eem2am
Banned
Hi
I am doing offline flyback with Vout = 36V and 22W.
The following feedback scheme, using TL431 biased by a current source, appears to work fine on the simulator, and solves the problem of running too much current through a bias resistor to the TL431 during times of light load......
CIRCUIT DIAGRAM:-
http://i52.tinypic.com/14b3sw.jpg
Though can you foresee any problems with this?
..since it seems too good to be true.
(i will replace the LT3092 current source with a cheaper LM334 in the real circuit......and ZR431L will be replaced by the higher voltage rated ZR431)
LM334 CURRENT SOURCE DATASHEET:
**broken link removed**
ZR431 DATASHEET
**broken link removed**
LT3092 DATASHEET:-
http://cds.linear.com/docs/Datasheet/3092fb.pdf
LTSpice simulation file:-
2shared - download NCP1217 TL431 CURR SOURCE and ZR431.asc
I am doing offline flyback with Vout = 36V and 22W.
The following feedback scheme, using TL431 biased by a current source, appears to work fine on the simulator, and solves the problem of running too much current through a bias resistor to the TL431 during times of light load......
CIRCUIT DIAGRAM:-
http://i52.tinypic.com/14b3sw.jpg
Though can you foresee any problems with this?
..since it seems too good to be true.
(i will replace the LT3092 current source with a cheaper LM334 in the real circuit......and ZR431L will be replaced by the higher voltage rated ZR431)
LM334 CURRENT SOURCE DATASHEET:
**broken link removed**
ZR431 DATASHEET
**broken link removed**
LT3092 DATASHEET:-
http://cds.linear.com/docs/Datasheet/3092fb.pdf
LTSpice simulation file:-
2shared - download NCP1217 TL431 CURR SOURCE and ZR431.asc
Last edited: