Protection circuit of laser and laser therapeutic instrument

Abstract

The utility model discloses a protection circuit of a laser and a laser therapeutic instrument, relates to the field of electronic circuits, and solves the problem that an open circuit or a short circuit cannot be found in time in the use process of the laser. According to the laser driving circuit, the output signal of the driving transistor in the laser driving circuit is detected, the window comparison circuit detects the transistor output end signal in the laser driving circuit, and the window comparison circuit outputs the corresponding voltage signal according to the output voltage state; and a high-level signal is output to control the switch control circuit to act to turn off the laser driving circuit, so that timely turn-off when the circuit is abnormal is realized, and the problem that open circuit or short circuit cannot be found in time in the use process of the laser is solved.

Description

Technical Field

[0001] The utility model relates to the field of electronic circuits, in particular to a laser protection circuit and a laser therapeutic apparatus. Background Art

[0002] Lasers are usually driven by Metal-Oxide-Semiconductor Field-Effect Transistor (MOS), which is used as a switching element in the laser drive circuit. The drive circuit controls the output of the laser by controlling the on and off states of the MOS.

[0003] During the use of the laser, the connecting cable may fall off, or it may break down and cause the laser to be in an open circuit state, or the positive and negative poles may be short-circuited for some reason, resulting in the laser driver driving the laser normally, but the laser does not output laser light. The operator may mistakenly believe that the laser is in normal working condition, which may lead to safety risks.

[0004] It can be seen that how to solve the problem of not being able to promptly detect an open circuit or short circuit during the use of a laser is a technical problem that needs to be urgently solved by people in this field. Utility Model Content

[0005] The utility model aims to provide a laser protection circuit and a laser therapeutic apparatus, so as to solve the problem that an open circuit or a short circuit cannot be found in time during the use of the laser.

[0006] In order to solve the above technical problems, the utility model provides a laser protection circuit, which is applied to a laser driving circuit, comprising: a first transistor, a first diode, and a laser diode; the control end of the first transistor is connected to the control signal output end of the controller, the output end of the first transistor is connected to the positive electrode of the first diode and the negative electrode of the laser diode, the input end of the first transistor is grounded, and the negative electrode of the first diode is connected to the positive electrode of the laser diode and the power supply end;

[0007] It also includes: a window comparison circuit and a switch control circuit; the input end of the window comparison circuit is connected to the output end of the first transistor, and the output end of the window comparison circuit is connected to the input end of the switch control circuit;

[0008] The switch control circuit includes: a first resistor, a second resistor, a first capacitor, and a first transistor;

[0009] The input end of the switch control circuit is connected to the base of the first transistor through a first resistor and a second resistor connected in parallel, the base of the first transistor is connected to the emitter of the first transistor through the second resistor, and the collector of the first transistor is connected to the control end of the first transistor.

[0010] Optionally, in the above laser protection circuit, the output end of the window comparison circuit is connected to the voltage detection end of the controller.

[0011] Optionally, the above laser protection circuit further includes: a signal amplification circuit;

[0012] The control signal output terminal of the controller is connected to the control terminal of the first transistor through a signal amplifying circuit.

[0013] Optionally, in the protection circuit of the above laser, the signal amplification circuit includes: a dual-channel operational amplifier, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, and a second capacitor;

[0014] The in-phase end of the A channel of the dual-channel operational amplifier is connected to the control signal output end of the controller, the inverting end of the A channel of the dual-channel operational amplifier is connected to the output end of the B channel of the dual-channel operational amplifier and the first end of the second capacitor through the third resistor, the second end of the second capacitor is connected to the output end of the A channel of the dual-channel operational amplifier and the control end of the first transistor, the output end of the B channel of the dual-channel operational amplifier is connected to the inverting end of the B channel of the dual-channel operational amplifier and the first end of the fifth resistor through the seventh resistor, the in-phase end of the B channel of the dual-channel operational amplifier is connected to the input end of the first transistor and the first end of the sixth resistor through the fourth resistor, and the second end of the fifth resistor is connected to the second end of the sixth resistor and the ground end.

