Laser cleaning galvanometer power supply time sequence control circuit

Abstract

The utility model relates to a laser cleaning galvanometer power supply time sequence control circuit, which comprises a + 15V external switch input power supply and a-15V external switch input power supply, and is characterized by further comprising a time sequence control circuit, and the + 15V external switch input power supply and the-15V external switch input power supply sequentially output controllable-12V, + 5V and + 12V power supplies according to a preset time sequence after passing through the time sequence control circuit. The time sequence control circuit is built by using discrete devices, so that the cost is low, and the design is simple and reliable.

Description

Technical Field

[0001] The utility model relates to a timing control circuit, in particular to a laser cleaning galvanometer power supply timing control circuit. Background Art

[0002] Today's microprocessors, Soc chips, analog-to-digital converters, FPGAs and other ICs generally have certain requirements for the power-on sequence of each power supply. In particular, the galvanometer of the laser cleaning system requires the use of multiple power supplies, including positive power supplies and negative power supplies, and has certain requirements for the power-on sequence of the power supply. If the power-on sequence of the relevant chips is not met, it will affect the overall function and performance of the galvanometer.

[0003] In the prior art, there are many solutions that can effectively realize power supply timing control. Common solutions include using a dedicated timing control chip, using a resistor voltage divider combined with a comparator to control the timing, etc. However, when using a dedicated timing control chip, there are problems of high cost and complex design; when using a resistor voltage divider combined with a comparator to control the timing, an independent comparison benchmark needs to be set, which is relatively complicated to implement. Therefore, how to provide a simple and reliable timing control circuit including a positive power supply and a negative power supply is a technical problem that needs to be solved at present. Summary of the invention

[0004] The utility model aims to provide a laser cleaning galvanometer power supply timing control circuit, which can simply and reliably provide timing control including a positive power supply and a negative power supply.

[0005] The above purpose is achieved through the following technical solution: a laser cleaning galvanometer power supply timing control circuit, including +15V and -15V external switch input power supplies, which also includes a timing control circuit. After the +15V and -15V external switch input power supplies pass through the timing control circuit, they output controllable -12V, +5V and +12V power supplies in sequence according to a predetermined timing.

[0006] A further technical solution is that the timing control circuit includes three-terminal voltage regulators MC7912BTG and MC7812BTG, and a power supply chip TPS54202DDCR; the -15V external switch input power supply directly outputs a -12V power supply through the three-terminal voltage regulator MC7912BTG in priority; the +15V external switch input power supply is connected to the VIN terminal of the power supply chip TPS54202DDCR, and the EN pin level of the power supply chip TPS54202DDCR enables the output of a +5V power supply; the +5V power supply controls the +15V external switch input power supply through a discrete circuit to output a +15V_Ctrl power supply, and the +15V_Ctrl power supply outputs a +12V power supply through the three-terminal voltage regulator MC7812BTG.

[0007] A further technical solution is that the discrete circuit includes transistors Q1 and Q2, the +5V power supply is connected to the base of the transistor Q1 through resistors R4, R5 and R6, the emitter of the transistor Q1 is grounded, the collector of the transistor Q1 is connected to the gate of the MOSFET Q2, the source of the MOSFET Q2 is connected to the +15V external switch input power supply, and the drain of the MOSFET Q2 outputs the +15V_Ctrl power supply to the three-terminal regulator MC7812BTG.

[0008] A further technical solution is that the transistor Q1 is an NPN transistor and the MOSFET Q2 is a P-type MOSFET.

[0009] A further technical solution is that a resistor R7 is further provided between the gate and the source of the MOSFETQ2.

[0010] A further technical solution is that the +15V external switch input power supply is connected to the ground through the series voltage divider resistors R1 and R2, the common end of the resistors R1 and R2 is connected to the enable pin EN of the chip TPS54202DDCR through the resistor R3, and the enable pin EN of the chip TPS54202DDCR is grounded through the capacitor C1.

[0011] Compared with the prior art, the beneficial effects of the utility model are:

[0012] The laser cleaning galvanometer power supply timing control circuit described in the utility model is constructed using discrete devices, which has low cost, simple design and reliability; and can control the power-on timing of -12V, +5V, and +12V, so that the system -12V is powered on first, followed by +5V, and finally +12V. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation on the present invention.

