[fzman]

i am building a power supply to do both V+ and V- for an opamp circuit. i am modifying a dual mono supply which has two seprate circuits starting with a dual winding transformer.

i am getting a -V regulator tomorrow. if i "flip" the polarity of the diode bridge on one "channel" of the supply, and sub a V- reg for a V+ reg, willl that work? do i just have to join their grounds at one point where they enter the star ground for the amp circuit?

in other words, can i do this without a centertap tranny, and without using both sides of the same bridge rectifier to get both polarities with rspect to each other?

thanks for your help.

 

[FallenAngel]

Why not use the dual mono supply and tie a V+ line to a V- line and use that as ground?

 

[deaconblues]

fallen angel speaks the truth. No need at all for that -v regulator if you've already got a dual mono supply.

 

[fzman]

i guess i did not mention that the dual mono supply is just +12v. it's 2 +12v supplies which are completely seperate except for sharing a primary and iec inlet (seperate windings on the tranny).

what i want to do is take one of them, and invert the wirign out of the bridge, and sub a neg reg for the pos reg. that will give me a +12 supply and a -12 supply. their grounds would still be electrically seperate in the supply.

if i simply tie those grounds together, will that work -- maybe that's a better way of asking the question.

this may be a stupid queston, but i don;t want to fry the whole thing because i was not willing to ask first.

 

[nikongod]

If ANYTHING in the "negative" supply (correctly a positive supply you are trying to push below ground...) is grounded it is hopeless.

It may be easier to just build a floating supply (like the steps) or find one that already has a dedicated negative line.