21 Feb
2007
21 Feb
'07
8:51 a.m.
On 20 Feb 2007 at 15:26, Allison wrote:
Before that (mt Cessna still has one) there were
clocks that used
A solenoid and contact to wind a mainspring for the usual wound
clock style balance wheel and escapement.
Used in automobiles (at least US ones) for donkey's years--and at
least in the case of US cars, one of the dashboard instruments that
failed first.
But that doesn't count as using an electrical timing element, but
rather as using electricity in place of a hand-wound timer. Curious
that a clock from some sort of Russian military vehicle that I
obtained was still manual-wind.
I can remember seeing at least one project for a crystal-controlled
timing source using tubes (I think it used push-pull 6F6's in the
output stage) to run an ordinary synchronous-motor wall clock. This
would probably be during the 1940s or 50s.
Does anyone remember that the oldest of said wall clocks required the
owner to start the motor manually by spinning a little knurled shaft
located on the back?
Cheers,
Chuck