>
> Have you considered using a capacitive reactance instead of a resistor to drop
> line voltage?  I think I remember an RCA temperature controller chip, CA30??
> maybe, that worked this way.  You can use a capacitive divider or a capacitor
> sourcing current across a resistor to get low voltage AC and then rectify and
> filter it after the divider.
>
>
Yes, capacitive reactance is a more elegant solution from a conceptual
standpoint. But you need a voltage rating equal to the max peak line
voltage plus safety factor. The capacitance needed for practical values
of output current, combined with the required voltage rating, result in
a capacitor that's physically pretty large. A lot larger than the
power resistor it would replace. But if you have plenty of space and are
more worried about heat, it could be a good design approach.


....Reg Neale.............standard disclaimer applies.......
"Ignorance is a renewable resource."    P. J. O'Rourke......