+/-15v power supply

[PMowdes]

Hi

I'm trying to get my head around this but clearly i don't understand well enough



When i draw this up in eagle the AC- connects to the GND net which seems totally wrong.  Can anyone shed a bit of light on wtf is going on??

The build which i hijacked the power supply from is here

https://www.dropbox.com/s/dnizjzbetec84gu/aion-lab-series-preamp-documentation.pdf?dl=1

Cheers

[Silver Blues]

Well you do have AC- connected to ground, it looks like. The trace that passes through the middle of that schematic through the two regulators is AC- on one end and ground on the other.

[PMowdes]

That's how it's laid out into the build doc though. It is supposed to be a voltage multiplier from 9vAC, then regulated down to +/-15v.
I don't know much of the theory but it just looks wrong to me.

[scimitar]

Why wouldn't the AC neutral connect to ground, it is after all connected to ground at the generator, it is only the live conductor that swings +ve and -ve relative to the neutral (ground).

[PMowdes]

scimitar wrote

Why wouldn't the AC neutral connect to ground, it is after all connected to ground at the generator, it is only the live conductor that swings +ve and -ve relative to the neutral (ground).

Thanks Scimitar,

I'm not very familiar with AC, the way you have described it makes sense.  I was after some reassurance that the schematic wasn't wrong before I commit it to a board.  

[scimitar]

Sorry, just read my reply back and it sounded a bit short, not intended, glad it made sense though. Actually never realised that myself and was surprised that in some installations the earth connect is actually attached at source to the neutral.

[Silver Blues]

Right yeah that makes sense, never mind me

[PMowdes]

No worries guys, got there in the end