A laser power switch control circuit, control system and control method

Abstract

The application provides a laser power switch control circuit, a control system and a control method. The laser power switch control circuit comprises: a main circuit switch control module, which is used for outputting a main circuit driving power when turned on; a pre-charge switch control module, which is used for outputting a pre-charge working voltage when turned on; a filter module, which is used for charging according to the pre-charge working voltage and the main circuit driving power; a detection control module, which is used for outputting a pre-charge start signal to the pre-charge switch control module when the voltage difference between the filter voltage and the pump driving voltage is greater than a critical voltage value, and outputting a main circuit start signal to the main circuit switch control module when the voltage difference is less than the critical voltage value. The pre-charge switch control module is started to pre-charge the filter module when the voltage difference between the filter voltage and the pump driving voltage is greater than the critical voltage value, so that the laser output stability is improved, and other devices in the circuit are prevented from being damaged by overcurrent or over-power due to the huge impact current generated by the power-on impact.

Description

Technical Field

[0001] This invention relates to the field of laser power supply technology, specifically to a laser power supply switch control circuit, control system, and control method. Background Technology

[0002] The pump source, as a device that excites the laser working substance, is responsible for converting external energy such as electrical energy into light energy of a specific wavelength, providing the necessary energy input for laser generation.

[0003] In laser pump source circuits, a filter module is typically included. This filter module contains capacitive device structures for filtering, eliminating input AC ripple and ensuring a clean and stable DC power supply to the pump source. However, when the filter module is located downstream of the switching controller, the initial voltage across the filter module is zero at the moment of system power-on. When the switching controller closes, the two ends of the filter module are effectively short-circuited, resulting in an inrush current much larger than the steady-state operating current within a very short time. This can lead to overcurrent or over-power damage to the device.

[0004] Therefore, existing technologies still need to be improved and developed. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the purpose of this invention is to provide a laser power switch control circuit, control system and control method to solve the problem that the filter module of the existing switch control circuit is prone to generate uncontrollable huge inrush current when powered on, which leads to overcurrent or overpower damage to the device.

[0006] The technical solution of the present invention is as follows: This invention provides a laser power switch control circuit for controlling the operation of a pump source, comprising: The main circuit switch control module is connected to the pump drive voltage and is connected to the power input terminal of the pump source, and is used to output the main circuit drive power when it is turned on. The precharge switch control module is connected to the pump drive voltage and is connected to the common terminal of the main switch control module and the pump source, and is used to output the precharge working voltage when it is turned on. The filter module has its positive terminal connected to the common terminal of the main circuit switch control module and the precharge switch control module, and its negative terminal grounded, for charging according to the precharge working voltage and the main circuit drive power supply. The detection control module has a control terminal that receives an activation signal, a first signal terminal that is connected to the control terminal of the main circuit switch control module, and a second signal terminal that is connected to the control terminal of the precharge switch control module. The detection and control module powers on when an on-signal is detected and is used to detect the filter voltage of the filter module. When the voltage difference between the filter voltage and the pump drive voltage is greater than a critical voltage value, it outputs a pre-charge on signal to the pre-charge switch control module, which controls the pre-charge switch control module to turn on. When the voltage difference between the filter voltage and the pump drive voltage is less than a critical voltage value, it outputs a main circuit on signal to the main circuit switch control module, which controls the main circuit switch control module to turn on. The filter module outputs a stable operating current to the pump source when the main circuit switch control module is turned on.

[0007] A further embodiment of the present invention includes a constant current module, wherein the first connection terminal of the constant current module is connected to the pump source, and the second connection terminal of the constant current module is grounded; the third signal terminal of the detection and control module is connected to the control terminal of the constant current module; the detection and control module outputs a precharge shutdown signal to the precharge switch control module when the voltage difference between the filter voltage and the pump drive voltage is zero, and outputs a constant current control signal to the constant current module after a delay of the constant current delay time; the constant current module adjusts the stable operating current to obtain a constant current operating signal when it acquires the constant current control signal; the pump source outputs a stable laser under the constant current operating signal.

[0008] In a further embodiment of the present invention, the constant current module includes a first voltage divider resistor and a third field-effect transistor. One end of the first voltage divider resistor is grounded, and the other end of the first voltage divider resistor is connected to the source of the third field-effect transistor. The gate of the third field-effect transistor is connected to the third signal terminal of the detection and control module, and the drain of the third field-effect transistor is connected to the pump source.

[0009] In a further embodiment of the present invention, the precharge switch control module includes: a thermistor, a second switch transistor, an eleventh resistor, and a twelfth resistor. One end of the thermistor is connected to the pump drive voltage, and the other end of the thermistor is connected to the first connection terminal of the second switch transistor. The second connection terminal of the second switch transistor is connected to the common connection terminal of the main circuit switch control module and the pump source. The control terminal of the second switch transistor is connected to one end of the eleventh resistor and one end of the twelfth resistor. The other end of the eleventh resistor is connected to the second connection terminal of the second switch transistor. The other end of the twelfth resistor is connected to the detection control module.

[0010] In a further embodiment of the present invention, the filtering module includes an electrolytic capacitor, the anode of which is connected to the common terminal of the pump source, the main circuit switch control module and the precharge switch control module, and the cathode of which is grounded.

[0011] In a further embodiment of the present invention, the detection control module includes a control chip, the control terminal of the control chip is connected to an on signal, the first signal terminal of the control chip is connected to the control terminal of the main circuit switch control module, the second signal terminal of the control chip is connected to the control terminal of the precharge switch control module, and the third signal terminal of the control chip is connected to the control terminal of the constant current module.

