LED Driver (MADE IN CHINA)

[free_matrex2010]

I am planning to hack this circuit from china to know some info about led driver in the market.:evil::evil:
first they delete name plate of the IC but i get it by my method :lol::lol::lol::lol: NOT big deal.
second it`s my problem :the topology of this circuit i consider it flyback but it seem not .
this circuit drawn from tracks of pcb (reverse engineering) .
so i want to know the behavior of this circuit??

schematic updated

 

[Venkadesh_M]

Hi without the IC name how to tell the behavior??

 

[free_matrex2010]

sorry IC name TNY268
datasheet :**broken link removed**

 

[Venkadesh_M]

Hi this IC is a switcher and having a Mosfet switching at 136khz which have the pins 5 is Drain and 7,8 are Source... so when you powered the circuit the LED and both inductors will be powered by 136khz and by proper voltage division the LED will glow, It uses inductor to divide the voltage because It makes no loss of power, It uses high frequency because we need very low value of inductor(with resistor) to divide the voltage so very less power loss........

 

[mtwieg]

Are L1 and L2 coupled together? If not I think you made a mistake drawing the schematic.

 

[free_matrex2010]

sorry ::schematic updated as i made mistake
View attachment 97614

 

[necati]

www.baidu.com
search
led driver ic
https://bbs.dianyuan.com/topic/876919

 

[rajudp]

now also there is some mistake with circuit

D1 will block IC supply

 

[Venkadesh_M]

Yeah now there is a mistake.... The line to the primary cant go through the reverse diode..

 

[free_matrex2010]

No I think , first current goes through L2 &led &L1 so it will bias ic

 

[Venkadesh_M]

yeah may be through LED and L1, Are the wire gauges of primary and secondary are same, can you measure the resistance of winding ratio. what is the input AC voltage to the rectifier??

 

[free_matrex2010]

L1= 1.1 ohm l2=0.5 ohm ac input =220 vac