Overvoltage protection power supply circuit and power supply equipment

Abstract

The utility model discloses an overvoltage protection power supply circuit and power supply equipment, the overvoltage protection power supply circuit comprises a power supply module, a switch module, a constant current module and an overvoltage protection module, and the voltage output end of the power supply module is used for being connected with a first bus of a power supply bus; the first end of the switch module is used for being connected with a second bus of the power supply bus; the constant current module is used for controlling current flowing through the constant current module; the overvoltage protection module is connected with the switch module, and the overvoltage protection module is used for monitoring the voltage of the first end of the switch module and controlling the switch module to be switched off when the voltage of the first end of the switch module is larger than an overvoltage threshold value. The switch module is controlled to be switched off through the overvoltage protection module when the voltage of the first end of the switch module is larger than the overvoltage threshold value, the power supply loop can be switched off in time under the condition that the DALI bus is connected with high voltage by mistake, and the stability and safety of the DALI bus are improved.

Description

Technical Field

[0001] The present application belongs to the field of power supply technology, and in particular, relates to an overvoltage protection power supply circuit and power supply equipment. Background Art

[0002] At present, the Digital Addressable Lighting Interface (DALI) protocol is a commonly used lighting dimming protocol that supports direct and inter-level dimming and can be widely used in intelligent lighting control systems such as factories, shopping malls, and office buildings. DALI signals can transmit information through the high and low level changes of the voltage on the DALI bus.

[0003] Since the voltage on the DALI bus is low, when the DALI bus is mistakenly connected to 220V AC or high voltage, it is easy to cause damage to all devices on the DALI bus. Utility Model Content

[0004] The purpose of the present application is to provide an overvoltage protection power supply circuit and power supply equipment, aiming to solve the problem that the traditional DALI bus is easily damaged by high voltage electricity.

[0005] The first aspect of an embodiment of the present application provides an overvoltage protection power supply circuit, comprising: a power supply module, wherein a voltage output end of the power supply module is used to connect to a first bus of a power supply bus; a switch module, wherein a first end of the switch module is used to connect to a second bus of the power supply bus; a constant current module, wherein a first end of the constant current module is connected to a second end of the switch module, and a second end of the constant current module is connected to a ground end of the power supply module, and the constant current module is used to control a current flowing through the constant current module; and an overvoltage protection module, wherein the overvoltage protection module is connected to the switch module, and the overvoltage protection module is used to monitor a voltage at a first end of the switch module, and when a voltage at a first end of the switch module is greater than an overvoltage threshold, control the switch module to shut down.

[0006] In one embodiment, the switch module includes a first switch unit, and the overvoltage protection module includes a second switch unit and a reverse breakdown protection unit; the first end of the first switch unit is connected to the second bus for the power supply bus, the second end of the first switch unit is connected to the first end of the constant current module, the control end of the first switch unit is connected to the first end of the second switch unit, the second end of the second switch unit is connected to the second end of the first switch unit, the control end of the second switch unit is connected to the anode of the reverse breakdown protection unit, and the cathode of the reverse breakdown protection unit is connected to the first end of the first switch unit; the overvoltage threshold is equal to the breakdown voltage of the reverse breakdown protection unit.

[0007] In one embodiment, the first switch unit includes a first switch tube, a first voltage-dividing resistor and a second voltage-dividing resistor, the first end of the first switch tube is connected to the second bus used for the power supply bus, the second end of the first switch tube is connected to the first end of the constant current module, and the control end of the first switch tube is connected to the first end of the second switch unit; the first end of the first voltage-dividing resistor is connected to the control end of the first switch tube, the second end of the first voltage-dividing resistor is connected to the voltage output end of the power module, the first end of the second voltage-dividing resistor is connected to the control end of the first switch tube, and the second end of the second voltage-dividing resistor is connected to the second end of the first switch tube.

