. it worked very good . if you want to increase 
A and T labs Power supply
Dear CHASE1.
I need your help, if you have managed the a - and T labs power supply to works,
I need to know the wire type you used to wind the transformers,
Do you have a pcb for it? is it worth to do it?
thank you
Microsim4@yahoo.com
Dear CHASE1.
I need your help, if you have managed the a - and T labs power supply to works,
I need to know the wire type you used to wind the transformers,
Do you have a pcb for it? is it worth to do it?
thank you
Microsim4@yahoo.com
Here is a good reference for a 250W design using the SG3525 part.
http://www.qrp4u.de/docs/en/smps_new/
To be very honest... FB designs are overkill for anything less than 1KW. There are other more practical ways of doing the design that are cheaper and usually better than the FB design.
For example a very low noise Resonant HB design is my choice for the 250W-500W power supplies. But I must admit this topology will not treat the uninformed well as the math is pretty bad.
Anyway... sorry to run off at the mouth. I hope you get this working.
http://www.qrp4u.de/docs/en/smps_new/
To be very honest... FB designs are overkill for anything less than 1KW. There are other more practical ways of doing the design that are cheaper and usually better than the FB design.
For example a very low noise Resonant HB design is my choice for the 250W-500W power supplies. But I must admit this topology will not treat the uninformed well as the math is pretty bad.
Anyway... sorry to run off at the mouth. I hope you get this working.
HB Schematic
microsim444
Sorry for the late reply, As I mentioned in my email I didn't construct or use any part of the FB supply as my requirement could be realized using the HB topology. I don't have a schematic of my design but I am enclosing a pdf file of a design that is posted on this forum and the designer's name is clearly visible. I don't know if this works but the designer claims it does and by the looks it should work. It has been reviewed by a few member's of this forum. The heart of any supply is the magnetics and proper sizing of the supporting parts and above all the actual test under load conditions and I have noted many supplies by DIY have little or no load protection which should be included.
chas1
microsim444
Sorry for the late reply, As I mentioned in my email I didn't construct or use any part of the FB supply as my requirement could be realized using the HB topology. I don't have a schematic of my design but I am enclosing a pdf file of a design that is posted on this forum and the designer's name is clearly visible. I don't know if this works but the designer claims it does and by the looks it should work. It has been reviewed by a few member's of this forum. The heart of any supply is the magnetics and proper sizing of the supporting parts and above all the actual test under load conditions and I have noted many supplies by DIY have little or no load protection which should be included.
chas1
Sorry I missed that frst part. HP should be fine.
A few issues I note with the schematic...
1) The 22uF cap on the Vs pin might be too large for the HB driver to drive.. I've had problems with anything over about 0.47uF.
2) The loop compensation network doesn't look right. Of course they may be running voltage mode but still I would have expected a TL431 and a type 2 compensation network at a minimum.
3) You might want to add a pinch off resistor across the cathode/anode of the optoisolator so that the leakage current through the zeners does not go through the opto when you get to light loads.
4) There really isn't much need for the center tap on the transformer if you use full bridge rectification.
Anyway... that is my $0.02 so take it for what it cost you to ask.
Good luck.
Tony
A few issues I note with the schematic...
1) The 22uF cap on the Vs pin might be too large for the HB driver to drive.. I've had problems with anything over about 0.47uF.
2) The loop compensation network doesn't look right. Of course they may be running voltage mode but still I would have expected a TL431 and a type 2 compensation network at a minimum.
3) You might want to add a pinch off resistor across the cathode/anode of the optoisolator so that the leakage current through the zeners does not go through the opto when you get to light loads.
4) There really isn't much need for the center tap on the transformer if you use full bridge rectification.
Anyway... that is my $0.02 so take it for what it cost you to ask.
Good luck.
Tony