Hi, I am using TOP257YN to prototype a flyback transformer circuit. I am ultimately going to be using the surface mount version but right now I just want to a proof of concept point. So my diagram is a little different from my actual circuit I am testing. The main difference being X and F pins are being jumped to the source pin which is grounded.
That just to get that all out of the way. My issue is that the TOP IC is not "firing" as in the signal I am measuring with the primary referenced to ground is not oscillating at 132kHz like it is supposed to(or oscillating whatsoever) so I am not seeing any voltage on my secondary. I am however seeing voltage on my bias winding(using a 750871110 transformer) but at about 5V instead of the 10V it is rated for. Nothing is obviously wrong with my breadboard wiring but I am continuing to comb it. One weird thing is that the breadboard RAIL that the D pin is on is getting 160Vdc and other components on that rail are getting 160V except the D pin itself is only reading like 28V. I measured resistance between the pin and the rail and it is 0Ohms according to my multimeter.
Im just looking for a point in the right direction for this one because I believe it should work.
That just to get that all out of the way. My issue is that the TOP IC is not "firing" as in the signal I am measuring with the primary referenced to ground is not oscillating at 132kHz like it is supposed to(or oscillating whatsoever) so I am not seeing any voltage on my secondary. I am however seeing voltage on my bias winding(using a 750871110 transformer) but at about 5V instead of the 10V it is rated for. Nothing is obviously wrong with my breadboard wiring but I am continuing to comb it. One weird thing is that the breadboard RAIL that the D pin is on is getting 160Vdc and other components on that rail are getting 160V except the D pin itself is only reading like 28V. I measured resistance between the pin and the rail and it is 0Ohms according to my multimeter.
Im just looking for a point in the right direction for this one because I believe it should work.
Attachments
-
253.5 KB Views: 34