Dual voltage switching circuit and method for machine vision light source

Abstract

The application provides a double-voltage control circuit for a machine vision light source, comprising a voltage switching circuit, the voltage switching circuit comprising a triode Q5, a MOS tube Q3, a diode D4 and a diode D3, the base of the triode Q5 being connected to a controller, the controller realizing the on-off of the triode Q5 through an output signal; the MOS tube Q3 is a P-type MOS tube, the source of the MOS tube Q3 being connected to a first power supply through a second line, the drain of the MOS tube Q3 being connected to the anode of the light source through a third line, the diode D4 being arranged on the third line, the diode D4 making the third line unidirectionally conduct from the MOS tube Q3 to the anode of the light source, the collector of the triode Q5 being connected to the second line through a fifth line, the resistor R34 and the resistor R36 being connected in series on the fifth line, the gate of the MOS tube Q3 being connected to the part of the fifth line between the resistor R34 and the resistor R36, and the emitter of the triode Q5 being grounded.

Description

Technical Field

[0001] This invention relates to the field of machine vision, and more particularly to a dual-voltage switching circuit and method for machine vision light sources. Background Technology

[0002] Machine vision is very common in current industrial production. By taking pictures of workpieces and processing the images, it is possible to inspect the surface of the workpieces. When taking pictures, a light source is needed to supplement the light to achieve better shooting results. Depending on the type of inspection, the number or brightness of the light source needs to be different. Therefore, it is sometimes necessary to adjust the input voltage. In the current technology, two sets of circuits are often designed to adjust the voltage. Although this can solve the problem, the two sets of circuits are complex to control and have a high failure rate. Summary of the Invention

[0003] The main objective of this invention is to provide a dual-voltage switching circuit and method for machine vision light sources, which can control the voltage required by the light source through a single circuit.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is as follows: a dual-voltage control circuit for machine vision light source, including a voltage switching circuit, wherein the voltage switching circuit includes a transistor Q5, a MOSFET Q3, a diode D4, and a diode D3, wherein the base of the transistor Q5 is connected to a controller, and the controller realizes the switching on and off of the transistor Q5 through an output signal; The MOSFET Q3 is a P-type MOSFET. The source of the MOSFET Q3 is connected to the first power supply through the second line, and the drain of the MOSFET Q3 is connected to the positive terminal of the light source through the third line. The diode D4 is disposed on the third line, and the diode D4 enables the third line to conduct unidirectionally from the MOSFET Q3 to the positive terminal of the light source. The collector of the transistor Q5 is connected to the second line through the fifth line. Resistors R34 and R36 are connected in series on the fifth line. The gate of the MOSFET Q3 is connected to the portion of the fifth line located between resistors R34 and R36. The emitter of the transistor Q5 is grounded. The voltage switching circuit further includes a fourth line, one end of which is connected to a second power supply and the other end of which is connected to the positive terminal of the light source; a diode D3 is provided on the fourth line, which enables the fourth line to conduct unidirectionally from the 24V power supply to the positive terminal of the light source; the voltage of the second power supply is less than the voltage of the first power supply.

[0005] Preferably, the circuit further includes a switch control circuit, which includes a MOSFET Q4. The gate of the MOSFET Q4 is connected to the controller via a sixth line, the drain of the MOSFET Q4 is connected to the negative terminal of the light source via an eighth line, and the source of the MOSFET Q4 is grounded.

[0006] A dual-voltage control method for machine vision light sources, employing the aforementioned dual-voltage control circuit, specifically includes the following steps: Step 1: The controller outputs a signal to turn on MOSFET Q4; Step 2: When a second power supply is required, transistor Q5 is turned off, MOSFET Q3 is turned off, the first power supply and the light source are not connected, and the second power supply supplies power to the light source through the fourth line. Step 3: When the first power supply is required, the controller outputs a control signal, transistor Q5 is turned on, the gate of MOSFET Q3 is at a high level, MOSFET Q3 is turned on, the first power supply is connected to the light source, and the first power supply supplies power to the light source.

[0007] Compared with the prior art, the present invention has the following beneficial effects: This invention designs a voltage dual-switching circuit, in which the controller can switch the voltage by controlling the switching of the transistors on the circuit, thus simplifying the voltage switching process. Attached Figure Description

[0008] Figure 1 This is the schematic diagram of a voltage switching circuit; Figure 2 This is the schematic diagram of a switch control circuit. Detailed Implementation

[0009] The following description is intended to disclose the invention and enable those skilled in the art to implement it. The preferred embodiments described below are merely examples, and other obvious variations will occur to those skilled in the art.

