[GreenKeys] Frequency deviations in Continental Europe including impact on electric clocks steered by frequency

[Richard Knoppow]

    In the past the generators were slightly speeded up or slowed 
down but I am not sure if they can do that now because of the 
"grid". Power from different sources must match in phase 
requiring rather close control of frequency. In the old days when 
a generator was brought on line its output had to be brought into 
phase with the other machines. Speed is not the only method of 
controlling load variations, all these machines have separate 
exciters so the amount of excitation can be varied to change the 
output.
     I also don't know how school or factory master clocks work 
now but at one time they were pulse operated with the pulses 
generated from a central source. I also have seen these catch up 
or slow down by a little but I don't know how they handle 
daylight saving time. I was an election clerk recently were we 
were set up in a school. We had just come off daylight saving 
time. The clocks were off by an hour when we arrived to set up in 
the early morning but by about mid day they were back on. I think 
they may just have shut them down for a hour.
     I wonder how many remember the old Western Union clocks, 
once in every radio station? These ran on a governed DC motor 
with a local battery. Once an hour a pulse was delivered over a 
wire line which would set the clock exactly on the hour. The 
service from Western Union cost something like a dollar a month 
or maybe it was a dollar per week. The clocks were made for WU by 
the Self-Winding Clock Company. In radio stations they were 
usually in square wooden cases to muffle any noise they made. I 
think the railroads also used these. There were also Postal 
Telegraph clocks but these were just regular synchronous clocks 
referenced to the power line.
    In the Los Angeles area until about 1950 some suburban areas 
had 50Hz power while the city was 60Hz so one could find electric 
clocks for both for sale. Burbank had 50Hz power so Warner 
Brothers had rotary converters for frequency changing to operate 
the synchronous motors in their RCA sound equipment. At some 
point around 1950 Southern California Edison and the smaller 
companies like Burbank Light and Power got on the grid with the 
LADWP and changed to 60Hz. Everyone with electric clocks had to 
change them.

On 3/6/2018 7:09 AM, Bob kb8tq wrote:
> Hi
> 
> Most schools / factories / train systems, even back in the 1950’s 
> ran on a “master clock”
> system rather than a bunch of independent clocks. The issue was 
> not so much line
> frequency as a power outage. Going around to a bazillion clocks 
> to re-set them all to the
> correct time cost a lot of money.
> 
> Back when I was in school (yes school had been invented that far 
> back) the ham radio club
> guys noticed that WWV and the wall clock had an interesting 
> relationship. The wall clock
> drifted during the day and between 4 and 5 pm went faster (or I 
> suppose slower) to eventually
> match up with WWV by 5 pm. The largest deviation that I recall 
> seeing was around 30 seconds.
> 
> Bob


-- 
Richard Knoppow
1oldlens1 at ix.netcom.com
WB6KBL