CN203618173U

CN203618173U - LED lamp driving power based on primary side feedback

Info

Publication number: CN203618173U
Application number: CN201320760799.5U
Authority: CN
Inventors: 张新安
Original assignee: Individual
Current assignee: Individual
Priority date: 2013-11-28
Filing date: 2013-11-28
Publication date: 2014-05-28
Anticipated expiration: 2023-11-28

Abstract

An LED lamp driving power based on a primary side feedback is formed by an EMI filtering circuit, an electric supply rectifying filtering circuit, a PFC correcting circuit, an integrated circuit chip BP3105, an MOS switch, a switch transformer, an output voltage sampling circuit, an output current sampling circuit and a high-frequency rectifying filtering circuit, and the above components are arranged as shown in the drawings. The BP3105 is a high-precision LED lamp constant current control chip adopting the primary side feedback; a constant current control can be realized without a secondary feedback circuit; and the system size can be greatly reduced and the system cost can be greatly saved. An output voltage of a driving power is 33V; an output current of the driving power is 303mA; and the driving power is provided with an undervoltage protection, overvoltage protection, FB short circuit protection, chip over temperature protection, LED lamp short circuit protection, LED lamp open circuit protection and other protection functions. The beneficial effects of the utility model are that: the simple circuit, small size, light weight, low cost, high efficiency, perfect protection function, and long service life are realized.

Description

A kind of LED lamp driving power source based on former limit feedback

Technical field

The utility model relates to LED driving power technical field, is specifically related to a kind of LED lamp driving power source based on former limit feedback.

Background technology

In power consumption, the ratio that China's electric consumption on lighting accounts for generating total amount is 11%, and developed country reaches 19%.Along with expanding economy, the electric consumption on lighting of China is by the raising of vast scale, and therefore, the research of green energy conservation illumination more and more comes into one's own.With existing lighting apparatus comparison, LED illumination has a lot of outstanding advantages.1. luminous efficiency is high, and less, the monochromaticjty of light is good, spectrum is narrow in power consumption.Under same illuminating effect, the power consumption of LED lamp is 1/2nd of fluorescent lamp, 1/8th of incandescent lamp.2. safety and environmental protection, LED lamp is all solid state luminous element, shock-resistant, and non-thermal radiation is pollution-free, and caloric value is low.3. start-up time short, the response time of LED lamp only had for tens nanoseconds, can be suitable for use in some needs fast occasions of response.4. long service life, can reach nearly 100,000 hours the useful life of LED lamp, and fluorescent lamp is 6000～8000 hours, and incandescent lamp is generally 1000～2000 hours.5. volume is little, and LED lamp has miniaturization, complanation, the feature that designability is strong.But the bright number of output light stream of LED lamp and electric current and the temperature of wavelength and PN junction are closely related, conventional drive circuit, as switch voltage-stabilizing circuit, will cause the premature aging of LED lamp, can not effectively meet the requirement that the illumination of LED lamp drives.Therefore, LED lamp must provide constant current to light work by design specialized driving power, fully meets the required driving requirement of LED lamp work, in order to avoid electric current increases the damage by LE lamp D, thereby brings into play to greatest extent the performance of LED lamp, reduces failure rate.But existing various LED lamp driving power circuit costs are high, cost performance is low, has affected applying of LED lamp.

Summary of the invention

For solving the deficiency of existing LED lamp driving power source, the utility model discloses a kind of LED lamp driving power source based on former limit feedback.This driving power circuit is simple, volume is little, lightweight, cost is low, efficiency is high, defencive function is perfect, and long service life can be widely used in LED lamp driving power source field.

