resistor R7, one end of capacitor C4, and the negative terminal of diode D5; the positive terminal of diode D5 is connected to the base of transistor Q2; and the emitter of transistor Q2, the other end of capacitor C4, the other end of resistor R7, the other end of capacitor C2, and the other end of resistor R3 are all grounded.

2. The solid-state laser energy storage capacitor charging soft-start system as described in claim 1, characterized in that: The resistance of the charging resistor is greater than the resistance of the working resistor.

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