[Healeys] USA time

[John Harper]

Al

Those of us who lived in London during the war and relied on a 
synchronous motor clock had to be careful that the time shown was 
correct. Due to power shortages not only was the voltage reduced during 
the day (I believe that the Americans call the Brown Out) but the 
frequency was also reduced. What this meant that a clock might read 
around 10 minutes slow by the end of an evening.  However somehow the 
generating companies were able to increase the frequency during the 
night so by first thing the next morning the clocks would read correct 
again.

Regards

>Cycles per second (CPS) is important for clocks driven by electrical
>motors and those motors were synchronous motors because their speed
>was governed by CPS.  These motors operate in synchronization with
>the frequency of the electrical power, hence the name "synchronous"
>motor.
>
>The power companies work hard to maintain a close frequency tolerance
>that's why this type of motor was used extensively with old analog
>clocks (and turntables).  The gearing for the hands was set for the
>market the clock was sold in, that's why a clock bought in Britain
>couldn't keep time in the U.S. and vice versa.
>
>Al Malin
>Tricarb
>
>
>On Oct 31, 2007, at 9:48 AM, insptwo at msn.com wrote:
>
>
-- 
John Harper