CN203136273U

CN203136273U - High-power-factor LED drive power supply circuit of AP3970P

Info

Publication number: CN203136273U
Application number: CN 201320118280
Authority: CN
Inventors: 田津龙
Original assignee: Individual
Current assignee: Individual
Priority date: 2013-03-15
Filing date: 2013-03-15
Publication date: 2013-08-14
Anticipated expiration: 2023-03-15

Abstract

The utility model relates to a high-power-factor LED drive power supply circuit of an AP3970P. An AC input protection circuit of the circuit is output to a rectification and power factor correction circuit after being connected to an external power supply, and the rectification and power factor correction circuit is used for providing power to a power-on power supplying circuit, an MOSFET drain electrode clamping protection circuit, a drive power supply control chip power supplying circuit and a high-frequency transformer. The power-on power supplying circuit and the drive power supply control chip power supplying circuit are used for providing power to a control chip AP3970 in an AP3970P constant voltage and constant current control circuit. The output of the MOSFET drain electrode clamping protection circuit and the output of the high-frequency transformer helps to protect the control chip AP3970 in the AP3970P constant voltage and constant current control circuit. The high-frequency transformer, through coupling, helps to provide input electric energy for a DC output circuit of an LED lamp drive power supply. The drive power supply is composed of the AP3970 serving as the control chip from the BCD company and a peripheral circuit that is optimized for multiple times, is above 0.9 in terms of high power factor and above 85% in terms of efficiency, helps to realize multi-protection, is stable in terms of running of the circuit and is low in production cost.

Description

The LED driving power circuit of the AP3970P of High Power Factor

Technical field

The utility model belongs to the applied technical field of AP3970P chip, the LED driving power circuit of especially a kind of AP3970P of High Power Factor.

Background technology

The LED driving power is the key components of LED lamp, LED (Light Emitting Diode) light-emitting diode.The characteristics of LED are very obvious, long, the high and low radiation of light efficiency of life-span and low-power consumption.But the LED lamp not only has only LED, also drive circuit must be arranged; The requirement of the driving power of LED is near harshness, and this is that characteristic by LED determines that this has increased the drive circuit development difficulty; Because the problem of driving power, the advantage of LED lamp can be had a greatly reduced quality; The performance of LED lamp is said in some sense and is depended on drive circuit thus.The driving power of research high efficiency, low cost, high reliability becomes the key that the LED lamp is promoted, popularized.Send out and to change ring money [2013] 188 notices, in " semiconductor lighting energy-saving estate planning " main task special column 2 new materials, equipment and the key technology that six ministries and commissions formulate, just key technology is classified in, cheaply LED driving power exploitation efficient, highly reliable development as.

The LED lamp is a light, and the industrial chain of vast market, LED lamp is driving driving power producer and occurring like the mushrooms after rain, because 1 standard of low-power LED lamp is unclear, so the low-power driving power is very different on the present market, has a long way to go.Subject matter is reliability, life-span, stability and the cost proportion in the whole LED lamp of driving power.

Driving power circuit is the integrated application of electronic technology, LED is the low voltage drive of 2～3V, can not directly connect the 220V alternating current, must design complicated translation circuit, and the LED of different purposes, be equipped with different power supply adaptors, design a good driving power and must take all factors into consideration several factors, because the effect of driving power in the whole LED lamp is the same like human heart.At present, LED lamp driving power source scheme majority is core with a certain producer control chip, is equipped with the peripheral element road; What type of drive was current has two kinds: constant pressure source of the first is for a plurality of constant-current sources, and each constant-current source is given every paths of LEDs power supply separately.This mode, combination is flexible, and a paths of LEDs fault do not influence other LED work, but cost can be slightly higher.Another kind is direct constant current power supply, the operation of LED serial or parallel connection.Its advantage is that cost is a little low, but very flexible also needs to solve certain LED fault, does not influence the problem of other LED operation.These two kinds of forms can be parallel in a period of time.Multiple constant current output supply power mode can be later main flow direction better at cost and aspect of performance.

The LED lamp driving power source is the assurance of the development of LED industrial chain, the quality of LED driving power is directly restricting the LED reliability of products, driving power is the weakest link of LED light fixture, serious hysteresis LED lamp pearl development, therefore in LED industrial chain perfect today progressively, LED driving power ripe most important.

Summary of the invention

The purpose of this utility model is to overcome the deficiencies in the prior art, and the LED driving power circuit of a kind of AP3970P of High Power Factor is provided.