[0012] In a further embodiment of the present invention, the detection control module further includes a first isolation unit and a second isolation unit. The control terminal of the first isolation unit is connected to the first signal terminal of the detection control module, and the signal output terminal of the first isolation unit is connected to the main circuit switch control module. When the voltage difference between the filter voltage and the pump drive voltage is less than a critical voltage value, the detection control module outputs a main circuit command signal to the first isolation unit. When the first isolation unit acquires the main circuit command signal, the voltage input terminal of the first isolation unit and the signal output terminal of the first isolation unit are connected, and a main circuit start signal is output to the main circuit switch control module. The main circuit switch control module is turned on when it acquires the main circuit start signal. The control terminal of the second isolation unit is connected to the second signal terminal of the detection control module, and the signal output terminal of the second isolation unit is connected to the precharge switch control module. When the voltage difference between the filter voltage and the pump drive voltage is greater than the critical voltage value, the detection control module outputs a precharge command signal to the second isolation unit. When the second isolation unit acquires the precharge start signal, it outputs a precharge start signal to the precharge switch control module. When the precharge start signal is acquired, the precharge switch control module is turned on.

[0013] Based on the same inventive concept, the present invention also provides a control system, which includes the laser power switch control circuit, the host computer, and the pump source described above; wherein, The host controller is connected to the control terminal of the detection and control module and is used to output an activation signal to the laser power switch control circuit. The laser power switch control circuit is connected to the pump source and is connected to the pump drive voltage. It is used to output a stable operating current to the pump source after detecting the turn-on signal. The pump source outputs a stable laser according to the stable operating current.

[0014] Based on the same inventive concept, the present invention also provides a control method for controlling the laser power switch control circuit described above, the steps of which include: In the first time period, the activation signal is sent to the detection and control module, and the detection and control module outputs a precharge activation signal to the precharge switch control module when the voltage difference between the filter voltage and the pump drive voltage is greater than the critical voltage value. In the second time period, the precharge switch control module activates to charge the filter module after receiving the precharge start signal. During the third time period, when the voltage difference between the filter voltage and the pump drive voltage is less than the critical voltage value, the detection control module outputs a main circuit start signal to the main circuit switch control module. The main circuit switch control module turns on and starts working when it receives the main circuit start signal.

[0015] A further provision of the present invention, wherein, in the third time period, the detection control module outputs a main circuit start signal to the main circuit switch control module when the voltage difference between the filter voltage and the pump drive voltage is less than a critical voltage value, and the main circuit switch control module turns on and starts working upon receiving the main circuit start signal, further includes: In the fourth time period, the detection and control module outputs a pre-charge shutdown signal to the pre-charge switch control module when the voltage difference between the filter voltage and the pump drive voltage is zero; the pre-charge switch control module shuts down when it receives the pre-charge shutdown signal. In the fifth time period, the detection and control module outputs a constant current control signal to the constant current module. When the constant current module acquires the constant current control signal, it starts to adjust the stable operating current and obtains a constant current operating signal. The pump source outputs a stable laser under the constant current operating signal. During the sixth time period, when the detection and control module receives the shutdown signal, it outputs a main road shutdown signal to the main road switch control module, and the main road switch control module shuts down when it receives the main road shutdown signal. During the seventh time period, the detection and control module outputs a constant current shutdown signal to the constant current module, and the constant current module shuts down when it receives the constant current shutdown signal.

[0016] This invention provides a laser power switch control circuit, a control system, and a control method. The laser power switch control circuit is used to control the operation of a pump source and includes: a main circuit switch control module, which receives the pump drive voltage and is connected to the power input terminal of the pump source, for outputting the main circuit drive power when the laser is turned on; a pre-charge switch control module, which receives the pump drive voltage and is connected to the common terminal of the main circuit switch control module and the pump source, for outputting a pre-charge working voltage when the laser is turned on; a filter module, the positive terminal of which is connected to the common terminal of the main circuit switch control module and the pre-charge switch control module, and the negative terminal of which is grounded, for charging according to the pre-charge working voltage and the main circuit drive power; and a detection control module, the control terminal of which receives an on signal. The first signal terminal of the detection control module is connected to the control terminal of the main circuit switch control module, and the second signal terminal of the detection control module is connected to the control terminal of the precharge switch control module. The detection control module powers on when it detects an on-line signal and is used to detect the filter voltage of the filter module. When the voltage difference between the filter voltage and the pump drive voltage is greater than a critical voltage value, it outputs a precharge on-line signal to the precharge switch control module, which is used to control the precharge switch control module to conduct. When the voltage difference between the filter voltage and the pump drive voltage is less than a critical voltage value, it outputs a main circuit on-line signal to the main circuit switch control module, which is used to control the main circuit switch control module to conduct. The filter module is used to output a stable operating current to the pump source when the main circuit switch control module is conducted. When the laser power switch control circuit of this invention is powered on, the pre-charge switch control module is activated to pre-charge the filter module when the voltage difference between the filter voltage and the pump drive voltage is greater than the critical voltage value. This improves the stability of laser output, prevents the filter module from being damaged by overcurrent or overpower due to the huge inrush current generated by the power-on impact, and the circuit structure is simple, reducing production costs. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of an existing switch control circuit.

[0019] Figure 2 This is a schematic diagram of another existing switch control circuit.

[0020] Figure 3 This is a schematic diagram of a laser power switch control circuit in a preferred embodiment of the present invention.

[0021] Figure 4 This is a schematic diagram of a laser power switch control circuit in another preferred embodiment of the present invention.

[0022] Figure 5 This is a circuit diagram of a laser power switch control circuit using a main circuit switch control module, as described in this invention.

[0023] Figure 6 This is a circuit diagram of a laser power switch control circuit using a different main switch control module according to the present invention.

[0024] Figure 7 This is a signal timing diagram of the laser power switch control circuit of the present invention.

[0025] Figure 8 This is a schematic diagram of the steps of the control method of the present invention.

