[GreenKeys] Why Dual Coil Electromagnets?

[bill riches]

I have had one of the WU clocks running for about 10 years.  The
originally used two #6 dry cells that would last 5  years or so or until
they would start leaking.  I am powering mine with two D cells and
change them once a year.  For all you need to know about those clocks
look in "American Clocks - volume 2 by Gtran Duy Ly starting on page
177.

73,

Bill Riches, WA2DVU
Cape May, NJ


> Maybe it relates to efficiency?  For example I have a Self Winding  
> "Western Union" clock that uses a pair of coils for the self  
> winding vibratory motor and another bigger pair of coils for the  
> hourly synchronizing electromagnet.  The winding motor runs from 3  
> volts (two 1.5 volt batteries).  It sounds like a small air  
> compressor that might be driven by a fractional horsepower motor,  
> yet the batteries are supposed to last a year.  I'll know in a  
> year, but for now think it must be a very efficient motor.
>
>