[0008] In one embodiment, the second switch unit includes a second switch tube, a third voltage-dividing resistor and a fourth voltage-dividing resistor; the first end of the third voltage-dividing resistor is connected to the anode of the reverse breakdown protection unit, the second end of the third voltage-dividing resistor is respectively connected to the control end of the second switch tube and the first end of the fourth voltage-dividing resistor, the first end of the second switch tube is connected to the control end of the first switch unit, the second end of the second switch tube is connected to the second end of the first switch unit, and the second end of the fourth voltage-dividing resistor is connected to the second end of the second switch tube.

[0009] In one embodiment, the reverse breakdown protection unit includes a first diode and a current limiting resistor; the anode of the first diode is connected to the control end of the second switch unit, and the cathode of the first diode is connected to the first end of the first switch unit through the current limiting resistor.

[0010] In one embodiment, the constant current module includes a dual-tube constant current unit, a first end of the dual-tube constant current unit is connected to the second end of the switch module, and a second end of the dual-tube constant current unit is connected to the ground end of the power module.

[0011] In one embodiment, the power supply bus includes a DALI bus.

[0012] In one embodiment, a control module is further included, wherein the control module is connected to the constant current module and the power module, and the control module is used to transmit a control signal to the DALI bus.

[0013] In one embodiment, an interface module is further included, through which the voltage output end of the power supply module is connected to the first bus of the power supply bus, and the first end of the switch module is connected to the second bus of the power supply bus.

[0014] A second aspect of an embodiment of the present application provides a power supply device, comprising the overvoltage protection power supply circuit as described above.

[0015] Compared with the prior art, the embodiments of the present application have the following beneficial effects: when the voltage at the first end of the switch module is greater than the overvoltage threshold, the overvoltage protection module controls the switch module to shut down, so that the power supply circuit can be shut down in time when the DALI bus is mistakenly connected to a high voltage, thereby improving the stability and safety of the DALI bus. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A schematic diagram of an overvoltage protection power supply circuit provided in an embodiment of the present application;

[0017] Figure 2 An exemplary circuit diagram of an overvoltage protection power supply circuit provided in an embodiment of the present application;

[0018] Figure 3 A schematic diagram of a power supply device provided in one embodiment of the present application. DETAILED DESCRIPTION

[0019] 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.

[0020] 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.

[0021] 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.

[0022] Figure 1 A schematic diagram of an overvoltage protection power supply circuit provided by an embodiment of the present application is shown. For ease of explanation, only the part related to the present embodiment is shown, which is described in detail as follows:

[0023] The overvoltage protection power supply circuit 10 includes: a power supply module 100 , a switch module 200 , a constant current module 300 and an overvoltage protection module 400 .

[0024] The voltage output terminal of the power module 100 is used to connect to the first bus of the power supply bus 20 . The first terminal of the switch module 200 is used to connect to the second bus of the power supply bus 20 .

[0025] The first end of the constant current module 300 is connected to the second end of the switch module 200, and the second end of the constant current module 300 is connected to the ground end of the power module 100. The constant current module 300 is used to control the current flowing through the constant current module 300. The overvoltage protection module 400 is connected to the switch module 200, and the overvoltage protection module 400 is used to monitor the voltage of the first end of the switch module 200, and when the voltage of the first end of the switch module 200 is greater than the overvoltage threshold, the switch module 200 is controlled to be turned off.

[0026] It should be noted that, when the switch module 200 is turned on, the current output from the voltage output terminal of the power module 100 is transmitted to the switch module 200 after passing through the load connected to the first bus and the second bus, and finally returns to the ground terminal of the power module 100 through the constant current module 300, forming a complete power supply loop. When the switch module 200 is turned off, the power supply loop will be turned off, and the overvoltage protection power supply circuit 10 will stop supplying power.

[0027] When the switch module 200 is turned on, the overvoltage protection module 400 can monitor the voltage at the first end of the switch module 200. When the voltage at the first end of the switch module 200 is greater than the overvoltage threshold, the overvoltage protection module 400 can control the switch module 200 to be turned off, thereby timely shutting down the power supply circuit when the DALI bus is mistakenly connected to a high voltage, thereby improving the stability and safety of the DALI bus.

