Re: Transformer wiring (for CNC controller, of course)

Carlos,

Here's what you can do with a small transformer and a digital
multimeter to identify what you have:

(1) Set the meter to Ohms and have a note pad and pencil handy. Use
the ohmmeter to find continuity for all your wires. Write down which
connect to which.

(2) Take a very small transformer (6VAC "wall-wart") and apply its 6
VAC to any winding pair.

(3) Set your multimeter to Volts AC and start measuring the voltages
on the other winding pairs. The highest reading one will be the
primary. You already know the voltage ratios (120, 240, 86, 12, etc)
so it should take very little time to puzzle out what is what.

(4) After you have identified the primaries, hook them in series.
Measure the voltage again. If you read "0" then you need to swap the
wire making the series connection. If the voltage is twice what you
had before, you got it right the first time.

You probably have a pair of 120VAC primaries (series = 240, parallel
= 120). The 46VAC CT is probably what you need for CNC work. Wire the
primary in series (240) and run it on 120. The 86VAC will turn into
43VAC and give you 60VDC @ 20A. Nice supply.

Mariss

--- In CAD_CAM_EDM_DRO@y..., "Carlos Guillermo" <carlos@v...> wrote:
> Hi all -
>
> Can anyone help me figure out the wiring for my transformer? I
> purchased a Banner Magnetics toroidal transformer from Brigar,
> which was rated at 2KVA, 120/240VAC input (50/60 HZ), 86V @ 20A
> center tapped output, with a 12V @ 1A tertiary winding. It
> arrived, and turned out to have 11 leads coming out of it. I
> couldn't find a trace of Banner Magnetics on the web, so I'm
> hoping there's a standard, or a way to figure it out.
>
> These are the leads coming out of it, along with the number of
> conductors spliced to each and the gage:
>
> Red 1 14
> Yellow 2 14
> Red 1 14
> Brown 1 22
> Brown 1 22
> White 1 16
> Blue 2 16
> Purple 1 16
> Grey 1 16
> Green 2 16
> Black 1 16
>
>
> I can guess that the brown 22 gage wires are probably for the 12V
> winding, and that the center tapped input and output might require
> 3 or 4 leads each, but I'm still short of 11. Hmmm.
>
> TIA,
>
> Carlos Guillermo
> VERVE Engineering & Design