[0014] Figure 1 A schematic diagram of a laser cleaning galvanometer power supply timing control circuit proposed in an embodiment of the utility model;

[0015] Figure 2 A circuit diagram of a laser cleaning galvanometer power supply timing control circuit proposed in an embodiment of the utility model;

[0016] Figure 3 This is an output power timing diagram of a laser cleaning galvanometer power timing control circuit proposed in an embodiment of the utility model. DETAILED DESCRIPTION

[0017] The present invention is described in detail below in conjunction with the accompanying drawings. The description in this section is only exemplary and explanatory and should not have any limiting effect on the scope of protection of the present invention. In addition, those skilled in the art can make corresponding combinations of the features in the embodiments and in different embodiments of the present invention according to the description of this document.

[0018] The utility model embodiments are as follows, see Figure 1 and Figure 2 : A laser cleaning galvanometer power supply timing control circuit, including +15V and -15V external switch input power supplies, and a timing control circuit. After the +15V and -15V external switch input power supplies pass through the timing control circuit, they output controllable -12V, +5V and +12V power supplies in sequence according to a predetermined timing.

[0019] Preferably, the timing control circuit includes a three-terminal voltage regulator MC7912BTG, a three-terminal voltage regulator MC7812BTG and a power chip TPS54202DDCR, and the -15V external switch input power directly outputs a -12V power supply through the three-terminal voltage regulator MC7912BTG, which is a first priority output.

[0020] The +5V power supply is input through the +15V external switch and output through the power chip TPS54202DDCR. Specifically, the +15V external switch input power supply is connected to the VIN terminal of the power chip TPS54202DDCR, the EN pin level of the power chip TPS54202DDCR enables the output of +5V power supply, and the +5V output is controlled by setting the rise time of the level of the EN enable pin of the TPS54202DDCR, so that the +5V power supply lags behind the -12V power supply; the +5V power supply controls the +15V external switch input power supply to output +15V_Ctrl power supply through a discrete circuit, and the +15V_Ctrl power supply outputs +12V power supply through a three-terminal regulator MC7812BTG, and the +5V controls the output level rise time of the +5V level through a discrete circuit to control the +15V output +15V_Ctrl, and the +15V_Ctrl outputs +12V through the three-terminal regulator MC7812BTG. The above scheme derives the timing of -12V priority output, +5V secondary output, and +12V final output.

[0021] Preferably, the +15V external switch input power supply is connected to the ground through the series voltage-dividing resistors R1 and R2, the common end of the resistors R1 and R2 is connected to the enable pin EN of the chip TPS54202DDCR through the resistor R3, and the enable pin EN of the chip TPS54202DDCR is grounded through the capacitor C1.

[0022] Preferably, the discrete circuit includes a transistor Q1 and a MOSFETQ2, the +5V power supply is connected to the base of the transistor Q1 through resistors R4, R5 and R6, the emitter of the transistor Q1 is grounded, the collector of the transistor Q1 is connected to the gate of the MOSFETQ2, the source of the MOSFETQ2 is connected to the +15V external switch input power supply, and the drain of the MOSFETQ2 outputs the +15V_Ctrl power supply to the three-terminal regulator MC7812BTG.

[0023] Preferably, the transistor Q1 is an NPN transistor, and the MOSFET Q2 is a P-type MOSFET. In this way, the minimum enable voltage of the EN pin of the power chip TPS54202DDCR is 1.2V, and the +15V external switch input power is divided by resistors R1 and R2 to a lower voltage, so as to control the time. The connection point of resistors R1 and R2 is point A, and the voltage at point A is set to 2.5V; the rear stage controls the voltage rise through the RC charging circuit, and after time t1, the EN pin level reaches 1.2V, at which time the power chip TPS54202DDCR output is enabled; the RC circuit uses R3 and C1, and the RC time constant is designed to be 9.4ms.

[0024] +5V output has a rise time, which is determined by the performance of the power chip TPS54202DDCR. The emitter conduction voltage of the rear transistor Q1 is about 0.6V. The voltage divider circuit is formed by resistors R4 and R5. The connection point of resistors R4 and R6 is point B. When the voltage at point B is greater than 0.6V, transistor Q1 is turned on. This ensures that transistor Q1 is turned on only when the output level of the power chip TPS54202DDCR reaches 4.688V, avoiding premature conduction. The role of R6 is to limit the base current of transistor Q1. The transistor Q1 can use the NPN transistor SMMBT2222ALT1G. When the 5V of the front stage of R4 is stable, the voltage at point B is designed to be 0.64V.

[0025] Preferably, a resistor R7 is further provided between the gate and source of the MOSFETQ2. When the transistor Q1 is turned on to GND, the MOSFETQ2 is turned on. The MOSFETQ2 uses a P-type MOSFET model SMMBT2222ALT1G. When the MOSFETQ2 is turned on, +15V is output to +15V_Ctrl. The resistor R7 ensures that when the transistor Q1 is not turned on, the MOSFETQ2 is in a non-conducting state.

