MFOS power supply

daryll · Joined: Feb 07, 2021 Posts: 2 Location: UK

Is it possible to run the MFOS wallwart power supply from a 25VA 0-12 0-12 transformer , if I wire the transformer as a centre tapped 12-0-12 where does the 0v go to on the board , the only place I can see is the GND between C7 and C8 , the ww1 and ww2 terminals presumably are connected to the two 12v AC outs

Cheers
Daryll

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PHOBoS · Posted: Wed Feb 10, 2021 1:57 pm Post subject:

The MFOS wallwart supply is designed for a single AC input voltage and uses half wave rectification to turn it into a bipolar DC supply.
The GND connection is the GND for the DC output and is directly connected to WW2. You could use that transformer and wire the outputs
in parallel for more power but with a transformer like that it makes more sense to use full wave rectification. You can either use it as a
center-tapped transformer with a positive and negative voltage regulator or use the 2 windings to make 2 seperate positive DC supplies
that you wire in series like I did for my supply: https://electro-music.com/forum/post-431610.html#431610

daryll · Joined: Feb 07, 2021 Posts: 2 Location: UK

Thank you , I might try the power supplies from here
https://www.dsl-man.de/display/DSO/Bipolar+Powersupply+BIPO
my synth has a mix of 12v and 15v modules , I have , in addition to the 0-12 0-12 chassis transformer , which I can use for the 12v stuff , I have a 15-0 15-0 toroidal , which I shall use for the 15v stuff , so two of the PSU boards should be OK , one for the +-12v stuff and the other for +-15 , both PSU`s use the LM317/337 adj voltage out`s , I just had a couple of MFOS power supply`s which I dont use (yet....lol)
Cheers

Daryll