Hi all.
I'm looking to replace a 24VAC power supply. Currently, the board takes 24VAC with a center tap. Piece of cake taking the + and - sides, rectifying them, sending them to 7812s, 7805s and 7912s, and away we go. I need to convert to one that does not use a center tap. I've eliminated the negative rail needs of the board, so now just need
+12/+5 VDC outputs. The current requirements are ~ 1.5A on the 12V line and 500mA on the +5.I've used the national semi webbench stuff and it puts a nice little switching supply together for me. The problem is, it sticks a big ol' inductor on there. This thing is a beast (like 1.5" by 0.75" by
0.75"). I can find a horizontal mount one, but it takes up a ton of board real estate.The linear regulator design gets to the Vin limits of a typical 7812. Max input voltage is 35VDC, and the full wave rectified voltage is about 36VDC (the actual transformer voltage varies between 19 and
28VAC.) Needless to say, that regulator gets too darn hot and eventually blows.I'm just a lowly firmware guy, so any hardware types have any answers to a smaller component version of that power supply? I'd really like something that didn't take up so much room and have such a high profile.