Driving power supply circuit

Abstract

The utility model belongs to the technical field of power supply circuits, and particularly relates to a driving power supply circuit for loads such as an LED. The circuit comprises an AC-DC constant-voltage circuit which is used for converting commercial power into constant-voltage direct current and outputting the constant-voltage direct current to the outside, and the constant-voltage direct current provides a working power supply for a load; the constant current control circuit is used for controlling the working current of the load; the first voltage acquisition circuit is connected with the first power supply end of the load and measures the voltage of the first power supply end of the load; the second voltage acquisition circuit is connected with a second power supply end of the load and measures the voltage of the second power supply end of the load; and the processor unit is electrically connected with the first voltage acquisition circuit, the second voltage acquisition circuit and the constant current control circuit, and the processor unit is provided with a signal interface and is connected with a wireless signal communication unit. The driving power supply circuit can obtain load working power utilization parameters, transmits the parameters to external intelligent equipment through the signal interface and the wireless signal communication unit, and can judge the load state.

Description

Technical Field

[0001] The present application belongs to the technical field of power supply circuits, and in particular, relates to a driving power supply circuit for loads such as LEDs. Background Art

[0002] At present, when many places hold events, temporary buildings will be built near the event venue. In order to reflect the festive atmosphere, the building or some decorations will hang some mood lights; the mood lights are generally LED lights, and their brightness and color temperature can be adjusted as needed during use; for ease of use, many manufacturers have developed driving power supplies, which can directly dim and adjust the LED through the driving power supply. For example, the application number is: CN201922364840.7, and the name of the invention is: A new type of dimming and color adjustment power supply invention patent, by setting a dimming and color adjustment single-chip microcomputer in the circuit, the dimming and color adjustment single-chip microcomputer controls the LED current circuit, controls the current output to the LED, and thus achieves the purpose of dimming and color adjustment.

[0003] Since the mood lights are dimmed and adjusted during use, their power usage may be in a dynamic state, that is, the power consumption is in a fluctuating state. When the holiday is over and the mood lights are removed, the maximum power consumption corresponding to the maximum power is generally used for settlement, which causes unnecessary cost increase for the user. In order to avoid unnecessary cost increase, some users temporarily install electricity meters, but this brings inconvenience to the use and installation.

[0004] To this end, the applicant is committed to developing a driving power supply that can obtain the power consumption parameters of the load, and can accurately obtain the power consumption, power consumption, etc. based on the power consumption parameters, and accurately settle the electricity bill. Summary of the invention

[0005] The purpose of the present application is to provide a driving power supply circuit, aiming to solve the problem that the traditional driving power supply circuit is unable to obtain the load power consumption parameters.

[0006] A driving power supply circuit, comprising:

[0007] AC-DC constant voltage circuit, used to convert the mains electricity into constant voltage direct current, and output the constant voltage direct current to the outside, and the constant voltage direct current provides working power for the load;

[0008] Constant current control circuit, used to control the working current of the load;

[0009] A first voltage acquisition circuit is connected to a first power supply terminal of the load and measures a voltage of the first power supply terminal of the load;

[0010] A second voltage acquisition circuit is connected to the second power supply terminal of the load and measures the voltage of the second power supply terminal of the load;

[0011] The processor unit is electrically connected to the first voltage acquisition circuit, the second voltage acquisition circuit and the constant current control circuit respectively.

[0012] The processor unit is provided with a signal interface and / or is connected with a wireless signal communication unit.

[0013] Preferably, the signal interface is connected to a touch display screen or a display screen and a button via a signal line.

[0014] Furthermore, the first voltage acquisition circuit includes a resistor RA and a resistor RB connected in series, an input end of the resistor RA is connected to the first power supply end of the load, an output end of the resistor RB is grounded, a connection point between the resistor RA and the resistor RB is set to point A, and point A is connected to the processor unit.

[0015] Preferably, the second voltage acquisition circuit includes a resistor RA1 and a resistor RB1 connected in series, the input end of the resistor RA1 is connected to the second power supply end of the load, the output end of the resistor RB1 is grounded, and the connection point between the resistor RA1 and the resistor RB1 is set to point B, and point B is connected to the processor unit.

[0016] Furthermore, the output end of the AC-DC constant voltage circuit is connected to a filter circuit; preferably, the filter circuit includes a resistor R1, a capacitor C3 and a capacitor C1 connected in parallel.

