15 Dec 2003, 22:26, David Drummond (3:640/305), wrote to Jasen Betts:

Hi David.

 DD>>> How do you achieve the -12V? You'd have to set up your 12 
 DD>>> volters to produce 24V overall, with the centre tap as zero...

 JB>> nah, get ten of them in series and feed 120V DC into the power 
 JB>> socket of the powersupply.

 DD> Does a switchmode supply not need an AC source (as in is it 
 DD> somehow locked to the frequency of the mains)?

The very first step inside the PS is to convert the AC input to DC.  No
need for _any_ frequency on the mains.

     Good luck...  M.

--- Msged/386 TE 06 (pre)