For achieving the above object, the utility model adopts following technical scheme: the utility model is made up of EMI filter circuit, commercial power rectification filter circuit, PFC correcting circuit, integrated circuit (IC) chip BP3105, MOS switching tube, switch transformer, output voltage sample circuit, output current sample circuit and rectifier filter circuit.The input termination electric main power supply of EMI filter circuit, the input of output termination commercial power rectification filter circuit; The output of the input commercial power rectification filter circuit of pfc circuit, 1 end of output termination switch transformer armature winding N1, the drain electrode of the 2 termination MOS switching tubes of armature winding N1; 3 ends of the output voltage sampling winding N2 of the input termination switch transformer of output voltage sample circuit, the 5 pin FB ends of output termination integrated circuit (IC) chip BP3105; The source electrode of the input termination MOS switching tube of output current sample circuit, the 4 pin CS ends of output termination integrated circuit (IC) chip BP3105; The grid of MOS switching tube connects the 3 pin GATE ends of integrated circuit (IC) chip BP3105 through resistance R 6; 5 ends of the output winding N3 of the input termination switch transformer of rectifier filter circuit, output termination LED lamp.The sample resistance R4 of output voltage sample circuit and R5 are designed to respectively 36K Ω and 5.1K Ω, and the output voltage of driving power is 33V.Sample resistance R7 and the R8 of output current sample circuit are designed to 2.2 Ω, and the output current of driving power is 303mA.

Good effect of the present utility model is: circuit is simple, volume is little, lightweight, cost is low, efficiency is high, defencive function is perfect, long service life.

Accompanying drawing explanation

Fig. 1 is block diagram of the present utility model.

Fig. 2 is circuit theory diagrams of the present utility model.

Embodiment

As shown in Figure 1, the utility model is made up of EMI filter circuit, commercial power rectification filter circuit, PFC correcting circuit, integrated circuit (IC) chip BP3105, MOS switching tube, switch transformer, output voltage sample circuit, output current sample circuit and rectifier filter circuit.

As shown in Figure 2.

The low-pass filter circuit that EMI filter circuit is made up of capacitor C 1, C2 and common mode inductance L1, the high-frequency electromagnetic that can suppress between driving power and mains supply disturbs.Wherein C1, C2 are used for suppressing series mode interference signal, and L1 is used for suppressing common mode interference signal.

The bridge rectifier filter circuit that commercial power rectification filter circuit is made up of bridge rectifier BD1 and capacitor C 3.To 85V～264V line voltage rectifying and wave-filtering of input, be driving power power supply by the direct voltage obtaining.

Pfc circuit is by diode D1, D2, D3, the valley fill type Passive Power factor correction circuit that capacitor C 4, C5 and resistance R 1 form.Within each half period of AC voltage, when the amplitude of AC voltage higher than its peak value 50% time, D2 conducting, D1 and D3 cut-off, C4 and C5 are charged with series system.When the amplitude of AC voltage be down to its peak value 50% time below, D2 cut-off, D1 and D3 conducting, C4 and C5 parallel discharge.The access of R1 can limit the peak current of C4 and C5, also contributes to improve power factor by level and smooth input current spike.In the time not adding pfc circuit, within the half period of AC voltage, only 60 ° of the input current angles of flow, power factor is no more than 0.6.Adopt this valley fill type pfc circuit, current lead-through angle will be increased to 120 °, and power factor reaches more than 0.9, and 3 times and 5 subharmonic currents are down to respectively below 17% and 15%, total harmonic distortion THD<30%, meets the requirement that Energy Star SSL power factor is greater than 0.9.

The input termination electric main power supply of EMI filter circuit, the input of output termination commercial power rectification filter circuit; The output of the input commercial power rectification filter circuit of pfc circuit, 1 end of output termination switch transformer armature winding N1, the drain electrode of the 2 termination MOS switching tubes of armature winding N1; 3 ends of the output voltage sampling winding N2 of the input termination switch transformer of output voltage sample circuit, the 5 pin FB ends of output termination integrated circuit (IC) chip BP3105; The source electrode of the input termination MOS switching tube of output current sample circuit, the 4 pin CS ends of output termination integrated circuit (IC) chip BP3105; The grid of MOS switching tube connects the 3 pin GATE ends of integrated circuit (IC) chip BP3105 through resistance R 6; 5 ends of the output winding N3 of the input termination switch transformer of rectifier filter circuit, output termination LED lamp.