[0028] In some embodiments, the power module 100 may include a DC power supply or an AC / DC converter. The AC / DC converter may be connected to an AC power supply and convert the AC power provided by the AC power supply into DC power before providing the power supply bus 20 .

[0029] In one embodiment, the switch module 200 includes a first switch unit 210 , and the overvoltage protection module 400 includes a second switch unit 410 and a reverse breakdown protection unit 420 .

[0030] The first end of the first switch unit 210 is connected to the second bus for connecting to the power supply bus 20, the second end of the first switch unit 210 is connected to the first end of the constant current module 300, the control end of the first switch unit 210 is connected to the first end of the second switch unit 410, the second end of the second switch unit 410 is connected to the second end of the first switch unit 210, the control end of the second switch unit 410 is connected to the anode of the reverse breakdown protection unit 420, and the cathode of the reverse breakdown protection unit 420 is connected to the first end of the first switch unit 210. The overvoltage threshold is equal to the breakdown voltage of the reverse breakdown protection unit 420.

[0031] It can be understood that when the voltage at the first end of the first switch unit 210 is less than the breakdown voltage of the reverse breakdown protection unit 420, the reverse breakdown protection unit 420 is in the cut-off state, the second switch unit 410 is in the off state, and the first switch unit 210 is in the on state.

[0032] When the voltage at the first end of the first switch unit 210 is greater than the breakdown voltage of the reverse breakdown protection unit 420, the reverse breakdown protection unit 420 will be broken down by the voltage and thus turned on. When the reverse breakdown protection unit 420 is turned on, the second switch unit 410 will be turned on due to the increase in the voltage at its control end, so that the voltage at the control end of the first switch unit 210 is equal to the voltage at the second end of the first switch unit 210, and finally the first switch unit 210 is turned off.

[0033] Therefore, the breakdown voltage of the reverse breakdown protection unit 420 is the overvoltage threshold of the overvoltage protection module 400 .

[0034] In one embodiment, the first switch unit 210 includes a first switch tube Q1, a first voltage-dividing resistor R1, and a second voltage-dividing resistor R2. The first end of the first switch tube Q1 is connected to the second bus for connecting to the power supply bus 20, the second end of the first switch tube Q1 is connected to the first end of the constant current module 300, and the control end of the first switch tube Q1 is connected to the first end of the second switch unit 410. The first end of the first voltage-dividing resistor R1 is connected to the control end of the first switch tube Q1, the second end of the first voltage-dividing resistor R1 is connected to the voltage output end of the power module 100, the first end of the second voltage-dividing resistor R2 is connected to the control end of the first switch tube Q1, and the second end of the second voltage-dividing resistor R2 is connected to the second end of the first switch tube Q1.

[0035] Specifically, the first switch tube Q1 may include an N-type MOS tube, the drain of the N-type MOS tube serves as the first end of the first switch tube Q1, the source of the N-type MOS tube serves as the second end of the first switch tube Q1, and the gate of the N-type MOS tube serves as the control end of the first switch tube Q1.

[0036] It should be noted that when the second switch unit 410 is turned off, the voltage at the voltage output end of the power module 100 will control the first switch tube Q1 to be turned on after being divided by the first voltage-dividing resistor R1 and the second voltage-dividing resistor R2, and the voltage difference between the second end of the first switch tube Q1 and the control end of the first switch tube Q1 is VCC / (R1+R2)*R2, where VCC is the voltage at the voltage output end of the power module 100. When the second switch unit 410 is turned on, there is no voltage difference between the second end of the first switch tube Q1 and the control end of the first switch tube Q1, so the first switch tube Q1 is turned off.