[0015] Optionally, in the protection circuit of the above laser, the window comparison circuit includes: a second operational amplifier, a third operational amplifier, an eighth resistor, a ninth resistor, a tenth resistor, an eleventh resistor, a twelfth resistor, a second diode, a third diode, and a fourth diode;

[0016] The input end of the window comparison circuit is connected to the anode of the second diode, the cathode of the second diode is connected to the first end of the eighth resistor, the non-inverting end of the second operational amplifier, and the inverting end of the third operational amplifier, and the second end of the eighth resistor is grounded; the inverting end of the second operational amplifier is connected to the power supply through the ninth resistor and to the ground through the tenth resistor; the non-inverting end of the third operational amplifier is connected to the power supply through the eleventh resistor and to the ground through the twelfth resistor; the output end of the second operational amplifier is connected to the anode of the third diode, the output end of the third operational amplifier is connected to the anode of the fourth diode, and the cathode of the third diode and the cathode of the fourth diode are connected to the output end of the window comparison circuit.

[0017] Optionally, in the above laser protection circuit, the window comparison circuit further includes: a thirteenth resistor and a fifth diode;

[0018] A first end of the thirteenth resistor is connected to the cathode of the third diode, a second end of the thirteenth resistor is connected to the cathode of the fifth diode and the output end of the window comparison circuit, and an anode of the fifth diode is grounded.

[0019] Optionally, in the above laser protection circuit, the fifth diode is a voltage regulator diode.

[0020] Optionally, in the above laser protection circuit, the first transistor is an N-type MOS transistor.

[0021] Optionally, in the above laser protection circuit, the dual-channel operational amplifier is ADA4522-2ARZ.

[0022] In order to solve the above technical problems, the utility model also provides a laser therapeutic apparatus, including the above laser protection circuit.

[0023] The utility model provides a laser protection circuit, which is applied to a laser driving circuit and comprises: a first transistor, a first diode and a laser diode; the control end of the first transistor is connected to the control signal output end of a controller, the output end of the first transistor is connected to the positive electrode of the first diode and the negative electrode of the laser diode, the input end of the first transistor is grounded, and the negative electrode of the first diode is connected to the positive electrode and the power supply end of the laser diode; and further comprises: a window comparison circuit and a switch control circuit; the input end of the window comparison circuit is connected to the output end of the first transistor, and the output end of the window comparison circuit is connected to the input end of the switch control circuit; the switch control circuit comprises: a first resistor, a second resistor, a first capacitor and a first triode; the input end of the switch control circuit is connected to the base of the first triode through the first resistor and the second resistor connected in parallel, the base of the first triode is connected to the emitter of the first triode through the second resistor, and the collector of the first triode is connected to the control end of the first transistor. The window comparison circuit detects the signal at the output end of the transistor in the laser driving circuit. When the state of the circuit to which it is connected is abnormal, it outputs a high-level signal to control the switch control circuit to shut down the laser driving circuit, thereby achieving timely shutdown when the circuit is abnormal, solving the problem of not being able to detect open circuit or short circuit in time during the use of the laser.

[0024] In addition, the utility model also provides a laser therapeutic device, including the protection circuit of the above laser, and the effect is the same as above. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present utility model, the following is a brief introduction to the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0026] Figure 1 A circuit diagram of a laser protection circuit provided in an embodiment of the present application. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of them. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the protection scope of the utility model.

[0028] The core of the utility model is to provide a laser protection circuit and a laser therapeutic apparatus.

[0029] In order to enable those skilled in the art to better understand the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0030] When the laser connection cable falls off or breaks down, causing the laser to be in an open circuit state, the laser cannot work properly and cannot output laser light. This may be due to the inability to transmit the signal to the laser or the laser cannot receive sufficient power supply. If the laser is in a positive and negative short-circuited state, the laser will also be unable to output laser light. This may cause the laser to malfunction or excessive current to flow through the laser, causing it to be damaged. The failure of the laser to output laser light means that the expected power and performance cannot be achieved, which may cause shutdowns or delays in the production line or workflow. When the laser does not output laser light, it may cause misjudgment or misoperation, which may bring safety risks and adversely affect applications, production and safety.

[0031] In order to solve the above problems, an embodiment of the present application provides a protection circuit for a laser, which is applied to a laser driving circuit, including: a first transistor Q1, a first diode D1, and a laser diode J1; the control end of the first transistor Q1 is connected to the control signal output end of the controller, the output end of the first transistor Q1 is connected to the anode of the first diode D1 and the cathode of the laser diode J1, the input end of the first transistor Q1 is grounded, and the cathode of the first diode D1 is connected to the anode of the laser diode J1 and the power supply end;

[0032] Figure 1 A circuit diagram of a laser protection circuit provided in an embodiment of the present application, such as Figure 1 As shown, it also includes: a window comparison circuit and a switch control circuit; the input end of the window comparison circuit is connected to the output end of the first transistor Q1, and the output end of the window comparison circuit is connected to the input end of the switch control circuit;

[0033] The switch control circuit includes: a first resistor R1, a second resistor R2, a first capacitor C1, and a first transistor Q2;

[0034] The input end of the switch control circuit is connected to the base of the first transistor Q2 through the first resistor R1 and the second resistor R2 connected in parallel, the base of the first transistor Q2 and the emitter of the first transistor Q2 are connected through the second resistor R2, and the collector of the first transistor Q2 is connected to the control end of the first transistor Q1.

