CN101166000A

CN101166000A - Loaded self-adaptive switch electric power source

Info

Publication number: CN101166000A
Application number: CNA200610107277XA
Authority: CN
Inventors: 周常柱
Original assignee: Individual
Current assignee: Individual
Priority date: 2006-10-16
Filing date: 2006-10-16
Publication date: 2008-04-23

Abstract

This invention relates to a designing circuit for switch supply composed of an electronic switch device, an energy storage inductor, a switch drive circuit, an output voltage sample and signal drive circuit, a filter circuit and continuous flow diodes, in which, the electronic switch is controlled by the switch drive circuit, the output signal of which comes from the sample and signal output circuit and the signal of the circuit outputs a related signal enabling cutting off of the electronic device automatically in the instance before the voltage of an inductor output end reaches to the maximum value, and when the load costs the voltage to a level, the sample and signal output circuit will output a signal shutting the electronic switch finally and begin charging current to the energy stored inductor to increase voltage of the load further.

Description

Loaded self-adaptive switch electric power source

Technical field

The invention belongs to the Switching Power Supply design field, particularly relate to a kind of switching power supply design circuit and implementation method for loaded self-adaptive.

Technical background

At present, switching power supply adopts alien frequencies as driving pulse substantially, or adopts self circuit excitation generation fixed cycle pulse.Therefore require restriction ratio strict for the load size.

Summary of the invention

The objective of the invention is to provide for the load size and in a relative broad range, change the switching mode voltage stabilizer that can both adapt to.

Technical scheme of the present invention is: in the moment that direct voltage source is opened, adopt the electronic circuitry design technology, make electronic switching device 2 be in closed conducting state, improve direct voltage 8 by inductance component, moment before the maximum in direct voltage 8 reaches the required value scope, sampling begins to export an associated level signal with signal output apparatus 6, and the signal that makes one of switch drive 3 output that electronic switching device 2 is disconnected, control electronic switching device 2 are converted to off-state by closure.At this moment, direct voltage source 1 no longer provides charging current to inductance component 4, and inductance component 4 constitutes the loop that load is provided electric current with continued flow tube 5.It is after 0 that the electric current that inductance component 4 and continued flow tube 5 formations provide the loop of electric current to make inductance to load exhausts, direct voltage 8 slowly reduces because of load consumption, before near the minimum of load request sometime, in the time of also can being certain fixed value of design, sampling begins to export a signal with output circuit 6, this signal makes coherent signal of switch drive 3 outputs, this coherent signal is as the closed control signal of electronic switching device 2, make electronic switching device 2 beginning conductings, reach the purpose that requirement is charged to direct voltage 6 once more.Circulation and so forth.

Fig. 2 is the specific implementation circuit of this self-adaption switch electric power source.Operation principle is as follows:

Vdd represents direct voltage source 1, and Q1 is as electronic switching device 2, and D2 is a continued flow tube 5, and D1, R4, R3, C1 and Q3 constitute sampling and export 6 realization circuit with signal, and R1, R2 and Q2 constitute switch drive 3; L1 is an inductance component 4, and C2, C3 are a kind of realization circuit of filtering 7.Vcc is a direct voltage 8.

When Vdd just added circuit, Q3 ended, and Vdd makes the Q2 conducting through R1, Q1 so conducting, give C2, C3 charging through L1, as Vcc during greater than the voltage stabilizing value of D1, the D1 conducting is when being charged to the base-on voltage of 0.7V to C1, the Q3 conducting ends Q2, and Q1 enters off-state.When Vcc was reduced to voltage stabilizing value less than D1, Q3 ended, and makes the Q2 conducting, and Q1 enters conducting state.New charging process begins again, and so circulation repeatedly.Here, C1, R3 have the effect of control Q1 conduction delay and width.

Utilize Fig. 3 and Fig. 2 combination, can realize the AC/DC loaded self-adaptive switch electric power source.

This circuit is reliable, and cost is low and to adaptive load wider range.

Fig. 1 is a theory diagram of the present invention;

Fig. 2 is a kind of realization circuit form of the present invention;

Fig. 3 is a kind of AC-DC road form;

Fig. 4 is a kind of circuit block diagram form of Fig. 3;

Fig. 5 realizes a kind of circuit form of AC/DC loaded self-adaptive switch electric power source for the present invention.

Claims

1. the implementation method of the Switching Power Supply of a loaded self-adaptive is characterized in that its formation is made of direct voltage source 1, electronic switching device 2, switch drive 3, inductance component 4, continued flow tube 5, sampling and signal output 6, filtering 7, voltage output dc voltage 8 and circuit ground 9.

2. as described in claims 1, electronic switching device 2 is made of Q1, R0 and R2, and switch drive 3 is made of R1, Q2, continued flow tube 5 is made of D2, inductance component 4 is made of L1, and sampling and signal output 6 are made of D1, R3, R4, C1 and Q3, and filtering 7 is made of C2, C3 filtering device.And the connected mode of each device is retrained by the circuit form of Fig. 2.

3. as in claims 1 described structure, drive circuit 3 is at the initial time of power initiation, by with being connected of direct voltage source 1, itself produce one and make electronic switching device 2 first closed signals and make.

4. as described in claims 2, electronic switching device 2 first closed signals are by R1 base stage, the Q3 that driving voltage offers Q2 to be ended for low because of Vcc, Q2 conducting and make electronic switching device 2 first closed by R2.

5. as described in claims 2, after the electronic switching device 2 first closures, after L1 made direct voltage 8 meet the requirements of operating voltage, circuit entered normal operating voltage range.

6. as described in claims 5, after circuit enters normal operating voltage range, the conducting of electronic switching device is relevant with the size of the value of output dc voltage, especially after direct voltage 8 is lower than the voltage stabilizing value of D1, Q3 enters off-state, and Q2 drives because of R1 is subjected to Vdd, enters conducting state, make Q1 enter switch closed condition, output capacitance is charged by L1.

7. as described in claims 6, the shutoff of electronic switching device, relevant with sampled signal output.Especially after direct voltage 8 was higher than the voltage stabilizing value of D1, Q3 charged to C1 because of D1, and when charging made the voltage of C1 equal the base-on voltage of Q3, Q3 entered conducting state, and Q2 is ended, and Q1 disconnects, and charging finishes.Especially C1 can guarantee the normal switch state of Q3 to reduce the main switch caloric value.