A switching power supply and device

Abstract

The present invention relates to the technical field of power supply control, and particularly relates to a switching power supply and a device. By combining a relay and a PMOS transistor to control the switching power supply, indirect control of a second-stage high-voltage device by a first-stage low-voltage device is achieved, greatly improving the safety and reliability of the switching power supply for high-voltage and high-power equipment, being capable of adapting to space environment applications, and meeting the technical requirements of the space station.

Description

Technical Field

[0001] The present invention relates to the technical field of power control, and particularly relates to a switching power supply and a device. Background Art

[0002] In space computers such as satellites and space stations, many space computers need to perform switching power control on various high-voltage 100V high-power electronic valves, fans, and pumps on the periphery, such as a space station drinking water controller, a space station microwave oven, a space station collection controller, etc.

[0003] In the early days, space computers and peripheral devices were all powered by a DC 28V bus. Due to its low voltage and small power, many mature DC 28V magnetic latching relay switching power supplies were developed, which have high reliability and a service life of more than 100,000 times. When it came to the development of the space station, the space computers and peripheral devices it equipped were all powered by a DC 100V bus. There are mature magnetic latching relay switching power supplies for DC 100V low-power devices, and the service life can also reach more than 100,000 times to meet the requirements. However, there are many devices that are DC high-voltage 100V high-power devices with a power of hundreds of watts or more. Currently, the service life of such DC high-voltage high-power magnetic latching relays is only thousands of times, which cannot meet the application requirements. Therefore, it is necessary to develop other switching power technologies for DC high-voltage 100V high-power devices to perform frequent switching power to meet the application requirements of the space station.

[0004] Since DC mechanical relays are prone to generating arc sparks when switching power, especially when the load voltage is higher and the current is larger, it is easier to generate arc sparks, and in severe cases, the relay switch will be burned out. Currently, the high-voltage DC mechanical relay switches used in space applications are mainly for small-power currents. The service life of high-current high-voltage relays is very short, and the volume is also relatively large. Summary of the Invention

[0005] Aiming at the problem of poor safety of DC mechanical relay switches in the prior art, the present invention provides a switching power supply and a device.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] In a first aspect, the present invention provides a switching power supply, including a control power supply, a relay, a voltage-dividing resistor, and a PMOS transistor, wherein:

[0008] The control power supply is connected to the control switch ON port after being connected in series with the holding coil of the relay, and the control power supply is connected to the control switch OFF port after being connected in series with the reset coil of the relay;

[0009] The input contact of the relay is connected to the DC power input terminal, and the output contact of the relay is connected to the middle port of the voltage-dividing resistor;

[0010] The first port of the voltage-dividing resistor is connected to the DC power input terminal, and the second port of the voltage-dividing resistor is connected to the DC power return line;

[0011] The middle port of the voltage-dividing resistor is connected to the gate of the PMOS transistor, the drain of the PMOS transistor is connected to the DC power input terminal, and the source of the PMOS transistor is connected to the DC power output terminal.

[0012] Further, a current-limiting resistor is connected in series between the control power supply and the relay.

[0013] Further, a voltage-regulating diode is further included. The positive pole of the voltage-regulating diode is connected to the middle port of the voltage-dividing resistor, and the negative pole of the voltage-regulating diode is connected to the first port of the voltage-dividing resistor.

[0014] Further, a protection resistor is connected in series between the middle port of the voltage-dividing resistor and the gate of the PMOS transistor.

[0015] Further, a suppression capacitor is further included. The suppression capacitor includes two serially redundant capacitors, and both ends of the suppression capacitor are respectively connected to the first port and the middle port of the voltage-dividing resistor.

[0016] Further, there are two PMOS transistors. The drain of the first PMOS transistor is connected to the DC power input terminal, the source of the first PMOS transistor is connected to the drain of the second PMOS transistor, and the source of the second PMOS transistor is connected to the DC power output terminal.

[0017] Further, an elimination unit is included. The elimination unit includes two switching diodes. The positive pole of the first switching diode serves as the positive pole of the elimination unit, the negative pole of the first switching diode is connected to the positive pole of the second switching diode, and the negative pole of the second switching diode serves as the negative pole of the elimination unit.

[0018] Further, in the elimination unit, the positive pole of the first elimination unit is connected to the negative pole of the holding coil, and the negative pole of the first elimination unit is connected to the positive pole of the holding coil; the positive pole of the second elimination unit is connected to the negative pole of the reset coil, and the negative pole of the second elimination unit is connected to the positive pole of the reset coil.

[0019] Further, in the elimination unit, the positive pole of the third elimination unit is connected to the DC power return line, and the negative pole of the third elimination unit is connected to the DC power output terminal.

