Quote Originally Posted by Lee Roberts View Post
Yes it DC i am after !

The TT i have are:
Primary x2 120 Volt
Secondary 2 x 15 Volt

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Cheers,
Well you have options... wire secondaries in parallel 15v AC 10A will give a 0 - 20v 10A supply, or in series will give 30v 5A will give a 0 - 40v 5A supply.

To make it variable you need to go down the switched mode supply route, else the heatsinking arrangements will be extensive (ask if you want explanation)... this will mean milling a PCB, you can't bird nest a switcher (any more than you can a high current stepper driver, indeed the two are very similar). A suitable fully-integrated chip for this will cost around £10 or a cheaper one with external MOSFET around £3 (again same issues as steppers) with about £10 worth external parts. You might be able to get the chip as a sample tho...

If you want we can do this as a design/learning exercise and I'll take you through it - then you'll have the satisfaction of both building it and designing it. And of course others can chip in with their views...

regards,
Irving...