Laser tube driving circuit

Abstract

The utility model provides a laser tube driving circuit which comprises an analog voltage conversion circuit and a constant current circuit. The input end of the analog voltage conversion circuit is connected with a power supply circuit and a control circuit of the laser system, and the analog voltage conversion circuit is used for converting power supply voltage provided by the power supply circuit into analog voltage. The input end of the constant current circuit is connected with the output end of the analog voltage conversion circuit, the output end of the constant current circuit is connected with a laser tube of the laser system, and the constant current circuit is used for providing stable current for the laser tube. The utility model provides stable current for the laser tube, and ensures the stable operation of the laser tube.

Description

Technical Field

[0001] The utility model relates to the technical field of laser tubes, in particular to a laser tube driving circuit. Background Art

[0002] Laser tubes are generally driven by driving circuits, but currently most driving circuits of laser tubes cannot provide stable current for the laser tubes, resulting in unstable operation of the laser tubes. Utility Model Content

[0003] The utility model provides a laser tube driving circuit, aiming to solve the problem of unstable running state of the current laser tube.

[0004] The utility model provides a laser tube driving circuit, which comprises an analog voltage conversion circuit and a constant current circuit; the input end of the analog voltage conversion circuit is respectively connected to the power supply circuit and the control circuit of the laser system, and is used for converting the power supply voltage provided by the power supply circuit into an analog voltage; the input end of the constant current circuit is connected to the output end of the analog voltage conversion circuit, and the output end of the constant current circuit is connected to the laser tube of the laser system, and is used for providing a stable current for the laser tube.

[0005] Furthermore, the analog voltage conversion circuit includes an analog switch, the input end of the analog switch is connected to the power supply circuit and the control circuit respectively, and the output end of the analog switch is connected to the input end of the constant current circuit.

[0006] Furthermore, the analog voltage conversion circuit also includes a first resistor, a second resistor and a third resistor; one end of the first resistor is connected to the power supply circuit, the other end of the first resistor is connected to one end of the second resistor, the other end of the second resistor is connected to one end of the third resistor, the other end of the third resistor is grounded, and the second resistor is also connected to the analog switch.

[0007] Furthermore, the second resistor is an adjustable resistor, and a controlled end of the second resistor is connected to the analog switch.

[0008] Furthermore, it also includes a feedback circuit, which is connected to the laser tube and the constant current circuit respectively.

[0009] Furthermore, the feedback circuit includes a first operational amplifier, a non-inverting input terminal of the first operational amplifier is connected to the laser tube, and an inverting input terminal and an output terminal of the first operational amplifier are both connected to the constant current circuit.

[0010] Furthermore, the constant current circuit includes a second operational amplifier, a first switch tube and a fourth resistor; the inverting input terminal of the second operational amplifier is respectively connected to the inverting input terminal and the output terminal of the first operational amplifier, the non-inverting input terminal of the second operational amplifier is connected to the output terminal of the analog voltage conversion circuit, the output terminal of the second operational amplifier is connected to the controlled terminal of the first switch tube, the first switch tube is connected to one end of the fourth resistor, the second electrode of the first switch tube is connected to the laser tube, and the other end of the fourth resistor is grounded.

[0011] Furthermore, it also includes a current limiting circuit, which is connected to the feedback circuit and the constant current circuit respectively.

[0012] Furthermore, a protection circuit is also included, and the protection circuit is connected to the power supply circuit and the laser tube respectively.

[0013] Furthermore, the protection circuit includes a fifth resistor, a first capacitor and a first diode; one end of the fifth resistor, one end of the first capacitor and the cathode of the first diode are all connected to the power supply circuit, and the other end of the fifth resistor, the other end of the first capacitor and the anode of the first diode are all connected to the laser tube.

[0014] The laser tube driving circuit disclosed in the utility model comprises an analog voltage conversion circuit and a constant current circuit. The analog voltage conversion circuit can convert a power supply voltage into an analog voltage and output the analog voltage to the constant current circuit. The constant current circuit generates a stable current according to the analog voltage, thereby driving the laser tube and improving the stability of the laser tube. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0016] Figure 1 It is a block diagram of a laser tube driving circuit provided by the first embodiment of the utility model;

[0017] Figure 2 It is a block diagram of a laser tube driving circuit provided by the second embodiment of the utility model;

[0018] Figure 3 It is a block diagram of a laser tube driving circuit provided by the third embodiment of the utility model;

[0019] Figure 4It is a block diagram of a laser tube driving circuit provided by the fourth embodiment of the utility model;

[0020] Figure 5 This is a circuit diagram of a laser tube driving circuit provided by the first embodiment of the utility model;

[0021] Figure 6 It is a circuit diagram of a protection circuit provided by the first embodiment of the utility model. DETAILED DESCRIPTION

[0022] 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 part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0023] It should be understood that when used in this specification and the appended claims, the terms "include" and "comprises" indicate the presence of described features, integers, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, operations, elements, components and / or groups thereof.