The utility model solves its technical problem and takes following technical scheme to realize:

The LED driving power circuit of a kind of AP3970P of High Power Factor; comprise the interchange input protection circuit; rectification and circuit of power factor correction; the start power supply circuits; MOSFET pipe drain electrode clamping protective circuit; driving power control chip power supply circuits; high frequency transformer; LED lamp driving power source dc output circuit and AP3970P constant pressure and flow control circuit; exchange and export to rectification and circuit of power factor correction after input protection circuit inserts external electrical network 220V power supply; the interchange that rectification and circuit of power factor correction will be imported changes direct current into through bridge rectifier; and carry out exporting to the start power supply circuits after the power factor correction; MOSFET pipe drain electrode clamping protective circuit; driving power control chip power supply circuits and high frequency transformer; the output of start power supply circuits and driving power control chip power supply circuits is connected with AP3970P constant pressure and flow control circuit; be the power supply of the control chip AP3970 in the AP3970P constant pressure and flow control circuit; the output of MOSFET pipe drain electrode clamping protective circuit and high frequency transformer is connected with AP3970P constant pressure and flow control circuit; for the control chip AP3970 in the AP3970P constant pressure and flow control circuit provides inner high power valve protection; high frequency transformer provides the input electric energy by being coupled as LED lamp driving power source dc output circuit, and LED lamp driving power source dc output circuit provides LED lamp driving power source.

And, described AP3970P constant pressure and flow control circuit comprises control chip AP3970, capacitor C 2, resistance R 5, R6, R7, R8, capacitor C 2 is connected between control chip AP3970 pin 1 and the ground, be connected between control chip AP3970 pin 4 and the ground behind the resistance R 7 parallel resistance R8, be connected behind the resistance R 5 series resistor R6 between the Nfb winding positive terminal and ground of high frequency transformer, and resistance R 5 is connected pin 8 ground connection of control chip AP3970 with node between the resistance R 6 with the pin 2 of control chip AP3970.

Advantage of the present utility model and good effect are:

1, the High Power Factor LED lamp driving power source of the utility model AP3970 chip, power factor can reach more than 0.9.

2, this driving power constant voltage of the utility model, constant current output: output voltage DC=42V, output current 350mA.Power output can be adjusted between 8～12W, mainly adjusts output voltage.

3, the utility model driving power is control chip with the AP3970 of BCD company, is equipped with through the peripheral circuit of Multiple Optimization to form.Accomplished that High Power Factor reaches more than 0.9, efficient reaches more than 85 ﹪ multiple protective, low cost.

4, the utility model line work is stable, and produces facility, the advantage that cost is low.

Description of drawings

Fig. 1 is schematic circuit of the present utility model.

Embodiment

Below in conjunction with accompanying drawing the utility model embodiment is further described:

It is emphasized that the utility model embodiment is illustrative, rather than determinate, can not be with this embodiment as to restriction of the present utility model.

The LED driving power circuit of a kind of AP3970P of High Power Factor; as shown in Figure 1; comprise and exchange input protection circuit 1; rectification and circuit of power factor correction 2; start power supply circuits 3; MOSFET pipe drain electrode clamping protective circuit 4; driving power control chip power supply circuits 5; high frequency transformer 6; LED lamp driving power source dc output circuit 7; AP3970P constant pressure and flow control circuit 8; exchange and export to rectification and circuit of power factor correction 2 after input protection circuit 1 inserts external electrical network 220V power supply; the interchange that rectification and circuit of power factor correction 2 will be imported changes direct current into through bridge rectifier; and carry out exporting to start power supply circuits 3 after the power factor correction; MOSFET pipe drain electrode clamping protective circuit 4; driving power control chip power supply circuits 5 and high frequency transformer 6; the output of start power supply circuits 3 and driving power control chip power supply circuits 5 is connected with AP3970P constant pressure and flow control circuit 8; be the power supply of the control chip AP3970 in the AP3970P constant pressure and flow control circuit 8; the output of MOSFET pipe drain electrode clamping protective circuit 4 and high frequency transformer 6 is connected with AP3970P constant pressure and flow control circuit 8; for the control chip AP3970 in the AP3970P constant pressure and flow control circuit 8 provides inner high power valve protection; high frequency transformer 6 provides the input electric energy by being coupled as LED lamp driving power source dc output circuit 7, and LED lamp driving power source dc output circuit 7 provides LED lamp driving power source.