[0026] The following labels in the attached diagram represent: 1. Pump source; 100. Main circuit switch control module; 200. Precharge switch control module; 300. Filtering module; 400. Detection control module; 410. First isolation unit; 420. Second isolation unit; 500. Constant current module. Detailed Implementation

[0027] This invention provides a laser power switch control circuit, control system, and control method. To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the invention will be further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0028] In the implementation methods and claims, unless otherwise specified in the text, the terms "a," "an," "the," and "the" may also include plural forms. If the embodiments of the present invention involve descriptions of "first," "second," etc., such descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features.

[0029] It should be further understood that the term "comprising" as used in this specification means the presence of the stated features, integers, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. It should be understood that when we say an element is "connected" or "coupled" to another element, it can be directly connected or coupled to the other element, or there may be intermediate elements. Furthermore, "connected" or "coupled" as used herein can include wireless connections or wireless coupling. The term "and / or" as used herein includes all or any unit and all combinations of one or more associated listed items.

[0030] It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It should also be understood that terms such as those defined in general dictionaries should be understood to have the same meaning as in the context of the prior art, and should not be interpreted in an idealized or overly formal sense unless specifically defined as herein.

[0031] Furthermore, the technical solutions of the various embodiments can be combined with each other, but only if they are feasible for those skilled in the art. If the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0032] The inventors discovered that as lasers continue to evolve, the structure of a single laser is shrinking while power application demands are increasing. To further improve laser application power within a limited laser structure, the electrical control system of high-power lasers (especially those exceeding 10,000 watts) employs a scheme of a front-stage high-power AC / DC constant voltage source coupled with multiple parallel constant current drives. A constant current source and pump source are set on each branch, and the operating state of the pump source is controlled independently by each constant current source. In each independent branch, existing laser systems use switching control circuits to achieve constant current control. In some existing embodiments, such as... Figure 1 As shown, in the first existing switch control circuit A1, the filter module is far from the constant current module and pump source load relative to the high-side switch control module. During operation, the pump source cannot draw power from the electrolytic capacitor over a short distance. This results in parasitic inductance and resistance in the power supply circuit causing the load current ripple to be unable to be effectively suppressed. Consequently, the ripple current is too large when the pump source is operating, affecting the stability of the output laser. Therefore, as... Figure 2As shown, in another part of the existing switch control circuit, namely the second existing switch control circuit A2, an attempt is made to place the filter module at the rear end of the high-end switch control module. In this setting, the filter module is equivalent to a short circuit state at the moment the high-end switch control module is turned on, thereby generating an uncontrollable huge inrush current. The huge inrush current flowing through the switching device can easily cause the device to be damaged by overcurrent or overpower.

[0033] To address the technical problems existing in the prior art, the present invention provides a laser power switch control circuit, which is used to control the operation of pump source 1, such as... Figure 3 As shown, it includes: a main circuit switch control module 100, which receives the pump drive voltage Vin and is connected to the power input terminal of the pump source 1, for outputting the main circuit drive power when turned on; a pre-charge switch control module 200, which receives the pump drive voltage Vin and is connected to the common terminal of the main circuit switch control module 100 and the pump source 1, for outputting the pre-charge working voltage when turned on; a filter module 300, the positive terminal of which is connected to the common terminal of the main circuit switch control module 100 and the pre-charge switch control module 200, and the negative terminal of which is grounded, for charging according to the pre-charge working voltage and the main circuit drive power; and a detection control module 400, the control terminal SW of which receives the turn-on signal, and the first signal terminal of which is connected to the control terminal of the main circuit switch control module 100. The second signal terminal of the detection control module 400 is connected to the control terminal of the precharge switch control module 200. The detection control module 400 powers on when it detects an on-signal and is used to detect the filter voltage Vc of the filter module 300. When the voltage difference between the filter voltage Vc and the pump drive voltage Vin is greater than a critical voltage value, it outputs a precharge on-signal to the precharge switch control module 200. The precharge on-signal is used to control the precharge switch control module 200 to turn on. When the voltage difference between the filter voltage Vc and the pump drive voltage Vin is less than a critical voltage value, it outputs a main circuit on-signal to the main circuit switch control module 100. The main circuit on-signal is used to control the main circuit switch control module 100 to turn on. The filter module 300 is used to output a stable operating current to the pump source 1 when the main circuit switch control module 100 is turned on.

[0034] The activation signal is a control signal input by the user or a host computer. This activation signal can be directly input from the microcontroller chip on the control board or from various mechanical switches, as long as the control logic is aligned with the terminal application. The filter detection terminal of the detection control module 400 is connected to the filter module 300. The input detection terminal of the detection control module 400 is connected to the pump drive voltage Vin to detect the filter voltage Vc and the externally input pump drive voltage Vin, and to calculate the voltage difference between them. The filter voltage Vc is the voltage across the filter module 300, which is a capacitive load. At the moment of power-on, the filter voltage Vc is equivalent to zero, therefore the voltage difference between the filter voltage Vc and the externally input pump drive voltage Vin is greater than a critical voltage value. The equivalent resistance of the pre-charge switch control module 200 is greater than that of the main switch control module 100. Therefore, when the system is powered on, it is first powered on through the pre-charge switch control module 200, reducing the voltage applied to the parasitic resistance of the filter module 300 at power-on and thus reducing the inrush current generated by the filter module 300 at that moment. When the voltage difference between the filter voltage Vc and the pump drive voltage Vin is less than the critical voltage value, the detection control module 400 outputs a main circuit start signal to the main switch control module 100, and the main switch control module 100 is turned on. At this time, because the voltage difference between the filter voltage Vc and the pump drive voltage Vin is reduced, the inrush current generated when the main switch control module 100 is turned on is reduced, making it less likely for the main switch control module 100 to be damaged by the inrush current, thus ensuring the stable operation of the main switch control module 100.