[0017] Furthermore, the constant current control circuit includes a constant current drive chip and a switch unit, the switch unit is connected in series between the second power supply terminal and the ground, the control end of the switch unit is electrically connected to the constant current drive chip; the detection end of the constant current drive chip is electrically connected to the output end of the switch unit.

[0018] Furthermore, the switch unit includes a MOS tube, the drain of the MOS tube is connected to the second power supply terminal of the load through the inductor L2; the source of the MOS tube is grounded through the resistor R22, and the gate of the MOS tube is connected to the control terminal of the constant current drive chip.

[0019] Furthermore, the AC-DC constant voltage circuit includes a transformer T1, which includes a primary coil, a first secondary coil and a second secondary coil. The first secondary coil supplies power to the load through a pre-stage filter circuit; the second secondary coil is connected to a constant voltage power supply output circuit, which provides power for the constant current control circuit and the processor unit.

[0020] Furthermore, the constant voltage power supply output circuit includes a constant voltage chip Q1, the output end of the second secondary coil is connected to the input end of the constant voltage chip Q1 through a diode D4, the input end and the output end of the constant voltage chip Q1 are grounded through capacitors CE1 and C5 respectively, and the ground end of the constant voltage chip is grounded.

[0021] Furthermore, the pre-stage filter circuit includes a resistor R2 and a capacitor C2 connected in series; and also includes a diode D1 connected in parallel with the resistor R2 and the capacitor C2.

[0022] Furthermore, the AC-DC constant voltage circuit includes a constant voltage control chip U1, the output end of the primary coil is grounded through a series-connected electronic switch tube Q3 and a resistor R25; the control end of the electronic switch tube Q3 is connected to the control end of the constant voltage control chip U1 through a resistor R13; the transformer T1 also includes a third secondary coil; the output end of the third secondary coil is connected to the power supply end of the constant voltage control chip U1 through a series-connected diode D6 and a resistor R14; the input end of the primary coil is grounded through a series-connected resistor R7, a resistor R9 and a capacitor C8, and the output end of the resistor R9 is connected to the detection end of the constant voltage control chip U1.

[0023] Furthermore, the driving power supply circuit also includes an EMI circuit and a rectifier circuit which are sequentially connected to the mains.

[0024] Preferably, the EMI circuit includes a common mode inductor L3, a varistor MOV1 and a capacitor CX1.

[0025] Preferably, the rectifier circuit is a full-bridge rectifier circuit.

[0026] Furthermore, the processor unit includes a single chip microcomputer, a CPU or a control IC.

[0027] Compared with the prior art, the embodiments of the present invention have the following beneficial effects: the processor unit in the driving power supply circuit obtains the voltage across the load through the first and second voltage acquisition circuits, controls the working current and working state of the load by controlling the constant current control circuit, and can obtain the load working power parameters, which are transmitted to the external intelligent device through the signal interface and the wireless signal communication unit, and secondly, can also judge the load state. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a schematic diagram of the first circuit structure of this embodiment.

[0029] Figure 2 This is a schematic diagram of the second circuit structure of this embodiment.

[0030] Figure 3 4 is a circuit schematic diagram of this embodiment.

[0031] The accompanying drawings are marked as follows:

[0032] 1——AC-DC constant voltage circuit; 2——pre-stage filter circuit; 3——filter circuit; 4——constant current control circuit; 5——constant voltage power supply output circuit; 6——EMI circuit; 7——processor unit; 8——load; 9——first voltage acquisition circuit; 10——second voltage acquisition circuit; 11——wireless signal communication unit; 12——rectifier circuit; 13——memory; 14——signal interface. DETAILED DESCRIPTION

[0033] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0034] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0035] It should be understood that the orientation or position relationship indicated by terms such as "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0036] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0037] Figure 1 The schematic diagram of the structure of the driving power supply circuit provided by the preferred embodiment of the present application is shown. For the convenience of explanation, only the part related to the present embodiment is shown, which is described in detail as follows:

