Re: TI-H: Extending the battery life.
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Re: TI-H: Extending the battery life.
On Wed, 06 Nov 1996 10:41:54 EST, you wrote:
>
>On Tue, 5 Nov 1996 22:03:10 -0700 (MST) jmacha <jmacha@xmission.com>
>writes:
>> With all this talk about putting circuits in internally, it=20
>>only
>>seems natural to me to point this out, your batteries will drain a lot
>>sooner. So I was wondering, wouldn't 2 9volt batteries outlast 4 aaa
>>bateries? Common sense tells me it would, and it also looks like it's
>>possible to add 2 9 volt batteries in there, or at leats one. and with=20
>>a
>>couple of resistors you could drop the voltage down to 4.5( I figured=20
>>this
>>out by plugging my calc into an AC adapter at 4.5 volts).. Would this
>>work??
>probably just make sure you check out the battery output w/ resistors on
>a voltage meter. Those things are great for assembling projects
>
2 9V batteries probably wouldn't last any longer. 9V batteries don't
put out a lot of current, and their mAH rating isn't very high, so 4
AAA batteries will end up lasting longer. 2 9V batteries are also
usually more expensive than 4 AAA batteries, depending on the brand
and type. If you want your calculator to last a year, just use string
together 4 D batteries and have an external "battery pack" for the
calc.
If you did want to use a 2 9V batteries, you'd need to setup a voltage
divider circuit using 2 resistors (you'll need the bigger 1 watt type
resistors). The internal voltage regulator may just let you use the
raw 9V, however, so just string the 9V batteries in parallel and
connect them at the terminals and you're set. Of course, if you do
something wrong and melt your calculator, don't blame me!
-Mel
<pre>
--
The TI Memory Expansion Homepage
http://pilot.msu.edu/user/tsaimelv/expander.htm
</pre>
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