[0024] It should also be understood that the terms used in this utility model specification are only for the purpose of describing specific embodiments and are not intended to limit the utility model. As used in the utility model specification and the appended claims, the singular forms of "a", "an" and "the" are intended to include plural forms unless the context clearly indicates otherwise. It should also be further understood that the term "and / or" used in the utility model specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes these combinations.

[0025] In addition, the directional terms mentioned in the present invention, such as "upper", "lower", "front", "back", "left", "right", "inner", "outer", "side", etc., are only for reference to the directions of the attached drawings and the use status of the product. Therefore, the directional terms used are used to illustrate and understand the present invention, but not to limit the present invention. In addition, in the drawings, structures with similar or identical structures are represented by the same reference numerals.

[0026] See also Figures 1 to 6 , Figure 1 1 is a block diagram of a laser tube driving circuit 100 provided in the first embodiment of the utility model; Figure 2 1 is a block diagram of a laser tube driving circuit 100 provided in a second embodiment of the present utility model; Figure 31 is a block diagram of a laser tube driving circuit 100 provided in a third embodiment of the present utility model; Figure 4 1 is a block diagram of a laser tube driving circuit 100 provided in a fourth embodiment of the present utility model;

[0027] Figure 5 1 is a circuit diagram of a laser tube driving circuit 100 provided in the first embodiment of the utility model; Figure 6 1 is a circuit diagram of a protection circuit 50 provided in the first embodiment of the present utility model.

[0028] like Figure 1 As shown, the laser tube driving circuit 100 includes an analog voltage conversion circuit 10 and a constant current circuit 20; the input end of the analog voltage conversion circuit 10 is respectively connected to the power supply circuit 200 and the control circuit 300 of the laser system, and is used to convert the power supply voltage provided by the power supply circuit 200 into an analog voltage; the input end of the constant current circuit 20 is connected to the output end of the analog voltage conversion circuit 10, and the output end of the constant current circuit 20 is connected to the laser tube 400 of the laser system, and is used to provide a stable current for the laser tube 400.

[0029] Specifically, the laser tube driving circuit 100 includes an analog voltage conversion circuit 10 and a constant current circuit 20. The input end of the analog voltage conversion circuit 10 is connected to the power supply circuit 200 and the control circuit 300 of the laser system. The control circuit 300 may include a controller, which may be a control chip such as a CPU, MCU, DSP, FPGA, or a combination of multiple control chips, for outputting a control signal to control the analog voltage conversion circuit 10 and the power supply circuit 200. The power supply circuit 200 may be a power supply, such as a DC-DC power supply, which is connected to the control circuit 300 and may adjust the output voltage according to the control signal of the control circuit 300.

[0030] The input end of the analog voltage conversion circuit 10 is connected to the power supply circuit 200, that is, the power supply circuit 200 provides a power supply voltage for the analog voltage conversion circuit 10, and the power supply voltage is converted into an analog voltage after passing through the analog voltage conversion circuit 10. The analog voltage conversion circuit 10 is also connected to the control circuit 300, and can receive a control signal of the control circuit 300, such as a PWM signal, and adjust the magnitude of the output analog voltage according to the PWM of the control circuit 300, thereby adjusting the magnitude of the voltage received by the constant current circuit 20.

[0031] The input end of the constant current circuit 20 is connected to the output end of the analog voltage conversion circuit 10 . The constant current circuit 20 is a current source, which is used to provide a stable driving current for the laser tube 400 , so as to facilitate the stable operation of the laser tube 400 .

[0032] See also Figure 5As a further embodiment, the analog voltage conversion circuit 10 includes an analog switch U1, the input end of the analog switch U1 is respectively connected to the power supply circuit 200 and the control circuit 300, and the output end of the analog switch U1 is connected to the input end of the constant current circuit 20.

[0033] The analog switch U1 may include multiple pins, such as Figure 5 As shown, the NO pin of the analog switch U1 is connected to the power supply circuit 200, the IN pin is connected to the control circuit 300, and the COM pin is connected to the constant current circuit 20. The analog switch U1 can convert the voltage into an analog voltage and output it to the constant current circuit 20, and at the same time, it can also receive the PWM signal of the control circuit 300 to adjust the magnitude of the output analog voltage.

[0034] As a further embodiment, the analog voltage conversion circuit 10 also includes a first resistor R1, a second resistor R2 and a third resistor R3; one end of the first resistor R1 is connected to the power supply circuit 200, the other end of the first resistor R1 is connected to one end of the second resistor R2, the other end of the second resistor R2 is connected to one end of the third resistor R3, the other end of the third resistor R3 is grounded, and the second resistor R2 is also connected to the analog switch U1.

