Maynard A. Philbrook Jr.
- Jan 1, 1970
* Use a 5V (unregulated) adapter. Regulate to 5V with a 7805.
* Use a charge pump IC to generate a -5V rail from the regulated +5V rail.
You can get a center-tapped transformer for a couple of dollars, or rip it out
of something. You can build your own dual-voltage AC adapter easily with a
center tapped transformer and bridge rectifier or discrete diodes. Your device
then just has to provide the reservoir capacitors and regulators.
Why not find some discarded old device (e.g. piece of audio gear) which has
a dual supply in it already and re-use its power entry and perhaps more.
Throw out the circuit board and build your own device in its place.
You can also use two identical AC adapters to get the equivalent of a
center-tapped transformer, if you can live with the clunkiness.
I just scabbed an old DC drive that had a lots of pulse transformers for
the SCR's, nice ones too. Also, I got the dual SCR's and full heat sink
which like 10x15 inches..
I save parts like this for bench concept theories and home projects,
anything else, like at work, we buy new stuff. But saving parts from
these large units gives lots of parts you can hang together with jumper
wires (fuses) as some one I know referred to them, and experiment.