[0010] A dual-voltage control circuit for a machine vision light source includes a voltage switching circuit and a switching control circuit. The voltage switching circuit includes a transistor Q5, a MOSFET Q3, a diode D4, and a diode D5. The base of transistor Q5 is connected to a controller via a first line 1, and the controller controls the switching of transistor Q5 via an output signal. MOSFET Q3 is a P-type MOSFET. The source of MOSFET Q3 is connected to a 48V power supply via a second line 2, and the drain of MOSFET Q3 is connected to the positive terminal of the light source via a third line 3. Diode D4 is mounted on the third line 3, enabling unidirectional conduction from MOSFET Q3 to the positive terminal of the light source. The collector of transistor Q5 is connected to the second line 2 via a fifth line 5. Resistors R34 and R36 are connected in series on the fifth line 5. The gate of MOSFET Q3 is connected to the portion of the fifth line 5 located between resistors R34 and R36. The emitter of transistor Q5 is grounded.

[0011] The voltage switching circuit further includes a fourth line 4, one end of which is connected to a 24V power supply, and the other end is connected to the positive terminal of the light source. A diode D3 is disposed on the fourth line 4, which enables the fourth line 4 to conduct unidirectionally from the 24V power supply to the positive terminal of the light source.

[0012] When transistor Q5 is not conducting, there is no current in line 5, MOSFET Q3 is off, and the 48V power supply is disconnected from the positive terminal of the light source. At this time, the 24V power supply provides voltage to the light source, and due to the effect of diode D4, the current in line 4 will not flow to MOSFET Q3. When 48V voltage is needed, the controller outputs a voltage signal to transistor Q5 through line 1, transistor Q5 conducts, and 48V, line 2, line 5, transistor Q5 and ground form a circuit. There is voltage across resistor R36, and the gate of MOSFET Q3 collects the voltage across R36, turning on MOSFET Q3. At this time, 48V, line 2, MOSFET Q3, line 3 and the positive terminal of the power supply are connected, and thus the 48V power supply provides power. Since the voltage of 48V is higher than 24V, 24V no longer provides voltage to the light source.

[0013] The switching control circuit includes a MOSFET Q4. The gate of the MOSFET Q4 is connected to the controller via a sixth line 6, and the drain of the MOSFET Q4 is connected to the negative terminal of the light source via an eighth line 8. The source of the MOSFET Q4 is grounded. When the controller outputs a voltage signal to the gate of the MOSFET Q4, the MOSFET Q4 is turned on, and current flows from the positive terminal of the light source, the negative terminal of the light source, the eighth line 8, the MOSFET Q4, to ground.

[0014] The switch control circuit also includes a resistor R30 and a diode D5, which are connected in parallel with the light source, and the diode D5 is conducting in the direction from the negative terminal of the light source to the positive terminal of the light source.

[0015] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention. The scope of protection claimed by the appended claims and their equivalents is defined.

Claims

1. A dual-voltage control circuit for a machine vision light source, characterized in that, The device includes a voltage switching circuit, which comprises a transistor Q5, a MOSFET Q3, a diode D4, and a diode D3. The base of the transistor Q5 is connected to a controller, and the controller controls the switching on and off of the transistor Q5 by outputting a signal. The MOSFET Q3 is a P-type MOSFET. The source of the MOSFET Q3 is connected to the first power supply through the second line, and the drain of the MOSFET Q3 is connected to the positive terminal of the light source through the third line. The diode D4 is disposed on the third line, and the diode D4 enables the third line to conduct unidirectionally from the MOSFET Q3 to the positive terminal of the light source. The collector of the transistor Q5 is connected to the second line through the fifth line. Resistors R34 and R36 are connected in series on the fifth line. The gate of the MOSFET Q3 is connected to the portion of the fifth line located between resistors R34 and R36. The emitter of the transistor Q5 is grounded. The voltage switching circuit further includes a fourth line, one end of which is connected to a second power supply and the other end of which is connected to the positive terminal of the light source; a diode D3 is provided on the fourth line, which enables the fourth line to conduct unidirectionally from the 24V power supply to the positive terminal of the light source; the voltage of the second power supply is less than the voltage of the first power supply.

2. The dual-voltage control circuit for a machine vision light source according to claim 1, characterized in that, It also includes a switch control circuit, which includes a MOSFET Q4. The gate of the MOSFET Q4 is connected to the controller through a sixth line, the drain of the MOSFET Q4 is connected to the negative terminal of the light source through an eighth line, and the source of the MOSFET Q4 is grounded.

3. A dual-voltage control method for a machine vision light source, employing the dual-voltage control circuit described in claim 2, specifically comprising the following steps: Step 1: The controller outputs a signal to turn on MOSFET Q4; Step 2: When a second power supply is required, transistor Q5 is turned off, MOSFET Q3 is turned off, the first power supply and the light source are not connected, and the second power supply supplies power to the light source through the fourth line. Step 3: When the first power supply is required, the controller outputs a control signal, transistor Q5 is turned on, the gate of MOSFET Q3 is at a high level, MOSFET Q3 is turned on, the first power supply is connected to the light source, and the first power supply supplies power to the light source.

Images