CN214281252U

CN214281252U - Multi-output switch power supply

Info

Publication number: CN214281252U
Application number: CN202021547263.1U
Authority: CN
Inventors: 缪玮
Original assignee: Suzhou Tianyi Xinde Environmental Protection Science & Technology Co ltd
Current assignee: Suzhou Tianyi Xinde Environmental Protection Science & Technology Co ltd
Priority date: 2020-07-30
Filing date: 2020-07-30
Publication date: 2021-09-24
Anticipated expiration: 2030-07-30

Abstract

The utility model discloses a multiplexed output switching power supply, which comprises a circuit board, be equipped with filter circuit on the circuit board, RCD clamp circuit, converting circuit and output circuit, filter circuit, RCD clamp circuit, converting circuit and output circuit connect gradually, filter circuit is used for filtering EMI electromagnetic interference, RCD clamp circuit shifts the unnecessary energy of voltage that filter circuit carried, converting circuit is used for reducing switching power supply's power loss, output circuit is used for controlling the undulant voltage of input and exports steady voltage. The utility model can meet the voltage power requirements of different devices in the instrument by integrating the multi-path voltage output on a circuit board, and realizes the purposes of stable output, customization, cost reduction and space saving; the output voltage has little variation, whether empty or full.

Description

Multi-output switch power supply

Technical Field

The utility model relates to an environmental protection pollutant control technical field relates to a multiplexed output switching power supply.

Background

The technical field of environmental pollution monitoring has various detection equipment instruments, and alternating current commercial power needs to be converted into stable direct current power supplies with various voltage levels inside the equipment instruments, so that the help of a switching power supply is needed. The switching Power supply is abbreviated as smps (switch Mode Power supply), and is based on the basic principle of inductive energy storage, so that efficient and energy-saving Power conversion is realized. The switching power supply represents the development direction of a voltage-stabilized power supply, and is a mainstream product of the voltage-stabilized power supply. The switching power supply, commonly referred to as an AC/DC power converter, is most commonly converted from 220V, 50Hz AC voltage to one or more DC voltages.

The existing detection equipment needs switching power supplies with a plurality of specifications, so that the cost is increased, and the voltage power requirements of different equipment in the equipment cannot be met.

SUMMERY OF THE UTILITY MODEL

The to-be-solved technical problem of the utility model is to provide a satisfy the voltage power demand of different equipment in the instrument simultaneously, the output is stable, realizes wide voltage input's multiplexed output switching power supply.

In order to solve the technical problem, the utility model provides a technical scheme that its technical problem adopted is:

the utility model provides a multiple output switching power supply, includes filter circuit, RCD clamp circuit, converting circuit and output circuit, filter circuit, RCD clamp circuit, converting circuit and output circuit connect gradually, and filter circuit is used for filtering EMI electromagnetic interference, and RCD clamp circuit shifts the unnecessary energy of voltage that filter circuit carried, and converting circuit is used for reducing switching power supply's power loss, and output circuit is used for the ripple voltage of control input and exports steady voltage.

Preferably, the filter circuit includes filter capacitors (CE1, CE2) and an inductor L1, a No. 1 interface and a No. 3 interface of the inductor L1 are respectively connected to two ends of the filter capacitor CE1, and the positive phase of the filter capacitor CE1 is connected to the No. 1 interface of the inductor L1; the interface 2 and the interface 4 of the inductor L1 are respectively connected to two ends of the filter capacitor CE2, and the non-phase of the filter capacitor CE2 is connected to the interface 2 of the inductor L1.

Preferably, the RCD clamp circuit includes resistors (R1, R2, R3), a capacitor C1, and a diode D1, the capacitor C1 is connected in parallel with the resistor R1, the resistor R1 is connected in parallel with the resistor R2, the diode D1 is connected with the resistor R3, and the resistor R2 is connected with the resistor R3.

Preferably, the conversion circuit includes a transformer T1, resistors (R4, R5, R8) diodes (D2, D3), a capacitor C5, and a capacitor CY1, wherein the capacitor C5 is connected in series with the resistor R8 and then connected in parallel with the diode D3, a forward direction of the diode D3 is connected to a connection terminal of the capacitor C5 and a No. 7 interface of the transformer T1, one end of the capacitor CY1 is connected to a No. 2 interface of the transformer T1, the other end of the capacitor CY1 is connected to a No. 6 interface of the transformer T1, one end of the resistor R4 is connected to the diode D2, and the resistor R5 and a No. 5 interface of the transformer T1 are respectively connected to the resistor R5 and the resistor R4.

