Laser pump source overcurrent protection self-locking circuit

Abstract

The utility model provides a laser pump source overcurrent protection self-locking circuit comprising a laser pump source, a constant current control unit, and a current sampling module used for sampling current signal voltage after the laser pump source works normally; the current latch module comprises a comparison unit and a latch unit, the comparison unit is used for comparing the sampled current signal voltage with a set voltage, and when the current signal voltage is higher than the set voltage, the latch unit latches the high-level data signal; when the voltage of the current signal is lower than the set voltage, the latch unit does not latch the low-level data signal; and the high-level data signal latched by the latch unit is used for triggering the overcurrent protection module to disconnect the laser pump source from the power supply. According to the utility model, the possibility of damage to the laser caused by an unstable state of the circuit can be avoided, and when the circuit is over-current, the laser pumping source can be protected in a rapid and stable manner.

Description

Technical Field

[0001] The utility model relates to the technical field of data latch circuits, and particularly relates to a self-locking circuit for overcurrent protection of a laser pump source. Background Art

[0002] In an existing technology, the current feedback voltage is compared with a set overcurrent value, the output of the comparison is connected to an SR latch, and the on / off of the power supply for the laser is controlled to achieve the function of latching and completing overcurrent protection. The disadvantage of this technology is that the output is uncertain, and under specific input conditions, the output state of the SR latch is uncertain.

[0003] When an overcurrent situation occurs, the output signal is unstable, making it impossible to output the correct signal, and the pump source cannot be protected in time, thus damaging the laser pump source and causing a large economic loss. Summary of the Utility Model

[0004] Aiming at the deficiencies of the prior art, the purpose of the utility model is to provide a self-locking circuit for overcurrent protection of a laser pump source, which can avoid the possibility of damaging the laser caused by an unstable circuit state. When the circuit is overcurrent, it can protect the laser pump source quickly and stably.

[0005] The embodiments of the utility model are realized through the following technical solutions:

[0006] A self-locking circuit for overcurrent protection of a laser pump source, comprising:

[0007] A laser pump source;

[0008] A constant current control unit;

[0009] A current sampling module for sampling the current signal voltage after the laser pump source works normally;

[0010] A current latching module, including a comparison unit and a latching unit. The comparison unit is used to compare the sampled current signal voltage with a set voltage. When the current signal voltage is higher than the set voltage, the current signal voltage is a high-level data signal, and the latching unit latches the high-level data signal; when the current signal voltage is lower than the set voltage, the current signal voltage is a low-level data signal, and the latching unit does not latch the low-level data signal;

[0011] An overcurrent protection module, and the high-level data signal latched by the latching unit is used to trigger the overcurrent protection module to disconnect the power supply of the laser pump source.

[0012] According to a preferred embodiment, when the current signal voltage is the low-level data signal, the overcurrent protection module does not interfere with the electrical connection between the power supply and the laser pump source.

[0013] According to a preferred embodiment, the latching unit includes a unidirectional switching transistor, and the unidirectional switching transistor is electrically connected to one end of the comparison unit.

[0014] According to a preferred embodiment, the latching unit further includes a resistor to prevent the latching unit from being damaged by overheating.

[0015] According to a preferred embodiment, the overcurrent protection module includes a control signal unit, a third switch, and a first switch. The first switch is disposed between the power supply and the laser pump source to control the electrical connection between the power supply and the laser pump source; the third switch is used to control the first switch to be turned on or off.

[0016] According to a preferred embodiment, the overcurrent protection module further includes a second switch, and the second switch is used to control the first switch to be turned on or off.

[0017] According to a preferred embodiment, the second switch controls the first switch to be turned on or off by converting the voltage signal of the control signal unit.

[0018] According to a preferred embodiment, the current sampling module includes a differential amplifier circuit and a follower circuit, and the constant current control unit, the differential amplifier circuit, and the follower circuit are connected in sequence.

[0019] According to a preferred embodiment, the first switch includes a resistor R4, a MOS transistor Q1, and a resistor R7. The resistor R4 is connected in series with the resistor R7, and the resistor R4 is connected in parallel with a pin of the MOS transistor Q1.

[0020] According to a preferred embodiment, the second switch includes a resistor R8, a resistor R12, and a MOS transistor Q2. The resistor R8 is connected in series with the resistor R12, and the resistor R12 is connected in parallel with a pin of the MOS transistor Q2.