[0035] Furthermore, the second resistor R2 is an adjustable resistor, and a controlled end of the second resistor R2 is connected to the analog switch U1.

[0036] Among them, one end of the first resistor R1 is connected to the power supply circuit 200, the other end of the first resistor R1 is connected to one end of the second resistor R2, the other end of the second resistor R2 is connected to one end of the third resistor R3, the other end of the third resistor R3 is grounded, and the second resistor R2 is also connected to the analog switch U1. The first resistor R1, the second resistor R2 and the third resistor R3 form a voltage divider circuit for dividing the power supply voltage provided by the power supply circuit 200. At the same time, the second resistor R2 can be an adjustable resistor, and the magnitude of the output analog voltage can be adjusted by adjusting the resistance value of the second resistor R2.

[0037] See also Figure 2 As a further embodiment, it further includes a feedback circuit 30, and the feedback circuit 30 is connected to the laser tube 400 and the constant current circuit 20 respectively.

[0038] One end of the feedback circuit 30 is connected to the laser tube 400, and the other end of the feedback circuit 30 is connected to the constant current circuit 20, which is used to provide overcurrent protection for the laser tube 400. When the laser tube 400 is in normal operation, the light emitted by the laser tube 400 will irradiate its receiving end, thereby generating an output voltage, which is processed by the feedback circuit 30 and output to the constant current circuit 20, and then the current output by the constant current circuit 20 can be adjusted to prevent the laser tube 400 from burning.

[0039] As a further embodiment, the feedback circuit 30 includes a first operational amplifier U2 , a non-inverting input terminal of the first operational amplifier U2 is connected to the laser tube 400 , and an inverting input terminal and an output terminal of the first operational amplifier U2 are both connected to the constant current circuit 20 .

[0040] The non-inverting input terminal of the first operational amplifier U2 is connected to the laser tube 400, and the inverting input terminal and the output terminal of the first operational amplifier U2 are connected to the constant current circuit 20. The voltage generated by the laser tube 400 during normal operation is input from the non-inverting input terminal of the first operational amplifier U2, and after being processed by the first operational amplifier U2, a voltage is output to the constant current circuit 20. When the voltage output by the laser tube 400 increases, the voltage output by the first operational amplifier increases, so that the output current of the constant current circuit 20 decreases.

[0041] As a further embodiment, the constant current circuit 20 includes a second operational amplifier U3, a first switch tube Q1 and a fourth resistor R4; the inverting input terminal of the second operational amplifier U3 is respectively connected to the inverting input terminal and the output terminal of the first operational amplifier, the non-inverting input terminal of the second operational amplifier U3 is connected to the output terminal of the analog voltage conversion circuit 10, the output terminal of the second operational amplifier U3 is connected to the controlled terminal of the first switch tube Q1, the first switch tube Q1 is connected to one end of the fourth resistor R4, the second electrode of the first switch tube Q1 is connected to the laser tube 400, and the other end of the fourth resistor R4 is grounded.

[0042] Among them, the inverting input terminal of the second operational amplifier U3 is respectively connected to the inverting input terminal and the output terminal of the first operational amplifier, the non-inverting input terminal of the second operational amplifier U3 is connected to the output terminal of the analog voltage conversion circuit 10, the output terminal of the second operational amplifier U3 is connected to the controlled terminal of the first switch tube Q1, the first switch tube Q1 is connected to one end of the fourth resistor R4, the second electrode of the first switch tube Q1 is connected to the laser tube 400, and the other end of the fourth resistor R4 is grounded. The non-inverting input terminal of the second operational amplifier receives the analog voltage output by the analog voltage conversion circuit 10, and then generates a stable current, which is output to the laser tube 400 through the first switch tube Q1, and the fourth resistor R4 is used as a sampling resistor for current sampling.

[0043] The first switch tube Q1 can be a triode, a MOS tube or a thyristor. Taking the first switch tube Q1 as a triode as an example, the base of the first switch tube Q1 is connected to the output end of the second operational amplifier U3, the emitter of the first switch tube Q1 is grounded, and the collector of the first switch tube Q1 is connected to the laser tube 400.

[0044] As a further embodiment, a current limiting circuit 40 is further included, and the current limiting circuit 40 is connected to the feedback circuit 30 and the constant current circuit 20 respectively.

[0045] The current limiting circuit 40 may include a second switch tube Q2, which may be a triode, the gate of the second switch tube Q2 is connected to the output end of the feedback circuit 30, the emitter of the second switch tube Q2 is grounded, and the collector of the second switch tube Q2 is connected to the constant current circuit 20. When the voltage of the laser tube 400 increases, the output voltage of the feedback circuit 30 increases, the second switch tube Q2 is turned off, and the voltage output by the constant current circuit 20 decreases, that is, the second switch tube Q2 is used to limit the maximum current of the constant current circuit 20.