Preferably, the output circuit includes a conversion chip U1, resistors (R7, R10, R11, R13, and R12), an optical coupler U2, a capacitor C6, and a voltage reference chip U3, one end of the resistor R7 is connected to the No. 3 interface of the conversion chip U1, the other end is connected to the No. 4 interface of the optical coupler U2, the No. 3 interface of the optical coupler U2 is grounded, the No. 1 interface and the No. 2 interface of the optical coupler U2 are respectively connected to two ends of the resistor R10, the resistor R10 is respectively connected to the voltage reference chip U3 and the resistor R13, the resistor R13 is connected to the capacitor C6, and the resistor R12 is respectively connected to the capacitor C6 and the resistor R11.

Preferably, the diode D2 is a fast recovery diode, and the diode D3 is a schottky diode.

Preferably, the output circuit further includes capacitors (C3, C2) and a filter capacitor CE3, the capacitor C3 is connected to the interface No. 3 of the conversion chip U1, the filter capacitor CE3 is connected in parallel to the capacitor C2, and the interface No. 2 of the conversion chip U1 is connected to the positive phase of the filter capacitor CE3 and the capacitor C2, respectively.

The utility model has the advantages that:

the utility model integrates the multi-path voltage output to a circuit board, which can meet the voltage power requirements of different devices in the instrument, realize the purposes of stable output, customization, cost reduction and space saving, and realize the wide voltage input, and can be directly used without adding a voltage converter in various regions at home and abroad, thereby being very convenient; the output voltage has little variation, whether empty or full.

Drawings

Fig. 1 is a schematic diagram of the filter circuit of the present invention.

Fig. 2 is a schematic diagram of the RCD clamp of the present invention.

Fig. 3 is a schematic diagram of the conversion circuit of the present invention.

Fig. 4 is a schematic diagram of an output circuit of the present invention.

Fig. 5 is a schematic diagram of a multiple output switching power supply according to the present invention.

Detailed Description

The present invention is further described with reference to the following drawings and specific embodiments so that those skilled in the art can better understand the present invention and can implement the present invention, but the embodiments are not to be construed as limiting the present invention.

Referring to fig. 1 to 5, the multiple output switching power supply includes a filter circuit, an RCD clamp circuit, a converter circuit, and an output circuit, where the filter circuit, the RCD clamp circuit, the converter circuit, and the output circuit are connected in sequence, the filter circuit is configured to filter EMI electromagnetic interference, the RCD clamp circuit transfers excess voltage energy transmitted by the filter circuit, the converter circuit is configured to reduce power loss of the switching power supply, and the output circuit is configured to control input ripple voltage and output stable voltage.

The utility model realizes wide voltage input, meets the voltage input of 90-264VAC, and can be directly used without adding a voltage converter in various regions at home and abroad even if the product is taken to be used at home and abroad, thereby being very convenient; the output is stable 15V/1.5A, 12V/1.5A and 5V/1A, and the output voltage change is extremely small no matter the output is empty or full.

The filter circuit comprises filter capacitors (CE1, CE2) and an inductor L1, wherein a No. 1 interface and a No. 3 interface of the inductor L1 are respectively connected with two ends of the filter capacitor CE1, and the positive phase of the filter capacitor CE1 is connected with a No. 1 interface of the inductor L1; the interface 2 and the interface 4 of the inductor L1 are respectively connected to two ends of the filter capacitor CE2, and the non-phase of the filter capacitor CE2 is connected to the interface 2 of the inductor L1.

The filter capacitors (CE1 and CE2) (double aluminum electrolytic capacitors) and the inductor L1 (common mode inductor) are adopted to form pi-type filtering, so that EMI electromagnetic interference in a mains supply can be filtered, the stability of a product is improved, and EMI electromagnetic interference generated by the filter capacitors can be prevented from returning to a power grid and interfering other surrounding electric equipment.

The RCD clamping circuit comprises resistors (R1, R2 and R3), a capacitor C1 and a diode D1, wherein the capacitor C1 is connected with a resistor R1 in parallel, the resistor R1 is connected with a resistor R2 in parallel, the diode D1 is connected with the resistor R3, and the resistor R2 is connected with the resistor R3.

