Magnus Danielson wrote: > I would consider a dedicated 1 PPS output. > > I would consider a synchronise feature with a PPS/synchronise input. It should > be wise to not directly wire it to the counter resets, but provide an arm > button and maybe a very simple arrangement to indicate "left", "on mark" and > "right" with red, gren, red LEDs. Just a tought. The arm button could also > have an electrical input, but I am running into creaping featurism here. > I think however that synchronisation might be a good thing. That way you can > shift the phase of the signal to fit your need. Pulling and inserting the > 10 MHz cable is a very crude way of doing it. > Maybe it would be just too much fuzz for too little gain, what do I know, but > I know I would enjoy seeing it. > A pulse-add/pulse-swallow technique (with a shift in initial divide by 10) > could be used to provide inc/dec functionality for a manual movement of phase. > > Cheers, > Magnus > > Hej Magnus
The easiest way to add a synchronise feature is to use a shift register clocked at 10MHz (if the input PPS pulse width is sufficient > 1us?) as the synchroniser. The various shift register taps can be used to generate a synchronous preload pulse for the input divider and a wider reset pulse for the 74HC4017's. If narrower sync pulses are likely then use the sync pulse to toggle a flipflop than connect the flipflop output to the shift register input and use 74XX86 XOR gates to generate the preload and REST pulses from the shift register taps. Bruce _______________________________________________ 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.
