: [sdiy] Notch Filter for Logon's Human-Capacitor Filter

[Paul Perry]

----- Original Message ----- 
From: "Mike I"
> Only half-kidding... a  60 Hz + harmonics notch filter capable of
tracking
> minor variations in line freq would make a good project in and of itself,
> whether BBD/switched cap/DSP or some other technology is utilized   :D
>
......but if you want to filter out mains hum, the mains waveform is so
screwed up
these days (switchmode power supplies)  that there's a LOT of energy in the
higher harmonics...
OK, I guess I really am a sad old fart, waxing nostalgic about when the
mains was
a sine wave ;-)


paul perry melbourne australia