Through RCD clamp circuit, can shift the unnecessary energy that produces, finally finish by resistance consumption, effectively avoid because transformer leakage inductance's existence, the flyback converter can produce very big peak voltage in the moment of the switch tube shutoff for the switch tube bears higher voltage stress, probably leads to the switch tube to damage even, effectively ensures the flyback converter safe and reliable work.

The conversion circuit comprises a transformer T1, resistors (R4, R5 and R8), diodes (D2 and D3), a capacitor C5 and a capacitor CY1, wherein the capacitor C5 is connected with a resistor R8 in series and then connected with the diode D3 in parallel, the forward direction of the diode D3 is connected with the No. 7 interface of the transformer T1 through the connection end of the capacitor C5, one end of the capacitor CY1 is connected with the No. 2 interface of the voltmeter T1, the other end of the capacitor CY1 is connected with the No. 6 interface of the transformer T1, one end of the resistor R4 is connected with the diode D2, and the resistor R5 and the No. 5 interface of the transformer T1 are respectively connected with the resistor R5 and the resistor R4.

Transformer T1 is a high frequency transformer for converting voltage, with the left side of transformer T1 being a high voltage input and the right side being a low voltage output.

The output circuit comprises a conversion chip U1, resistors (R7, R10, R11, R13 and R12), an optocoupler U2, a capacitor C6 and a voltage reference chip U3, one end of a resistor R7 is connected with a No. 3 interface of the conversion chip U1, the other end of the resistor R7 is connected with a No. 4 interface of the optocoupler U2, a No. 3 interface of the optocoupler U2 is grounded, a No. 1 interface and a No. 2 interface of the optocoupler U2 are respectively connected with two ends of the resistor R10, the resistor R10 is respectively connected with the voltage reference chip U3 and the resistor R13, the resistor R13 is connected with the capacitor C6, and the resistor R12 is respectively connected with the capacitor C6 and the resistor R11.

The optocoupler U2 samples an output voltage signal and feeds back the output voltage signal to the integrated conversion chip, and the integrated conversion chip adjusts the switching duty ratio of the mos tube to stabilize the output voltage.

When the input voltage value fluctuates, the output voltage of the secondary winding fluctuates along with the fluctuation, the sampling resistor of the voltage reference chip U3 (reference voltage source TL431) at the output voltage end collects the changed voltage, the output of the reference voltage is further adjusted, the light emitting brightness inside the optical coupler U2 is changed, the output end of the optical coupler U2 is connected with the feedback pin FB (interface No. 3) of the conversion chip U1, and then the conversion chip U1 adjusts the pulse width modulation controller inside to control the fluctuated input voltage. In the continuous adjustment, the output voltage of the final product approaches to the output voltage of a voltage reference chip U3 (reference voltage source TL431), and the output voltage is still stable under the condition of wider voltage input by introducing a reference voltage source and isolation optocoupler control into the circuit.

The diode D2 is a fast recovery diode and the diode D3 is a schottky diode.

Special treatment is performed on the selection of the two diodes, so that the power loss of the switching power supply can be effectively reduced; firstly, a diode D2 between the tap of the primary winding and the No. 2 interface (power supply) of the switching chip U1 can shorten the time for power restoration when the power MOSFET is turned on and off at high frequency; second, the rectifying diode D3 of the secondary winding of the transformer T1, which is a schottky diode, is selected, and the lower voltage drop reduces the voltage loss.

The output circuit further comprises capacitors (C3 and C2) and a filter capacitor CE3, wherein the capacitor C3 is connected with a No. 3 interface of the conversion chip U1, the filter capacitor CE3 is connected with the capacitor C2 in parallel, and a No. 2 interface of the conversion chip U1 is respectively connected with a positive phase of the filter capacitor CE3 and a positive phase of the capacitor C2.

The VDD filter capacitor CE3 (fig. 4) of the switch chip U1 is placed at a distance as close as possible to the VDD pin and the GND pin, which is less than 1cm apart from the VDD pin, so as to reduce interference of other signals with the power supply of the IC.

As shown in fig. 1, after the ac mains is connected to the power panel, the ac mains is primarily rectified and then connected to each switching power supply. The peripheral components can be packaged by a paster, so that the volume is reduced.