[0035] Please refer to the following: Figure 3 and Figure 4The filter module 300 includes an electrolytic capacitor C0. The anode of the electrolytic capacitor C0 is connected to the common terminal of the pump source 1, the main circuit switch control module 100, and the pre-charge switch control module 200, while the cathode of the electrolytic capacitor C0 is grounded. Since the filter module 300 is placed at the rear end of the main circuit switch control module 100, the electrolytic capacitor C0 is placed closer to the pump source 1. The pump source 1 can achieve power extraction over the shortest distance. When the pump source 1 emits high-speed pulsed light, it requires a large instantaneous current. Therefore, the electrolytic capacitor C0, placed close to the pump source 1, is used to quickly discharge and replenish energy, reducing the ripple current caused by attenuation and delay from excessively long conductors. The short-distance application of the electrolytic capacitor C0 ensures stable and smooth current. In actual operation, the uncontrollable inrush current of capacitor C when it is in a short-circuit state at the moment the circuit is turned on is converted into a controllable inrush current through the pre-charge switch control module 200, protecting the safe operation of the main circuit switch control module 100 circuit. When pump source 1 requires high current operation, the main circuit switch control module 100 is turned on to reduce line losses. When the circuit is turned off, capacitor C has a discharge circuit, so that after short-distance power intake during power-on, charge can be quickly discharged when operation stops.

[0036] Furthermore, such as Figure 4 As shown, the laser power switch control circuit also includes a constant current module 500 for outputting a stable laser drive current. The first connection terminal of the constant current module 500 is connected to the pump source 1, and the second connection terminal of the constant current module 500 is grounded. The third signal terminal of the detection control module 400 is connected to the control terminal of the constant current module 500. When the voltage difference between the filter voltage Vc and the pump drive voltage Vin is zero, the detection control module 400 outputs a precharge shutdown signal to the precharge switch control module 200, and outputs a constant current control signal to the constant current module 500 after delaying the constant current delay time. When the constant current control signal is acquired, the constant current module 500 adjusts the stable operating current and obtains a constant current operating signal. The pump source 1 outputs a stable laser under the constant current operating signal.

[0037] The constant current module 500 is located on the low-voltage side, i.e., between the pump source 1 and ground. In some preferred embodiments, the constant current module 500 typically adopts a negative feedback topology and is directly driven by low-voltage PWM (Pulse Width Modulation) or analog control signals. The constant current module 500 includes a first voltage divider resistor RS1 and a third field-effect transistor Q3. One end of the first voltage divider resistor RS1 is grounded, and the other end of the first voltage divider resistor RS1 is connected to the source of the third field-effect transistor Q3. The gate of the third field-effect transistor Q3 is connected to the third signal terminal of the detection and control module 400, and the drain of the third field-effect transistor Q3 is connected to the pump source 1. The constant current module 500 can be implemented using any existing linear constant current circuit or BUCK (step-down) constant current circuit. It detects the load current through a sampling resistor, compares it with a reference voltage via a precision operational amplifier, and then drives a series regulating transistor, such as a MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) or a bipolar transistor, to dynamically adjust its duty cycle, thereby precisely locking the pump current to a set value. This suppresses current variations caused by voltage fluctuations, temperature drift, or parasitic parameters, ensuring a stable, overshoot-free drive current for the laser diode. It prevents damage to the laser chip due to current surges, significantly reduces noise and ripple in the output optical power, ensures the stability of the laser wavelength and linewidth, and extends the operating life of the pump source 1, achieving high-reliability, high-beam-quality laser output.

[0038] Please see Figures 3 to 5 The precharge switch control module 200 includes: a thermistor RT, a second switch Q2, an eleventh resistor R11, and a twelfth resistor R12. One end of the thermistor RT is connected to the pump drive voltage Vin, and the other end of the thermistor RT is connected to the first connection terminal of the second switch Q2. The second connection terminal of the second switch Q2 is connected to the common connection terminal of the main switch control module 100 and the pump source 1. The control terminal of the second switch Q2 is connected to one end of the eleventh resistor R11 and one end of the twelfth resistor R12. The other end of the eleventh resistor R11 is connected to the second connection terminal of the second switch Q2. The other end of the twelfth resistor R12 is connected to the detection control module 400. When the second switch Q2 is powered on, the thermistor RT is used to divide the input pump drive voltage Vin, reducing the impact caused by the surge current generated by the filter module 300.

[0039] In some preferred embodiments, the main circuit switch control module 100 includes a sixteenth resistor R16, a nineteenth resistor R19, and a first switch Q1. The first terminal of the first switch Q1 is connected to the pump drive voltage Vin, and the second terminal of the first switch Q1 is connected to an external pump source 1 structure. The control terminal of the first switch Q1 is connected to one end of the nineteenth resistor R19, and the other end of the nineteenth resistor R19 is connected to the detection control module 400. When the first switch Q1 is turned on, it outputs a stable operating current to the pump source 1. The second switch Q2 and the first switch Q1 are field-effect transistors, preferably NMOS transistors, but they can also be one or more of electronic components such as power transistors, relays, thyristors, and IGBTs (Insulated Gate Bipolar Transistors). When the voltage difference between the filter voltage and the pump drive voltage is less than the critical voltage value, the gate of the first switch Q1 is connected to the main circuit turn-on signal output by the detection and control module 400, the source and drain of the first switch Q1 are turned on, and the main circuit drive power is output to the filter module 300 and pump source 1 in the subsequent circuit.

[0040] Please refer to the following: Figure 4 and Figure 6 In another preferred embodiment, the main circuit switch control module 100 may include a first relay RLY1, a first freewheeling diode D1, a fourth switch Q4, a first capacitor C1, a fourteenth resistor R14, and a fifteenth resistor R15. The first connection terminal of the first relay RLY1 is connected to the pump drive voltage Vin, and the second connection terminal of the first relay RLY1 is used to connect to an external pump source 1 structure. The first winding terminal of the first relay RLY1 is connected to the operating voltage VDD, and the second winding terminal of the first relay RLY1 is connected to the first connection terminal of the fourth switch Q4. The anode of the first freewheeling diode D1 is connected to the second winding terminal of the first relay RLY1, and the cathode of the first freewheeling diode D1 is connected to the first winding terminal of the first relay RLY1. The second connection terminal of the fourth switch Q4 is grounded. The control terminal of the fourth switch Q4 is connected to one end of the fourteenth resistor R14, and the other end of the fourteenth resistor R14 is connected to the detection and control module 400. One end of the fifteenth resistor R15 and one end of the first capacitor C1 are connected to the common connection terminal of the fourteenth resistor R14 and the fourth switch Q4. The other ends of the first capacitor C1 and the other end of the fifteenth resistor R15 are grounded. Preferably, the fourth switch Q4 can be a transistor.

