CN201174804Y - Separation type general illuminating LED driving circuit - Google Patents

Abstract

The utility model belongs to the electronic technical field and relates to a universal illuminating LED drive circuit which comprises an input rectification circuit, a power factor correcting (PFC) control circuit, a transformer surge current and peak voltage absorption circuit, an optical coupling isolation feedback circuit, an isolated type switch transformer and a unidirectional rectification output circuit. The drive circuit uses a power management chip NCP1653 of Osemi company as a control core; primary current of the switch transformer is detected to realize the function of power factor correction; a topological structure of the circuit is a flyback and isolated type; the working mode of the circuit is a continuous conduction mode; and the circuit has the functions of correcting power factors, regulating light, outputting constant current and stable voltage, absorbing surge current to conduct a switch element and cutting off peak voltage. Simultaneously, as the drive circuit adopts the power management chip NCP1653 and can save a mass of peripheral circuits, thereby having the advantages of low cost and small size, and being suitable for batch production.

Description

A kind of insulation type general use illumination LED driving circuit

Technical field

The utility model belongs to electronic technology field, relates to general illumination LED (light-emitting diode) drive circuit, particularly a kind of isolated high reliability illumination LED drive circuit.

Background technology

The LED lighting technology has advantages such as energy-saving and environmental protection, life-span are long and easy to control, is one of the high-tech sector of tool development prospect of 21 century, becomes the leading of illumination market with replacing incandescent lamp and fluorescent lamp.Under LED Lighting Industry bright prospect like this, at the different application of lighting field, also in development rapidly, it mostly adopts switch power technology to various LED lamp drive circuits.But, what present many led drive circuits adopted is non-isolated Drive Structure or the isolated Drive Structure that does not have Active PFC (PFC) function, non-isolated led drive circuit poor reliability, the led drive circuit power utilization rate of no PFC function is low.In addition, for isolated circuit structure, owing to there is isolating transformer, can produce very big surge current when making the switch element conducting, shutdown moment can produce very big peak voltage, and this can influence the life-span of power-efficient and switching tube.Existing isolation type switching power supply is at the absorption circuit comparative maturity of switch element shutdown moment, and the absorption circuit in the time of the switch element conducting seldom, therefore, how can absorb the peak voltage of switch element shutdown moment, can absorb the surge current of opening moment again and just become a technical barrier.

The utility model content

The utility model overcomes the deficiency of existing led drive circuit, a kind of isolated high performance universal illumination LED drive circuit is provided, this circuit has isolated led drive circuit high reliability features, have Active PFC function and dimming function simultaneously, and have the switch element opening and closing surge absorption function of moment.

The utility model detailed technology scheme is as follows:

A kind of insulation type general use illumination LED driving circuit, by input rectification circuit, adjusting control circuit, Active PFC (PFC, Power Factor Correction) control circuit, transformer inrush current and peak voltage absorb circuit, light-coupled isolation feedback circuit, isolated switch transformer and unidirectional rectifying output circuit composition, it is characterized in that:

Adjusting control circuit is made of diode D8 and capacitor C 11; The Active PFC control circuit comprises PFC control module circuit that the power management chip NCP1653 by resistance R 1, R2, R3, R4, R5, R6, R7, R8, R9, R11, R12, diode D1, capacitor C 1, C2, C3, C4, C5 and ON company constitutes and the start-up circuit of the NCP1653 that is made of resistance R 10, diode D2, capacitor C 9 is formed; Transformer inrush current and peak voltage absorb circuit and are made of diode D4, D5, capacitor C 6, inductance L 1, L2; The light-coupled isolation feedback circuit is made of resistance R 13, R14, R15, R16, R17, R18, capacitor C 8, triode Q2, three terminal device TL431 and optical coupling isolator U2A, U2B; Unidirectional rectifying output circuit by transformer secondary output winding, diode D6, inductance L 3, capacitor C 7, C10 and as the LED 1 of load, LED2 ..., LED19, LED20 form;