[0021] According to a preferred embodiment, the current latching module includes a diode D2, capacitors C1, C2, resistors R1, R2, R5, R6, R9, R14, and an operational amplifier IC1.

[0022] According to a preferred embodiment, the third switch includes a resistor R3, resistors R10, R13, and a bipolar junction transistor Q3. The resistor R10 is connected in series with the resistor R13, the resistor R13 is connected in parallel with a pin of the bipolar junction transistor Q3, and the resistor R3 is connected in series with a pin of the bipolar junction transistor Q3.

[0023] According to a preferred embodiment, the current sampling module includes resistor R15, resistor R16, resistor R17, resistor R18, resistor R19, resistor R20, resistor R21, operational amplifier IC2, and diode D1.

[0024] According to a preferred embodiment, the current latching module further includes a non-inverting amplifier circuit, and the non-inverting amplifier circuit includes resistor R1, resistor R2, resistor R5, resistor R6, and capacitor C1.

[0025] The technical solution of the embodiment of the present utility model has at least the following advantages and beneficial effects:

[0026] The present utility model can avoid the possibility of damaging the laser caused by an unstable circuit state. When the circuit is overcurrent, that is, when the current signal voltage is higher than the set voltage, the current signal voltage is a high-level data signal. The latching unit latches the high-level data signal and triggers the overcurrent protection module, which can protect the laser pump source quickly and stably. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the following will briefly introduce the drawings required in the embodiments. It should be understood that the following drawings only show some embodiments of the present utility model, and thus should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other relevant drawings can also be obtained based on these drawings.

[0028] Figure 1 It is a circuit layout diagram of an overcurrent protection self-locking circuit for a laser pump source provided by an embodiment of the present utility model.

[0029] Reference numerals: 1, laser pump source; 2, constant current control unit; 3, current sampling module; 4, current latching module; 5, overcurrent protection module. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0030] For better understanding and implementation, the following will clearly and completely describe the technical solutions in the embodiments of the present utility model with reference to the drawings in the embodiments of the present utility model.

[0031] In the description of the present utility model, it should be noted that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation of the present utility model.

[0032] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this utility model belongs. The terms used in the description of this utility model herein are for the purpose of describing specific embodiments only and are not intended to limit this utility model.

[0033] Embodiment

[0034] Please refer to Figure 1 , the embodiments of this utility model are realized through the following technical solutions:

[0035] An overcurrent protection self-locking circuit for a laser pump source 1, comprising: a laser pump source 1; a constant current control unit 2; a current sampling module 3 for sampling the current signal voltage after the laser pump source 1 operates normally; a current latching module 4, including a comparison unit and a latching unit, the comparison unit is used to compare the sampled current signal voltage with a set voltage, when the current signal voltage is higher than the set voltage, the current signal voltage is a high-level data signal, and the latching unit latches this high-level data signal; when the current signal voltage is lower than the set voltage, the current signal voltage is a low-level data signal, and the latching unit does not latch this low-level data signal; an overcurrent protection module 5, the high-level data signal latched by the latching unit is used to trigger the overcurrent protection module 5 to disconnect the power supply of the laser pump source 1.

[0036] Further, when the current signal voltage is a low-level data signal, the overcurrent protection module 5 does not interfere with the electrical connection between the power supply and the laser pump source 1.

[0037] Further, the latching unit includes a unidirectional switch tube, and the unidirectional switch tube is electrically connected to one end of the comparison unit.

[0038] Further, the latching unit further includes a resistor to avoid burning out of the latching unit.

[0039] Further, the overcurrent protection module 5 includes a control signal unit, a third switch and a first switch, the first switch is arranged between the power supply and the laser pump source 1 to control the electrical connection between the power supply and the laser pump source 1; the third switch is used to control the first switch to be disconnected or closed. When the current signal voltage is a low-level data signal, the third switch remains open, so that the closed first switch can conduct the power supply and the laser pump source 1 to control the electrical connection between the power supply and the laser pump source 1. When the control signal unit receives a high-level data signal, the third switch is closed, and the external controller corresponds to a low-level data signal on the circuit to trigger both the second switch and the first switch to be disconnected. ENABLE is the external controller, that is, the control signal unit, which can control the disconnection or closing of the second switch and the first switch.

[0040] Further, the overcurrent protection module 5 further includes a second switch, and the second switch is used to control the closing or opening of the first switch.

[0041] Further, the second switch controls the closing or opening of the first switch by converting the voltage signal of the conversion control signal unit.