[0035] In the laser driving circuit, the cathode of the first diode D1 is connected to the anode of the laser diode J1, and the anode of the first diode D1 is connected to the cathode of the laser diode J1, which is used to prevent the reverse voltage generated by the lead inductance of the laser diode J1 when the circuit is in the limit switch state, thereby protecting the laser diode J1. Specifically, the first transistor Q1 is an N-type MOS tube. The laser driving circuit usually needs to be driven by a MOS tube to control the current of the laser diode. The MOS driving circuit can control the brightness and working state of the laser diode by adjusting the voltage.

[0036] In this application, laser diode is used to represent a laser. In specific implementation applications, the laser may also be in other forms.

[0037] The window comparison circuit is a common electronic circuit used to compare the magnitude relationship between the input signal and the reference signal. The principle of the window comparison circuit is that when the voltage of the input signal exceeds the upper limit of the reference signal, the comparator outputs a high level; when the voltage of the input signal is lower than the lower limit of the reference signal, the comparator outputs a low level; and between the upper and lower limits of the reference signal, the comparator output state is uncertain, which may be a high level or a low level. Since when the laser is working normally, the detection signal VLD at the output end of the first transistor Q1 is approximately 3V, when the circuit is open, the detection signal VLD is 0V, and when the circuit is short, the detection signal VLD is approximately 5V, then the voltage of the detection signal VLD at the output end of the first transistor Q1 can be detected by the window comparison circuit to determine whether an open circuit or a short circuit occurs. The embodiment of the present application does not limit the specific design scheme of the window comparison circuit. It is necessary to select an appropriate comparator and a reference voltage source according to the requirements of the specific application, and perform appropriate adjustments and calibrations to ensure accurate comparison results and reliable operation.

[0038] Specifically, the window comparison circuit outputs a high level signal when it is open or short-circuited, and outputs a low level signal when it is normal.

[0039] The detection signal VLD (the output signal of the first transistor Q1) in the laser driving circuit is sent to the window comparison circuit, and the detection signal outputs a state signal VCTL through the window comparison circuit. The output state signal VCTL is sent to the input end of the switch control circuit. The switch control circuit can control the switch state of the switch control circuit according to the VCTL state signal, and further control the current output of the first transistor Q1 in the laser driving circuit.

[0040] When the state signal VCTL is at a low level, the first transistor Q2 is in a cut-off state, so the laser drive current enable signal LD_EN is not pulled low. When the state signal VCTL is at a high level, the first transistor Q2 is in a conduction state, so the laser drive current enable signal LD_EN is pulled low, so that the control terminal voltage of the first transistor Q1 is 0, and then the drain-source of the first transistor Q1 is cut off, and the laser diode J1 does not output laser.

[0041] The laser protection circuit provided by the present embodiment is applied to a laser driving circuit, and includes: a first transistor Q1, a first diode D1, and a laser diode J1; the control end of the first transistor Q1 is connected to the control signal output end of the controller, the output end of the first transistor Q1 is connected to the positive electrode of the first diode D1 and the negative electrode of the laser diode J1, the input end of the first transistor Q1 is grounded, and the negative electrode of the first diode D1 is connected to the positive electrode and the power supply end of the laser diode J1; it also includes: a window comparison circuit and a switch control circuit; the input end of the window comparison circuit is connected to the output end of the first transistor Q1, and the output end of the window comparison circuit is connected to the input end of the switch control circuit; the switch control circuit includes: a first resistor R1, a second resistor R2, a first capacitor C1, and a first triode Q2; the input end of the switch control circuit is connected to the base of the first triode Q2 through the first resistor R1 and the second resistor R2 connected in parallel, the base of the first triode Q2 is connected to the emitter of the first triode Q2 through the second resistor R2, and the collector of the first triode Q2 is connected to the control end of the first transistor Q1. The window comparison circuit detects the signal at the output end of the transistor in the laser driving circuit. When the state of the circuit to which it is connected is abnormal, it outputs a high-level signal to control the switch control circuit to shut down the laser driving circuit, thereby achieving timely shutdown when the circuit is abnormal, solving the problem of not being able to detect open circuit or short circuit in time during the use of the laser.

