AC Adapter mod

[timetrap]

This is for a case mod I'm doing, its my first and will likely suck immensely, so sorry if I am somewhat naive...

I'm integrating speakers into my computer's case and the speakers come with a block type adapter that plugs into the wall (as opposed to a block that is seperate from the wall plug like for laptops). I hate the block being plugged into the wall as it takes up a needed plug. I have a broken house fan that I want to break apart and take the power cord and solder that to the outs on the AC adaptor, so that I can leave the block inside the computer and have only a normal cord exit the back of the computer case. Does anyone see this as being possible?

If this isn't possible, could I somehow find an adaptor to allow the speakers to run off the PSU? They take 9v at 1000ma, so I don't know what converter that would require.

I've been a longtime lurker - you guys here at [H] are simply amazing in your mods and have inspired multitudes, such as myself. Keep it up.

 

[Token User]

If this isn't possible, could I somehow find an adaptor to allow the speakers to run off the PSU? They take 9v at 1000ma, so I don't know what converter that would require.

9VDC is a pretty standard voltage for transformers. From a Molex, you can get 12V, 5V, and 7V (using the fan mod trick). To be honest, your speakers will probably run on 7V. You are going to have to slice off the wall wart, so you can then try out running at 7V (search the forums on 7V fan mod trick - its no fun if we tell you how to do everything ).

If 7V doesn't work, don't worry. Ohm's Law (and google) will be your friend. You have the V (9V), the I (impedance == amps == 1000ma ... just remember that ma is milliamp, not amp), so you have everything you need to calculate the R (resistance, or the size of the resistor you will need to buy to drop the 12V from the molex down to 9V @ 1000ma).

Good luck.

 

[timetrap]

Thanks for the helpful reply. I was always told that the 7v mod puts a lot of strain on your PSU - I have an Antec Truepower 480 so I'm kind of afraid to do anything that'll waste my $80 investment. I'll look around for that resistor - would certainly be cool not to have to plug anything else in.

 

[jpmkm]

The speakers will not draw a constant current so you cannot use a resistor to regulate the voltage. If you use a resisitor then your voltage will be all over the place. The easiest(though not necessarily the best) way to accomplish this is with a simple linear voltage regulator(lm5809??). You will probably need a heatsink since the speakers can draw close to an amp, but just bolt it somewhere in your case and you should be fine.