[0042] Further, the current sampling module 3 includes a differential amplifier circuit and a follower circuit, and the constant current control unit 2, the differential amplifier circuit, and the follower circuit are connected in sequence.

[0043] Further, the first switch includes a resistor R4, a MOS transistor Q1, and a resistor R7. The resistor R4 and the resistor R7 are connected in series, and the resistor R4 is connected in parallel with a pin of the MOS transistor Q1. One pin of the above MOS transistor Q1 is the twelfth pin. Specifically, an LED1 is connected in this embodiment to display the closing or opening state of the first switch.

[0044] Further, the second switch includes a resistor R8, a resistor R12, and a MOS transistor Q2. The resistor R8 and the resistor R12 are connected in series, and the resistor R12 is connected in parallel with a pin of the MOS transistor Q2. One pin of the above MOS transistor Q2 is the twelfth pin.

[0045] Further, the current latching module 4 includes a diode D2, a capacitor C1, a capacitor C2, a resistor R1, a resistor R2, a resistor R5, a resistor R6, a resistor R9, a resistor R14, and an operational amplifier IC1.

[0046] Further, the third switch includes a resistor R3, a resistor R10, a resistor R13, and a bipolar junction transistor Q3. The resistor R10 and the resistor R13 are connected in series, the resistor R13 is connected in parallel with a pin of the bipolar junction transistor Q3, and the resistor R3 is connected in series with a pin of the bipolar junction transistor Q3. One pin of the above bipolar junction transistor Q3 is the third pin.

[0047] Further, the current sampling module 3 includes a resistor R15, a resistor R16, a resistor R17, a resistor R18, a resistor R19, a resistor R20, a resistor R21, an operational amplifier IC2, and a diode D1.

[0048] Further, the current latching module 4 further includes a non-inverting amplifier circuit, and the non-inverting amplifier circuit includes a resistor R1, a resistor R2, a resistor R5, a resistor R6, and a capacitor C1.

[0049] The working principle of the present utility model:

[0050] To implement an overcurrent protection self-locking circuit for a laser pump source 1, this embodiment includes, from input to output: a current sampling module 3, a current latching module 4, and an overcurrent protection module 5. The following is the signal flow from input to output.

[0051] The current sampling module 3. After the constant current control unit 2 controls the normal operation of the laser pump source 1 LD1, it samples the current signal voltage of the sampling resistor through a differential amplification circuit, and the current signal voltage collected by the differential amplification circuit is transmitted to the latch circuit through a voltage follower circuit.

[0052] The current latching module 4 amplifies the OC_REF+ voltage through a non-inverting amplifier circuit and transmits the amplified OC_REF+ voltage to the latch circuit. The latch circuit compares the current signal voltage with the amplified OC_REF voltage. When the current signal voltage is greater than the amplified OC_REF+ voltage, the output terminal of the latch circuit outputs a high level to the overcurrent protection module 5. At the same time, the voltage at the output terminal of the latch circuit is output to the current signal voltage through the series-connected resistor R2 and diode D3. As long as the current signal voltage is always greater than the amplified OC_REF+ voltage, the output terminal of the latch circuit is at a high level, completing the overcurrent latching protection. Only after restarting the entire system, the output of the latch circuit returns to a low level, and the constant current control unit 2 starts to control the normal operation of the laser pump source 1 LD1 again. OC_REF is the comparison voltage, which is set according to the actual situation. The OC_REF voltage is used to compare the current signal voltage to determine whether the signal of the current signal voltage needs to be latched.

[0053] The constant current control unit 2 is used to perform constant current control output on the working current of the laser pump source 1;

[0054] The overcurrent protection module 5. When the overcurrent latching module outputs a high level, it makes the crystal triode Q3 conduct, and the voltage at the first end of the MOS transistor Q2 changes from a high level to a low level. The MOS transistor Q2 is in a cut-off state, that is, the second switch is disconnected, and the LED1 light goes out. The MOS transistor Q1 is in a cut-off state, and there is no voltage input at the first end of the laser pump source 1 LD1, that is, the first switch is disconnected, and the laser pump source 1 Figure 1 i.e., LD1 in it stops working. The change of the voltage at the first end of the MOS transistor Q2 from a high level to a low level is used to control the first switch. Controlling the first switch by converting a high-level data signal into a low-level signal is likely to generate abnormal signals during the control process, resulting in incorrect actions of the first switch. It can effectively reduce or avoid the problem of incorrect actions of the first switch mentioned above.