[0038] A driving power supply circuit includes: an AC-DC constant voltage circuit 1, a constant current control circuit 4, a first voltage acquisition circuit 9, a second voltage acquisition circuit 10 and a processor unit 7, wherein the AC-DC constant voltage circuit 1 is used to convert AC mains power into constant voltage DC power and output constant voltage DC power to the outside, and the constant voltage DC power provides working power for the load 8; the constant current control circuit 4 is used to control the working current of the load 8; the first voltage acquisition circuit 9 is connected to the first power supply end of the load 8 and measures the voltage of the first power supply end of the load 8; the second voltage acquisition circuit 10 is connected to the second power supply end of the load 8 and measures the voltage of the second power supply end of the load 8; the processor unit 7 is electrically connected to the first voltage acquisition circuit 9, the second voltage acquisition circuit 10 and the constant current control circuit 4 respectively, and the processor unit 7 obtains the working voltage of the load 8 through the first voltage acquisition circuit 9 and the second voltage acquisition circuit 10, and obtains the working current of the load 8 through the constant current control circuit 4. The processor unit 7 is provided with a signal interface 14 or / and is connected with a wireless signal communication unit 11; the processor unit 7 is also connected with a memory 13.

[0039] When the embodiment of the present application is implemented, the AC-DC constant voltage circuit 1 is connected to the mains to convert the AC mains into constant voltage DC and provide a working power supply DC to the load 8; the load 8 can be an LED lamp, a DC fan, etc. In order to control the working state of the load 8, the present application also sets a constant current control circuit 4 for controlling the working current of the load 8; the working state of the load 8 is adjusted by controlling the working current, such as: when the load 8 is an LED lamp, the lighting brightness of the LED lamp can be controlled, or the color temperature can be adjusted; when the load 8 is a DC fan, the rotation speed of the DC fan can be controlled, that is, the rotation level of the fan. While controlling the load 8, it is also necessary to monitor the working voltage, working current and working power of the load 8, so as to avoid excessive power and problems in the line; for this purpose, the present application designs a first voltage acquisition circuit 9, a second voltage acquisition circuit 10 and a processor unit 7. During use, the first voltage acquisition circuit 9 is connected to the first power supply terminal of the load 8, and transmits the voltage signal of the first power supply terminal to the processor unit 7. The second voltage acquisition circuit 10 is connected to the second power supply terminal of the load 8, and transmits the voltage signal of the second power supply terminal to the processor unit 7. The processor unit 7 calculates the voltage difference between the two power supply terminals of the load 8 according to the above two voltage signals, and the voltage difference is the working voltage of the load 8. Secondly, the processor unit 7 sends a control signal to the constant current control circuit 4 to control the constant current control circuit 4 to control the working current of the load 8. Therefore, the working current of the load 8 is controlled by the processor unit 7. The processor unit 7 obtains the working voltage of the load 8 by calculation, and then combines the known working current, current duty cycle, etc.; the real-time working power of the load 8 can be calculated. Secondly, the processor unit includes a single-chip microcomputer, a CPU or a control IC.

[0040] In this embodiment, the processor unit 7 can calculate the working voltage, working power, power consumption of the load 8 and control the constant current control circuit 4 to control the working current of the load 8; that is, the working power parameters of the load 8 can be obtained, and the parameters include: working voltage, working current, working power and power consumption; these parameters can be stored in the memory 13, and the memory 13 can be flash, etc.

[0041] When this information needs to be obtained, the processor unit 7 can communicate with external intelligent devices by setting a signal interface, such as connecting to an external computer by connecting a signal line. The external computer can send control information of the load 8 to the processor unit 7, that is, control the working state of the load 8. The processor sends a control signal to the constant current control circuit 4 according to the control information. The control signal is generally a PWM signal or a high or low level signal. The constant current control circuit 4 controls the working current of the load 8 according to the control signal, thereby completing the control process. Secondly, the processor unit 7 transmits the calculated working voltage, working power, and output working current and other information to the computer through the signal line, and the computer can also directly retrieve the information in the memory 13 through the processor unit 7. The operator can send control information to the processor unit 7 through the intelligent device to control the working state of the load 8, and can also obtain the power consumption parameters of the load 8 through the processor unit 7.

[0042] Secondly, the processor unit 7 can achieve long-distance communication by connecting with the wireless signal communication unit 11; the wireless signal communication unit 11 can be: a Bluetooth circuit, an infrared circuit, a WiFi circuit and other circuits, which can establish communication with corresponding smart devices, such as mobile phones, tablet computers, etc., for easy use and control. The wireless signal communication unit 11 can be existing technology and will not be repeated here.

[0043] Preferably, the signal interface 14 is connected to a touch display screen or a display screen and buttons via a signal line.

[0044] The touch screen can 1. display various working status information of the load 8; 2. send control signals to the processor unit 7. At the same time, the processor unit 7 can also retrieve information in the memory 13 for display, such as working current, working voltage, working power and power consumption in each time period.

