> -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of Tom Van Baak > Sent: Thursday, September 04, 2008 11:17 PM > To: Discussion of precise time and frequency measurement > Subject: Re: [time-nuts] Driving clocks from 1pps > > >> 50% duty cycle is way overkill, perhaps even harmful. In > the 'scope > >> traces below you can see the IC generates just 50 ms > biphase pulses > >> every second. That's 1/20, or 5% duty cycle. > > > > No Tom, you misunderstand. The 50% duty cycle pulse provides the > > rising and falling edges. The small capacitor > differentiates that to > > produce a positive going, or a negative going pulse to make > the motor > > move. > > > > -Chuck Harris > > Ah, I see now. It's a 0.5 Hz square wave. Cool. Yes, that > looks like it might work. Has someone tried this on a quartz > clock stepper motor to make sure you reliably get sufficient impulse? > I wonder why no commercial clocks use this trick. > > /tvb > >
The capacitor gets too large for a commercial watch or clock, silicon is cheaper. Didier KO4BB _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