The BP3105 that the utility model uses is the high accuracy LED lamp constant current control chip of the former limit of a employing feedback, can realize constant current control without secondary feedback circuit and compensating circuit, can greatly reduce system bulk and save system cost.BP3105 is operated in discontinous mode, adopts constant current control mode, can reach excellent load regulation and line regulation.In chip, with high-precision current sampling circuit, can make the precision of driving power output current in ± 3%.BP3105 has the multi-protective functions such as under-voltage protection, overvoltage protection, FB short-circuit protection, chip overheat protector, LED lamp short-circuit protection and LED open lamp protection.

The electric main of input, after capacitor C 1, C2 and inductance L 1 low-pass filtering, through the direct voltage of BD1 rectification C3 filtering output, by starting resistance R2, the capacitor C 7 on VCC pin is charged, in the time that VCC voltage reaches the turn-on threshold voltage (representative value 14V) of chip, chip internal control circuit is started working.After system starts, VCC is powered through D5 rectification C7 filtering by the induced voltage of assisting winding N2.

The peak current of BP3105 Cycle by Cycle sense switch primary winding, CS end is connected to the input of inner peak current comparator, compares with inner 500mV threshold voltage.In the time that CS external voltage reaches 500mV, power tube turn-offs.Sample resistance R7 and the R8 of the utility model output current sample circuit are designed to 2.2 Ω, and the output current of driving power is 303mA.

BP3105 adopts transformer primary side feedback constant flow control technology, and the voltage of feedback winding N2 is used for indirectly reflecting the height of output voltage, without using primary side feedback element, succinctly reliable.Chip feeds back the state of output voltage by FB, the threshold voltage of FB is 1V.The sample resistance R4 of the utility model output voltage sample circuit and R5 are designed to respectively 36K Ω and 5.1K Ω, and the output voltage of driving power is 33V.

The built-in multi-protective function of BP3105.When VCC voltage is higher than 16V(representative value) time, chip turn-offs external power pipe, and autoboot is until the releasing of outside overvoltage condition; VCC inside carries the clamped circuit of 19V, for preventing that under exceptional condition, chip damages.Chip internal thermal protection circuit detects junction temperature, and overtemperature protection threshold value is 160 ° of C, and in the time that junction temperature exceedes threshold value (160 ° of C), by switch-off power MOSFET, until junction temperature declines after 30 ° of C, MOSFET just can enable again.In the time that the short circuit of LED lamp or LED lamp open circuit appear in output, system will enter low-power consumption mode automatically, constantly detect load condition, until trouble shooting simultaneously.After trouble shooting, system is recovered normal work automatically.

This LED lamp driving power source delivery efficiency >=85% in the full voltage range of 85V～264VAC, power factor >=0. 9.

Claims

1. the LED lamp driving power source based on former limit feedback, is characterized in that: it is made up of EMI filter circuit, commercial power rectification filter circuit, PFC correcting circuit, integrated circuit (IC) chip BP3105, MOS switching tube, switch transformer, output voltage sample circuit, output current sample circuit and rectifier filter circuit; The input termination electric main power supply of EMI filter circuit, the input of output termination commercial power rectification filter circuit; The output of the input commercial power rectification filter circuit of pfc circuit, 1 end of output termination switch transformer armature winding N1, the drain electrode of the 2 termination MOS switching tubes of armature winding N1; 3 ends of the output voltage sampling winding N2 of the input termination switch transformer of output voltage sample circuit, the 5 pin FB ends of output termination integrated circuit (IC) chip BP3105; The source electrode of the input termination MOS switching tube of output current sample circuit, the 4 pin CS ends of output termination integrated circuit (IC) chip BP3105; The grid of MOS switching tube connects the 3 pin GATE ends of integrated circuit (IC) chip BP3105 through resistance R 6; 5 ends of the output winding N3 of the input termination switch transformer of rectifier filter circuit, output termination LED lamp.

2. a kind of LED lamp driving power source based on former limit feedback according to claim 1, is characterized in that: the sample resistance R4 of output voltage sample circuit and R5 are designed to respectively 36K Ω and 5.1K Ω, and the output voltage of driving power is 33V.

3. a kind of LED lamp driving power source based on former limit feedback according to claim 1, is characterized in that: sample resistance R7 and the R8 of output current sample circuit are designed to 2.2 Ω, and the output current of driving power is 303mA.