18.12.2005, 09:49 PM
I am thinking about how to desing my dual output voltage push-pull PSU design. I want to run the output voltages close to MOSFET breakdown voltages, thus reasonable load regulation is needed. Since the output will have two voltages driving a pair of halv-bridge SODFAs (one channel running with inverted phase to reduce rail pumping), and the fact that I only plan to take voltage feedback from one of the rails (say the positive rail), how much will the unregulated rail differ in voltage compared to the regulated rail?
I guess they wont fluctuate at all as long as the amplifiers draw symmetric current from the rails, but say worst case is to happen - full current load from the regulated rail and no current draw from the unregulated rail. Depending on magnatic coupling between the windings, the unregulated output will rise, but to what extent?
My design will be using an enormously large ferrite E-core (I have one from an old project), so tight winding will be no problem, input voltage of 12V (13.8V) and output of 2x45V @300W is the plan.
Has anyone here built this and have any practical tips?
I guess they wont fluctuate at all as long as the amplifiers draw symmetric current from the rails, but say worst case is to happen - full current load from the regulated rail and no current draw from the unregulated rail. Depending on magnatic coupling between the windings, the unregulated output will rise, but to what extent?
My design will be using an enormously large ferrite E-core (I have one from an old project), so tight winding will be no problem, input voltage of 12V (13.8V) and output of 2x45V @300W is the plan.
Has anyone here built this and have any practical tips?