[0020] In a second aspect, the present invention provides a switching power supply device having the switching power supply as described above.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] First, the present invention combines a relay and a PMOS transistor to control a switching power supply, achieving indirect control of a second-stage high-voltage device by a first-stage low-voltage device, greatly improving the safety and reliability of the switching power supply for high-voltage high-power equipment, being able to adapt to space environment applications, and meeting the technical requirements of the space station.

[0023] Second, the lifespan of the first-stage small magnetic latching relay of the present invention can reach more than 100,000 times, and the lifespan of the second-stage MOS transistor can even reach more than one million times. Therefore, the lifespan of the DC high-voltage high-power switching power supply technology of the present invention can reach more than 100,000 times, far higher than the service life of several thousand times of a single high-voltage high-power relay, and can provide reliable and long-life switching power technology for high-voltage high-power equipment such as space station microwave ovens, drinking water controllers, and collection controllers. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings forming a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0025] Figure 1 is a circuit schematic diagram of a switching power supply of the present invention.

[0026] In the figure, R1, R2, R3, R4, R5, and R6 represent resistors, D1, D2, D3, D4, D5, and D6 represent diodes, C1 and C2 represent capacitors, and ZD represents a voltage-regulating diode;

[0027] K represents a relay, and X+, X-, Y+, Y-, A1, A2, B1, and B2 respectively represent the positive pole of the holding coil, the negative pole of the holding coil, the positive pole of the reset coil, the negative pole of the reset coil, the first input contact, the first output contact, the second input contact, and the second output contact of the relay;

[0028] PMOS1 and PMOS2 represent PMOS transistors, and D, G, and S respectively represent the drain, gate, and source of the PMOS transistor;

[0029] VIN represents the DC power input terminal, VOUT represents the DC power output terminal, CR represents the DC power return line, CP represents the control power supply, and ON and OFF represent the ON port and OFF port of the control switch. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0030] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments. It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other.

[0031] The following detailed descriptions are all exemplary descriptions, aiming to provide further details of the present invention. Unless otherwise specified, all technical terms adopted in the present invention have the same meaning as commonly understood by those of ordinary skill in the art to which the present invention pertains. The terms used in the present invention are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention.

[0032] As Figure 1 shown, a DC high-voltage high-power switching circuit specifically includes a first-stage switching circuit and a second-stage switching circuit.

[0033] The first-stage switching circuit specifically includes a control power supply, a relay, and a current-limiting unit.

[0034] The positive voltage of the control power supply is +28V.

[0035] The model of the relay is 2JB1-910 / 28, and its interfaces include: the positive terminal of the holding coil, the negative terminal of the holding coil, the positive terminal of the reset coil, the negative terminal of the reset coil, the first input contact, the first output contact, the second input contact, and the second output contact.

[0036] The current-limiting unit includes two parallel current-limiting resistors R1 and R2, and the values of both R1 and R2 are 20Ω.

[0037] The control power supply is connected to the first end of the current-limiting unit, and the second end of the current-limiting unit is connected to the positive terminals of the holding coil and the reset coil. The negative terminal of the holding coil is connected to the ON port of the control switch, and the negative terminal of the reset coil is connected to the OFF port of the control switch. The first input contact and the second input contact are connected as the relay load input terminal, and the relay load input terminal is connected to the DC power input terminal. The first output contact and the second output contact are connected as the relay load output terminal, and the relay load output terminal is connected to the middle port of the voltage-dividing resistor.

[0038] The middle port of the voltage-dividing resistor divides the voltage-dividing resistor into two sections of resistance. The resistance from the middle port of the voltage-dividing resistor to the first port is R3, with a value of 20KΩ. The resistance from the middle port of the voltage-dividing resistor to the second port is R4, with a value of 82KΩ. The first port is connected to the DC power input terminal, and the second port is connected to the DC power return line.

[0039] The second - stage switch circuit specifically includes two PMOS transistors. The drain - source voltage of the PMOS transistor is greater than 200V, and the current is greater than 20A. The middle port of the voltage - dividing resistor is connected to the gate of the first PMOS transistor after being serially connected with the first gate resistor R5. The middle port of the voltage - dividing resistor is connected to the gate of the second PMOS transistor after being serially connected with the second gate resistor R6. The values of both the first gate resistor R5 and the second gate resistor R6 are 1KΩ. The drain of the first PMOS transistor is connected to the DC power input terminal, the source of the first PMOS transistor is connected to the drain of the second PMOS transistor, and the source of the second PMOS transistor is connected to the DC power output terminal.

[0040] When the relay is closed, its load input and output are conductively short - circuited, and the PMOS transistor gate and drain have no voltage difference and turn off. When the relay resets and the load input and output are disconnected, the PMOS transistor gate and drain are turned on due to a voltage difference of about - 10V caused by resistor voltage division, thereby controlling the switch of the + 100VIN high - voltage DC power supply.