[0037] In one embodiment, the second switch unit 410 includes a second switch tube Q2, a third voltage-dividing resistor R3, and a fourth voltage-dividing resistor R4. The first end of the third voltage-dividing resistor R3 is connected to the anode of the reverse breakdown protection unit 420, the second end of the third voltage-dividing resistor R3 is connected to the control end of the second switch tube Q2 and the first end of the fourth voltage-dividing resistor R4, respectively, the first end of the second switch tube Q2 is connected to the control end of the first switch unit 210, the second end of the second switch tube Q2 is connected to the second end of the first switch unit 210, and the second end of the fourth voltage-dividing resistor R4 is connected to the second end of the second switch tube Q2.

[0038] The second switch tube Q2 can be configured to be turned on at a high level. Specifically, the second switch tube Q2 can include an NPN transistor, the collector of the NPN transistor serves as the first end of the second switch tube Q2, the emitter of the NPN transistor serves as the second end of the second switch tube Q2, and the base of the NPN transistor serves as the control end of the second switch tube Q2.

[0039] When the reverse breakdown protection unit 420 is not broken down, the NPN transistor is in the off state. When the reverse breakdown protection unit 420 is broken down, the base voltage of the NPN transistor gradually increases, and finally the NPN transistor is turned on, that is, the second switch unit 410 is turned on, and finally overvoltage protection is achieved for the switch module 200.

[0040] In one embodiment, the reverse breakdown protection unit 420 includes a first diode D1 and a current limiting resistor R5. The anode of the first diode D1 is connected to the control terminal of the second switch unit 410, and the cathode of the first diode D1 is connected to the first terminal of the first switch unit 210 through the current limiting resistor R5.

[0041] It can be understood that before the first diode D1 is broken down, the current cannot be transmitted to the switch module 200 through the first diode D1. After the first diode D1 is broken down, the current can be transmitted to the switch module 200 through the first diode D1. The current limiting resistor R5 is used to protect the switch module 200 to avoid excessive current transmitted to the switch module 200.

[0042] In one embodiment, the constant current module 300 includes a dual-tube constant current unit 310, the first end of the dual-tube constant current unit 310 is connected to the second end of the switch module 200, and the second end of the dual-tube constant current unit 310 is connected to the ground end of the power module 100, and the dual-tube constant current unit 310 is used to control the current flowing through the constant current module 300.

[0043] Specifically, in some embodiments, the dual-tube constant current unit 310 includes a third switch tube Q3, a fourth switch tube Q4, a fifth voltage-dividing resistor R6, and a sixth voltage-dividing resistor R7.

[0044] The first end of the fifth voltage-dividing resistor R6 and the first end of the third switch tube Q3 are both connected to the second end of the switch module 200, the second end of the fifth voltage-dividing resistor R6 is respectively connected to the control end of the third switch tube Q3 and the first end of the fourth switch tube Q4, the second end of the third switch tube Q3 is respectively connected to the control end of the fourth switch tube Q4 and the first end of the sixth voltage-dividing resistor R7, the second end of the fourth switch tube Q4 and the second end of the sixth voltage-dividing resistor R7 are both connected to the ground end of the power module 100 and are grounded. Wherein, the third switch tube Q3 and the fourth switch tube Q4 both include PNP transistors, the emitter of the PNP transistor serves as the first end of the third switch tube Q3 and the fourth switch tube Q4, the collector of the PNP transistor serves as the second end of the third switch tube Q3 and the fourth switch tube Q4, and the base of the PNP transistor serves as the control end of the third switch tube Q3 and the fourth switch tube Q4.

[0045] It can be understood that constant current control can be achieved through the two switch tubes in the dual-tube constant current unit 310, so that the current in the circuit remains stable.

[0046] In one embodiment, the power supply bus 20 includes a DALI bus.

[0047] It can be understood that the DALI bus includes two buses in total, through which electric energy can be transmitted and control signals can also be transmitted.

[0048] In one embodiment, a control module 500 is further included. The control module 500 is connected to the constant current module 300 and the power module 100. The control module 500 is used to transmit a control signal to the DALI bus.

