I have been working on a project titled GSM based remote monitoring of energy meter with power factor correction for which i need power supply with +5v, -5v,+12v,-12v
i am using isis proteus for simulation
and i need to use only one transformer
when i simulate a 5v power supply circuit individually output is right
but when i connect a 12v supply circuit with simulation both voltages i.e 5v and 12v comes out to be 3.1 volt
can anybody please look at it and solve?

 

Look at what? No schematic attached to your post.

ak

 

post the schematic.