The output terminals A of electric main after the rectification circuit rectification meets the port C of the elementary winding of isolated switch transformer T1, and the output B ground connection GND of rectification circuit links to each other by capacitor C 1 between two output terminals A, the B; The PWM dim signal connects the negative pole of diode D8, the positive pole of diode D8 connects the pin two of power management chip NCP1653, the negative pole of diode D8 connects the pin 6 of chip NCP1653 by capacitor C 11, also is chip ground GND_IC, and the positive pole of diode D8 meets chip ground GND_IC by capacitor C 4; The pin 3 of power management chip NCP1653 meets chip ground GND_IC by capacitor C 3 on the one hand, successively by meeting the port C of the elementary winding of isolated switch transformer T1 after resistance R 2 and the resistance R 1, the tie point of resistance R 1 and resistance R 2 meets chip ground GND_IC by capacitor C 2 on the other hand; The pin 4 of power management chip NCP1653 is by resistance R 5 ground connection GND; Meet chip ground GND_IC behind the parallel circuits of the pin 5 of power management chip NCP1653 by resistance R 9 and capacitor C 5; The pin 6 of power management chip NCP1653 meets chip ground GND_IC; Link to each other by resistance R 7 between chip ground GND_IC and the ground GND; The pin 7 of power management chip NCP1653 connects the grid of MOS switching tube Q1 by resistance R 11, the grid of MOS switching tube Q1 meets chip ground GND_IC by resistance R 12 simultaneously, the source electrode of MOS switching tube Q1 meets chip ground GND_IC, and the drain electrode of MOS switching tube Q1 meets the port D of the elementary winding of isolated switch transformer T1 by inductance L 2; The pin 8 of power management chip NCP1653 meets chip ground GND_IC by capacitor C 9 on the one hand, connect the negative pole of diode D2, diode D3 and the collector electrode of the controlled part U2B of optical coupling isolator on the other hand simultaneously, the positive pole of diode D2 meets the port C of the elementary winding of isolated switch transformer T1 by resistance R 10, meet chip ground GND_IC by resistance R 3 when the emitter of the controlled part U2B of optical coupling isolator connects the positive pole of diode D1 by resistance R 6, the negative pole of diode D1 connects the pin one of power management chip NCP1653 by resistance R 4; The pin one of power management chip NCP1653 also connects the pin 8 of power management chip NCP1653 successively by resistance R 4, resistance R 8; The positive pole of diode D3 meets the port E of isolated switch transformer T1 feedback winding, and the port F of isolated switch transformer T1 feedback winding meets chip ground GND_IC; The port C of the elementary winding of isolated switch transformer T1 connects the negative pole of diode D4, and the positive pole of diode D4 links to each other with the port D of the elementary winding of isolated switch transformer T1 by capacitor C 6; The positive pole of diode D4 links to each other by the negative pole that inductance L 1 meets diode D5, and the positive pole of diode D5 meets chip ground GND_IC; The port G of isolated switch transformer T1 secondary winding connects the positive pole of diode D6, and port H meets output ground GND_out; The negative pole of diode D6 meets output ground GND_out by capacitor C 10 on the one hand, on the other hand successively by meeting output ground GND_out after inductance L 3, the capacitor C 7; The tie point of inductance L 3 and capacitor C 7 meets output ground GND_out by resistance R 17, resistance R 18 on the one hand successively, connects the positive pole of optical coupling isolator control section U2A on the other hand by resistance R 15; The negative pole of optical coupling isolator control section U2A connects the collector electrode of triode Q2 and the negative pole of three terminal device TL431 simultaneously, and resistance R 16 is in parallel with optical coupling isolator control section U2A; The positive pole of three terminal device TL431 connects output ground GND_out, the control utmost point connecting resistance R17 of three terminal device TL431 and the tie point of resistance R 18; The emitter of triode Q2 meets output ground GND_out, and the base stage of triode Q2 links to each other with the collector electrode of triode Q2 by capacitor C 8 on the one hand, on the other hand successively by meeting output ground GND_out after resistance R 14, the resistance R 13;

Whole isolated formula general illumination LED drive circuit when work, as LED for illumination LED1, the LED2 of load ... the positive termination inductance L 3 after LED19 and the LED20 series connection and the tie point of resistance R 15, the tie point of negative terminal connecting resistance R13 and resistance R 14.