[0049] It should be noted that the control module 500 can short-circuit the voltage output end of the power module 100 and the first end of the constant current module 300 when data "0" needs to be sent, and disconnect the voltage output end of the power module 100 and the first end of the constant current module 300 when a certain current is detected to complete the sending of data "0".

[0050] In one embodiment, the overvoltage protection power supply circuit 10 also includes an interface module 600, the voltage output end of the power supply module 100 is connected to the first bus of the power supply bus 20 through the interface module 600, and the first end of the switch module 200 is connected to the second bus of the power supply bus 20 through the interface module 600.

[0051] Specifically, the interface module 600 includes a first internal terminal, a second internal terminal, a first external terminal, and a second external terminal, wherein the first internal terminal is connected to the first external terminal, and the second internal terminal is connected to the second external terminal. The voltage output terminal of the power module 100 is connected to the first internal terminal, the first external terminal is connected to the first bus, the second external terminal is connected to the second bus, and the second internal terminal is connected to the first end of the switch module 200.

[0052] It can be understood that the interface module 600 can be a socket, and the power supply bus 20 can be connected to the interface module 600 through a corresponding plug to achieve a detachable connection.

[0053] In some embodiments, the overvoltage protection power supply circuit 10 also includes an interface protection module 700, which includes a varistor MOV and a seventh voltage-dividing resistor R8, an eighth voltage-dividing resistor R9 and a ninth voltage-dividing resistor R10. The varistor MOV and the seventh voltage-dividing resistor R8 are connected in parallel between the first internal terminal and the second internal terminal, the eighth voltage-dividing resistor R9 is connected in series between the interface module 600 and the voltage output end of the power supply module 100, and the ninth voltage-dividing resistor R10 is connected in series between the interface module 600 and the first end of the switch module 200.

[0054] The resistance value of the varistor MOV changes with the voltage at both ends to absorb surge voltage. The varistor MOV and the seventh voltage-dividing resistor R8 , the eighth voltage-dividing resistor R9 and the ninth voltage-dividing resistor R10 are used to protect the interface module 600 .

[0055] In some embodiments, the switch module 200 further includes a second diode D2, an anode of the second diode D2 is connected to the ninth voltage-dividing resistor R10, a cathode of the second diode D2 is connected to the first end of the first switch tube Q1, and the second diode D2 is used to rectify the current.

[0056] In some embodiments, the first switch unit 210 further includes a third diode D3, a fourth diode D4, a tenth-decision resistor R11, and a capacitor C1. The first end of the tenth-decision resistor R11 is connected to the second end of the first switch tube Q1, the second end of the tenth-decision resistor R11 is connected to the anode of the third diode D3, the cathode of the third diode D3 is connected to the cathode of the fourth diode D4, the anode of the fourth diode D4 is connected to the control end of the first switch tube Q1, and the two ends of the capacitor C1 are respectively connected to the control end of the first switch tube Q1 and the second end of the first switch tube Q1.

[0057] The third diode D3, the fourth diode D4 and the tenth-decade voltage resistor R11 are used to provide overvoltage protection for the control end of the first switch tube Q1.

[0058] In some embodiments, the first switch unit 210 further includes a fifth diode D5, the cathode of the fifth diode D5 is connected to the second end of the first switch tube Q1, and the anode of the fifth diode D5 is grounded. The fifth diode D5 can stabilize the voltage of the second end of the first switch tube Q1 and protect the switch module 200.

[0059] Figure 3 A schematic diagram of a power supply device provided in an embodiment of the present application is shown. For ease of description, only the parts related to the present embodiment are shown, which are described in detail as follows:

[0060] The power supply device 30 includes the overvoltage protection power supply circuit 10 according to any one of the above embodiments.

[0061] The power supply device 30 may be a power supply device connected to the DALI bus, and may provide power and control signals to the DALI bus.

[0062] The technicians in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In practical applications, the above-mentioned function allocation can be completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated in a processing unit, or each unit can exist physically separately, or two or more units can be integrated in one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, which will not be repeated here.

