CN2177962Y - Semiconductor isolation type switch regulated power supply - Google Patents

Abstract

The utility model relates to a semiconductor isolation type switch regulated power supply, comprising a rectifying filter circuit, an over-current protection and buffer circuit, a semiconductor switch isolation circuit, a lowpass filter circuit, an overvoltage protection circuit, an isolation feedback circuit and a semiconductor switch impulse width control circuit, wherein, the semiconductor switch isolation circuit comprises 4 switch power semiconductors, a photoelectric coupler and a capacitor. The capacitor is connected between two pairs of semiconductor switches. When the front two semiconductor switches are into conduction, the rear two semiconductor switches can be cut off, and the capacitor can be charged; inversely, the capacitor can make discharge toward the rear level, and thus the isolation transference of the electric energy and the voltage regulation action can be realized.

Description

Semiconductor isolation type switch regulated power supply

The isolated switching power supply of a kind of semiconductor belongs to the power supply of doing to isolate and have concurrently the switch voltage-stabilizing effect with semiconductor devices.

Switching power supply commonly used at present all adopts high-frequency transformer to realize isolating, to dwindle its volume.But, realize reduced volume by the frequency that improves power transformer, will bring the increase of switching loss again, and improve transformer frequencies and reach dwindling of volume certain limit is also arranged.

In order further to improve the efficient of power supply, dwindle the volume of switching power supply, adapt to the integrated development trend of power supply miniaturization, this novel purpose provides the isolated switching power supply of a kind of semiconductor.It is to adopt semiconductor devices to realize isolating and finishing the switch voltage-stabilizing effect.

The utility model is by current rectifying and wave filtering circuit, overcurrent protection and buffer circuit, and the switch isolation circuit, low-pass filter circuit, overvoltage crowbar, isolation feedback circuit and semiconductor switch pulse width control circuit are formed.Described disconnector circuit is made up of semiconductor switch and energy storage capacitor that the secondary side of four switch power triodes and photoelectrical coupler is connected into the Darlington form.Energy storage capacitor is serially connected between two pairs of semiconductor switchs, forms former and later two loops, and its input end links to each other with the output terminal of overcurrent protection and buffer circuit, and its output terminal is connected to the output of power supply with low-pass filter circuit.

When electric main was imported, alternating current was through current rectifying and wave filtering circuit, and overcurrent protection and buffer circuit are added in the two ends of preceding two semiconductor switchs.When at this moment the primary side of the photoelectrical coupler in the semiconductor switch pulse width control circuit did not send signal, its secondary side was in off state, and semiconductor switch is also located a day off state, and energy storage capacitor does not charge.Current two photoelectrical coupler primary sides get electric, send to secondary side and make it conducting, then preceding two semiconductor switch conductings, and latter two semiconductor switch turn-offs, and power supply charges to energy storage capacitor.When latter two photoelectrical coupler primary side gets electricly, send to secondary side and make it conducting, then latter two semiconductor switch conducting, this moment, preceding two semiconductor switchs turn-offed, energy storage capacitor one-level discharge backward, and through extremely output of low-pass filter circuit, thereby the isolation transmission of realization electric energy.

Adopt semiconductor switch to isolate to be and use up or signal such as field is controlled the conducting shutoff of semiconductor switch, it is isolated on circuit.Therefore it have simple in structure, the power-efficient height, volume is little, reliable operation, cost is low, and can realize small integrated.

The concrete structure of utility model is enumeration in conjunction with the following drawings.

Fig. 1: the circuit block diagram of the isolated switching power supply of semiconductor.

Fig. 2: the circuit theory diagrams of the isolated switching power supply of semiconductor.

Fig. 3: the 11 pin EA the 14 pin EB of the isolated switching power supply 3524 chip 3524-1 of semiconductor goes up the driving pulse figure that produces.

Circuit structure of the present utility model and principle of work are as seen from the figure; this circuit is by current rectifying and wave filtering circuit 1; connect overcurrent protection and buffer circuit 2; connect semiconductor switch buffer circuit 3; connect low-pass filter circuit 4 again; with overvoltage crowbar 5, be connected to output and be added on the isolation feedback circuit 6 in the output terminal number of winning the confidence, link to each other by photoelectrical coupler through semiconductor switch pulse width control circuit 7 and semiconductor disconnector circuit 3 again.Wherein current rectifying and wave filtering circuit 1 is by bridge diode 1D1-4, and capacitor C 1 is formed.Overcurrent protection and buffer circuit 2 be by resistance R 4, R2, R3, capacitor C 3, and diode 2D, triode To forms.4 overcurrent protections of resistance R; resistance R 2 and R3 form bleeder circuit; R3 wherein〉R2, charge to C3 through R2 at the powered on moment power supply, capacitor C 3 voltages rise gradually; output voltage also rises along with the rising of C3 voltage; rise time T is adjusted T and just can be adjusted its rise of output voltage time by R2, C3 decision, makes it slowly to be risen by 0 beginning; thereby the buffering of realization reaches the purpose of protecting the switch power semiconductor devices in the semiconductor switch.Can also reduce requirement, reach the purpose that reduces cost the current parameters and the voltage parameter of switch power semiconductor device.Semiconductor switch buffer circuit 3 is made up of four semiconductor switchs and capacitor C 4, C5; Four semiconductor switchs in the semiconductor switch buffer circuit 3 are by the secondary side PCi-2 of switch power semiconductor devices Ti and photoelectrical coupler, and wherein i=1,2,3,4 forms; Semiconductor switch pulse width control circuit 7 is by 3524 chip 3524-1 outer meeting resistance R1, R7～R14, capacitor C 2, C7～C9, stabilivolt 1DW, 4DW, diode 5D and with semiconductor switch buffer circuit 3 in the corresponding photoelectrical coupler primary side of the secondary side PCi-2 PCi-1 of photoelectrical coupler, wherein i=1,2,3,4 forms; Low-pass filter circuit 4 is by diode 4D, inductance L, and capacitor C 6 is formed; Overvoltage crowbar 5, at pipe 3DW, resistance R 6, R13, R14 photoelectrical coupler PC5 form by surely; 6 of isolation feedback circuits add R5, R15～R21 by 3524 chip 3524-2, capacitor C 10～C12, and stabilivolt 2DW, diode 6D, photoelectrical coupler PC6 forms.