Wherein, exchanging input protection circuit 1 is made up of cartridge fuse F1, negative tempperature coefficient thermistor R0, the bold and vigorous capacitor C 0 of input filter, inductance L 0; cartridge fuse F1 one end connects of outside 220V power supply; other end serial connection negative tempperature coefficient thermistor R0; inductance L 0 one ends connect another of outside 220V power supply; the end of the other end and negative tempperature coefficient thermistor R0 is jointly as the output that exchanges input protection circuit 1, and input filter capacitor C0 is connected in parallel on the two ends of outside 220V input power supply.

Cartridge fuse F1 and negative tempperature coefficient thermistor R0 are the overcurrent protections of input circuit, and when the electric current that passes through when cartridge fuse surpassed 1.25～1.5 times of rated current, the fuse of cartridge fuse will quick fuse; Negative tempperature coefficient thermistor is energising moment current-limiting protection, and the effect of capacitor C 0 is that the high order harmonic component of filtering power supply is disturbed, and surge current and outside, internal electromagnetic were disturbed (EMI) effect of drawing up when inductance had circuit to open.

Wherein, rectification and circuit of power factor correction 2 are by bridge rectifier D 1～D4; diode D05, D06, D07; electrochemical capacitor C01, C02 form; between the D1 and D2 of bridge rectifier; the output of the node place incoming transport input protection circuit 1 between D3 and the D4; capacitor C 01 is with after diode D05 connects; capacitor C 02 and the output two ends that are connected in parallel on bridge rectifier D 1～D4 after diode D07 connects respectively, diode D06 is connected on capacitor C 01 and diode D05 and capacitor C 02 and the node that diode D07 is connected.

The effect of circuit is that the interchange that will import changes direct current into through bridge rectifier, and adopt current follow-up circuit to carry out power factor correction, to improve the power factor value of circuit, circuit of power factor correction (PFC) operation principle is: force the transient change track of AC line current floating voltage waveform, make electric current and voltage keep same-phase.

Wherein, start power supply circuits 3 are made up of resistance R 1 and the R2 of series connection, one end of this series circuit is connected the output of rectification and circuit of power factor correction 2, the other end is connected with the pin 3 of control chip AP3970, the effect of start power supply circuits 3 is to give control chip AP3970 power supply when start, to guarantee operate as normal when driving power starts.

Wherein, MOSFET pipe drain electrode clamping protective circuit 4 is made up of diode D6, resistance R 3, capacitor C 4; resistance R 3 is connected in series with diode D6 with capacitor C 4 backs in parallel; one end of this MOSFET pipe drain electrode clamping protective circuit 4 is connected with the output of bridge rectifier D 1～D4, and the other end is connected with pin 5 pin 6 of control chip AP3970.This circuit is a clamped protective circuit of drain electrode; its effect is that the high power valve of AP3970 inside is protected; in case high power valve is breakdown; this driving power is an inverse-excitation type switch power-supply; whenever power tube by conducting become by the time; see again on the winding that closes power supply and will produce peak voltage and induced voltage; peak voltage wherein is to form owing to there is leakage inductance (being the self-induction that leakage inductance produces) in high frequency transformer; high direct voltage U1 and induced voltage Uor that the back generation is sprinkled in it and rectification filter are superimposed; be added in the drain electrode of power tube; be easy to damage power tube; for this reason; must increase the clamped protective circuit of drain electrode, carry out clamped or absorption to peak voltage.Resistance R 3 and capacitor C 4 are absorber elements, and D6 is blocking diode, form R, C, the clamped circuit of VD type.

Wherein, driving power control chip power supply circuits 5 are made up of diode D5, capacitor C 3, electric capacity R4 and transformer Nfb winding, capacitor C 3 is with after electric capacity R4 is in parallel, one end connects ground, be connected the other end ground connection of transformer Nfb winding with the anode of transformer Nfb winding behind the other end serial connection diode D5.Driving power control chip power supply circuits 5 produce direct voltage by the induced voltage of Nfb winding through rectifying and wave-filtering behind circuit start, press for the control chip operate as normal provides galvanic current.Power initiation moment control chip AP3970 is by R1, R2 power supply, and R1, R2 have just finished task behind the circuit start.

Wherein, high frequency transformer 6 is high frequency transformer T1, its input winding Nfb winding and Np winding are arranged, the connection of Nfb winding as mentioned above, the two ends of Np winding connect the output of bridge rectifier and pin 5 pin 6 of control chip AP3970 respectively, its output winding be Ns.High frequency transformer is the vitals of Switching Power Supply, and it plays the effect of storage power, transmission energy.

Wherein, LED lamp driving power source dc output circuit 7 is made up of high frequency transformer Ns winding, the filter capacitor C5 and the load resistance R9 that are serially connected in the fast recovery diode D7 of Ns winding output cathode end and are connected in parallel on Ns winding two ends.

