If we get technical about words, you are talking apples and oranges. You say "drawing the same power". If you mean the power dissipated in a straight resistor vs. the power consumed at the DC load, then you can't compare the two. You haven't taken into account rectification ratio.
Regardless if the load is straight resistor or rectifier/capacitor, when you measure the true-rms of the SECONDARY WINDING CURRENT, heat loss will be identical for all practical purposes.
I suspect Tony and zigzagflux are saying the same thing in different ways.
Put a resistor straight onto a transformer secondary so it dissipates 10W. The transformer will dissipate, say, 0.5W. Now remove the resistor, add a rectifier and cap plus another resistor chosen so it also dissipates 10W. The transformer will now dissipate more, perhaps 1-2W. The two resistors will probably have different values.
Put a resistor straight onto a transformer secondary so it dissipates 10W. The transformer will dissipate, say, 0.5W. Now remove the resistor, add a rectifier and cap plus another resistor chosen so it also dissipates 10W. The transformer will now dissipate more, perhaps 1-2W. The two resistors will probably have different values.
By the way, thanks for posting the link to this thread. I spent a couple of hours last night reading through it. It gave me lots of things to think about!
Cheers,
-Charlie
thanks for elaborating, that's exactly my point....one day i am going to do experiments to find out by how much....
here is one more, this is from the National Semiconductors' AUDIO/RADIO handbook circa 1980, chapter 6....
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.