[0026] Furthermore, the working process of the laser cleaning galvanometer power supply timing control circuit of the present invention is as follows: the +15V and -15V external switch input power supplies are powered on at the same time, and the -15V external switch input power supply outputs the -12V power supply through the three-terminal regulator MC7912BTG without any control; the +15V external switch input power supply enables the output of the +5V power supply through the EN pin level of the power supply chip TPS54202DDCR, so that the +5V power supply output is later than the -12V power supply, and the hardware circuit automatically determines whether the EN pin level is greater than 1.2V, if it is less, continue to wait, if it is greater, enable the +5V output of the power supply chip TPS54202DDCR; the +5V power supply controls the transistor, thereby controlling the +15V power supply to be output to the three-terminal regulator MC7812BTG, so that the +12V power supply is output later than the +5V power supply, by determining whether the base level of the transistor Q1 is greater than 0.6V, if it is less, continue to wait, if it is greater, the transistor Q1 is turned on to the ground, and the MOSFET Q2 is turned on, and the +15V power supply is output to the three-terminal regulator MC7812BTG, which finally outputs the +12V power supply. The specific circuit output timing diagram is as follows: Figure 3 As shown, -12V power is output first, +5V power is output after time t1, and +12V power is output after time t2. Preferably, in the present invention, time t1 is preferably designed to be 7ms, and time t2 is designed to be 0.6ms. Delay time t1 can be flexibly and reasonably set by changing the values ​​of R1, R2, R3, and C1, and delay time t2 can be flexibly and reasonably set by changing the values ​​of R4 and R5.

[0027] Compared with the prior art, the beneficial effects of the utility model are:

[0028] The laser cleaning galvanometer power supply timing control circuit described in the utility model is constructed using discrete devices, which has low cost, simple design and reliability; and can control the power-on timing of -12V, +5V, and +12V, so that the system -12V is powered on first, followed by +5V, and finally +12V.

[0029] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A laser cleaning galvanometer power supply timing control circuit, including +15V and -15V external switch input power supplies, characterized in that: It also includes a timing control circuit. After the +15V and -15V external switch input power supplies pass through the timing control circuit, controllable -12V, +5V and +12V power supplies are output in sequence according to a predetermined timing.

2. The laser cleaning galvanometer power supply timing control circuit according to claim 1, characterized in that: The timing control circuit includes a three-terminal voltage regulator MC7912BTG, a three-terminal voltage regulator MC7812BTG and a power chip TPS54202DDCR. The -15V external switch input power supply directly outputs a -12V power supply preferentially through the three-terminal voltage regulator MC7912BTG; the +15V external switch input power supply is connected to the VIN terminal of the power chip TPS54202DDCR, and the EN pin level of the power chip TPS54202DDCR enables the output of a +5V power supply; the +5V power supply controls the +15V external switch input power supply to output a +15V_Ctrl power supply through a discrete circuit, and the +15V_Ctrl power supply outputs a +12V power supply through the three-terminal voltage regulator MC7812BTG.

3. The laser cleaning galvanometer power supply timing control circuit according to claim 2, characterized in that: The discrete circuit includes a transistor Q1 and a MOSFET Q2, a +5V power supply is connected to the base of the transistor Q1 through resistors R4, R5 and R6, the emitter of the transistor Q1 is grounded, the collector of the transistor Q1 is connected to the gate of the MOSFET Q2, the source of the MOSFET Q2 is connected to the +15V external switch input power supply, and the drain of the MOSFET Q2 outputs the +15V_Ctrl power supply to the three-terminal regulator MC7812BTG.

4. The laser cleaning galvanometer power supply timing control circuit according to claim 3, characterized in that: The transistor Q1 is an NPN transistor, and the MOSFET Q2 is a P-type MOSFET.

5. The laser cleaning galvanometer power supply timing control circuit according to claim 3, characterized in that: A resistor R7 is further provided between the gate and source of the MOSFET Q2 .

6. The laser cleaning galvanometer power supply timing control circuit according to any one of claims 2 to 5, characterized in that: The +15V external switch input power supply is connected to the ground through the series voltage divider resistors R1 and R2, the common end of the resistors R1 and R2 is connected to the enable pin EN of the chip TPS54202DDCR through the resistor R3, and the enable pin EN of the chip TPS54202DDCR is grounded through the capacitor C1.

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