[ARC5] Receiver AC Power Supplies

[hwhall at compuserve.com]

 >your naive multiplication of 25 by 2 to arrive at 50 W may not be correct.

Actually, I was referring to another poster's assumptions. I realize there's a lot of detail in a transformer, like the ones you mention, that were being handwaved away in the discussion.

>duty cycle - this last bit you seem to have missed

You're right, I did overlook that. So... if the load current doubled then the ohmic loss goes up by a factor of 4. But in changing from a bridge (current flow nearly fullcycle in full winding) to a centertap fullwave (current nearly halfcycle in only half the windings at a time) the total duty cycle in all windings is reduced by factor of 4. A wash on average (ignoring other factors that might play in reality but aren't known in the discussion). Did I get that right?

>A transformer rated at 25 V and 2 A, may not be designed to deliver both at once.

Good point. Most of the transformers I've used were labeled as "xx volts at yy amps" indicating simultaneous ratings.

Wayne
WB4OGM