Modifying ATX 2.2 PSU - PS229 voltage chip

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Further to all the help I had on this thread: https://www.techpowerup.com/articles/160/images/ps229.pdf

I have decided not to bugger around trying to run power supplies in parallel but instead to use one high power PSU for my ~14v power supply.

This will be to power an old JBL BP300.1 amplifier I had kicking around into a 4 ohm load.

I have identified what seems to be the IC to concentrate on:

https://www.techpowerup.com/articles/160/images/ps229.pdf

The PS229.

My question is firstly is it this chip that regulates the voltage or does it simply shut things down in case of out of spec voltage?

If the former than would it possible to doctor some voltage in or out of it to produce something in order of 13.-14.4v?

there is also a SMD 393 dual regulator which might need attention too, all help gratefully received.
 
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Thanks Jon. Looking at the data sheet it seems to monitor the voltage drop on the 12v line using a sensing resistor called Rs12 ( page 8 ) and gives recommended values of >0.002ohms.

Apart from not having come across a resistor that small in value can anything be done across this sense line?

Given it has nothing to do with regulation would it possible to fool it entirely by feeding it a regulated 12v supply from elsewhere?
 
Thanks for all your help chaps, I have in the end decided "bollocks to this" after being given two giant 12v toroidal transformers from a 12v lighting circuit.

The office next to mine was being refurbished and they pulled out all manner of stuff, mainly little 50W SMPS units but also these two toroids which I estimate to be around 800VA each.

They do almost exactly 12v RMS and so will be around 15.5v after rectifying.

Much easier than I think.
 
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