CN202231914U

CN202231914U - Start circuit, LED drive power supply and LED lighting device

Info

Publication number: CN202231914U
Application number: CN2011203379613U
Authority: CN
Inventors: 冯志伟; 龚志良
Original assignee: SHENZHEN AOCI POWER SUPPLY TECHNOLOGY Co Ltd
Current assignee: Shenzhen Austrian Magnetic Technology Co., Ltd.
Priority date: 2011-09-09
Filing date: 2011-09-09
Publication date: 2012-05-23
Anticipated expiration: 2021-09-09

Abstract

The utility model belongs to the technical field of the electronics and provides a start circuit. The startup circuit comprises a current limit voltage division unit with one end connected with an output end of a rectifying unit and a switch circuit switched off or on by induced electromotive force after a chip starts to work. The start switch circuit for closing the existing start after the chip starts to work, is added into the start circuit. Once the chip starts to work, the start circuit is switched off using the electromotive force, namely the start circuit is automatically switched off, so as not to form a loop without current flowing on the loop, thus the start loss (no-load standby power consumption) of the power supply is greatly reduced, the work efficiency of the power supply is increased. Especially, the start circuit can be used as the LED drive power supply.

Description

A kind of start-up circuit, LED driving power and LED lighting device

Technical field

The utility model belongs to electronic technology field, relates in particular to a kind of start-up circuit, LED driving power and LED lighting device.

Background technology

Along with energy-saving and emission-reduction advance energetically, all put into effect corresponding standard to electronic product various countries, like the Energy Star (Energy Star) of the U.S., the ERP in Europe or the like.Yet along with society is more and more stronger to the consciousness of energy conservation and low-carbon environment-friendly, for the more loss of the step reduction energy, improve its utilance better, relevant criterion such as Energy Star and ERP are more and more stricter to the energy conservation plan of power supply product.

Existing power initiation circuit is a significant loss source of power supply, and is as shown in Figure 1.Circuit analysis is following: when input AC100～240V, become direct voltage later through bridge rectifier.Rectification direct voltage later, an end is depressed into the power supply pin of power supply chip (PWM IC) by resistance R 2, R6 current limliting branch, constitutes start-up circuit; The other end is received primary winding pin 3.In case after the chip enable work, the chip drives pin can be exported a pulsed drive switching tube Q2, the electric current and voltage that is connected on the primary winding this moment flow to switching tube Q2 through primary winding pin 3,4 and forms a loop.Because there is induced electromotive force in transformer; The chip power supply circuit of this moment is made up of diode D9, capacitor C 1 and capacitor C 11; Resistance R 2 in the start-up circuit does not but cut any ice with R6; Make resistance R 2 and R6 all have electric current to flow through owing to directly receiving the chip power supply pin after resistance R 2, the R6 series connection on the contrary always,, seriously influenced the operating efficiency and the unloaded stand-by power consumption of power supply so all there is loss in this start-up circuit always.

The utility model content

The purpose of the utility model embodiment is to provide a kind of start-up circuit, is intended to solve the existing high problem of start-up circuit energy consumption.

The utility model embodiment is achieved in that a kind of start-up circuit, comprises that current limliting partial pressure unit and that the output of an end and rectification unit joins after chip enable work, utilizes induced electromotive force to make it turn-off the switching circuit of original startup.

Another purpose of the utility model embodiment is to provide a kind of LED driving power, and said LED driving power adopts above-mentioned start-up circuit.

Another purpose of the utility model embodiment is to provide a kind of LED lighting device, and said LED lighting device comprises above-mentioned driving power.

The utility model embodiment sets up one after chip enable work in start-up circuit; Make the switching circuit of its shutoff, in case after the said chip enable work, utilize induced electromotive force that start-up circuit is turn-offed; Promptly this start-up circuit does not constitute the loop; Do not have electric current to flow through, greatly reduced the startup loss (unloaded stand-by power consumption) of power supply, promoted the operating efficiency of power supply.Especially can be used as the start-up circuit of LED driving power.

Description of drawings

Fig. 1 is the start-up circuit figure that prior art provides;

Fig. 2 is the start-up circuit figure that the utility model embodiment provides.

Embodiment

For the purpose, technical scheme and the advantage that make the utility model is clearer,, the utility model is further elaborated below in conjunction with accompanying drawing and embodiment.Should be appreciated that specific embodiment described herein only in order to explanation the utility model, and be not used in qualification the utility model.

The utility model embodiment sets up one after chip enable work in start-up circuit, make the switching circuit of its shutoff, in case after the said chip enable work, utilize induced electromotive force that start-up circuit is turn-offed, i.e. this start-up circuit section of closing automatically; Promptly do not constitute the loop, do not have electric current to flow through, greatly reduced the startup loss (unloaded stand-by power consumption) of power supply, promoted the operating efficiency of power supply.

Being example with the LED driving power below is described in detail the realization of the utility model.

