Re: Voyager series power supply... Message #2 Posted by Ellis Easley on 17 May 2002, 6:01 a.m., in response to message #1 by WigglePig
I don't remember a discussion about voltage converters in the 48 or 49. What frequently comes up is that the PMOS machines (Classics, Woodstocks, ?Spice?) all have blocking oscillator-transformer DC-DC converters (not unlike the vibrator supplies in vacuum tube car radios!) that generate +6V and -12V for the logic and (I think) +4V for the LED display or drivers. I know there isn't anything on the Voyagers that looks like a charge pump, like an IC with several caps attached. Nowadays, "regular" CMOS runs at 3V and I think I've seen special purpose CMOS chips specified to run at 1V (maybe rather slowly?) I've been under the impression that NMOS and CMOS chips have internal charge pumps to generate "substrate bias".
I was amazed, while rebuilding my HP67 card reader, to find that the motor only draws 13 mA (no load) from the 3.75V battery.
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