[0055] Conversely, when the sampled current signal is lower than the set overcurrent signal, the latch circuit outputs a low level. At this time, the crystal triode Q3 is in a cut-off state, that is, the latch unit does not latch this low-level data signal and does not trigger the overcurrent protection module 5. At this time, both the second switch and the first switch are controlled by the control signal unit in the overcurrent protection module 5. The voltage at the first end of the MOS transistor Q2 is at a high level, the MOS transistor Q2 conducts, the LED1 light is on, the MOS transistor Q1 conducts, there is voltage at the first end of the laser pump source 1 LD1, and the laser pump source 1 LD1 operates normally.

[0056] The current sampling module 3 includes resistor R15, resistor R16, resistor R17, resistor R18, resistor R19, resistor R20, resistor R21, operational amplifier IC2, and diode D1. The differential amplifier includes resistor R16, resistor R17, resistor R20, and resistor R21. The first end of resistor R17 and the second end of resistor R16 are connected to the fifth end of operational amplifier IC2. The first end of resistor R20 and the second end of resistor R21 are connected to the sixth end of operational amplifier IC2. The first end of resistor R21 and the second end of resistor R15 are connected to the seventh end of the operational amplifier. The second end of resistor R17, the first end of resistor R18, and the first end of sampling resistor R19 are connected to the second end of the constant current control unit 2. The first end of resistor R16 is connected to the GND terminal. The second end of sampling resistor R18 and the second end of sampling resistor R19 are connected to the PGND terminal. The follower includes operational amplifier IC2 and resistor R11. The third end of operational amplifier IC3 is connected to the first end of resistor R15. The second end and the first end of operational amplifier IC3 are connected to the first end of resistor R11. The second end of resistor R11 is connected to the first end of diode D1. In this embodiment, the unidirectional switch tube is diode D3.

[0057] The current latching module 4 includes diode D2, capacitor C1, capacitor C2, resistor R1, resistor R2, resistor R5, resistor R6, resistor R9, resistor R14, operational amplifier IC1, and OC_REF+ signal. The non-inverting amplifier circuit includes resistor R1, resistor R2, resistor R5, resistor R6, and capacitor C1. The first end of resistor R2, the second end of capacitor C1, and the second end of resistor R6 are connected. The second end of resistor R2 and the first end of resistor R1 are connected to the sixth end of operational amplifier IC1B. The OC_REF+ signal is the overcurrent input set value. The OC_REF+ signal, the first end of resistor R1, and the first end of resistor R2 are connected to the fifth end of operational amplifier IC1B. The second end of resistor R1 and the first end of resistor R5 are connected to the seventh end of the operational amplifier. The latching circuit includes operational amplifier IC1A, resistor R14, diode D3, resistor R9, and capacitor C2. The said resistor R5 is connected to the second end of operational amplifier IC1A. The second end of resistor R9, the second end of capacitor C2, the second end of diode D1, and the first end of diode D3 are connected to the third end of operational amplifier IC1A. The first end of operational amplifier IC1A and the first end of resistor R10 are connected to the first end of resistor R14. The second end of resistor R14 is connected to the second end of diode D3.

[0058] The overcurrent protection module 5 includes an overcurrent protection circuit, which includes resistor R3, resistor R4, resistor R7, resistor R8, resistor R10, resistor R12, resistor R13, crystal triode Q3, MOS transistor Q1, MOS transistor Q2, LED1, and laser pump source 1LD1. The second end of resistor R10 and the first end of resistor R13 are connected to the first end of crystal triode Q3. The second end of resistor R13, the second end of resistor R12, the second end of crystal triode Q3, and the second end of MOS transistor Q2 are connected to the GND terminal. ENABLE is connected to the first end of resistor R3, and the second end of resistor R3 and the first end of resistor R8 are connected to the third end of crystal triode Q3. The second end of resistor R8 and the first end of resistor R12 are connected to the first end of MOS transistor Q2. The third end of MOS transistor Q2 is connected to the first end of LED1. The second end of LED1 and the second end of resistor R4 are connected to the first end of MOS transistor Q1, and the first end of resistor R4 and the second end of MOS transistor Q1 are connected to the power supply VIN+ terminal. The second end of MOS transistor Q1 is connected to the first end of laser pump source 1LD1, and the second end of laser pump source 1LD1 is connected to the first end of the constant current control unit 2. The above current signal voltage is the current signal voltage after being sampled by the current sampling module 3.