[0045] See also Figure 3The first voltage acquisition circuit 9 includes a resistor RA and a resistor RB connected in series, the input end of the resistor RA is connected to the first power supply end of the load 8, the output end of the resistor RB is grounded, the connection point between the resistor RA and the resistor RB is set to point A, and point A is connected to the processor unit 7. The second voltage acquisition circuit 10 includes a resistor RA1 and a resistor RB1 connected in series, the input end of the resistor RA1 is connected to the second power supply end of the load 8, the output end of the resistor RB1 is grounded, the connection point between the resistor RA1 and the resistor RB1 is set to point B, and point B is connected to the processor unit 7.

[0046] When measuring voltage, in order to avoid burning the processor unit 7 due to a large voltage during direct measurement, a voltage divider circuit is used to divide the voltage by a certain proportion, and then the divided voltage is measured, and finally the voltage at the measuring point is obtained by proportional calculation; therefore, the first voltage acquisition circuit 9 and the second voltage acquisition circuit 10 of the present technical solution both use voltage divider circuits respectively; assuming that the voltage at point A is VA, the voltage at point B is VB, and the input voltage of the resistor RA is V1, then: V1 / (RA+RB)=VA / RB, V1=VA*(RA+RB) / RB; the input voltage of the resistor RA1 is V2, then: V2 / (RA1+RB1)=VB / RB1, V2=VB*(RA1+RB1) / RB1; the working voltage of the load 8 is V, V=V1-V2.

[0047] For the convenience of calculation, it can be set that: the resistance value of resistor RA is equal to the resistance value of resistor RA1, that is: RA=RA1; the resistance value of resistor RB is equal to the resistance value of resistor RB1, that is: RB=RB1, then: V=(VA-VB)*(RA+RB) / RB.

[0048] The above are theoretical calculation values; in actual use, the working state of load 8 can be judged according to the measured V value; for example, in the initial stage of operation, the working voltage V of load 8 has been in a stable fluctuation state, such as: V = 35-37V, which is not much different from the theoretical calculation value; when the working voltage V value of load 8 suddenly increases to the first predetermined value, such as 50V, load 8 is in a fault open circuit state or no-load; when the working voltage V value of load 8 suddenly decreases to the second predetermined value, such as 2V, load 8 is in a fault short circuit state. When the working voltage V of load 8 is between the first predetermined value and the second predetermined value, it can be judged that load 8 is working normally, but the difference between the theoretical value and the reference value is required. If the difference is too large, load 8 should be regularly inspected and repaired, and the components inside load 8 may be aged, etc.; therefore, the working state of load 8 can be judged according to the voltage acquisition value.

[0049] See also Figure 3The output end of the AC-DC constant voltage circuit 1 is connected to a filter circuit 3, and the filter circuit 3 includes a resistor R1, a capacitor C3 and a capacitor C1 connected in parallel.

[0050] Resistor R1 and capacitor C1 form an RC filter circuit, capacitor C3 is an electrolytic capacitor used for energy storage. When load 8 is working, the power consumption is not always stable; the power consumption is sometimes large and sometimes small, resulting in induced currents in the line due to electromagnetic induction, which are filtered out by filter circuit 3; secondly, capacitor C3 has a large capacity and is used to temporarily store electrical energy; when the power consumption suddenly increases, capacitor C3 temporarily discharges to supplement the electrical energy in the line and stabilize the voltage in the line.

[0051] See also Figure 3 The constant current control circuit 4 includes a constant current driving chip and a switch unit. The switch unit is connected in series between the second power supply terminal and the ground. The control end of the switch unit is electrically connected to the constant current driving chip; the detection end of the constant current driving chip is electrically connected to the output end of the switch unit.

[0052] In the specific setting, the constant current driver chip can adopt a driver chip of model: TB99; of course, it can also be a driver chip of other models; the PWM end of the driver chip is electrically connected to the processor unit 7, and receives the PWM control signal sent by the processor unit 7; the GATE end of the driver chip is connected to the control end of the switch unit, and controls the on and off of the switch unit through high and low levels; the CS end of the driver chip is the detection end, which detects the potential flowing through the output end of the switch unit, adjusts the on and off frequency of the switch unit, and thus adjusts the working current of the load 8, so that the working current is maintained in a constant current state.

