newbie transfromer question....

[alecwek]

ok....so i looked up my electronics bible where it shows how to make a dual polarity power supply...problem is i dont have a centre taped transformer...but when i worked it out in my head it seemed to work fine without the centre tap....please look at the attached drawing to see what i mean....its a very small file ...will stur up fond memories of kindergarden............the red things are the current direction......so????whats wrong with this assumption....(unintellegent guess......will it work

[cpemma]

You can use something vaguely like that for creating a virtual earth at mid-rail, though you'll need to add two equal resistors across the caps as a potential divider.

Works for low current draws where the draw on each rail is roughly the same, and you can refine the method by various means as shown at http://tangentsoft.net/elec/vgrounds.html

[alecwek]

just what i need...........thanks....

[alecwek]

well...im wondring whether the voltage devider resistors will be neccessory wont they just reduce the loadd and then increase current drawn....(away fron the supply rails)...whats the impedance seen from an incomg 60hz sine cwave when entering an opamp or....TDA7295V..to be precise...its just an IC or CHIP amplifier.....what value resistor is needed.....and do the opamps or chip amps require much current in the Vcc and Vee ...to oparate.....

ill try it out with a resistor...to see what happens.....but i just thought that the supply rails were separated by the diodes.....in other words ...eg...the + supply rail drew all...and could only draw from, the positive voltage swing....there for the defrences between draws on the two different rails wouldnt make a difference....any answers??? please