[0063] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[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. An overvoltage protection power supply circuit, characterized in that: include: A power supply module, wherein a voltage output terminal of the power supply module is used to be connected to a first bus of a power supply bus; A switch module, wherein a first end of the switch module is used to connect to a second bus of the power supply bus; A constant current module, wherein a first end of the constant current module is connected to a second end of the switch module, a second end of the constant current module is connected to a ground end of the power module, and the constant current module is used to control a current flowing through the constant current module; An overvoltage protection module is connected to the switch module, and is used to monitor the voltage at the first end of the switch module, and control the switch module to shut down when the voltage at the first end of the switch module is greater than an overvoltage threshold.

2. The overvoltage protection power supply circuit according to claim 1, characterized in that: The switch module includes a first switch unit, and the overvoltage protection module includes a second switch unit and a reverse breakdown protection unit; The first end of the first switch unit is connected to the second bus used for the power supply bus, the second end of the first switch unit is connected to the first end of the constant current module, the control end of the first switch unit is connected to the first end of the second switch unit, the second end of the second switch unit is connected to the second end of the first switch unit, the control end of the second switch unit is connected to the anode of the reverse breakdown protection unit, and the cathode of the reverse breakdown protection unit is connected to the first end of the first switch unit; The overvoltage threshold is equal to the breakdown voltage of the reverse breakdown protection unit.

3. The overvoltage protection power supply circuit according to claim 2, characterized in that: The first switch unit includes a first switch tube, a first voltage-dividing resistor and a second voltage-dividing resistor. The first end of the first switch tube is connected to the second bus used for the power supply bus, the second end of the first switch tube is connected to the first end of the constant current module, and the control end of the first switch tube is connected to the first end of the second switch unit; the first end of the first voltage-dividing resistor is connected to the control end of the first switch tube, the second end of the first voltage-dividing resistor is connected to the voltage output end of the power module, the first end of the second voltage-dividing resistor is connected to the control end of the first switch tube, and the second end of the second voltage-dividing resistor is connected to the second end of the first switch tube.

4. The overvoltage protection power supply circuit according to claim 2, characterized in that: The second switch unit includes a second switch tube, a third voltage-dividing resistor and a fourth voltage-dividing resistor; The first end of the third voltage-dividing resistor is connected to the anode of the reverse breakdown protection unit, the second end of the third voltage-dividing resistor is respectively connected to the control end of the second switch tube and the first end of the fourth voltage-dividing resistor, the first end of the second switch tube is connected to the control end of the first switch unit, the second end of the second switch tube is connected to the second end of the first switch unit, and the second end of the fourth voltage-dividing resistor is connected to the second end of the second switch tube.

5. The overvoltage protection power supply circuit according to claim 2, characterized in that: The reverse breakdown protection unit includes a first diode and a current limiting resistor; An anode of the first diode is connected to the control end of the second switch unit, and a cathode of the first diode is connected to the first end of the first switch unit through the current limiting resistor.

6. The overvoltage protection power supply circuit according to any one of claims 1 to 5, characterized in that: The constant current module includes a dual-tube constant current unit, a first end of the dual-tube constant current unit is connected to the second end of the switch module, a second end of the dual-tube constant current unit is connected to the ground end of the power module, and the dual-tube constant current unit is used to control the current flowing through the constant current module.

7. The overvoltage protection power supply circuit according to any one of claims 1 to 5, characterized in that: The power supply bus includes a DALI bus.

8. The overvoltage protection power supply circuit according to claim 7, characterized in that: It also includes a control module, which is connected to the constant current module and the power supply module, and is used to transmit a control signal to the DALI bus.

9. The overvoltage protection power supply circuit according to any one of claims 1 to 5, characterized in that: It also includes an interface module, through which the voltage output end of the power supply module is connected to the first bus of the power supply bus, and the first end of the switch module is connected to the second bus of the power supply bus.

10. A power supply device, characterized in that: The invention comprises an overvoltage protection power supply circuit as claimed in any one of claims 1 to 9.

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