[0053] For the convenience of design, the switch unit includes a MOS tube, the drain of which is connected to the second power supply terminal of the load 8 through the inductor L2; the source of the MOS tube is grounded through the resistor R22, and the gate of the MOS tube is connected to the control terminal of the constant current driver chip. The driver chip controls the on and off of the MOS tube by controlling the gate voltage of the MOS tube; the MOS tube is used as the switch unit, which is convenient to control; of course, its electronic components, such as triodes, thyristors, etc., can also be used as the switch unit.

[0054] See also Figure 3 The AC-DC constant voltage circuit 1 includes a transformer T1, which includes a primary coil, a first secondary coil and a second secondary coil. The first secondary coil supplies power to a load 8 through a pre-stage filter circuit 2; the second secondary coil is connected to a constant voltage power supply output circuit 5, which provides power for a constant current control circuit 4 and a processor unit 7.

[0055] The power supply voltage of the constant current control circuit 4 and the processor unit 7 is different from the working voltage of the load 8. In order to avoid setting up an additional power supply circuit, a constant voltage power supply output circuit 5 is directly connected through the AC-DC constant voltage circuit 1. By setting multiple secondary coils on the secondary side of the transformer, the second secondary coil is used to power the constant voltage output circuit, and the constant voltage output circuit outputs a stable 5V power supply to the outside.

[0056] See specifically Figure 3 The constant voltage power supply output circuit 5 includes a constant voltage chip Q1. The output end of the second secondary coil is connected to the input end of the constant voltage chip Q1 through a diode D4. The input end and the output end of the constant voltage chip Q1 are grounded through capacitors CE1 and C5 respectively. The ground end of the constant voltage chip is grounded.

[0057] The constant voltage power supply output circuit 5 adopts a constant voltage chip to adjust the voltage and output a 5V power supply stably to the outside; this is a prior art and will not be described in detail. Secondly, in order to keep the input and output voltages of the constant voltage chip Q1 stable, capacitors CE1 and C5 are provided to filter out background clutter. Capacitor CE1 is an electrolytic capacitor, which also has the function of temporary energy storage and assisting in maintaining voltage stability. Diode D4 can prevent reverse connection during wiring; protect the constant voltage chip Q1. When the line is reversed, since diode D4 is cut off, the circuit where the constant voltage chip is located is open circuit and no current flows through.

[0058] In order to stabilize the output voltage of the first secondary coil, the pre-stage filter circuit 2 includes a resistor R2 and a capacitor C2 connected in series; and also includes a diode D1 connected in parallel with the resistor R2 and the capacitor C2.

[0059] In specific implementation, the resistor R2 is also connected in parallel with the resistor R3; the diode D1 is connected in parallel with the diode D3. The resistor R2 and the capacitor C2 form an RC filter circuit for filtering the output current of the first secondary coil; the diode D1 is used to prevent the line from being reversely connected.

[0060] See also Figure 3 The AC-DC constant voltage circuit 1 includes a constant voltage control chip U1, the output end of the primary coil is grounded through a series-connected electronic switch tube Q3 and a resistor R25; the control end of the electronic switch tube Q3 is connected to the control end of the constant voltage control chip U1 through a resistor R13; the transformer T1 also includes a third secondary coil; the output end of the third secondary coil is connected to the power supply end of the constant voltage control chip U1 through a series-connected diode D6 and a resistor R14; the input end of the primary coil is grounded through a series-connected resistor R7, a resistor R9 and a capacitor C8, and the output end of the resistor R9 is connected to the detection end of the constant voltage control chip U1.

[0061] The AC-DC constant voltage circuit 1 may be of prior art; the constant voltage control chip U1 may be a TL431 chip or the like; by detecting the input voltage, the on-off frequency of the electronic switch tube Q3 is controlled, thereby controlling the voltage output by the first secondary coil to achieve the purpose of outputting a constant voltage.

[0062] In order to stabilize the input current of the AC-DC constant voltage circuit 1, the driving power supply circuit further includes an EMI circuit 6 and a rectifier circuit 12 connected to the mains in sequence. Preferably, the EMI circuit 6 includes a common mode inductor L3, a varistor MOV1 and a capacitor CX1.

[0063] The two input ends of the common-mode inductor L3 are respectively connected to the neutral line and the live line of the mains; preferably, one of the input ends is also connected to a fuse F1. The varistor MOV1 is connected in parallel with the capacitor CX1, and the two output ends of the common-mode inductor L3 are respectively connected to the two ends of the varistor MOV1. The fuse F1 is used to prevent excessive current in the line and protect the line; when the current is too large, the fuse F1 melts; the common-mode inductor L3 is used to eliminate the common-mode noise signal generated in the line; the capacitor CX1 is used to eliminate the differential-mode noise signal generated in the line; the varistor MOV1 is used to prevent surge voltage, the voltage suddenly increases greatly, the varistor MOV1 is broken down to form a short circuit, and the internal circuit is protected. The rectifier circuit 12 can adopt a full-bridge rectifier circuit 12.

