Hi I am building a synthesizer from boards I bought from Synthrotek. Each of the boards takes 9V but I don't know the mA requirments. To power all 3 of them at the same time I plan to use this Velleman 1 A power supply kit to power all three of them: http://www.vellemanusa.com/products/view/?country=us&lang=enu&id=350481

My question about this is if I used a 12.6 VAC 300mA transformer to power this kit would this power supply be capable of supplying 1 A of current? Or does it depend on whats coming in from the transformer? The kits voltage output can be adjusted. I have a basic voltmeter, so I really have no way of testing the Amps.

Ω

 

You can get 9 volts out of that but you can't get an amp. The transformer isn't big enough.
Assuming a full wave bridge rectifier, your transformer should be rated for at least 1.6 amps to get 1 amp output.

 

Measure the current on one board using a 9-Volt supply, that will give you the basis on how to multiply them by how many boards you want to use,

so if each synthesizer takes say 100-mA and your using 4 of them that's 4x 100mA = 400-mAmp.


Failing that get a bigger psu with an heatsink.