More VSS

[xxalexx at ix.netcom.com]

The 8 pin pics have built in oscillator.
while(input_A0);
t=timer;
timer=0;
d=t/2
output_high(A1);
while(timer < d);
output_low(A1);
This will generate a phase diff. and the pulse can not drop
over 50 % in one cycle.
alex
> This sounds like a perfect place for a PIC. Since the pulse rate is really
> low by microprocessor standards, any normal speed PIC should work. If a
> duty cycle close to 50% is important, as several other people have
> indicated, the PIC could look for an edge and deliver a pulse half the
> duration from the previous edge. Startup (or is it stopping?) is
> interesting but the rest appears simple. Admittedly, it's not a perfect
> duplication of a clipped and squared AC generator output but it's darn
> close. Or is this a waste since it reduces the circuit to only 2 IC's: the
> PIC and a regulator? A crystal and bypass caps are needed for the PIC.
> Don't forget bypass caps for the TTL circuit earlier in this thread!. Noise
> and transient suppression on circuit I/O pins would be strong wants for
> either circuit as would a quiet rugged power source.