Laser beam generating circuit

Abstract

A driving circuit of the laser beam generating circuit comprises a third field effect transistor and a fifth triode, an input end of the third field effect transistor is connected with a first working voltage source of a power supply conversion module through a twenty-ninth resistor, and an output end of the third field effect transistor is connected with a second working voltage source of the power supply conversion module through a twenty-ninth resistor. The output end of the third field effect transistor is connected with the positive electrode of the laser diode assembly through a thirty-th resistor, and the G pole end of the third field effect transistor is connected with a second working voltage source of the power supply conversion module through a thirty-eighth resistor and a thirty-fourth resistor in sequence. The G pole end of the third field effect transistor is also connected with the collector electrode end of the fifth triode through a fortieth resistor; and the base end of the fifth triode is connected with an on-off control signal of an external control chip through a forty-fourth resistor. According to the scheme, through the dual-reliability design of the driving circuit and the power supply, the working stability and reliability of the laser light source are remarkably improved, the service life of the device is prolonged, the measurement accuracy is improved, and the power consumption is reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to laser generator technical field, concretely is a laser beam generating circuit. BACKGROUND

[0002] Laser beams are widely used in the field of measurement, such as for speedometer to realize impact test on parts, speed measurement for automobile pedestrian protection test and other mobile speed measurement, and the speed measurement principle is to measure the moving speed of an object by laser ranging. Laser speedometer determines the distance between the object and the test point by emitting laser beams and receiving the reflected waves, and records the time difference, that is, by twice laser ranging of the same object with a specific time interval, the moving distance of the object in the time period is obtained, and the moving speed of the object is calculated.

[0003] However, the laser source of the laser speedometer is limited by its driving circuit, and there is still room for improvement in the stability and power consumption of the laser source. Therefore, the purpose of the present patent is to provide a driving circuit that improves the stability and reliability of the laser source module. SUMMARY

[0004] The utility model provides a laser beam generating circuit for solving the stability and reliability of the laser source module in the prior art.

[0005] In order to solve the above technical problems, the technical scheme of the utility model is:

[0006] A laser beam generating circuit comprises a laser diode assembly, a driving circuit and a power conversion module.

[0007] The driving circuit comprises a third field effect tube and a fifth triode, the input end of the third field effect tube is connected with the first working voltage source of the power conversion module through the twenty-ninth resistor, the output end of the third field effect tube is connected with the anode of the laser diode assembly through the thirtieth resistor, the G pole end of the third field effect tube is connected with the second working voltage source of the power conversion module through the thirty-eighth resistor and the thirty-fourth resistor in turn, and the G pole end of the third field effect tube is also connected with the collector pole end of the fifth triode through the fortieth resistor; the emitter pole end of the fifth triode is grounded, the base pole end of the fifth triode is connected with the on-off control signal of the external control chip through the forty-fourth resistor, and the fourth-sixth resistor is connected between the base pole end and the emitter pole end of the fifth triode.

[0008] Further, the driving circuit further comprises a third current sensing amplifier, a positive input end of the third current sensing amplifier is connected with one end of the third field effect tube through the twenty-eighth resistor and the thirtieth resistor, a negative input end of the third current sensing amplifier is connected with one end of the laser diode assembly through the thirty-sixth resistor and the thirtieth resistor, the thirty-sixth resistor is grounded through the fifth transient voltage suppressor, the positive input end and the negative input end of the third current sensing amplifier are further connected with the thirteenth capacitor, and an output end of the third current sensing amplifier is connected with a signal acquisition end of the external control chip through the forty-third resistor, and the forty-third resistor is further grounded through the seventeenth capacitor.

[0009] Further, the laser diode assembly is an RGB type laser assembly, the third field effect tube is a P-channel field effect tube with a model of CJAB35P03, and the third current sensing amplifier is a current sensing amplifier with a model of INA199 series.

[0010] The scheme avoids directly applying the driving voltage output by the power supply to the laser diode, but realizes driving start and stop through the third field effect tube and the fifth triode, according to the high and low levels of the on-off control signal of the external control chip, controls the conduction between the D pole and the S pole of the third field effect tube, and controls the output voltage of the third field effect tube to be off, that is, controls the voltage applied to the laser diode assembly to be off. Since it is controlled by the external control chip, the laser diode assembly avoids hard start of the laser beam, is beneficial to prolong the service life of the device, and improves the reliability of driving; meanwhile, the laser diode assembly needs to work only when the laser speed measuring instrument measures the speed, so the laser diode assembly is powered on and works only after the built-in speed measuring program of the external control chip starts, thereby avoiding waste of energy consumption and service life of the device.