The utlity model has following characteristics:

1, adopt the power management chip NCP1653 of ON company to be the control core, the primary current of sense switch transformer T1 realizes Active PFC.

2, the topological structure of this circuit is isolated anti-(FlyBack) circuit that swashs, and mode of operation is continuous conduction mode (CCM, Continuous Current Mode).

3, constitute adjusting control circuit by diode D8 and capacitor C 11, can with the PWM ripple to LED brightness regulate, thereby have dimming function.

4, constitute the isolated form feedback circuit by resistance R 13, R14, R15, R16, R17, R18, capacitor C 8, triode Q2, three terminal device TL431 and optical coupling isolator (U2A, U2B), guarantee constant current voltage stabilizing output, realize overcurrent and LED open-circuit-protection.

5, constitute transformer inrush current and peak voltage by diode D4, D5, capacitor C 6, inductance L 1, L2 and absorb circuit, have the function of the peak voltage of the surge current that absorbs switch element conducting moment and shutdown moment.

In sum, insulation type general use illumination LED driving circuit of the present invention has Active PFC, light modulation, crossing current voltage stabilizing output and absorbs the surge current of switch element conducting moment and the function of the peak voltage of shutdown moment.The present invention simultaneously can save a large amount of peripheral circuits, thereby have the advantage that cost is low, volume is little owing to adopted power management chip NCP1653, is fit to produce in batches.

Description of drawings

Fig. 1 is the utility model circuit diagram.

Embodiment

As Fig. 1; circuit is mainly by NCP1653; isolated switch transformer T1; surge absorbing circuit (diode D4; D5; capacitor C 6; inductance L 1; L2); optical coupling isolator (U2A; U2B) and resistance; electric capacity constitutes; the electric current of the CS pin of NCP1653 (the 4th pin) detection branch is to change pulse duration; realize PFC; by diode D4; D4; D5; inductance L 1; capacitor C 6 absorbs the peak voltage that the switching tube shutdown moment produces; inductance L 2 absorbs the surge current of switching tube conducting moment generation; the FB pin of NCP1653 (the 1st pin) detects the feedback signal of optical coupling isolator; realize output overcurrent and LED open circuit protecting function, the V of NCP1653 _ControlPin (the 2nd pin) inserts pwm control signal through diode D8 can realize the LED dimming function.

Claims (1)

1, a kind of insulation type general use illumination LED driving circuit, absorb circuit, light-coupled isolation feedback circuit, isolated switch transformer and unidirectional rectifying output circuit by input rectification circuit, adjusting control circuit, Active PFC control circuit, transformer inrush current and peak voltage and form, it is characterized in that:

Adjusting control circuit is made of diode D8 and capacitor C 11; The Active PFC control circuit comprises PFC control module circuit that the power management chip NCP1653 by resistance R 1, R2, R3, R4, R5, R6, R7, R8, R9, R11, R12, diode D1, capacitor C 1, C2, C3, C4, C5 and ON company constitutes and the start-up circuit of the NCP1653 that is made of resistance R 10, diode D2, capacitor C 9 is formed; Transformer inrush current and peak voltage absorb circuit and are made of diode D4, D5, capacitor C 6, inductance L 1, L2; The light-coupled isolation feedback circuit is made of resistance R 13, R14, R15, R16, R17, R18, capacitor C 8, triode Q2, three terminal device TL431 and optical coupling isolator U2A, U2B; Unidirectional rectifying output circuit by transformer secondary output winding, diode D6, inductance L 3, capacitor C 7, C10 and as the LED 1 of load, LED2 ..., LED19, LED20 form;