[0041] Specifically, in standby mode, when the detection control module 400 does not output a main circuit start signal, the fourth switch Q4 remains off, the coil in the first relay RLY1 is not powered, and the first and second connection terminals of the first relay RLY1 are disconnected. The pre-charge switch control module 200 then conducts and outputs a pre-charge working voltage to slowly charge the electrolytic capacitor C0 in the filter module 300. When the electrolytic capacitor C0 is pre-charged to near the filter voltage Vc and the pump drive voltage Vin, the detection control module 400 outputs a main circuit start signal, the transistor turns on, and the working voltage VDD powers the coil of the first relay RLY1. The contacts between the first and second connection terminals of the first relay RLY1 close, and the pump drive voltage Vin connects to the pump source 1 through the first relay RLY1, thus powering on the main circuit switch control module 100.

[0042] The detection and control module 400 includes a control chip U1. The control terminal of the control chip U1 receives an on-signal. The first signal terminal of the control chip U1 is connected to the control terminal of the main circuit switch control module 100, the second signal terminal of the control chip U1 is connected to the control terminal of the pre-charge switch control module 200, and the third signal terminal of the control chip U1 is connected to the control terminal of the constant current module 500. In this embodiment, the control chip U1 is preferably an MSPMOL1105, but it can also be implemented using other compilable processors or other types of microcontroller chips; no limitation is made here. The control chip U1 may also be provided with several voltage detection terminals. Specifically, the first voltage detection terminal is connected to the pump drive voltage Vin for acquiring the pump drive voltage Vin. The second voltage detection terminal is connected to the common terminal of the filter module 300 and the pre-charge switch control module 200 for acquiring the filtered voltage Vc across the filter module 300.

[0043] Please see Figure 5In some preferred embodiments, the detection control module 400 further includes a first isolation unit 410 and a second isolation unit 420. The control terminal of the first isolation unit 410 is connected to the first signal terminal of the detection control module 400, and the signal output terminal of the first isolation unit 410 is connected to the main circuit switch control module 100. When the voltage difference between the filter voltage Vc and the pump drive voltage Vin is less than a critical voltage value, the detection control module 400 outputs a main circuit command signal to the first isolation unit 410. When the first isolation unit 410 acquires the main circuit command signal, the voltage input terminal of the first isolation unit 410 and the signal output terminal of the first isolation unit 410 are connected, and a main circuit start signal is output to... The main circuit switch control module 100 is turned on when the main circuit start signal is acquired; the control terminal of the second isolation unit 420 is connected to the second signal terminal of the detection control module 400, and the signal output terminal of the second isolation unit 420 is connected to the precharge switch control module 200; when the voltage difference between the filter voltage Vc and the pump drive voltage Vin is greater than the critical voltage value, the detection control module 400 outputs a precharge command signal to the second isolation unit 420; when the precharge start signal is acquired, the second isolation unit 420 outputs a precharge start signal to the precharge switch control module 200; and the precharge switch control module 200 is turned on when the precharge start signal is acquired.

[0044] Specifically, the first isolation unit 410 and the second isolation unit 420 are respectively disposed between the detection control module 400 and the main circuit switch control module 100, and between the detection control module 400 and the precharge switch control module 200. The first isolation unit 410 includes a second optocoupler U3 and a second eleventh resistor R21. One end of the second eleventh resistor R21 is connected to the first signal terminal of the detection control module 400, and the other end of the second eleventh resistor R21 is connected to the transmitting anode terminal of the second optocoupler U3. The transmitting cathode terminal of the second optocoupler U3 is grounded. The first receiving terminal of the second optocoupler U3 is connected to the driver. The DC voltage DRV_VCC is used. The second receiving end of the second optocoupler U3 is connected to the main circuit switch control module 100. The second isolation unit 420 includes a first optocoupler U2 and a thirteenth resistor R13. One end of the thirteenth resistor R13 is connected to the second signal terminal of the detection control module 400, and the other end of the thirteenth resistor R13 is connected to the transmitting anode of the first optocoupler U2. The transmitting cathode of the first optocoupler U2 is grounded. The first receiving end of the first optocoupler U2 is connected to the driving DC voltage DRV_VCC, and the second receiving end of the first optocoupler U2 is connected to the precharge switch control module 200. In this embodiment, optocoupler isolation devices are respectively provided in the first isolation unit 410 and the second isolation unit 420. By setting the first optocoupler U2 and the second optocoupler U3, electrical isolation between the detection control module 400 and the main circuit switch control module 100 and the precharge switch control module 200 is achieved, protecting the safety of the switch control circuit while improving the overall communication efficiency and reliability.

[0045] The control logic of the circuit described in this invention is as follows: In terms of timing, the signal timing of the laser power switch control circuit can be divided into the following... Figure 7 The following are several time intervals, among which: In the first time period T1, an activation signal is input from the outside. The detection control module 400 chip receives the activation signal and outputs a precharge start signal to the precharge switch control module 200.

[0046] During the second time period T2, the second switch Q2 of the precharge switch control module 200 is saturated and turned on after receiving the turn-on signal. The pump drive voltage Vin charges the electrolytic capacitor C0 through the thermistor RT and the second switch Q2. At this time, the inrush current Ic of the electrolytic capacitor C0 is Ic=Vin / RT. The inrush current at the moment the switch is turned on is effectively suppressed, reducing the instantaneous inrush current of the second switch Q2 and ensuring the stable operation of the second switch Q2.

