Battery charger with Hiper-TFS2 Do I have to have a flyback section?

2 posts / 0 new

I'm not really making an LED driver. It's a battery charger but they're essentially the same problem. I need a voltage limit and a current limit. You could also say I need a current source with a precise voltage limit.

The HiperTFS has two supplies, a two-switch forward and a standby flyback. I only want a forward converter. Do I have to include a flyback stage? In all the schematics, the flyback stage has the bias winding. If I put the bias winding on the forward transformer, will the supply be able to start up?

Your bias supply for two switch forward is coming from the standby flyback output so you need it to operate. Unless you have separate supply for BP. The internal tap current is used to start the flyback converter to provide bias supply for two switch forward.