[0042] In a specific embodiment, in the protection circuit of the laser, the output end of the window comparison circuit is connected to the voltage detection end of the controller.

[0043] The output status signal VCTL of the window comparison circuit is sent to the controller to inform the laser access circuit of abnormal status, which can be used to remind the user or stop the output of the control signal.

[0044] In a specific embodiment, the protection circuit of the laser further includes: a signal amplification circuit;

[0045] The control signal output terminal of the controller is connected to the control terminal of the first transistor Q1 through a signal amplifying circuit.

[0046] Lasers usually require a higher current or voltage to stimulate the generation of lasers. However, the current or voltage of the control signal usually output by the controller is small and cannot directly meet the driving requirements of the laser. Therefore, it is necessary to amplify the current or voltage of the control signal to reach the driving level required by the laser.

[0047] The present application amplifies the control signal of the controller through a signal amplification circuit and then inputs it into the laser driving circuit to ensure that the laser driving circuit can provide sufficient current or voltage to drive the laser diode J1, thereby improving the stability, reliability and performance of the laser.

[0048] In a specific embodiment, in the protection circuit of the laser shown, the signal amplification circuit includes: a dual-channel operational amplifier, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, and a second capacitor C2;

[0049] The non-inverting end of the A channel U1A of the dual-channel operational amplifier is connected to the control signal output end of the controller, the inverting end of the A channel U1A of the dual-channel operational amplifier is connected to the output end of the B channel U1B of the dual-channel operational amplifier and the first end of the second capacitor C2 through the third resistor R3, the second end of the second capacitor C2 is connected to the output end of the A channel U1A of the dual-channel operational amplifier and the control end of the first transistor Q1, the output end of the B channel U1B of the dual-channel operational amplifier is connected to the inverting end of the B channel U1B of the dual-channel operational amplifier and the first end of the fifth resistor R5 through the seventh resistor R7, the non-inverting end of the B channel U1B of the dual-channel operational amplifier is connected to the input end of the first transistor Q1 and the first end of the sixth resistor R6 through the fourth resistor R4, and the second end of the fifth resistor R5 is connected to the second end of the sixth resistor R6 and the ground end.

[0050] The signal amplification circuit is a voltage-controlled constant current source circuit. The control voltage signal CTL_CW is input into the positive input terminal of the A channel U1A of the dual-channel operational amplifier. The difference between the positive input terminal and the reverse input terminal of the A channel U1A of the dual-channel operational amplifier is positive, so the output terminal of the A channel U1A of the dual-channel operational amplifier outputs a larger voltage, thereby turning on the drain-source electrode of the first transistor Q1 to form the driving current of the laser. As the laser driving current continues to increase, the voltage value of the sampling resistor (the sixth resistor R6) will increase. After the same-direction proportional amplification of the B channel U1B of the dual-channel operational amplifier, the voltage value of the output terminal of the B channel U1B of the dual-channel operational amplifier will approach the positive input terminal of the A channel U1A of the dual-channel operational amplifier, that is, the control voltage signal CTL_CW. As the difference between the positive input and the negative input of the A channel U1A of the dual-channel operational amplifier decreases, the output voltage of the output of the A channel U1A of the dual-channel operational amplifier will decrease, thereby reducing the gate-source voltage of the first transistor Q1, slowing down the increase in the laser drive current. Eventually, the difference between the positive input and the negative input of the A channel U1A of the dual-channel operational amplifier approaches 0, the gate-source voltage of the first transistor Q1 approaches stability, and the output current of the drive tube Q2 approaches a stable value. This circuit achieves adjustable laser power by controlling the voltage signal to drive the current of the laser. Specifically, the dual-channel operational amplifier is ADA4522-2ARZ. ADA4522-2ARZ is a dual-channel operational amplifier with two independent amplification paths that can process two input signals at the same time. It has the characteristics of high precision and low noise, and is suitable for applications that require high-precision amplification and signal processing.

[0051] In a specific embodiment, in the protection circuit of the laser shown, the window comparison circuit includes: a second operational amplifier U2, a third operational amplifier U3, an eighth resistor R8, a ninth resistor R9, a tenth resistor R10, an eleventh resistor R11, a twelfth resistor R12, a second diode D2, a third diode D3, and a fourth diode D4;

[0052] The input end of the window comparison circuit is connected to the positive electrode of the second diode D2, the negative electrode of the second diode D2 is connected to the first end of the eighth resistor R8, the non-inverting end of the second operational amplifier U2, and the inverting end of the third operational amplifier U3, and the second end of the eighth resistor R8 is grounded; the inverting end of the second operational amplifier U2 is connected to the power supply through the ninth resistor R9 and to the ground through the tenth resistor R10; the non-inverting end of the third operational amplifier U3 is connected to the power supply through the eleventh resistor R11 and to the ground through the twelfth resistor R12; the output end of the second operational amplifier U2 is connected to the positive electrode of the third diode D3, the output end of the third operational amplifier U3 is connected to the positive electrode of the fourth diode D4, and the negative electrode of the third diode D3 and the negative electrode of the fourth diode D4 are connected to the output end of the window comparison circuit.

[0053] The operational amplifier is the core component of the window comparison circuit. It receives the input signal and the reference signal, and outputs a high or low level signal according to their size relationship. The detection signal VLD is compared with URH and URL respectively. The voltage drop of the laser diode J1 when it is working normally is 1.8V to 2.2V. When the laser diode J1 is working normally, the detection signal VLD is about 3V. After passing through the second diode D2, the voltage is about 2.1V (for common silicon diodes, the forward voltage drop is generally between 0.6V and 0.7V). Then it is compared with URH and URL respectively, and the state signal VCTL is low. When the laser diode J1 is in an open circuit state, the detection signal VLD is in a suspended state, the positive input terminal of the second operational amplifier U2 is 0V, and then it is compared with URH and URL respectively, and the state signal VCTL is high. When the laser diode J1 is in a short circuit state, the detection signal VLD is 5V, the positive input terminal of the second operational amplifier U2 is 4.3V, and then it is compared with URH and URL respectively, and the state signal VCTL is high. In summary, when the laser diode J1 is working normally, the state signal VCTL is at a low level; when the laser diode J1 is open or short-circuited, the state signal VCTL is at a high level. The state signal VCTL is sent to the switch control circuit in one way and to the main control unit in another way to realize timely shutdown when the circuit is abnormal.

[0054] In a specific embodiment, in the protection circuit of the laser shown, the window comparison circuit further includes: a thirteenth resistor R13, a fifth diode D5;

[0055] A first end of the thirteenth resistor R13 is connected to the cathode of the third diode D3 , a second end of the thirteenth resistor R13 is connected to the cathode of the fifth diode D5 and the output end of the window comparison circuit, and an anode of the fifth diode D5 is grounded.

[0056] The compared voltage value then passes through a voltage stabilizing circuit composed of a thirteenth resistor R13 and a fifth diode D5, so that the maximum amplitude of the output state signal VCTL is 3.3V.

[0057] Specifically, the fifth diode D5 is a voltage stabilizing diode.

[0058] The present embodiment provides a laser therapeutic apparatus, including the above-mentioned protection circuit of the laser, which is applied to the laser driving circuit, including: a first transistor Q1, a first diode D1, and a laser diode J1; the control end of the first transistor Q1 is connected to the control signal output end of the controller, the output end of the first transistor Q1 is connected to the positive electrode of the first diode D1 and the negative electrode of the laser diode J1, the input end of the first transistor Q1 is grounded, and the negative electrode of the first diode D1 is connected to the positive electrode of the laser diode J1 and the power supply end; it also includes: a window comparison circuit and a switch control circuit; the input end of the window comparison circuit is connected to the output end of the first transistor Q1, and the output end of the window comparison circuit is connected to the input end of the switch control circuit; the switch control circuit includes: a first resistor R1, a second resistor R2, a first capacitor C1, and a first triode Q2; the input end of the switch control circuit is connected to the base of the first triode Q2 through the first resistor R1 and the second resistor R2 connected in parallel, the base of the first triode Q2 is connected to the emitter of the first triode Q2 through the second resistor R2, and the collector of the first triode Q2 is connected to the control end of the first transistor Q1. The window comparison circuit detects the signal at the output end of the transistor in the laser driving circuit. When the state of the circuit to which it is connected is abnormal, it outputs a high-level signal to control the switch control circuit to shut down the laser driving circuit, thereby achieving timely shutdown when the circuit is abnormal, solving the problem of not being able to detect open circuit or short circuit in time during the use of the laser.

