Analysis of feedback in converter using coreless Printed Circuit Board transformer

Power supply is an inevitable component for all electronic instruments as a constant DC source. Almost all power supplies use feedback loop to achieve constant DC output voltage. In a feedback loop, the galvanic isolation is required between input and output. It can be achieved either by implementation of opto-coupler feedback on the secondary side or magnetic feedback. In this paper both opto-coupler and auxiliary feed-back techniques are implemented and analyzed in a high frequency half bridge converter using coreless Printed Circuit Board (PCB) power transformer. The implementation of opto-coupler feedback is temperature sensitive and has relatively high cost. The auxiliary winding of transformer can also be used to provide feedback signals as alternate to opto-coupler. Auxiliary feedback implementation is cheaper, temperature stable and insensitive to temperature variations. In this paper, the feasibility of feedback using auxiliary winding of coreless PCB power transformer is investigated. It is observed that this technique can be used as an alternative to opto-coupler feedback.