[time-nuts] Sidereal timekeeping

[iovane at inwind.it]

I understand now why most analog wristwatches do tick every two seconds when 
the battery is low. I believed the logic used this trick to signal low battery.

Antonio I8IOV

>Analog quartz clocks may be used as slave clocks.
>You do not even have to disconnect the quartz movement.
>Just find the coil on the motor and drive it with a square-wave of  
>0.5 hertz,
>in series with a capacitor (about 50mfd) and a resistor (about 200 ohms)
>Each type of clock is different, though they all are driven by  
>something like 1.5 V
>20ms alternate polarity pulses.
>The actual values are not critical but must be determined for each  
>type of clock.
>If the capacitor resistor combination is wrong it will not work. Too  
>much signal
>will make motors "pole" and refuse to rotate. The capacitor charges  
>when the
>polarity changes and that current operates the clock. The resistor  
>sets the length
>of the pulse together with the capacitor value, as well as setting  
>the maximum current.
>Just swap values until the action is quiet, definite and reliable.
>I have used this method on at least 4 different types of quartz  
>clock, usually from a 5 volt
>logic signal.
>Cheers,
>Neville Michie
>
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