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Smoky McPot
Posted: Sat Sep 13, 2003 9:30 pm
Guest
I have a set of PC speakers that have an AC adaptor for power. It is
9vAC @ 1000ma. I know little about electronics, but I would like to be
able to make these speakers battery powered, even if only for a couple
of hours. What batteries/parts should I look for to put this together?
Thanks in advance
Mark
Posted: Sun Sep 14, 2003 6:24 am
Guest
In article <21o7mvgof61h9ignc6cao427icv576qov2@4ax.com>,
mcpotfakesREMOVE@hotREMOVEMEmail.com says...
Quote:
I have a set of PC speakers that have an AC adaptor for power. It is
9vAC @ 1000ma. I know little about electronics, but I would like to be
able to make these speakers battery powered, even if only for a couple
of hours. What batteries/parts should I look for to put this together?
Thanks in advance

Since the adaptor is AC, that means there's a rectifier

inside the speaker the adaptor plugs into. You would need
to get into that speaker, determine the point in the
circuitry that's post rectifier, but pre any voltage
regulation, and tie your batteries in there.

Without knowing what DC voltage is being used, it's
difficult to know what batteries to use, but the circuit is
probably rather forgiving, and 9-12 volts would do the
trick.

Given the amount of current it apparently pulls, you'd
probably want to use a small 12 volt gel-cell or something
similar.
--
Mark

The truth as I perceive it to be.
Your perception may be different.

Triple Z is spam control.
JeffM
Posted: Mon Sep 15, 2003 12:01 am
Guest
Quote:
I have a set of PC speakers...AC adaptor
...9vAC @ 1000ma.
battery powered...?
Smoky McPot


You need to find someone with an ammeter.
An o'scope and a 0.1 ohm resistor would be even better.
Got a community college around? Vocational high school?

9V x 1000mA = 9 Watts.
At peak levels maybe it develops that, but I doubt it's continuous.
A pack of D cells should power this thing for a while (think boom-box).
Emperical data would be cheap.
NiMH would be more cost-effective over time.
 
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