[0041] In a preferred embodiment of the present invention, an elimination unit is further provided for eliminating the back electromotive force. Each elimination unit includes two serially connected switching diodes. The positive electrode of the first switching diode serves as the positive electrode of the elimination unit, the negative electrode of the first switching diode is connected to the positive electrode of the second switching diode, and the negative electrode of the second switching diode serves as the negative electrode of the elimination unit.

[0042] As a specific example of the above - mentioned preferred embodiment, there are specifically three elimination units. The switching diodes D1 and D2 of the first elimination unit are both of the 2CK75D type. The positive electrode of the first elimination unit is connected to the negative electrode of the holding coil, and the negative electrode of the first elimination unit is connected to the positive electrode of the holding coil. The switching diodes D3 and D4 of the second elimination unit are both of the 2CK75D type. The positive electrode of the second elimination unit is connected to the negative electrode of the reset coil, and the negative electrode of the second elimination unit is connected to the positive electrode of the reset coil. The switching diodes D5 and D6 of the third elimination unit are of the 2CK81F type. The positive electrode of the third elimination unit is connected to the return line of the DC power supply to be controlled, and the negative electrode is connected to the source of the second PMOS transistor.

[0043] Specifically, a zener diode of the BWA62 type is further included to protect the PMOS transistor from being damaged by excessive gate - drain voltage. The negative electrode of the zener diode is connected to the relay load input terminal, and the positive electrode of the zener diode is connected to the relay load output terminal.

[0044] Specifically, a suppression capacitor is further included. Two serially redundant capacitors C1 and C2 are connected in parallel across the two ends of the first resistor of the voltage - dividing resistor to form an RC charge - discharge circuit. When the PMOS transistor switches, the RC charge - discharge effect plays a role in suppressing surges and protecting the upper - level power supply and distribution equipment. The values of C1 and C2 are both 22UF.

[0045] As is known by common technical knowledge, the present invention can be implemented by other embodiments that do not depart from its spiritual essence or essential features. Therefore, the above-disclosed embodiments are illustrative in all aspects and not exclusive. All changes within the scope of the present invention or within the scope equivalent to the present invention are encompassed by the present invention.

[0046] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: modifications or equivalent replacements can still be made to the specific embodiments of the present invention, and any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered within the scope of the claims of the present invention.

Claims

1. A switching power supply, characterized in that, It includes a control power supply, a relay, a voltage-dividing resistor, and a PMOS transistor, where: The control power supply is connected to the ON port of the control switch after being connected in series with the holding coil of the relay, and the control power supply is connected to the OFF port of the control switch after being connected in series with the reset coil of the relay; The input contact of the relay is connected to the DC power input terminal, and the output contact of the relay is connected to the middle port of the voltage-dividing resistor; The first port of the voltage-dividing resistor is connected to the DC power input terminal, and the second port of the voltage-dividing resistor is connected to the DC power return line; The middle port of the voltage-dividing resistor is connected to the gate of the PMOS transistor, the drain of the PMOS transistor is connected to the DC power input terminal, and the source of the PMOS transistor is connected to the DC power output terminal; A current-limiting resistor is connected in series between the control power supply and the relay; It further includes a zener diode, the positive electrode of the zener diode is connected to the middle port of the voltage-dividing resistor, and the negative electrode of the zener diode is connected to the first port of the voltage-dividing resistor; A protection resistor is connected in series between the middle port of the voltage-dividing resistor and the gate of the PMOS transistor; It further includes a suppression capacitor, the suppression capacitor includes two redundantly connected capacitors in series, and both ends of the suppression capacitor are respectively connected to the first port and the middle port of the voltage-dividing resistor; There are two PMOS transistors. The drain of the first PMOS transistor is connected to the DC power input terminal, the source of the first PMOS transistor is connected to the drain of the second PMOS transistor, and the source of the second PMOS transistor is connected to the DC power output terminal.

2. The switching power supply according to claim 1, wherein It includes an elimination unit, the elimination unit includes two switching diodes, where the positive electrode of the first switching diode serves as the positive electrode of the elimination unit, the negative electrode of the first switching diode is connected to the positive electrode of the second switching diode, and the negative electrode of the second switching diode serves as the negative electrode of the elimination unit.

3. A switching power supply according to claim 2, wherein In the elimination unit, the positive electrode of the first elimination unit is connected to the negative electrode of the holding coil, and the negative electrode of the first elimination unit is connected to the positive electrode of the holding coil; the positive electrode of the second elimination unit is connected to the negative electrode of the reset coil, and the negative electrode of the second elimination unit is connected to the positive electrode of the reset coil.

4. A switching power supply according to claim 2, wherein, In the elimination unit, the positive electrode of the third elimination unit is connected to the DC power return line, and the negative electrode of the third elimination unit is connected to the DC power output terminal.

5. A switching power supply device having the switching power supply according to any one of claims 1 to 4.

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