[0011] Compared with the prior art, the scheme significantly improves the stability and reliability of the laser light source in work through the double reliability design of the driving circuit and the power supply, prolongs the service life of the device, improves the measurement accuracy, and reduces the power consumption. BRIEF DESCRIPTION OF DRAWINGS

[0012] Figure 1 It is a circuit principle diagram of the driving circuit in a specific embodiment of the utility model.

[0013] Figure 2 It is a circuit principle diagram of the laser diode assembly in a specific embodiment of the utility model.

[0014] Figure 3 It is a circuit principle diagram of a connection part between the first voltage conversion submodule and the external voltage source in a specific embodiment of the utility model.

[0015] Figure 4The circuit principle diagram of the output voltage part of the first voltage conversion sub-module in an embodiment of the utility model.

[0016] Figure 5 The circuit principle diagram of the second voltage conversion sub-module in an embodiment of the utility model.

[0017] Figure 6 The circuit principle diagram of the power conversion module for 3.3V voltage conversion in an embodiment of the utility model. DETAILED DESCRIPTION

[0018] The specific embodiments of the utility model will be further described below with reference to the drawings. It should be noted that the description of these embodiments is used to help understand the utility model, but does not constitute the limitation of the utility model. In addition, the technical features involved in each embodiment of the utility model described below can be combined with each other as long as there is no conflict.

[0019] In the description of the utility model, it should be understood that the orientation or position relationship indicated by the terms "length", "width", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like is based on the orientation or position relationship shown in the drawings, and is only for the convenience of describing the utility model and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore it cannot be understood as the limitation of the utility model. In addition, in the description of the utility model, the meaning of "multiple" is two or more than two, unless otherwise specifically limited.

[0020] The patent provides a kind of laser beam generation circuit, it includes laser diode component, drive circuit and power conversion module.To ensure the switching reliability and driving efficiency of drive circuit, the present scheme is built with field effect transistor, such as Figure 1As shown, the drive circuit includes a third field effect tube Q3L and a fifth triode Q5L, an input end of the third field effect tube Q3L is connected with the first working voltage source of the power conversion module through a twenty-ninth resistor R29L, an output end of the third field effect tube Q3L is connected with the anode of the laser diode assembly through a thirtieth resistor R30L, a G pole end of the third field effect tube Q3L is connected with the second working voltage source of the power conversion module through a thirty-eighth resistor R38L and a thirty-fourth resistor R34L in sequence, the G pole end of the third field effect tube Q3L is also connected with a collector pole end of the fifth triode Q5L through a fortieth resistor R40L; an emitter pole end of the fifth triode Q5L is grounded, a base pole end of the fifth triode Q5L is connected with an on-off control signal of an external control chip through a forty-fourth resistor R44L, and the base pole end of the fifth triode Q5L is connected with the emitter pole end and is connected with a forty-sixth resistor R46L. The scheme avoids directly applying the driving voltage output by the power supply to the laser diode, but realizes driving start and stop through the third field effect tube Q3L combined with the fifth triode Q5L, according to different high and low levels of the on-off control signal of the external control chip, the conduction between the D pole and the S pole of the third field effect tube Q3L is controlled, so that the output voltage of the third field effect tube Q3L is turned off, that is, the voltage applied to the laser diode assembly is turned off. Since it is controlled by the external control chip, the laser diode assembly avoids hard start of the laser beam, which is beneficial to prolong the service life of the device and improve the reliability of the drive; at the same time, the laser diode assembly needs to work only when the laser speed meter measures the speed, so the laser diode assembly is powered on and works only after the built-in speed measurement program of the external control chip starts, thereby avoiding waste of energy consumption and service life of the device.

[0021] Preferably, the driving circuit of the present scheme also has a current back collection function. In an embodiment, the driving circuit further comprises a third current sensing amplifier U3L, a positive input terminal of the third current sensing amplifier U3L is connected to one end of the third field effect transistor Q3L through a twenty-eighth resistor R28L and a thirtieth resistor R30L, a negative input terminal of the third current sensing amplifier U3L is connected to one end of the laser diode assembly through a thirty-sixth resistor R36L and the thirtieth resistor R30L, the thirty-sixth resistor R36L is grounded through a fifth transient suppression diode SD5L, the positive and negative input terminals of the third current sensing amplifier U3L are further connected to a thirteenth capacitor C13L, and an output terminal of the third current sensing amplifier U3L is connected to a signal collection terminal of an external control chip through a forty-third resistor R43L, the forty-third resistor R43L is further grounded through a seventeenth capacitor C17L. The driving circuit directly affects the current stability of the laser light source. By collecting the working current of the laser diode assembly, the present embodiment can analyze whether the laser diode assembly is in a preset normal working state in real time, so as to adjust the working voltage applied to the laser diode assembly, and ensure the current stability of the laser diode, thereby improving the performance and service life of the laser light source.

