At work, there's a power supply which is used on one of our products. The guy who originally made the board has since left and none of the senior electronics guys could give me a good answer.
From my understanding, from the output of the transformer I've got 12V AC. With the centre tap being GND I would have expected my outputs to be +6V with respect to centre tap and -6V with respect to centre tap. What the actual circuit gives is ±9V (±0.2V), I'm unsure how I'm getting a total of 18V difference between + and - from 12V out the transformer.
I've never really dealt with transformers or AC before, is there a misunderstanding in my thinking? Or are the caps doing something more than just ripple smoothing?