[0059] The technical means disclosed in the solution of the present utility model are not limited to the technical means disclosed in the above embodiments, but also include technical solutions formed by any combination of the above technical features. It should be noted that for those of ordinary skill in the art in this technical field, without departing from the principle of the present utility model, several improvements and refinements can be made, and these improvements and refinements are also regarded as the protection scope of the present utility model.

Claims

1. A laser pump source overcurrent protection self-locking circuit, characterized in that: include: Laser pump source; Constant current control unit; A current sampling module, used for sampling the current signal voltage after the laser pump source works normally; A current latch module, comprising a comparison unit and a latch unit, wherein the comparison unit is used to compare the sampled current signal voltage with a set voltage, and when the current signal voltage is higher than the set voltage, the current signal voltage is a high-level data signal, and the latch unit latches the high-level data signal; when the current signal voltage is lower than the set voltage, the current signal voltage is a low-level data signal, and the latch unit does not latch the low-level data signal; An overcurrent protection module, wherein the high-level data signal latched by the latch unit is used to trigger the overcurrent protection module to disconnect the power supply of the laser pump source.

2. The laser pump source overcurrent protection self-locking circuit according to claim 1, characterized in that: When the current signal voltage is the low-level data signal, the overcurrent protection module does not interfere with the electrical connection between the power supply and the laser pump source.

3. The laser pump source overcurrent protection self-locking circuit according to claim 2, characterized in that: The latch unit includes a unidirectional switch tube, and the unidirectional switch tube is electrically connected to one end of the comparison unit.

4. The laser pump source overcurrent protection self-locking circuit according to claim 3, characterized in that: The latch unit further includes a resistor to prevent the latch unit from being burned.

5. The laser pump source overcurrent protection self-locking circuit according to claim 2, characterized in that: The overcurrent protection module includes a control signal unit, a third switch and a first switch. The first switch is arranged between the power supply and the laser pump source to control the electrical connection between the power supply and the laser pump source; the third switch is used to control the first switch to be opened or closed.

6. The laser pump source overcurrent protection self-locking circuit according to claim 5, characterized in that: The overcurrent protection module further includes a second switch, and the second switch is used to control the closing or opening of the first switch.

7. The laser pump source overcurrent protection self-locking circuit according to claim 6, characterized in that: The second switch controls the closing or opening of the first switch by converting the voltage signal of the control signal unit.

8. The laser pump source overcurrent protection self-locking circuit according to claim 1, characterized in that: The current sampling module comprises a differential amplifier circuit and a follower circuit, and the constant current control unit, the differential amplifier circuit and the follower circuit are connected in sequence.

9. The laser pump source overcurrent protection self-locking circuit according to claim 5, characterized in that: The first switch includes a resistor R4, a MOS transistor Q1, and a resistor R7. The resistor R4 and the resistor R7 are connected in series, and the resistor R4 is connected in parallel to a pin of the MOS transistor Q1.

10. The laser pump source overcurrent protection self-locking circuit according to claim 6, characterized in that: The second switch includes a resistor R8, a resistor R12, and a MOS transistor Q2. The resistor R8 is connected in series with the resistor R12, and the resistor R12 is connected in parallel with a pin of the MOS transistor Q2.

11. The laser pump source overcurrent protection self-locking circuit according to claim 1, characterized in that: The current latch module includes a diode D2, a capacitor C1, a capacitor C2, a resistor R1, a resistor R2, a resistor R5, a resistor R6, a resistor R9, a resistor R14, and an operational amplifier IC1.

12. The laser pump source overcurrent protection self-locking circuit according to claim 5, characterized in that: The third switch includes a resistor R3, a resistor R10, a resistor R13, and a transistor Q3. The resistor R10 is connected in series with the resistor R13. The resistor R13 is connected in parallel with one pin of the transistor Q3. The resistor R3 is connected in series with one pin of the transistor Q3.

13. The laser pump source overcurrent protection self-locking circuit according to claim 1, characterized in that: The current sampling module includes a resistor R15, a resistor R16, a resistor R17, a resistor R18, a resistor R19, a resistor R20, a resistor R21, an operational amplifier IC2, and a diode D1.

14. The laser pump source overcurrent protection self-locking circuit according to claim 1, characterized in that: The current latch module further includes a unidirectional amplifier circuit, and the unidirectional amplifier circuit includes a resistor R1, a resistor R2, a resistor R5, a resistor R6, and a capacitor C1.

Images