Please, take a look at this TL494 power supply, is everything OK?

[OhMy]

Hello!

It happened, that I once bought 10 TL494 chips, hoping one day to make some SMPS. But unfortunately I'm unable to find a trustworthy schematic for it. The biggest problem is to find a circuit for a gate drive transformer part. So many variations, but almost none for driving mosfets.
After looking through some hundred circuits and getting more and more confused I took these two for samples: not sure, but most likely from this site; and from here.
So I tried to combine them together, and this is the result: .

Please, share your thoughts, criticism and suggestions about my creation.

Thank you very much.

 

[OhMy]

Yep................................

Sad

 

[MicrosiM]

Your combined schematic should just work fine, Its impossible for any one to know if it will work 100% or not, but all seems OK to me, specially the 15-48V 16A design, because its 100% working design.

And to make things clear, HYPEX uses almost the same techniques + TL494 in there SMPS. very close to the circuits you have just shown.

So I think it would be a good idea to start your testings, and you will discover everything you are looking for.


Regards

 

[OhMy]

OK, Microsim, thank you for the replay.
I actually already made a PCB for the combined circuit , but it doesn't work- the 494 doesn't even want to oscillate. Could it be something to do with the open inputs of the second internal comparator (pins 15 + 16)?


P.S. Some posts got lost somewhere wiz:;...

 

[MicrosiM]

See below circuit, and compare with it, this is used for an unregulated SMPS, so at lease it will guide you to know whats going on

 

[OhMy]

Thanks for the samples, but they appear too small to see details.

 

[zeus_threat]

copy my TL494 schematics if you need half bridge I have just rebuilt it and it works straight. there is no regulation for the time being. you just need to adjust the turns for your core Ae and Bmax. I even tried one of your schematics you posted and fel into some issues: http://www.diysmps.com/forums/showt...ith-half-bridge&highlight=drive+signal+issues if you need bootstrap startup you fill it inside here http://www.diysmps.com/forums/showthread.php?213-EI-33-based-half-bridge

 

[OhMy]

Thank you, zeus_threat. I'll try to "digest" those threads.