[0047] During the third time period T3, the detection control module 400 detects the voltage of the electrolytic capacitor C0 and the pump drive voltage Vin. When the voltage difference between the filter voltage Vc and the pump drive voltage Vin is less than or equal to 5V, it gives the first switch Q1 of the main switch control module 100 an on signal, and the first switch Q1 is saturated and turned on. At this time, because the voltage difference between the filter voltage Vc and the pump drive voltage Vin across the electrolytic capacitor C0 is less than or equal to 5V, the inrush current through the first switch Q1 of the main switch control module 100 will be very low, ensuring the stable operation of the main switch control module 100.

[0048] In the fourth time period T4, after the first switch Q1 of the main circuit switch control module 100 is saturated and turned on, when the detection control module 400 detects the filter voltage Vc=Vin, it sends a precharge turn-off signal to the second switch Q2 of the precharge switch control module 200. After receiving the turn-off signal, the second switch Q2 of the precharge switch control module 200 turns off, and the precharge switch control module 200 turns off.

[0049] In the fifth time period T5, which serves as a constant current delay time, the detection and control module 400 sends a working signal to the third field-effect transistor Q3 in the constant current module 500, and the constant current module 500 is turned on and starts working. The pump drive voltage Vin supplies power to the electrolytic capacitor C0 through the first switching transistor Q1. The pump source 1 draws power from the filter electrolytic capacitor C0 over a short distance, and then returns to the negative terminal of the electrolytic capacitor C0 through the constant current module 500, so that the pump source 1 obtains a stable working current.

[0050] Subsequently, during the normal working period, pump source 1 outputs a stable laser.

[0051] During the sixth time period T6, a shutdown signal is sent to the control terminal SW of the detection control module 400, and the first switch Q1 of the main switch control module 100 achieves zero-voltage shutdown. The first switch Q1 is turned off when the voltage difference across it is 0V, thus achieving zero-voltage shutdown. This eliminates shutdown losses, avoids overheating of the switch, and reduces switching peak voltage. Furthermore, the first switch Q1 does not require extensive heat dissipation, allowing the use of a MOSFET with a smaller voltage rating, thereby reducing circuit material costs.

[0052] In the seventh time period T7, after the first switch Q1 of the main circuit switch control module 100 is turned off, the detection control module gives a turn-off signal to the constant current module 500, and the constant current module 500 shuts down.

[0053] It should be noted that when the circuit is turned off, the main circuit switch control module 100 and the pre-charge switch control module 200 can be turned off sequentially or simultaneously. However, if they are turned off simultaneously, the electrolytic capacitor C0 loses its discharge circuit, and the electrical energy stored in it can only be discharged through the ESR (Equivalent Series Resistance) of the electrolytic capacitor C0. The electrical energy stored in the electrolytic capacitor C0 will be retained for a long time. In this invention, it is preferable to turn off the switch module first and then the constant current module 500. This means that the power supply to the electrolytic capacitor C0 is first cut off, the electrical energy stored in the electrolytic capacitor C0 is discharged through the constant current module 500, and after the electrical energy stored in the electrolytic capacitor C0 is released, the constant current module 500 is then turned off. This eliminates the need to add a circuit to discharge the electrolytic capacitor C0, thereby further simplifying the power switch control circuit.

[0054] Based on the same inventive concept, please refer to Figure 3 and Figure 4 The present invention also provides a control system, which includes the laser power switch control circuit described above, a host controller (not shown in the figure), and a pump source 1; wherein, the host controller is connected to the control terminal of the detection control module and is used to output an on-signal to the laser power switch control circuit; the laser power switch control circuit is connected to the pump source and is connected to a pump drive voltage, and is used to output a stable operating current to the pump source after detecting the on-signal; the pump source outputs a stable laser according to the stable operating current. It should be noted that the control system may include one or more laser power switch control circuits and a host controller, and may also connect multiple pump sources, that is, at least one circuit may have a laser power switch control circuit and a corresponding pump source arranged in parallel, which can be used to realize the setting of multiple parallel constant current sources and pump sources. For the specific implementation method, please refer to the embodiment of the laser power switch control circuit described above, which will not be repeated here.

[0055] like Figure 8 As shown, based on the same inventive concept, the present invention also provides a control method for controlling the laser power switch control circuit described above, the steps of which include: S100. In the first time period, the activation signal is connected to the detection control module, and the detection control module is controlled to output a precharge activation signal to the precharge switch control module when the voltage difference between the filter voltage and the pump drive voltage is greater than the critical voltage value. After the system is powered on, an activation signal is sent to the detection and control module. This module samples the filter voltage and pump drive voltage in real time and calculates the voltage difference between them. When the voltage difference is determined to be greater than a preset critical voltage value, the detection and control module immediately outputs a high-level pre-charge activation signal to the pre-charge switch control module. In the initial stage, when the electrolytic capacitor voltage is much lower than the input voltage, the main circuit is not directly connected; instead, the pre-charge switch control module is activated first to prevent the main circuit containing the main circuit switch control module from experiencing a large inrush current.

[0056] S200, In the second time period, the precharge switch control module is saturated and turned on after acquiring the precharge start signal, and charges the filter module; After receiving the precharge start signal from the detection control module, the second switch Q2 of the precharge switch control module 200 enters a saturated conduction state. At this time, the pump drive voltage Vin charges the electrolytic capacitor of the filter module through the thermistor RT connected in series in the circuit and the saturated conduction second switch. The charging current is limited to Ic = Vin / RT. Since the thermistor has a high resistance in the cold state, the high resistance characteristic in the cold state is used to limit the charging current of the electrolytic capacitor within a safe range, allowing the capacitor voltage to rise slowly from zero, while providing low-stress operating conditions for the second switch Q2 of the precharge switch control module 200. This effectively suppresses instantaneous inrush current.