[0022] Preferably, in an embodiment, as shown in Figure 2 the laser diode assembly is an RGB type laser assembly LED1, the RGB laser beam is single-wavelength visible light without ultraviolet and infrared radiation, avoiding the disadvantage of excessive heat dissipation of traditional high-power light sources, and having higher brightness than a single laser diode, and being easier to be captured by a laser receiving end, thereby providing clearer and more accurate measurement results in the speed measurement process. Considering the excellent and reliable performance of the device, the third field effect transistor Q3L is a P-channel field effect transistor with a model number of CJAB35P03; and the third current sensing amplifier U3L is a current sensing amplifier with a model number of INA199 series.

[0023] The power conversion module of the present scheme is responsible for reducing and stabilizing the external high voltage, and converting it into the working voltage required by the driving circuit and the laser diode assembly. Taking two-stage voltage conversion as an embodiment, the power conversion module comprises a first voltage conversion submodule and a second voltage conversion submodule; the first voltage conversion submodule is composed of a battery charging management chip U9L, a field effect transistor and peripheral circuits, and is used for reducing and converting the external DC voltage into a 12V DC voltage as a second working voltage source; the second voltage conversion submodule is composed of a DC-DC step-down conversion chip U10L and peripheral circuits, and is used for converting the output voltage of the first voltage conversion submodule into a 5V DC voltage as a first working voltage source. Voltage fluctuations will cause laser beam mis-triggering and receiving errors, resulting in inaccurate measurement. The use of a battery charging management chip combined with a field effect transistor can ensure the stability of the output voltage and avoid the problem of voltage fluctuations.

[0024] like Figure 3 As shown, the first-stage voltage conversion submodule includes an eleventh field-effect transistor Q11L, a twelfth field-effect transistor Q12L, a thirteenth field-effect transistor Q13L, and a CN3765 battery charging management chip U9L. The input terminal of the twelfth field-effect transistor Q12L is connected to an external DC voltage via a second filter inductor LP2L and a resettable fuse. The output terminal of the twelfth field-effect transistor Q12L is connected to the input terminal of the eleventh field-effect transistor Q11L and the voltage input terminal of the battery charging management chip U9L. Figure 4 As shown. The gate terminal of the twelfth field-effect transistor Q12L is connected to the drive pin of the battery charging management chip U9L. The output terminal of the eleventh field-effect transistor Q11L is connected in sequence through the ninth Schottky diode SD9L, the first filter inductor LP1L, and the eightieth resistor R80L to serve as the output voltage terminal of the first-stage voltage conversion submodule.

[0025] The output voltage terminal of the first-stage voltage conversion submodule is connected to the input terminal of the thirteenth field-effect transistor Q13L. The gate (G) terminal of the thirteenth field-effect transistor Q13L is connected to the output voltage terminal of the first-stage voltage conversion submodule through the eighty-fifth resistor R85L. The output terminal of the thirteenth field-effect transistor Q13L is grounded. The peripheral circuit is as follows... Figure 3 , 4 As shown, no further details will be provided.

[0026] like Figure 5 As shown, the DC-DC buck converter chip U10L of the secondary voltage conversion submodule is model SCT2432STER. The VIN pin of the DC-DC buck converter chip U10L is connected to the output voltage terminal of the primary voltage conversion submodule. The SW pin of the DC-DC buck converter chip U10L, after passing through the third filter inductor LP3L, serves as the output voltage terminal of the secondary voltage conversion submodule.

[0027] In the embodiment, the required voltage for the laser diode assembly is 3.3V, such as Figure 2 As shown, the power conversion module can be further enhanced with a step-down converter, such as... Figure 6 The third-level voltage conversion submodule is shown.

[0028] This solution significantly improves the stability and reliability of the laser source through a dual reliability design of the drive circuit and power supply, which not only extends the life of the device but also improves measurement accuracy and reduces power consumption.

[0029] The embodiments of the present application are described in detail in combination with the drawings, but the present application is not limited to the described embodiments. For those skilled in the art, various changes, modifications, replacements and variations of the embodiments can be made without departing from the principles and spirits of the present application, and still fall within the protection scope of the present application.

