Members SweetPete Posted June 21, 2006 Members Share Posted June 21, 2006 Guys, I've got a basic question about electrical specs. When a device (fx pedal in this case) has a power supply requirement of, for example, 75mA @ 9VAC, does that mean: 1. The device draws 75ma @ 9VAC OR 2. The power supply providing power to the device must provide no more than 75ma @ 9VAC If the answer is 2. above, I assume that means I can't use it with a power supply that supplies 200ma @ 9VAC, right? But if the answer is 1. above, then the 200ma power supply is safe to use? Link to comment Share on other sites More sharing options...
Members The Gainster Posted June 21, 2006 Members Share Posted June 21, 2006 Yes. Link to comment Share on other sites More sharing options...
Members alteredsounds Posted June 21, 2006 Members Share Posted June 21, 2006 no.1. Link to comment Share on other sites More sharing options...
Members andreas Posted June 21, 2006 Members Share Posted June 21, 2006 1. As long as your power supply has more than (in this case) 75mA available, it will work just fine. /Andreas Link to comment Share on other sites More sharing options...
Members Narcosynthesis Posted June 21, 2006 Members Share Posted June 21, 2006 Number One there The rating on the device are what it needs to function Voltage needs to be the correct rating on the supply as the pedal (for most pedals, 9vDC) as voltage is set by the supply, and too much can fry many pedals Current on the other hand is set by the device, so you ideally want more with the supply, and the pedal will only take what it needs. So your 200mA supply would be fine for running the pedal David Link to comment Share on other sites More sharing options...
Members SweetPete Posted June 21, 2006 Author Members Share Posted June 21, 2006 Thanks guys! Link to comment Share on other sites More sharing options...
Members Gorgon90 Posted June 21, 2006 Members Share Posted June 21, 2006 The answer is No 1. Power supply capacity must be greater than or equal to the pedal's current draw (in this case 75mA @ 9VAC). One thing to watch out for is the difference between regulated and un-regulated power supplies. I don't know the electronics but I think from memory that an unregulated supply can deliver the wrong voltage at potentially damaging levels if the current draw is not matched reasonably well. I had a pedal that needed 100mA at 9V DC. I had a 200mA unregulated adaptor, a 300mA regulated one, and a 800mA unregulated one. I was advised that the 200mA would be ok as the current draw difference wasn't too bad, the 300mA would also be ok as the voltage would be regulated, but the 800mA would potentially deliver too high a voltage due to the relatively low current draw and could damage the pedal over time. This is all from memory (and possibly completely wrong). If someone knows the exact difference between regulated and unregulated adaptors please enlighten me. Link to comment Share on other sites More sharing options...
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