The SW legs of the switch chip U1 are the main path for heat dissipation of the device, and have the function of a heat sink, and the area of the PCB connected to the SW legs is enlarged as much as possible to dissipate the heat.

The conversion chip U1 can adopt PN8160 and PN8366, and power MOSFET and pulse width modulation controller are integrated in the two chips, so that the circuit performance is more stable, and peripheral components are more simplified.

And has the protection functions of output short-circuit protection, output overcurrent protection, VDD undervoltage and overvoltage protection, FB/DMG divider resistor open/short-circuit protection, circuit detection resistor Rcs short circuit, secondary rectifier tube short-circuit protection, over-temperature protection and the like.

The above-mentioned embodiments are merely preferred embodiments for fully illustrating the present invention, and the scope of the present invention is not limited thereto. Equivalent substitutes or changes made by the technical personnel in the technical field on the basis of the utility model are all within the protection scope of the utility model. The protection scope of the present invention is subject to the claims.

Claims

1. A multi-output switching power supply is characterized by comprising a circuit board, wherein a filter circuit, an RCD clamping circuit, a conversion circuit and an output circuit are arranged on the circuit board, the filter circuit, the RCD clamping circuit, the conversion circuit and the output circuit are sequentially connected, the filter circuit is used for filtering EMI electromagnetic interference, the RCD clamping circuit is used for transferring redundant voltage energy transmitted by the filter circuit, the conversion circuit is used for reducing power loss of the switching power supply, and the output circuit is used for controlling input fluctuating voltage and outputting stable voltage;

the filter circuit comprises filter capacitors (CE1, CE2) and an inductor L1, wherein a No. 1 interface and a No. 3 interface of the inductor L1 are respectively connected with two ends of the filter capacitor CE1, and the positive phase of the filter capacitor CE1 is connected with a No. 1 interface of the inductor L1; the No. 2 interface and the No. 4 interface of the inductor L1 are respectively connected with two ends of a filter capacitor CE2, and the positive phase of the filter capacitor CE2 is connected with the No. 2 interface of the inductor L1;

the RCD clamping circuit comprises resistors (R1, R2 and R3), a capacitor C1 and a diode D1, wherein the capacitor C1 is connected with a resistor R1 in parallel, the resistor R1 is connected with a resistor R2 in parallel, the diode D1 is connected with a resistor R3, and the resistor R2 is connected with a resistor R3;

the conversion circuit comprises a transformer T1, resistors (R4, R5 and R8), diodes (D2 and D3), a capacitor C5 and a capacitor CY1, wherein the capacitor C5 is connected with a resistor R8 in series and then connected with the diode D3 in parallel, the forward direction of the diode D3 is connected with the No. 7 interface of the transformer T1 through the connection end of the capacitor C5, one end of the capacitor CY1 is connected with the No. 2 interface of the transformer T1, the other end of the capacitor CY1 is connected with the No. 6 interface of the transformer T1, one end of the resistor R4 is connected with the diode D2, and the resistor R5 and the No. 5 interface of the transformer T1 are respectively connected with the resistor R5 and the resistor R4.

2. The multi-output switching power supply of claim 1, wherein the output circuit comprises a conversion chip U1, a resistor (R7, R10, R11, R13, R12), an optical coupler U2, a capacitor C6, a voltage reference chip U3, a resistor R7 with one end connected to the No. 3 interface of the conversion chip U1 and the other end connected to the No. 4 interface of the optical coupler U2, the No. 3 interface of the optical coupler U2 connected to ground, the No. 1 interface and the No. 2 interface of the optical coupler U2 connected to the two ends of the resistor R10, a resistor R10 connected to the voltage reference chip U3 and the resistor R13, a resistor R13 connected to the capacitor C6, and a resistor R12 connected to the capacitor C6 and the resistor R11.

3. The multi-output switching power supply of claim 2 wherein the diode D2 is a fast recovery diode and the diode D3 is a schottky diode.

4. The multi-output switching power supply according to claim 3, wherein the output circuit further comprises capacitors (C3, C2) and a filter capacitor CE3, the capacitor C3 is connected to the interface No. 3 of the conversion chip U1, the filter capacitor CE3 is connected in parallel to the capacitor C2, and the interface No. 2 of the conversion chip U1 is respectively connected to the positive phase of the filter capacitor CE3 and the capacitor C2.