Re: [CAD_CAM_EDM_DRO] Dual purpose power supply

James Owens wrote:

>Hi,
>
>You can use a yellow site transformer (the larger the better) designed for
>running 110 volt tool such as drills and saws. These are centre-tapped 59
>volts AC transformers. Remove the transformer from the box and cooling oil,
>spilt the centre-tap and then treat as two 59 volt transformers.
>
>

You don't need to open it up. Just use 2 rectifiers like this :


________|\ |___________Plus
( |/ | |
( |
( |
( |
------------minus |
( |
( |
( |
(________|\ |_______|
|/ |

>It is possible to join them together in parallel, thus doubling the
>available current. By the time you put rectifiers and caps it should be
>quite near 70 volts DC.
>
>

The circuit drawn above also gives you twice the current, since each
half of the winding only
carries the current half the time. You also save on rectifiers, it only
requires two. This
assumes the center tap is brought outside the case.

Jon