E Z Peaces wrote:
Brian Lawson wrote:
On Mon, 30 Jun 2008 20:17:24 -0400, E Z Peaces

wrote:

Brian Lawson wrote:
On Mon, 30 Jun 2008 09:29:33 -0400, E Z Peaces
wrote:

Smaug Ichorfang wrote:
The more I look at 1338, I wonder if it is indeed aa metal-foil
electroscope. Typically these have very thin pieces of metal
foil suspended from a central conductor. The center piece in
this looks way too thick to be an electroscope. Does the
center
piece move; can it pivot from side to side? Are the two
terminals on the sides adjustable? Is it possible this is a
tilt switch of some sort?

How about a line frequency monitor from a time when automated
equipment to keep a generator on frequency was not reliable.

SNIP

Naw. Prior to the 40's, flyball governors were used to do that.

A flyball governor can keep a motor running at a nearly constant
speed, but synchronous clocks, invented in 1916, require precise
speed control If the generator is 1% slow (59.4 Hz), clocks will
lose about 15 minutes a day.

Doesn't that point to the need for a tuning fork to monitor the
governor? A meter could provide the necessary information, but a
man might notice the absence of a hum before he would happen to
look at the meter.


All I know is what I see. 25 cycle power, using a BIIIIIIIGG brake
to govern the speed of the generator. Brake is operated by
fly-ball
governor. Whether or not synchronous clocks were "invented" in
1916,
they sure were not in regular use is common practice. Heck, I
still
do have a pendulum clock that keeps good time.

Brian Lawson,
Bothwell, Ontario.

Wouldn't a power company regulate with a throttle and let the
electrical
load serve as the brake?

The balls of a fly-ball governor move out to reduce the throttle.
Farther out, centrifugal force is greater. Without compensation
such
as
springs, the generator would spin slower with lighter loads. How
are
you going to design compensation that will keep the speed within
.006%
(necessary to keep a clock within 5 seconds a day), under all loads
and
in all temperatures?

He wouldn't design one, he'd buy one from Telechron, which in 1918
patented a governor system specifically for that purpose.

The lack of precise speed control would explain why from 1888 to
1916,
an electric clock was a self-winding pendulum clock. By 1919,
synchronous electric clocks had taken over.

I'd like to see a source to support that assertion.

I think the speed control
of power companies must have become more precise.

Not until a device to allow it became available in 1918.

I think consumer synchronous clocks weren't sold until 1931, so the
1919
revolution must have been in business clocks. Clocks told employees
and
customers when to come and go. They established when someone was
due
at
a meeting. If the electric company could keep everybody's clock on
time, that would have been popular for businesses. It would have
been a
reason for those without electricity to get electricity.

I think you've missed the key advantage of synchronous clocks--with
synchronous clocks all the clocks on a given power grid keep the same
time. Even if they're inaccurate they're all inaccurate by the same
amount.

--
--
--John
to email, dial "usenet" and validate
(was jclarke at eye bee em dot net)