TI-H: Switchable Power Sourecs.
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TI-H: Switchable Power Sourecs.
I have an old TI-1250 ( the 8 or 9 digit red bubble display, pixel LEDS,
not LCD) I disassembled for research purposes. It runs on NINE VOLTS!!!
HOwever it has an ac adaptor port that you can plug in W/ the 9V batery
in. The way it is wired is that negative goes to the board from the
9VBatt. The AC input is where the Pos. from batt. connects. Evidently,
when the ac adaptor is not producing current, a switch is closed,
letting the 9Vbatt work. When the AC plug delivers curent/plugged in, it
opens the switch that the 9Vbatt used, dissabling it? I assume this is
how it works. It is the best I know from examining the wiring. Can
anyone elaborate? It would make it so much easier to build an AC/DC
powered calc. I have plans for a cool design resembling that of an '82
viewscreen model. If I ever get the web page up, and the other designs
drawn, I hpoe to draw it. Maybe next week...
(note: when I say "closed" switch, I mean current flows. "Open"= no
flow)
~Larry C
Larry1492@juno.com
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