Its principle of work: electric main is added in the triode T1 in the semiconductor disconnector circuit 3, the two ends of T2 through current rectifying and wave filtering circuit 1 and overcurrent protection and buffer circuit 2.Semiconductor switch pulse width control circuit 7 is got operating voltage at the C2 two ends, when if primary side PC1-1, the PC2-1 of photoelectrical coupler do not send signal, semiconductor switch is in off state, capacitor C 5 is not charged, one energising of this power supply, 3524-1 and electricity work, then on its 11 pin EA and the 14 pin EB, produce pulse as shown in Figure 3, make its secondary side PC1-2, PC2-2 conducting,, make its conducting to capacitor C 5 chargings for switch power triode T1, T2 provide base current.This moment, T3, T4 turn-offed.At the high level place of pulse (2), photoelectrical coupler PC3-1, PC4-1 have electric current to flow through, its secondary side conducting, and triode T3, T4 be conducting thereupon also, and this moment, T1, T2 ended, capacitor C 5 one-level discharge backward, thereby the isolation transmission of realization electric energy.T among Fig. 3 is closing time.Under certain situation of recurrence interval, as long as adjust duty of ratio, size that just can control output voltage, electric energy through isolate transmit after, process low-pass filter circuit 4 obtains output voltage again.Isolation feedback circuit 6 is pressed in capacitor C 6 two ends power takings, through resistance R 19, after the R20 dividing potential drop, get reference voltage, 3524-2 is according to the size of reference voltage, export the pulse of certain dutycycle, PC6-1 of control photoelectrical coupler, thereby the conducting of control photoelectrical coupler secondary side PC6-2 or end, because the C2 utmost point of a photoelectrical coupler secondary side PC6-2 phototriode connects one 5 volts of stabilized voltage supplys, the e utmost point connects by R15, R16, the wave filter that C10 forms, then the e utmost point then only needs control its dutycycle, the i.e. output voltage of controllable filter according to its conducting or by also exporting the pulse that some dutycycles are θ.3524-1 in the semiconductor switch pulse width control circuit 7 is from capacitor C 10 two ends negate feedthrough voltages input INV pin, 3524-1 controls the primary side of photoelectrical coupler according to this feedback voltage, thereby controlled the conducting dutycycle of the semiconductor switch in the semiconductor switch buffer circuit 3, thereby reached the purpose of regulated output voltage.

Claims (1)

1, a kind of semiconductor disconnector stabilized voltage supply, connect overcurrent protection and buffer circuit 2 by current rectifying and wave filtering circuit 1, low-pass filter circuit 4, connect overvoltage crowbar 5, connecting isolation feedback circuit 6 again forms, wherein current rectifying and wave filtering circuit 1 is made up of bridge diode 1D1-4, capacitor C 1, and overcurrent protection and buffer circuit 2 are made up of resistance R 4 and R2, R3, capacitor C 3, diode 2D, triode T0; Low-pass filter circuit 4 is by diode 4D, inductance L, capacitor C 6, resistance R 5, surely form at pipe 2DW; Overvoltage crowbar 5 is by stabilivolt 3DW; resistance R 6; R13; R14 charging coupling mechanism is formed; it is characterized in that having and be connected with between slow-action circuit 2 and the low-pass filter circuit 4 by capacitor C 4 and two semiconductor switchs in overcurrent protection; after the serial connection capacitor C 5; connect again that two semiconductor switchs form; semiconductor switch buffer circuit 3; wherein said four semiconductor switchs by the secondary of four diode 3Di and switch power triode Ti and photoelectrical coupler then PCi-2 constitute Darlington form (i=1; 2; 3; 4); between current rectifying and wave filtering circuit 1 and isolation feedback circuit 6, be connected to by 3524 chip 3524-1 outer meeting resistance R1; R7～R14; capacitor C 2; C7～C9; stabilivolt 1DW; 4DW; diode 5D and 4 photoelectricity coupling devices be PCi-1 (i=1 then once; 2; 3; 4) the semiconductor switch pulse width control circuit 7 of Zu Chenging, described isolation feedback circuit 6 is by 3524 chip 3524-2 external resistor R15～R21; capacitor C 10～C12 diode 6D and photoelectrical coupler PC6 form.