Power Amplified Speakers from PC Power Supply

[CW]

Greetings! I'd like to power my external PC speakers with my computer
instead of using the bulky AC wall transformer/adapter that they were
shipped with. The wall adapter is rated for +9VDC @ 1A. When I measured the
output with a DMM, I get +12.5 Volts, so I presume the voltage goes way down
once it is loaded. So, what I'd like to do is drill out a card slot blank,
put in a cheap coaxial plug and wire that to one of the +12VDC PS connectors
in my PC. What I don't know is whether or not my amplified speakers can take
the somewhat regulated +12VDC. I really don't want to put a 3 Ohm, 3 Watt
resistor in series with the speakers, and would prefer not to have to build
up a DC to DC regulator circuit (i.e. LM317T). What I guess I'm looking for
is whether or not someone has already done this, and what the results were.
Anyone?

 

[JeB]

On Sun, 29 Aug 2004 20:05:36 GMT, "CW" <crazy_whizzo@yahoo.com> wrote:

Greetings! I'd like to power my external PC speakers with my computer
instead of using the bulky AC wall transformer/adapter that they were
shipped with. The wall adapter is rated for +9VDC @ 1A. When I measured the
output with a DMM, I get +12.5 Volts, so I presume the voltage goes way down

Try measuring the wall wart with the amplifer on. If it's still close to
12v then you might get away with it.

I'd use the regulator myself.

once it is loaded. So, what I'd like to do is drill out a card slot blank,
put in a cheap coaxial plug and wire that to one of the +12VDC PS connectors
in my PC. What I don't know is whether or not my amplified speakers can take
the somewhat regulated +12VDC. I really don't want to put a 3 Ohm, 3 Watt
resistor in series with the speakers, and would prefer not to have to build
up a DC to DC regulator circuit (i.e. LM317T). What I guess I'm looking for
is whether or not someone has already done this, and what the results were.
Anyone?

 

[Rheilly Phoull]

"JeB" <no@spam.org> wrote in message
news:d7g4j0dbs67upbqngqhqc7uft2th1if0de@4ax.com...

On Sun, 29 Aug 2004 20:05:36 GMT, "CW" <crazy_whizzo@yahoo.com> wrote:

Greetings! I'd like to power my external PC speakers with my computer
instead of using the bulky AC wall transformer/adapter that they were
shipped with. The wall adapter is rated for +9VDC @ 1A. When I measured
the
output with a DMM, I get +12.5 Volts, so I presume the voltage goes way
down

Try measuring the wall wart with the amplifer on. If it's still close to
12v then you might get away with it.

I'd use the regulator myself.

once it is loaded. So, what I'd like to do is drill out a card slot
blank,
put in a cheap coaxial plug and wire that to one of the +12VDC PS
connectors
in my PC. What I don't know is whether or not my amplified speakers can
take
the somewhat regulated +12VDC. I really don't want to put a 3 Ohm, 3 Watt
resistor in series with the speakers, and would prefer not to have to
build
up a DC to DC regulator circuit (i.e. LM317T). What I guess I'm looking
for
is whether or not someone has already done this, and what the results
were.
Anyone?


Why not use a 7809 reg ??

You could just about hang it off the socket terminals, I would use a DC
power socket and plug to avoid any confusion too

--
Regards ........... Rheilly Phoull

 

[Active8]

On Mon, 30 Aug 2004 16:49:53 GMT, CW wrote:

I've got a cigarette lighter adapter for an obsolete Escort radar detector
that has the 12vdc to 9vdc converter built in to a housed module--has the dc
power jack built-in also. It might look kinda funny, but I might just drill
a hole in the back of the case and add a cigarette lighter socket. I think
the old radar detectors had to use 9vdc because of the Gunn Diodes. Does
anyone know if newer radar detectors use the 12 to 9 vdc converters? Or are
they simply powered from 12 vdc now-a-days? This would be good to know in
case I decide to modify any other cases. Thanks!

My very antiquated radar detector ran off 12V. Note to self: get a
more modern one.
<snip>
--
Best Regards,
Mike