[0057] S300. In the third time period, when the voltage difference between the filter voltage and the pump drive voltage is less than the critical voltage value, the detection control module outputs a main circuit start signal to the main circuit switch control module. The main circuit switch control module turns on and starts working when it receives the main circuit start signal.

[0058] The detection and control module continuously monitors the voltage difference between the filter voltage and the pump drive voltage. When the voltage difference gradually decreases from above a critical value to below or equal to the critical voltage value (i.e., the difference between Vc and Vin ≤ 5V), the detection and control module outputs a main circuit start signal to the main circuit switch control module. Upon receiving the signal, the main circuit switch control module saturates and conducts, allowing the pump drive voltage to directly supply power to the laser pump source through the first switching transistor. Simultaneously, the electrolytic capacitor has completed pre-charging, and its voltage is close to the input voltage. This ensures that the electrolytic capacitor is pre-charged to a level close to the input voltage before the main switch is turned on, significantly reducing the voltage difference across the main switch.

[0059] A further provision of the present invention, wherein, in the third time period, the detection control module outputs a main circuit start signal to the main circuit switch control module when the voltage difference between the filter voltage and the pump drive voltage is less than a critical voltage value, and the main circuit switch control module turns on and starts working upon receiving the main circuit start signal, further includes: S400. In the fourth time period, when the voltage difference between the filter voltage and the pump drive voltage is zero, the detection control module outputs a pre-charge shutdown signal to the pre-charge switch control module; the pre-charge switch control module shuts down when it receives the pre-charge shutdown signal. Specifically, when the voltage difference between the filter voltage and the pump drive voltage is zero, that is, when the filter voltage and the pump drive voltage are approximately equal, the main circuit switch control module is saturated and turned on. At this time, the precharge switch control module can be turned off, and the filter module can stably obtain power only through the main circuit switch control module. At this time, there is no voltage difference across the precharge switch control module, and the precharge switch control module achieves zero-voltage turn-off, reducing turn-off losses.

[0060] S500. In the fifth time period, the detection and control module outputs a constant current control signal to the constant current module. When the constant current module acquires the constant current control signal, it starts to adjust the stable operating current and obtains a constant current operating signal. The pump source outputs a stable laser under the constant current operating signal. The constant current module is powered on later in the fifth phase to prevent surge current during power-on from passing through the pump source and causing it to malfunction and briefly emit laser light. In the fifth phase, the pump drive voltage supplies power to the electrolytic capacitor through the main switch control module. The pump source draws power from the electrolytic capacitor over a short distance and then returns it to the negative terminal of the electrolytic capacitor via the constant current module, thus ensuring that the pump source obtains a stable operating current and outputs a stable laser.

[0061] S600. During the sixth time period, when the detection control module receives the shutdown signal, it outputs a main road shutdown signal to the main road switch control module, and the main road switch control module shuts down when it receives the main road shutdown signal. S700. In the seventh time period, the detection and control module outputs a constant current shutdown signal to the constant current module, and the constant current module shuts down when it receives the constant current shutdown signal.

[0062] Specifically, the laser power switch control circuit of this invention is also used to control the pump source to stop working and shut down after the pump source has finished operating. In some preferred embodiments, by first turning off the main circuit switch module and then turning off the constant current module, the power supply to the electrolytic capacitor is cut off, and the electrical energy stored in the electrolytic capacitor can be discharged through the constant current module. After the electrical energy stored in the electrolytic capacitor is released, the constant current module is then turned off, eliminating the need for additional circuitry to discharge the electrolytic capacitor and preventing the constant current module from being mis-energized under abnormal conditions.

[0063] This invention provides a laser power switch control circuit, a control system, and a control method, the advantages of which are: A pre-charge switch control module was installed to solve the risk of generating an uncontrollable huge inrush current that could damage the main circuit switch control module when the electrolytic capacitor is in a short-circuit state at the moment the switch is turned on.

[0064] A detection and control module was set up, and control logic methods were added to solve the working timing of the entire control system, ensuring that the pump source obtains stable and smooth current and outputs stable laser when it is working.

[0065] By placing the electrolytic capacitor of the working system at the rear end of the main switch control module, the pump source can obtain current from the electrolytic capacitor in the shortest distance when working, reducing the generation of ripple current and stabilizing the laser output. At the same time, a pre-charge switch control module is set up. When the electrolytic capacitor is charged through the pre-charge switch control module at the moment of activation, the uncontrollable huge inrush current generated is reduced, and the risk of damage to the main switch control module is reduced.

[0066] When the laser power switch control circuit is powered on, if the voltage difference between the filter voltage and the pump drive voltage is greater than the critical voltage value, the pre-charge switch control module is activated to pre-charge the filter module, preventing the filter module from being damaged by overcurrent or overpower due to the huge inrush current generated by the power-on impact.

[0067] It should be understood that the application of the present invention is not limited to the examples above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A laser power switch control circuit, characterized in that, Used to control the operation of the pump source, including: The main circuit switch control module is connected to the pump drive voltage and is connected to the power input terminal of the pump source, and is used to output the main circuit drive power when it is turned on. The precharge switch control module is connected to the pump drive voltage and is connected to the common terminal of the main switch control module and the pump source, and is used to output the precharge working voltage when it is turned on. The filter module has its positive terminal connected to the common terminal of the main circuit switch control module and the precharge switch control module, and its negative terminal grounded, for charging according to the precharge working voltage and the main circuit drive power supply. The detection control module has a control terminal that receives an activation signal, a first signal terminal that is connected to the control terminal of the main circuit switch control module, and a second signal terminal that is connected to the control terminal of the precharge switch control module. The detection and control module powers on upon detecting an on-signal and detects the filter voltage of the filter module. When the voltage difference between the filter voltage and the pump drive voltage exceeds a critical voltage value, it outputs a pre-charge on signal to the pre-charge switch control module, which controls the pre-charge switch control module to turn on. Conversely, when the voltage difference between the filter voltage and the pump drive voltage is less than a critical voltage value, it outputs a main circuit on signal to the main circuit switch control module, which controls the main circuit switch control module to turn on. The filter module outputs a stable operating current to the pump source when the main circuit switch control module is on. The precharge switch control module includes: a thermistor, a second switch, an eleventh resistor, and a twelfth resistor. One end of the thermistor is connected to the pump drive voltage, and the other end of the thermistor is connected to the first connection terminal of the second switch. The second connection terminal of the second switch is connected to the common connection terminal of the main circuit switch control module and the pump source. The control terminal of the second switch is connected to one end of the eleventh resistor and one end of the twelfth resistor. The other end of the eleventh resistor is connected to the second connection terminal of the second switch. The other end of the twelfth resistor is connected to the detection control module.

