Voltage regulator with alternate voltage source...

Brent Hilpert hilpert at cs.ubc.ca
Fri Apr 8 18:31:27 CDT 2016

On 2016-Apr-08, at 11:58 AM, Bill Sudbrink wrote:

> I don't know why I bothering to be coy about it...
> My unit here:
> http://wsudbrink.dyndns.org:8080/images/cyclops-latest/P4060005.JPG
> http://wsudbrink.dyndns.org:8080/images/cyclops-latest/P4060006.JPG
> Actually, I'm further along than that, but I
> don't have more recent photos.
> Original unit here:
> http://www.swtpc.com/mholley/PopularElectronics/Feb1975/PE_Feb_1975_pg30.jpg
> Schematic here:
> http://www.swtpc.com/mholley/PopularElectronics/Feb1975/PE_Feb_1975_pg28.jpg

Well that's neat. I assembled the Cromemco kit version of the Cyclops ( https://en.wikipedia.org/wiki/Cromemco_Cyclops ) ca. 1976 for a friend with an IMSAI, and built the companion adapter to provide display on an oscilloscope, but I don't know that it was ever made to work.
(The kit version presented an interface for a computer rather than the scope drive of the magazine article.
Hopefully you're more successful with your unit.

(I think you'll find the MC7805 there is indeed plastic not ceramic. Moto produced various power transistors and regulators in those packages (case 90 in Moto parlance) as well as a smaller version from the same plastic material)

A 9V wall wart would probably do for the power supply, or remove the regulator and use a modern 5V switching wall wart (not that I wish to promote wall warts, but if they're on hand . . )

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