The output terminals A of electric main after the rectification circuit rectification meets the port C of the elementary winding of isolated switch transformer T1, and the output B ground connection GND of rectification circuit links to each other by capacitor C 1 between two output terminals A, the B; The PWM dim signal connects the negative pole of diode D8, the positive pole of diode D8 connects the pin two of power management chip NCP1653, the negative pole of diode D8 connects the pin 6 of chip NCP1653 by capacitor C 11, also is chip ground GND_IC, and the positive pole of diode D8 meets chip ground GND_IC by capacitor C 4; The pin 3 of power management chip NCP1653 meets chip ground GND_IC by capacitor C 3 on the one hand, successively by meeting the port C of the elementary winding of isolated switch transformer T1 after resistance R 2 and the resistance R 1, the tie point of resistance R 1 and resistance R 2 meets chip ground GND_IC by capacitor C 2 on the other hand; The pin 4 of power management chip NCP1653 is by resistance R 5 ground connection GND; Meet chip ground GND_IC behind the parallel circuits of the pin 5 of power management chip NCP1653 by resistance R 9 and capacitor C 5; The pin 6 of power management chip NCP1653 meets chip ground GND_IC; Link to each other by resistance R 7 between chip ground GND_IC and the ground GND; The pin 7 of power management chip NCP1653 connects the grid of MOS switching tube Q1 by resistance R 11, the grid of MOS switching tube Q1 meets chip ground GND_IC by resistance R 12 simultaneously, the source electrode of MOS switching tube Q1 meets chip ground GND_IC, and the drain electrode of MOS switching tube Q1 meets the port D of the elementary winding of isolated switch transformer T1 by inductance L 2; The pin 8 of power management chip NCP1653 meets chip ground GND_IC by capacitor C 9 on the one hand, connect the negative pole of diode D2, diode D3 and the collector electrode of the controlled part U2B of optical coupling isolator on the other hand simultaneously, the positive pole of diode D2 meets the port C of the elementary winding of isolated switch transformer T1 by resistance R 10, meet chip ground GND_IC by resistance R 3 when the emitter of the controlled part U2B of optical coupling isolator connects the positive pole of diode D1 by resistance R 6, the negative pole of diode D1 connects the pin one of power management chip NCP1653 by resistance R 4; The pin one of power management chip NCP1653 also connects the pin 8 of power management chip NCP1653 successively by resistance R 4, resistance R 8; The positive pole of diode D3 meets the port E of isolated switch transformer T1 feedback winding, and the port F of isolated switch transformer T1 feedback winding meets chip ground GND_IC; The port C of the elementary winding of isolated switch transformer T1 connects the negative pole of diode D4, and the positive pole of diode D4 links to each other with the port D of the elementary winding of isolated switch transformer T1 by capacitor C 6; The positive pole of diode D4 links to each other by the negative pole that inductance L 1 meets diode D5, and the positive pole of diode D5 meets chip ground GND_IC; The port G of isolated switch transformer T1 secondary winding connects the positive pole of diode D6, and port H meets output ground GND_out; The negative pole of diode D6 meets output ground GND_out by capacitor C 10 on the one hand, on the other hand successively by meeting output ground GND_out after inductance L 3, the capacitor C 7; The tie point of inductance L 3 and capacitor C 7 meets output ground GND_out by resistance R 17, resistance R 18 on the one hand successively, connects the positive pole of optical coupling isolator control section U2A on the other hand by resistance R 15; The negative pole of optical coupling isolator control section U2A connects the collector electrode of triode Q2 and the negative pole of triode TL431 simultaneously, and resistance R 16 is in parallel with optical coupling isolator control section U2A; The positive pole of three terminal device TL431 connects output ground GND_out, the control utmost point connecting resistance R17 of three terminal device TL431 and the tie point of resistance R 18; The emitter of triode Q2 meets output ground GND_out, and the base stage of triode Q2 links to each other with the collector electrode of triode Q2 by capacitor C 8 on the one hand, on the other hand successively by meeting output ground GND_out after resistance R 14, the resistance R 13;

Whole isolated formula general illumination LED drive circuit when work, as LED for illumination LED1, the LED2 of load ... the positive termination inductance L 3 after LED19 and the LED20 series connection and the tie point of resistance R 15, the tie point of negative terminal connecting resistance R13 and resistance R 14.

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