As shown in Figure 2, the start-up circuit 11 that the utility model embodiment provides comprises that current limliting partial pressure unit and that the output of an end and rectification unit 12 joins after chip 13 startup work, utilizes the transformer induction electromotive force to make the switching circuit of its shutoff.In case after the said chip 13 startup work; Utilize the induced electromotive force of transformer that whole start-up circuit 11 is turn-offed, promptly this start-up circuit does not constitute the loop, does not have electric current to flow through; Greatly reduce the startup loss (unloaded stand-by power consumption) of power supply, promoted the operating efficiency of power supply.

Said switching circuit comprises switching tube Q1 and is the bias unit that this switching tube Q1 provides base bias voltage that wherein the power supply pin of the emitter of switching tube Q1 and said chip 13 joins, and the other end of collector electrode and current limliting partial pressure unit joins.For reducing cost, switching tube Q1 is preferably common triode.Better control starting resistor like needs, triode Q1 can select for use and be switching tube (Mosfet).

Usually, bias unit comprises biasing resistor and bidirectional diode D8, wherein:

One end of biasing resistor and said one of them anode of bidirectional diode D8 join, the other end with join with the output of rectification unit;

The power supply pin of another anode of bidirectional diode D8 and said chip joins, and the base stage of common cathode contact and switching tube Q1 is joined.

The contact of biasing resistor and bidirectional diode D8 is via voltage-stabiliser tube Z2 ground connection among the utility model embodiment, the direct ground connection of anode of this voltage-stabiliser tube Z2.In addition, biasing resistor is formed by resistance R 1, R5 serial connection, and the current limliting partial pressure unit is formed by resistance R 2, R6 serial connection.At this moment, the start-up circuit of LED driving power is by resistance R 1, R5, R2, R6, switching tube Q1, and bidirectional diode D8 and voltage-stabiliser tube Z2 constitute.

Input AC100～240V becomes direct voltage later through bridge rectifier in rectification unit 12 places.This direct voltage one is connected to primary winding pin 3, and the other end is through resistance R 1, R5, and voltage-stabiliser tube Z2 and bidirectional diode D8 (pin 2-3 direction) provide base bias voltage for switching tube Q1.The base stage of switching tube Q1 gets and makes its emitter positively biased and conducting after electric, and this moment, electric current and voltage was depressed into the power supply pin of power supply chip (PWM IC) through resistance R 2, R6 and switching tube Q1 current limliting branch.In case after the chip 13 startup work, the chip drives human hair combing waste send a pulse signal, with driving switch pipe Q2.The voltage, the electric current that are connected on the primary winding this moment flow to switching tube Q1 through primary winding pin 3-4 and form a loop.Because the induced electromotive force of transformer, this moment, the power supply circuits of chip were made up of diode D9 and capacitor C 1, C11.Anti-conducting partially and not of the emitter of switching tube Q1 in the start-up circuit, resistance R 2 does not constitute the loop with R6, so there is not electric current to flow through.In sum, electric current flow through resistance R 2 and R6 are arranged when only the LED driving power starts, reduced the startup loss (unloaded stand-by power consumption) of power supply thus, greatly promoted the efficient of power supply.

The above is merely the preferred embodiment of the utility model; Not in order to restriction the utility model; Any modification of being done within all spirit and principles at the utility model, be equal to replacement and improvement etc., all should be included within the protection range of the utility model.

Claims

1. start-up circuit comprises the current limliting partial pressure unit that the output of an end and rectification unit joins, and it is characterized in that said start-up circuit also comprises one after chip enable work, utilizes induced electromotive force to make it turn-off the switching circuit of original startup.

2. start-up circuit as claimed in claim 1; It is characterized in that; Said switching circuit comprises switching tube Q1 and is the bias unit that said switching tube Q1 provides base bias voltage; The power supply pin of the emitter of said switching tube Q1 and said chip joins, and the other end of collector electrode and said current limliting partial pressure unit joins.

3. start-up circuit as claimed in claim 2 is characterized in that, said bias unit comprises biasing resistor and bidirectional diode D8, wherein:

One end of said biasing resistor and said one of them anode of bidirectional diode D8 join, the other end with join with the output of said rectification unit;

The power supply pin of said another anode of bidirectional diode D8 and said chip joins, and the base stage of common cathode contact and said switching tube Q1 is joined.

4. start-up circuit as claimed in claim 3 is characterized in that, the contact of said biasing resistor and bidirectional diode D8 is via voltage-stabiliser tube Z2 ground connection, the direct ground connection of the anode of said voltage-stabiliser tube Z2.

5. start-up circuit as claimed in claim 4 is characterized in that, said biasing resistor is formed by resistance R 1, R5 serial connection.

6. like each described start-up circuit in the claim 1～5, it is characterized in that said current limliting partial pressure unit is formed by resistance R 2, R6 serial connection, said rectification unit is the bridge rectifier unit.

7. a LED driving power is characterized in that, said LED driving power adopts like each described start-up circuit in the claim 1～6.

8. a LED lighting device is characterized in that, said LED lighting device comprises driving power as claimed in claim 7.