Wherein, AP3970P constant pressure and flow control circuit 8 is control circuits of driving power, core is control chip AP3970, be equipped with again and be connected between control chip AP3970 pin 4 and the ground behind the capacitor C 2 that is connected between control chip AP3970 pin 1 and the ground, the resistance R 7 parallel resistance R8, be connected between Nfb winding positive terminal and the ground behind the resistance R 5 series resistor R6, and resistance R 5 is connected pin 8 ground connection of control chip AP3970 with node between the resistance R 6 with the pin 2 of control chip AP3970.Capacitor C 2 is direct current output building-out capacitors; R5, R6 are former limit feedback voltage sampling resistors, and their ratio and Transformer Winding ratio determine the height of output voltage; R7, R8 resistance are high-power driving pipe source resistances, are current sampling resistors, just can control the size of output current by the size that changes these two parallel resistances.

Control chip AP3970 is the core of control section, is a frequency modulation(FM) chip (PFM).Characteristics are: limit, source feedback (PSR) constant voltage/constant current (CV/CC) control, and power switch pipe is built-in integrated; Utmost point low starting current: 0.2 μ A; Built-in soft start, overvoltage protection, short-circuit protection.

The operation principle of this driving power:

This driving power is a switch DC stabilized voltage power supply, is that a single-ended isolation of discontinuous mode instead swashs the AC-DC converter.

Operation principle is: during power tube (built-in) VT saturation conduction, input voltage (direct voltage behind the rectifying and wave-filtering) Ui is added to the elementary winding Np of high frequency transformer T1, with the relative non-same polarity of " " name end for just, secondary winding Ns diode D7 oppositely ends, and high frequency transformer moves as inductance; When power tube VT turn-offed, each winding induced electromotive force " " end of high frequency transformer was negative, the conducting of secondary diode D7 positively biased, and the magnetic core magnetic flux can not suddenly change, and excitation magnetic potential is constant, satisfies i _2p/ i _1p=Np/Ns relation, as the transformer operation, the magnetic field energy that will store conduction period is transferred to load, and in whole load and input voltage range, secondary current drops to zero in deadline.If output capacitance C5 is enough big, output voltage U o is constant substantially in the time at charge and discharge.

This is a frequency modulation(FM) control chip (PFM), when input voltage changes or load variations (being that output current changes), can feed back to the chip respective input by sampling resistor, chip will change operating frequency, keeps the stable of output voltage, electric current.

Claims

1. the LED driving power circuit of the AP3970P of a High Power Factor; it is characterized in that: comprise the interchange input protection circuit; rectification and circuit of power factor correction; the start power supply circuits; MOSFET pipe drain electrode clamping protective circuit; driving power control chip power supply circuits; high frequency transformer; LED lamp driving power source dc output circuit and AP3970P constant pressure and flow control circuit; exchange and export to rectification and circuit of power factor correction after input protection circuit inserts external electrical network 220V power supply; the interchange that rectification and circuit of power factor correction will be imported changes direct current into through bridge rectifier; and carry out exporting to the start power supply circuits after the power factor correction; MOSFET pipe drain electrode clamping protective circuit; driving power control chip power supply circuits and high frequency transformer; the output of start power supply circuits and driving power control chip power supply circuits is connected with AP3970P constant pressure and flow control circuit; be the power supply of the control chip AP3970 in the AP3970P constant pressure and flow control circuit; the output of MOSFET pipe drain electrode clamping protective circuit and high frequency transformer is connected with AP3970P constant pressure and flow control circuit; for the control chip AP3970 in the AP3970P constant pressure and flow control circuit provides inner high power valve protection; high frequency transformer provides the input electric energy by being coupled as LED lamp driving power source dc output circuit, and LED lamp driving power source dc output circuit provides LED lamp driving power source.

2. the LED driving power circuit of the AP3970P of High Power Factor according to claim 1, it is characterized in that: described AP3970P constant pressure and flow control circuit comprises control chip AP3970, capacitor C 2, resistance R 5, R6, R7, R8, capacitor C 2 is connected between control chip AP3970 pin 1 and the ground, be connected between control chip AP3970 pin 4 and the ground behind the resistance R 7 parallel resistance R8, be connected behind the resistance R 5 series resistor R6 between the Nfb winding positive terminal and ground of high frequency transformer, and resistance R 5 is connected pin 8 ground connection of control chip AP3970 with node between the resistance R 6 with the pin 2 of control chip AP3970.