Claims

1. A laser beam generating circuit, characterized in that: Includes laser diode components, driver circuits, and power conversion modules; The driving circuit includes a third field-effect transistor (Q3L) and a fifth transistor (Q5L). The input terminal of the third field-effect transistor (Q3L) is connected to the first operating voltage source of the power conversion module through a 29th resistor (R29L). The output terminal of the third field-effect transistor (Q3L) is connected to the positive terminal of the laser diode assembly through a 30th resistor (R30L). The gate terminal of the third field-effect transistor (Q3L) is connected to the second operating voltage source of the power conversion module through a 38th resistor (R38L) and a 34th resistor (R34L). The gate terminal of the third field-effect transistor (Q3L) is also connected to the collector terminal of the fifth transistor (Q5L) through a 40th resistor (R40L). The emitter terminal of the fifth transistor (Q5L) is grounded. The base terminal of the fifth transistor (Q5L) is connected to the on / off control signal of an external control chip through a 44th resistor (R44L). A 46th resistor (R46L) is connected between the base terminal and the emitter terminal of the fifth transistor (Q5L).

2. The laser beam generating circuit according to claim 1, characterized in that: The driving circuit also includes a third current sensing amplifier (U3L). The positive input terminal of the third current sensing amplifier (U3L) is connected to one end of the third field-effect transistor (Q3L) through the twenty-eighth resistor (R28L) and the thirtieth resistor (R30L). The negative input terminal of the third current sensing amplifier (U3L) is connected to one end of the laser diode assembly through the thirty-sixth resistor (R36L) and the thirtieth resistor (R30L). The thirty-sixth resistor (R36L) is grounded through the fifth transient suppression diode (SD5L). A thirteenth capacitor (C13L) is also connected between the positive and negative input terminals of the third current sensing amplifier (U3L). The output terminal of the third current sensing amplifier (U3L) is connected to the signal acquisition terminal of the external control chip through the forty-third resistor (R43L). The forty-third resistor (R43L) is also grounded through the seventeenth capacitor (C17L).

3. The laser beam generating circuit according to claim 2, characterized in that: The laser diode assembly is an RGB type laser assembly; the third field-effect transistor (Q3L) is a P-channel field-effect transistor of model CJAB35P03; and the third current sensing amplifier (U3L) is an INA199 series current sensing amplifier.

4. A laser beam generating circuit according to claim 1, characterized in that: The power conversion module includes a primary voltage conversion submodule and a secondary voltage conversion submodule. The primary voltage conversion submodule consists of a battery charging management chip (U9L), a field-effect transistor, and peripheral circuitry, and is used to step down an external DC voltage to a 12V DC voltage as a second operating voltage source. The secondary voltage conversion submodule consists of a DC-DC step-down converter chip (U10L) and peripheral circuitry, and is used to convert the output voltage of the primary voltage conversion submodule to a 5V DC voltage as a first operating voltage source.

5. A laser beam generating circuit according to claim 4, characterized in that: The first-stage voltage conversion submodule includes an eleventh field-effect transistor (Q11L), a twelfth field-effect transistor (Q12L), a thirteenth field-effect transistor (Q13L), and a CN3765 battery charging management chip (U9L). The input terminal of the twelfth field-effect transistor (Q12L) is connected to an external DC voltage via a second filter inductor (LP2L) and a resettable fuse. The output terminal of the twelfth field-effect transistor (Q12L) is connected to the input terminal of the eleventh field-effect transistor (Q11L) and the voltage input terminal of the battery charging management chip (U9L). The gate terminal of the twelfth field-effect transistor (Q12L) is connected to the drive pin of the battery charging management chip (U9L). The output terminal of the eleventh field-effect transistor (Q11L) is connected via a ninth Schottky diode (SD9L), a first filter inductor (LP1L), and an eightieth resistor (R80L) to serve as the output voltage terminal of the first-stage voltage conversion submodule. The output voltage terminal of the first-level voltage conversion submodule is connected to the input terminal of the thirteenth field-effect transistor (Q13L). The gate terminal of the thirteenth field-effect transistor (Q13L) is connected to the output voltage terminal of the first-level voltage conversion submodule through the eighty-fifth resistor (R85L). The output terminal of the thirteenth field-effect transistor (Q13L) is grounded.

6. A laser beam generating circuit according to claim 5, characterized in that: The DC-DC buck converter chip (U10L) of the secondary voltage conversion submodule is model SCT2432STER. The VIN pin of the DC-DC buck converter chip (U10L) is connected to the output voltage terminal of the primary voltage conversion submodule. The SW pin of the DC-DC buck converter chip (U10L) is connected to the output voltage terminal of the secondary voltage conversion submodule via the third filter inductor (LP3L).

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