CN202652088U

CN202652088U - Push-pull high-precision switching power supply

Info

Publication number: CN202652088U
Application number: CN 201220254761
Authority: CN
Inventors: 黄中军; 范月明; 何腾
Original assignee: SICHUAN EXTREME ELECTRIC CONTROL SYSTEM MANUFACTURING Co Ltd
Current assignee: SICHUAN EXTREME ELECTRIC CONTROL SYSTEM MANUFACTURING Co Ltd
Priority date: 2012-06-01
Filing date: 2012-06-01
Publication date: 2013-01-02
Anticipated expiration: 2022-06-01

Abstract

The utility model discloses a push-pull high-precision switching power supply, and belongs to the technical field of power supplies and electronics. The push-pull high-precision switching power supply comprises an alternating-current input end and a direct-current input end, the alternating-current input end is sequentially connected with an alternating-current input unit, a step-down transformer and a rectifier filter unit, the direct-current input end is connected with a redundant diode, and an output end of the rectifier filter unit and an output end of the redundant diode are connected with a push-pull step-down output unit. The push-pull high-precision switching power supply is high in output voltage precision, stable and multi-class in output voltage and high in output power and adjustability. A direct-current power supply can come from a high-voltage cabinet or a UPS (uninterrupted power supply), so that the power supply can still keep output no matter which input path fails, input of the power supply is redundant, and the requirement of a control loop on power supply in a plurality of fields can be met.

Description

Push-pull type high accuracy Switching Power Supply

Technical field

The utility model relates to a kind of DC power supply, and especially multi-output switch power source belongs to power supply and electronic technology field.

Background technology

At present, there are the defectives such as power output is less, output voltage is unstable, the output voltage grade is few, adjustability is poor in the multi-output switch power source for the control loop power supply.

The utility model content

For the problems referred to above, the utility model provides a kind of multichannel output high accuracy Switching Power Supply.

The technical scheme that its technical problem that solves the utility model adopts is: push-pull type high accuracy Switching Power Supply comprises ac input end and direct-flow input end; Ac input end connects with AC input cell, step-down transformer and rectification filtering unit successively; Direct-flow input end connects with redundant diode; The output of rectification filtering unit, the output of redundant diode and push-pull type reduced output voltage element connection.

The beneficial effects of the utility model are, the output voltage precision is high, and output voltage stabilization, grade are many, and power output is large, adjustability is strong.DC power supply can be from high-voltage board or UPS uninterrupted power supply.So just can realize that power supply still can keep output when no matter which input is broken down, realize that the power supply input is redundant.Can satisfy the control loop power demands in a lot of fields.

Description of drawings

Fig. 1 is the utility model theory diagram;

Fig. 2 is output voltage, the current waveform figure of transformer T among Fig. 3;

Fig. 3 is the electrical schematic diagram of inverse-excitation type reduced output voltage unit 5 among Fig. 1;

Fig. 4 is left part enlarged drawing among Fig. 3;

Fig. 5 is right part enlarged drawing among Fig. 3.

Parts and numbering among the figure:

The 1-AC input cell, the 2-step-down transformer, the 3-rectification filtering unit, the 4-redundant diode,

5-push-pull type reduced output voltage unit.

Embodiment

Below in conjunction with embodiment the utility model is further specified.

Referring to Fig. 1, push-pull type high accuracy Switching Power Supply comprises ac input end and direct-flow input end; Ac input end connects with AC input cell 1, step-down transformer 2 and rectification filtering unit 3 successively; Direct-flow input end connects with redundant diode 4; The output of the output of rectification filtering unit 3, redundant diode 4 connects with push-pull type reduced output voltage unit 5.

AC input cell 1 is protection and EMI filtration module, and fuse plays the effect of overcurrent protection, and EMI can suppress power supply and electrical network High-frequency Interference each other.

Step-down transformer 2 is with the input power step-down; Rectification filtering unit 3 is to its rectification, filtering.Improve the quality of DC power supply, increase Systems balanth.

Redundant diode 4 is independent of each other DC power supply and AC power.

Inverse-excitation type reduced output voltage unit 5 is through step-down, again multichannel output, and the output voltage grade has ± 24V, ± 15V, ± 12V, ± 5V, for the outside.

Referring to Fig. 3,4,5, inverse-excitation type reduced output voltage unit 5 operation principles: V1, V2 are two high-voltage three-pole pipes, during their work, and a connection, another shutoff, two high-voltage three-pole pipes turn on and off in turn, mutually alternation.When V1 connects, power input voltage is added to the two ends of the armature winding of transformer T by V1, effect by electromagnetic induction, a voltage that is directly proportional with primary coil winding input voltage also can be exported in two ends at the secondary winding of transformer T, and power supply is just exported the voltage of a positive half cycle like this.When V1 turn-offs, when V2 connects, because it is just in time opposite that supply voltage is added to the flow direction that the two ends of two windings of transformer T primary coil produce, this is at voltage that is directly proportional with the armature winding input voltage of transformer secondary output coil windings two ends output, negative half period voltage during the voltage of at this moment exporting by mutual inductance.So one of at this moment power supply output and two positive and negative polarity voltages that electromotive force that winding coil adds is corresponding.Positive half cycle is corresponding is V1 when connecting, and armature winding and secondary winding are responded to mutually output voltage; Negative half period is corresponding is V2 when connecting, and armature winding and secondary winding are responded to mutually output voltage.The output voltage of transformer, current waveform are as shown in Figure 2.What as can be seen from Figure 2, transformer T exported in fact is not direct voltage.So will be on the output string of transformer T a high-frequency diode, use again a LC filtering voltage regulation after, just can obtain a highly stable direct voltage at output.

Control chip IC1UC3527A among Fig. 3: in this system, what control IC1 selected is UC3527A regulating impulse width modulator, and it has following characteristics.Operating voltage 8～35V, the oscillator hunting range of 100Hz～500Hz can be regulated Dead Time control, built-in soft-start module, locking PWM prevents multi-pulse, double source receiver output driver; Its 14 pin is identical with 11 pin output two-way pulsewidth, and opposite polarity PWM ripple drives V1 and V2.1 pin is that the voltage detecting error amplifier is negative, 2 pin be the voltage detecting error amplifier just, detection system output voltage voluntarily.Simultaneously also can change output voltage by the output pwm pulse width that potentiometer R14 changes IC1.

The dual input of push-pull type AC and DC exchanges by the input of three-phase 380V control power supply, and direct current is inputted by 220V.Adopt the multiple-stage filtering mode: EMI filtering is adopted in the input of power supply.The High-frequency Interference that can suppress in the AC network also can suppress power supply to the interference of AC power to the interference while of power supply, and the LC filtering mode is adopted in the output of power supply, makes the Voltage-output of power supply more stable.The control IC1 chip of power supply is UC3527A, can realize the soft start of power supply, under-voltage detection, voltage compensation, adjustable PWM output.Power output is large, between 100～1000W.Switching tube is selected high pressure triode 2SC3319, can bear the 500V reverse voltage, can satisfy the requirement of system fully.

Claims

1. a push-pull type high accuracy Switching Power Supply comprises ac input end and direct-flow input end; It is characterized in that, ac input end connects with AC input cell (1), step-down transformer (2) and rectification filtering unit (3) successively; Direct-flow input end connects with redundant diode (4); The output of the output of rectification filtering unit (3), redundant diode (4) connects with push-pull type reduced output voltage unit (5).