I'm building a 18V+/- AC power supply and am looking for + and - 18v regulators like the LM7818 and LM7919. Are these suitable for AC or are they DC only?
For my mixer. Seems it will be a 2 month wait and over $50 to bring one in from Behringer. For some reason they went with an AC input and have the rectifiers on the mixer itself. Weird. I might just construct a DC power supply and bypass the on-board rectifiers since I can't seem to find any AC regulators suitable.
I bet a regular ol' 18VAC transformer would do the trick.
Actually that makes perfect sense to me. Except the power jack has 3 pins +18V, -18V and ground. How will I get a -18v from the transformer?
Actually that makes perfect sense to me. Except the power jack has 3 pins +18V, -18V and ground. How will I get a -18v from the transformer?
You can´t have negative AC amplitude, but you sure can have AC with opposite phase.OK, this is no longer making sense. You can't have negative AC. This sounds like a DC supply to me IF it is actually labeled -18V. AC would usually be labeled with two pins as "~" and ground.
If somehow they really just mean two AC legs plus ground, then do what dementedchord said.
You can´t have negative AC amplitude, but you sure can have AC with opposite phase.
My behringer PSU realy is a center-tapped 2x18v transformer.
Yes, but polarity would be a function of the rectifier circuit, not the incoming AC. That's why I don't understand the negative voltage label.
Yes, but polarity would be a function of the rectifier circuit, not the incoming AC. That's why I don't understand the negative voltage label.
Is that more clear?
Cheers
I was trying to say that polarity is not only a function of a rectifier, but that AC voltagel has polarity too.