MsStateDawg
New Member
I am designing a half-bridge converter that takes 12 VDC and converts it to 170 VDC. I have successfully got my two mosfets switching using an MC34025 PWM controller and a IR2181 high-low side driver. The 12 VAC wave shape coming off the mosfets isn't the greatest loking waveform but I would say that it works. I have also built a tranformer form scratch. The problem is that the 12VAC that I am feeding to the transformer(it is a high frequency transformer of course 100kHz) isn't being boosted by the transformer. I feed in 12VAC, 100kHz signal and I get out about the same when I measure on the secondary side of the transformer with an o-scope. Also if I feed the output of the secondary to a rectifier and measure on the recitfier I get double the voltage (About 27 VAC clean sine wave). The transformer has 2 turns on the primary and 37 on the secondary. I used the Power Supply Cookbook by Marty Brown to calculate the the turns ratio and I also used the recommendations given by Magnetics Inc. where I bought my cores. Does anyone have any idea why the transformer isn't operating properly and why I am not getting anything near the voltage that I need?