2. The laser power switch control circuit according to claim 1, characterized in that, It also includes a constant current module, the first connection terminal of which is connected to the pump source, and the second connection terminal of which is grounded; the third signal terminal of the detection and control module is connected to the control terminal of the constant current module, the detection and control module outputs a precharge shutdown signal to the precharge switch control module when the voltage difference between the filter voltage and the pump drive voltage is zero, and outputs a constant current control signal to the constant current module after a delay of the constant current delay time; the constant current module adjusts the stable operating current to obtain a constant current operating signal when it acquires the constant current control signal; the pump source outputs a stable laser under the constant current operating signal.

3. The laser power switch control circuit according to claim 2, characterized in that, The constant current module includes a first voltage divider resistor and a third field-effect transistor. One end of the first voltage divider resistor is grounded, and the other end of the first voltage divider resistor is connected to the source of the third field-effect transistor. The gate of the third field-effect transistor is connected to the third signal terminal of the detection and control module, and the drain of the third field-effect transistor is connected to the pump source.

4. The laser power switch control circuit according to claim 1, characterized in that, The filtering module includes an electrolytic capacitor. The anode of the electrolytic capacitor is connected to the common terminal of the pump source, the main circuit switch control module, and the precharge switch control module, and the cathode of the electrolytic capacitor is grounded.

5. The laser power switch control circuit according to claim 2, characterized in that, The detection and control module includes a control chip. The control terminal of the control chip receives an activation signal. The first signal terminal of the control chip is connected to the control terminal of the main circuit switch control module. The second signal terminal of the control chip is connected to the control terminal of the precharge switch control module. The third signal terminal of the control chip is connected to the control terminal of the constant current module.

6. The laser power switch control circuit according to claim 5, characterized in that, The detection and control module further includes a first isolation unit and a second isolation unit. The control terminal of the first isolation unit is connected to the first signal terminal of the detection and control module, and the signal output terminal of the first isolation unit is connected to the main circuit switch control module. When the voltage difference between the filter voltage and the pump drive voltage is less than a critical voltage value, the detection and control module outputs a main circuit command signal to the first isolation unit. When the first isolation unit acquires the main circuit command signal, the voltage input terminal of the first isolation unit and the signal output terminal of the first isolation unit are connected, and a main circuit start signal is output to the main circuit switch control module. The main circuit switch control module is turned on when it acquires the main circuit start signal. The control terminal of the second isolation unit is connected to the second signal terminal of the detection control module, and the signal output terminal of the second isolation unit is connected to the precharge switch control module. When the voltage difference between the filter voltage and the pump drive voltage is greater than the critical voltage value, the detection control module outputs a precharge command signal to the second isolation unit. When the second isolation unit acquires the precharge command signal, it outputs a precharge start signal to the precharge switch control module. When the precharge start signal is acquired, the precharge switch control module is turned on.

7. A control system, characterized in that, Includes the laser power switch control circuit, host computer, and pump source as described in any one of claims 1 to 6; wherein, The host controller is connected to the control terminal of the detection and control module and is used to output an activation signal to the laser power switch control circuit. The laser power switch control circuit is connected to the pump source and is connected to the pump drive voltage. It is used to output a stable operating current to the pump source after detecting the turn-on signal. The pump source outputs a stable laser according to the stable operating current.

8. A control method, characterized in that, For controlling the laser power switch control circuit as described in any one of claims 1 to 6, the steps include: In the first time period, an activation signal is sent to the detection and control module, which then outputs a pre-charge activation signal to the pre-charge switch control module when the voltage difference between the filter voltage and the pump drive voltage exceeds a critical voltage value; the pre-charge switch control module is then activated and begins operation. In the second time period, the precharge switch control module activates to charge the filter module after receiving the precharge start signal. During the third time period, when the voltage difference between the filter voltage and the pump drive voltage is less than the critical voltage value, the detection control module outputs a main circuit start signal to the main circuit switch control module. The main circuit switch control module turns on and starts working when it receives the main circuit start signal.

9. The control method according to claim 8, characterized in that, In the third time period, when the voltage difference between the filter voltage and the pump drive voltage is less than a critical voltage value, the detection control module outputs a main circuit start signal to the main circuit switch control module. After the main circuit switch control module receives the main circuit start signal and begins operation, the following steps are also included: In the fourth time period, the detection and control module outputs a pre-charge shutdown signal to the pre-charge switch control module when the voltage difference between the filter voltage and the pump drive voltage is zero; the pre-charge switch control module shuts down when it receives the pre-charge shutdown signal. In the fifth time period, the detection and control module outputs a constant current control signal to the constant current module. When the constant current module acquires the constant current control signal, it starts to adjust the stable operating current and obtains a constant current operating signal. The pump source outputs a stable laser under the constant current operating signal. During the sixth time period, when the detection and control module receives the shutdown signal, it outputs a main road shutdown signal to the main road switch control module, and the main road switch control module shuts down when it receives the main road shutdown signal. During the seventh time period, the detection and control module outputs a constant current shutdown signal to the constant current module, and the constant current module shuts down when it receives the constant current shutdown signal.

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