That means you cannot use the supply above as it will be unbalanced.

Use the principle of the following circuit and add another winding to get -5v.
And add another winding for the +5v if you want it to be isolated. Put the windings on an old 10mm antenna rod - 15mmm long.

Attached Thumbnails

 

 

The schematic attached , is a non isolated and I dont even know calculating turns properly for this topology.

BTW what is meant by "transistor induced shoot through"

PS : I dont have any hard-n fast rules the negative side could be provided more current if that causes an unbalance . Power availablity is a no problem . What I want is isolation . I cannot use a commercial product as I in the next step I will work out for a appropriate certification .


Thanks

 

It's not a matter of "providing" more current, it's a matter of "drawing" more current.

 

Why can't you use a commercial product? Certification is for the entire unit.

__________________

 

Hi , My client needs ATEX approval and some custom voltages .
Like 5V to 5.25V(200mA) isolation. 3V to 3.3V(250mA) etc . Also the size has to be too small.

 

Factory made DC - DC isolated converters are fairly cheap and very reliable. Check out any of the big on line electronics supply companies. Digikey, mouser, Allied, and countless more carry about every voltage input and output range you can think of and in power ratings from under a watt to over 100 watts.
All certification requirements are already met too!

__________________
"Issue a general safety warning. Then look the other way and allow stupidity the chance to eliminate itself." -- tcmtech
"Those who can, Will. Those who can't, will achieve positions of power over those who can and then promptly stop them." -- tcmtech
"Your impossibility may just be my day to day routine." -- tcmtech

 

Many of the "brick" modules have a terminal that may be used to adjust the output voltage to +/- 10%.

 

And get caught by the authorities for illegally broadcasting a radio signal.

The AM radio antenna will radiate half of the energy as RF.

A better option is to use the ferrite core from an old PC PSU.

__________________

I do not answer private messages asking for help because no one else can: benefit from advice I may give or correct me if I'm wrong.

Please ask on the open forum if you have a question and I'll be happy to help, if I know the answer.

 

With all of todays HF transforming frequencies I doubt the FCC is monitoring the 100KHz and below bands with much interest any more.
Technically everything that move electrons and makes an alternating magnetic field is a radio transmitter.

I have a pair of broad band hash transmitters I typically call my 300 amp MIG welder and my 105 amp plasma cutter.
The FCC doest seem to mind my multi KW broad band hash transmissions!

__________________
"Issue a general safety warning. Then look the other way and allow stupidity the chance to eliminate itself." -- tcmtech
"Those who can, Will. Those who can't, will achieve positions of power over those who can and then promptly stop them." -- tcmtech
"Your impossibility may just be my day to day routine." -- tcmtech

 

I don't see any output filter inductors. Also, where's the feedback loop? Do you need regulated outputs? This doesn't appear to be regulated. At the power levels you're dealing with, 1.25W, a push-pull is overkill. A flyback is a good choice if you need isolation. If noise is a problem, then a forward converter is right for the job. The forward requires an inductor for each output.

__________________
Claude