ODP: Power source

[Roman Sowa]

I guess you want a bipolar PS. There is a way to do it out of
a single voltage, but not with two resistors, unles they drain much more
current than the circuit powered with it. I can draw a schematic at home
and mail it tommorow (so bad at ascii drawing)

But since your power supply is nothing more than a transformer, rectifier
and case, then try to use two half-wave rectifiers, capacitors, and at least
79xx/79xx regulators, or transistors with zeners.

Roman

> -----Oryginalna wiadomość-----
> Od:	Plinio Andres Barraza [SMTP:pab210 at is8.nyu.edu]
> Wysłano:	11 marca 1999 14:24
> Do:	Roman Sowa
> DW:	synth-diy at mailhost.bpa.nl
> Temat:	Power source
> 
> 
> I agree, I really need a good power source and making one would be good
> experience.  I realized that this power source (from other members on the
> list and the display on my "new" scope, an RCA last calibrated on 1974) is
> simply fulwave rectified and no smoothing -probably because its just used
> to push little cars across a track. The cap I used worked well but now I
> have a problem.  I used two identical resistors to divide voltage and get
> a ground out, Problem is once I connect a circuit the voltages go crazy
> and ground moves to about two volts from the positive rail. 
> 
>  How can I buffer the power source so that other resistances in the
> circuit dont change the scale of the power source?
>