need a power transformer 120vprimary 12v, and 36v secondary

36v power transformer

I'm trying to convert a sat positioner box by replacing the 220 volt input transformer with a 120 volt input transformer.

I don't have definate specs on current, but something like this should be fine:

120 v primary
12 volt secondary at about .5 amps
36 volt secondary at about 2 amps

The 12 volts drives a small microcontroller board, so not much current needed there.
The 36 volts drives the accuator on the satellite dish, the original transformer was not marked, but it is not big so I'm pretty sure 2 or 3 amps should be enough.

Problem is every power transformer I have found with a dual ouput is 36v, and 18v or to put it another way 1/2-1/2. Do they not make a triple output transformer that would be 1/3-1/3-1/3? The original was a split bobbin transformer, but I don't think that matters does it? Does anyone know where I could get a 12v-36v. transformer?

I know I could use two seperate transformers to do the same thing, but that would be larger, and extra cost. I thought I'd take a shot at this first.

Thanks Mike B.

36v transformer

Hi !

Use a 120V pri to 18-0-18V (think as you would have 0 18V and 36V terminals) sec @3A. From the 18V tap, rectify (full wave or bridge rectifier) it and regulate with a 12V voltage regulator (a simple 7812 can do that, don´t forget to attach a good heatsink) for the uC supply. The 36V you obtain from the -18 and +18 terminals (again use the bridge rectifiers).