On Mon, 12 Nov 2001, Alan B. Pearce wrote:

> >I'm thinking of high frequency PWM switching of the AC line (like maybe
> >50 or 100 kHz). If you chop the AC line with a duty cycle of 50%, then
> >run it through a low pass filter, you'd get a 60V (in the US) sine wave.
> >This'd require a big LPF for incoming AC and a smaller LPF on each
> >output, thus driving costs up considerably. The output would be a sine
> >wave, which would be nice, and the input current would also be
> >sinusoidal. It's only a matter of money...
>
> There are IC's to do this. Motorola make one in an 8 pin package IIRC. They
> are used for minimising power factor problems on switch mode supplies. This
> may allow you to get a DC voltage which you can then use with chopping fets
> to deal with your lamp dimming. Sorry I cannot remember the IC number.
>
  UC3842/43/44?

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