Anyone has +/- 5VDC, 0.5A PS, Wall Wart

Try

DIGIKEY

Do they? The only Digikey catalog I have handy (a year old) shows only one

+/-5V modular supply, that one being a "table mount" style (rather than wall wart), for about $50.

They do have some wall warts that are multi-voltage, but I didn't see any that were +/-5V. Nor did I see any at the place Watson recommended. (Why am I bothering? Because a while ago I looked for +/-9V wall warts for a project of my own, and couldn't find any.)

Can you suggest a part number?

Thanks, -walter harley

"Walter Harley" wrote in news: snipped-for-privacy@speakeasy.net:

No digi-key, mpja, mouser. I gave up looking for the +/- 5 wall adapter. Acopian sells one for $135.00. But too much for my wallet. I went and got two used 9VDC 1 amp wall warts. I desoldered a 7805 and 7905, look at the Fairchild 7905 PDF. I built my own +/- 5. been working since friday nite. I think I'll pour fiberglass resin all over it.

"Walter Harley" wrote in news: snipped-for-privacy@speakeasy.net:

No digi-key, mpja, mouser. I gave up looking for the +/- 5 wall adapter. Acopian sells one for $135.00. But too much for my wallet. I went and got two used 9VDC 1 amp wall warts. I desoldered a 7805 and 7905, look at the Fairchild 7905 PDF. I built my own +/- 5. been working since friday nite. I think I'll pour fiberglass resin all over it.

When I need a split supply I've generally used an AC/AC adapter and incorporated a dual half-wave rectifier, filter, and regulator onto my circuit. But it's a pain, and I would love to find a reasonably priced dual-supply wall wart.

If you pour fiberglas resin all over your homebrew regulator, give some thought to heat dissipation. Assuming that your 9V wall warts climb up to around 11V when they're pushing 0.5A, that means that each of your regulators is dissipating (11V-5V)*0.5A = 3W. I don't know what the thermal conductivity of resin is, but a TO220 package in free air is around 50C/W, meaning that 3W will make it overheat unless it's heat-sinked. If resin is worse than free air, you've got a problem.