[0046] As a further embodiment, a protection circuit 50 is further included, and the protection circuit 50 is connected to the power supply circuit 200 and the laser tube 400 respectively.

[0047] As a further embodiment, the protection circuit 50 includes a fifth resistor R5, a first capacitor C1 and a first diode D1; one end of the fifth resistor R5, one end of the first capacitor C1 and the cathode of the first diode D1 are all connected to the power supply circuit 200, and the other end of the fifth resistor R5, the other end of the first capacitor C1 and the anode of the first diode D1 are all connected to the laser tube 400.

[0048] The protection circuit 50 includes a fifth resistor R5, a first capacitor C1 and a first diode D1; one end of the fifth resistor R5, one end of the first capacitor C1 and the cathode of the first diode D1 are all connected to the power supply circuit 200, and the other end of the fifth resistor R5, the other end of the first capacitor C1 and the anode of the first diode D1 are all connected to the laser tube 400. The fifth resistor R5 is a discharge resistor for discharging the laser tube 400, the first diode D1 is a voltage regulator for preventing the laser tube 400 from being burned due to overvoltage, and the first capacitor C1 is a filter capacitor for preventing the laser tube 400 from being burned due to spike voltage.

[0049] The laser tube driving circuit disclosed by the utility model can convert the power supply voltage into an analog voltage through an analog voltage conversion circuit, and provide a stable current for the laser tube through a constant current circuit, thereby ensuring the stable operation of the laser tube.

[0050] The above is only a specific implementation of the utility model, but the protection scope of the utility model is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed by the utility model, and these modifications or replacements should be included in the protection scope of the utility model. Therefore, the protection scope of the utility model should be based on the protection scope of the claims.

Claims

1. A laser tube driving circuit, characterized in that: Applications in laser systems, including: An analog voltage conversion circuit, the input ends of which are respectively connected to the power supply circuit and the control circuit of the laser system, and are used to convert the power supply voltage provided by the power supply circuit into an analog voltage; A constant current circuit, wherein the input end of the constant current circuit is connected to the output end of the analog voltage conversion circuit, and the output end of the constant current circuit is connected to the laser tube of the laser system, and is used to provide a stable current for the laser tube.

2. The laser tube driving circuit according to claim 1, characterized in that: The analog voltage conversion circuit includes an analog switch, the input end of the analog switch is connected to the power supply circuit and the control circuit respectively, and the output end of the analog switch is connected to the input end of the constant current circuit.

3. The laser tube driving circuit according to claim 2, characterized in that: The analog voltage conversion circuit also includes a first resistor, a second resistor and a third resistor; One end of the first resistor is connected to the power supply circuit, the other end of the first resistor is connected to one end of the second resistor, the other end of the second resistor is connected to one end of the third resistor, the other end of the third resistor is grounded, and the second resistor is also connected to the analog switch.

4. The laser tube driving circuit according to claim 3, characterized in that: The second resistor is an adjustable resistor, and a controlled end of the second resistor is connected to the analog switch.

5. The laser tube driving circuit according to claim 1, characterized in that: It also includes a feedback circuit, which is connected to the laser tube and the constant current circuit respectively.

6. The laser tube driving circuit according to claim 5, characterized in that: The feedback circuit comprises a first operational amplifier, a non-inverting input terminal of the first operational amplifier is connected to the laser tube, and an inverting input terminal and an output terminal of the first operational amplifier are both connected to the constant current circuit.

7. The laser tube driving circuit according to claim 6, characterized in that: The constant current circuit includes a second operational amplifier, a first switch tube and a fourth resistor; The inverting input terminal of the second operational amplifier is respectively connected to the inverting input terminal and the output terminal of the first operational amplifier, the non-inverting input terminal of the second operational amplifier is connected to the output terminal of the analog voltage conversion circuit, the output terminal of the second operational amplifier is connected to the controlled terminal of the first switching tube, the first switching tube is connected to one end of the fourth resistor, the second electrode of the first switching tube is connected to the laser tube, and the other end of the fourth resistor is grounded.

8. The laser tube driving circuit according to claim 5, characterized in that: It also includes a current limiting circuit, which is connected to the feedback circuit and the constant current circuit respectively.

9. The laser tube driving circuit according to claim 1, characterized in that: It also includes a protection circuit, which is connected to the power supply circuit and the laser tube respectively.

10. The laser tube driving circuit according to claim 9, characterized in that: The protection circuit includes a fifth resistor, a first capacitor and a first diode; One end of the fifth resistor, one end of the first capacitor and the cathode of the first diode are all connected to the power supply circuit, and the other end of the fifth resistor, the other end of the first capacitor and the anode of the first diode are all connected to the laser tube.

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