Re: TI-H: Switchable Power Sourecs.

To: ti-hardware@lists.ticalc.org
Subject: Re: TI-H: Switchable Power Sourecs.
From: Andy Muldowney <andy@microcosm.world-net.net>
Date: Tue, 11 Nov 1997 08:32:08 -0600 (CST)
In-Reply-To: <19971110.225335.5223.3.Larry1492@juno.com>
Reply-To: ti-hardware@lists.ticalc.org

The switch is called a closed circuit switch.  Normally, Two prings are
touching, when you stick in the plug for an ac adapter, they disconnect.
That cuts off the flow from the battery and uses the AC adapter.  And how
are you planning to turn somehtiing with and LED display into and 82 with
an LCD and probably totally different system architechture <sp>?
-Andy

On Mon, 10 Nov 1997, Larry G Currie wrote:

> 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
>

Follow-Ups:

Re: TI-H: Switchable Power Sourecs.

From: larry1492@juno.com (Larry G Currie)

References:

TI-H: Switchable Power Sourecs.

From: larry1492@juno.com (Larry G Currie)