On Sun, 17 Sep 2000, Jinx wrote:

> > I have a timer assembly here that uses transformerless power. The
> > 680n X2  type capacitor is probably not much smaller than a transformer
> > and much less versatile, especially as the timer has a VFD, so needs
> > multiple voltages.
> >
> > I think more than 10mA is questionable.
>
> My power supply reference book states that 1uF will pass 70mA. The

  Joe, this will depend on load resistor. I've built this kind of sources
up to 150mA but it's not a comercial solution. After a while the capacitor
will die even is up to 630Vca.
  Vasile

> few supplies I've built that use caps as the dropping element would
> bear that out. Using low quiescent regulators rather than zeners or
> 78 series regs will mean a smaller cap. Even a 2u2 isn't all that big
> and if it's reclaimed from a PSU or monitor board the price is right
>
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