[0059] The above is a detailed introduction to the protection circuit of the laser and the laser therapy device provided by the utility model. The various embodiments in the specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same and similar parts between the various embodiments can be referenced to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part description. It should be pointed out that for ordinary technicians in this technical field, without departing from the principle of the utility model, the utility model can also be improved and modified in a number of ways, and these improvements and modifications also fall within the scope of protection of the claims of the utility model.

[0060] It should also be noted that, in this specification, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the statement "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device including the element.

Claims

1. A laser protection circuit, characterized in that: Applicable to a laser driving circuit, comprising: a first transistor, a first diode, and a laser diode; the control end of the first transistor is connected to the control signal output end of a controller, the output end of the first transistor is connected to the positive electrode of the first diode and the negative electrode of the laser diode, the input end of the first transistor is grounded, and the negative electrode of the first diode is connected to the positive electrode of the laser diode and a power supply end; It also includes: a window comparison circuit and a switch control circuit; the input end of the window comparison circuit is connected to the output end of the first transistor, and the output end of the window comparison circuit is connected to the input end of the switch control circuit; The switch control circuit comprises: a first resistor, a second resistor, a first capacitor, and a first transistor; The input end of the switch control circuit is connected to the base of the first transistor through the first resistor and the second resistor in parallel, the base of the first transistor and the emitter of the first transistor are connected through the second resistor, and the collector of the first transistor is connected to the control end of the first transistor.

2. The laser protection circuit according to claim 1, characterized in that: The output end of the window comparison circuit is connected to the voltage detection end of the controller.

3. The laser protection circuit according to claim 1, characterized in that: Also includes: Signal amplification circuit; The control signal output terminal of the controller is connected to the control terminal of the first transistor through the signal amplifying circuit.

4. The laser protection circuit according to claim 3, characterized in that: The signal amplification circuit comprises: a dual-channel operational amplifier, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, and a second capacitor; The non-inverting end of channel A of the dual-channel operational amplifier is connected to the control signal output end of the controller, the inverting end of channel A of the dual-channel operational amplifier is connected to the output end of channel B of the dual-channel operational amplifier and the first end of the second capacitor through the third resistor, the second end of the second capacitor is connected to the output end of channel A of the dual-channel operational amplifier and the control end of the first transistor, the output end of channel B of the dual-channel operational amplifier is connected to the inverting end of channel B of the dual-channel operational amplifier and the first end of the fifth resistor through the seventh resistor, the non-inverting end of channel B of the dual-channel operational amplifier is connected to the input end of the first transistor and the first end of the sixth resistor through the fourth resistor, and the second end of the fifth resistor is connected to the second end of the sixth resistor and the ground end.

5. The laser protection circuit according to claim 1, characterized in that: The window comparison circuit includes: a second operational amplifier, a third operational amplifier, an eighth resistor, a ninth resistor, a tenth resistor, an eleventh resistor, a twelfth resistor, a second diode, a third diode, and a fourth diode; The input end of the window comparison circuit is connected to the anode of the second diode, the cathode of the second diode is connected to the first end of the eighth resistor, the non-inverting end of the second operational amplifier, and the inverting end of the third operational amplifier, and the second end of the eighth resistor is grounded; the inverting end of the second operational amplifier is connected to the power supply through the ninth resistor and to the ground through the tenth resistor; the non-inverting end of the third operational amplifier is connected to the power supply through the eleventh resistor and to the ground through the twelfth resistor; the output end of the second operational amplifier is connected to the anode of the third diode, the output end of the third operational amplifier is connected to the anode of the fourth diode, and the cathode of the third diode and the cathode of the fourth diode are connected to the output end of the window comparison circuit.

6. The laser protection circuit according to claim 5, characterized in that: The window comparison circuit further includes: a thirteenth resistor and a fifth diode; The first end of the thirteenth resistor is connected to the cathode of the third diode, the second end of the thirteenth resistor is connected to the cathode of the fifth diode and the output end of the window comparator circuit, and the anode of the fifth diode is grounded.

7. The laser protection circuit according to claim 6, characterized in that: The fifth diode is a voltage regulator diode.

8. The laser protection circuit according to claim 1, characterized in that: The first transistor is an N-type MOS transistor.

9. The laser protection circuit according to claim 4, characterized in that: The dual-channel operational amplifier is ADA4522-2ARZ.

10. A laser therapeutic apparatus, characterized in that: A protection circuit for a laser comprising the laser according to any one of claims 1 to 9.

Images