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Main => Main Forum => Topic started by: captainpotato on November 14, 2004, 08:04:37 am

Title: Wiring up speakers to PSU?
Post by: captainpotato on November 14, 2004, 08:04:37 am
Hello all,

I'm working on my project and am getting to the point of wanting to have sound in it. I have a pair of powered speakers that run off of a 6v adapter. Is it possible to rig up a connector so that they can be run off of a 5v output on the computer's PSU, or is the difference in voltage too much?

I'm not electrical genius, so using various components to raise/lower voltage may be beyond me, but I can follow instructions fine :) I am hoping that a simple wiring job may do it. Is it possible?
Title: Re:Wiring up speakers to PSU?
Post by: b3atmania on November 14, 2004, 09:16:16 am
Hello all,

I'm not electrical genius, so using various components to raise/lower voltage may be beyond me, but I can follow instructions fine :) I am hoping that a simple wiring job may do it. Is it possible?
It won't hurt the amplifier to feed it 5V. Make sure you got the polarity right though. If the amplifier won't work well with 5V you can this to use the 12V output from the PSU. For this to work you can put a resistor in series with the amplifier. Assuming your amplifier needs max 500mA you can calculate the resistor value as follows: R=U / I where R = (12 - 6) / 0,5 = 12 Ohm. Next you need to calculate the power dissenpation of the resisitor as follows: P = U x I = (12 - 6) / 3 = 3 Watts. Adjust these values to match the maximum current your amplifier needs.