[0064] The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A driving power supply circuit, characterized in that: It includes: AC-DC constant voltage circuit, used to convert the mains electricity into constant voltage direct current, and output the constant voltage direct current to the outside, and the constant voltage direct current provides working power for the load; Constant current control circuit, used to control the working current of the load; A first voltage acquisition circuit is connected to a first power supply terminal of the load and measures a voltage of the first power supply terminal of the load; A second voltage acquisition circuit is connected to the second power supply terminal of the load and measures the voltage of the second power supply terminal of the load; The processor unit is electrically connected to the first voltage acquisition circuit, the second voltage acquisition circuit and the constant current control circuit respectively; The processor unit is provided with a signal interface and / or is connected with a wireless signal communication unit.

2. The driving power supply circuit according to claim 1, characterized in that: The processor unit is connected to a memory.

3. The driving power supply circuit according to claim 1, characterized in that: The first voltage acquisition circuit includes a resistor RA and a resistor RB connected in series, the input end of the resistor RA is connected to the first power supply end of the load, the output end of the resistor RB is grounded, the connection point between the resistor RA and the resistor RB is set to point A, and point A is connected to the processor unit; the second voltage acquisition circuit includes a resistor RA1 and a resistor RB1 connected in series, the input end of the resistor RA1 is connected to the second power supply end of the load, the output end of the resistor RB1 is grounded, the connection point between the resistor RA1 and the resistor RB1 is set to point B, and point B is connected to the processor unit.

4. The driving power supply circuit according to claim 1, characterized in that: The constant current control circuit includes a constant current drive chip and a switch unit. The switch unit is connected in series between the second power supply terminal and the ground. The control terminal of the switch unit is electrically connected to the constant current drive chip. The detection terminal of the constant current drive chip is electrically connected to the output terminal of the switch unit.

5. The driving power supply circuit according to claim 4, characterized in that: The switch unit includes a MOS tube, the drain of the MOS tube is connected to the second power supply terminal of the load through the inductor L2; the source of the MOS tube is grounded through the resistor R22, and the gate of the MOS tube is connected to the control terminal of the constant current drive chip.

6. The driving power supply circuit according to claim 1, characterized in that: The output end of the AC-DC constant voltage circuit is connected to a filter circuit; the filter circuit includes a resistor R1, a capacitor C3 and a capacitor C1 connected in parallel.

7. The driving power supply circuit according to claim 1, characterized in that: The AC-DC constant voltage circuit includes a transformer T1, which includes a primary coil, a first secondary coil and a second secondary coil. The first secondary coil supplies power to the load through a pre-stage filter circuit; the second secondary coil is connected to a constant voltage power supply output circuit, which provides power for a constant current control circuit and a processor unit.

8. The driving power supply circuit according to claim 7, characterized in that: The constant voltage power supply output circuit includes a constant voltage chip Q1. The output end of the second secondary coil is connected to the input end of the constant voltage chip Q1 through a diode D4. The input end and output end of the constant voltage chip Q1 are grounded through capacitors CE1 and C5 respectively. The ground end of the constant voltage chip is grounded.

9. The driving power supply circuit according to claim 7, characterized in that: The pre-stage filter circuit includes a resistor R2 and a capacitor C2 connected in series; and also includes a diode D1 connected in parallel with the resistor R2 and the capacitor C2.

10. The driving power supply circuit according to claim 1, characterized in that: The AC-DC constant voltage circuit includes a constant voltage control chip U1, and the output end of the primary coil is grounded through a series-connected electronic switch tube Q3 and a resistor R25; the control end of the electronic switch tube Q3 is connected to the control end of the constant voltage control chip U1 through a resistor R13; the transformer T1 also includes a third secondary coil; the output end of the third secondary coil is connected to the power supply end of the constant voltage control chip U1 through a series-connected diode D6 and a resistor R14; the input end of the primary coil is grounded through a series-connected resistor R7, a resistor R9 and a capacitor C8, and the output end of the resistor R9 is connected to the detection end of the constant voltage control chip U1.

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