Odd request
...And i forgot one thing...
The Telechron solenoid assembly is symmetric and
reversible.
That allowed some manufacturers to sell "Bar clocks"
that had their hands run backwards!!
73 de Normnad VE2UM
--- Normand Martel martelno@yahoo.com wrote:
Hi Tom...
Not only Telechron were very popular electric clock
movements, they were BY FAR the very best
mechanical
movements ever made.
When young, i've opened A LOT of used
electro-mechanical clock movements, and most of them
showed evident traces of wear. Worn-out gear
pinions,
dried-out and seized brass/steel bushings, dried-out
and cracked nylon pinions (Nylon tends to harden and
shrink with time and heat, so Nylon parts shall
NEVER
be put on a traction stress when manufactured) were
frequent on old clock movements, but NEVER on
Telechrons, except very
rare cases of pinion wear on the output shaft (3.6
RPM)
Telechron movements were very unique. The motors
were
two-pole shaded pole synchronous motors with an
external solenoid and a completly sealed rotor
stuck within the poles pieces. The self-starting
rotor, composed of three spring steel disks forced
in
place on a smooth shaft and spinning at 3600 RPM (60
Hz) was inside a sealed cylindrical aluminum gearbox
(older gearboxes were in a copper sealed box)
containing not only the rotor shaft, but also a
1000:1
reduction geartrain. Pinions were made of stacked
thin
steel pinion disks forced on the shaft to form
single
solid pinions. The faster rotating gears plates were
made of some kind of red-orange colored fiber
material
and the slower rotating (higher torque) plates, of
soft brass. The gear holding plates were made of
thick
alunimum with a thinner aluminum subplate that
prevented the gears from sliding longitudinally, but
far more important, the thin space between the
plates
and subplates had a capital role: Keeping a fine
capillary oil film between the plate and subplate,
that film kept the gear shafts permanently
lubricated,
thus eliminating all trace of wear. Even the gears
themselves (the rotor was spinning at 3600 RPM and
the
second gear, at 864 RPM) didn't show any trace of
wear, even under a magnifying glass.
I even remember the gear ratios of a Telechron:
Rotor: 12 toothed pinion (3600 RPM)
Second gear: 50 tooth fiber plate coupled to a 12
tooth pinion R:r: 4.1666667:1
Third gear: 54 tooth fiber plate coupled to a 18
tooth pinion R:r: 4.5:1
Fourth gear: 60 tooth fiber plate coupled to a 12
tooth pinion R:r: 3.3333333:1
Fifth gear: 60 tooth brass plate coupled to a 12
tooth pinion R:r: 4:1
Output gear: 60 tooth brass plate coupled to an
external 10 tooth pinion R:r: 4:1
4.166674.53.33333344=1000
Definitely a fine movement! I still use an oooold
Telechron at my shop.
73 de Normand VE2UM
--- "Tom Van Baak (mobile)" tvb@LeapSecond.com
wrote:
See Mitchell's SWCC page at:
http://www.telechron.com/
/tvb
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As I type this, my solenoid actuated mechanical slave clock is being driven
by my GPS receiver. The 1PPS signal drives a two stage divide-by-sixty
counter. The two counter stages, 7490 divide by ten and 7492 divide by
twelve used as a divide by six, are interfaced to two large Nixie tubes to
display seconds and tens of seconds respectively. I use a 7420 four input
NAND gate to detect "59" which is output to the slave clock driver. The
slave clock advances when the drive solenoid releases, hence it increments
at the end of the 59th second. The output from the divider section drives
the mechanical slave clock which displays minutes and hours. I hope to
finish breadboarding the control panel tomorrow and then start boxing up the
unit. Now, I am just comparing the sound of the once per minute, 1PPM?,
click of the slave clock movement to the voice announcements from CHU.
Sure, it is a strange clock, but I like the mixture of mechanical, Nixie,
and GPS.
John WA4WDL
----- Original Message -----
From: "jmfranke" jmfranke@cox.net
To: "Discussion of precise time and frequency measurement"
time-nuts@febo.com
Sent: Thursday, January 25, 2007 5:57 PM
Subject: Re: [time-nuts] Odd request
I am going the same route and have discovered slave clocks which are
solenoid driven clocks. The clocks were once very popular in schools and
factories. The hands typically step in one minute steps.
See: http://www.clockhistory.com/setclocks/index.html
I plan to use one of the clock movements to display minutes and hours and
a
two digit LED digital display for the seconds. I will divide the 1PPS
output from a Z3801A by 60 to get 1PPM.
John WA4WDL
----- Original Message -----
From: "Mark Amos" mark.amos@toast.net
To: time-nuts@febo.com
Sent: Thursday, January 25, 2007 4:50 PM
Subject: [time-nuts] Odd request
Time-nuts
I appreciate the comments regarding horological obsession. Mine started
with a desire for an accurate master
oscillator for my ham shack (built and use a couple Shera GPSDO's) and
has
blossomed into a much broader interest
in time (Ex tempus, sapientia?)
This has led me to a silly quest. I'd like to use a traditional clock
face and hands as an output device for a
1PPS signal from my GPSDO.
I know this is a very broad question, but does anyone have advice on
where
I might start hacking (or making) a
mechanical clock face to accomplish this? Is there a simple clock design
that I could start with to build my own?
Maybe replacing a pendulum or escapement with a solenoid? Any examples
to
work from?
Mark
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As I type this, my solenoid actuated mechanical slave clock is being driven
by my GPS receiver. The 1PPS signal drives a two stage divide-by-sixty
counter. The two counter stages, 7490 divide by ten and 7492 divide by
twelve used as a divide by six, are interfaced to two large Nixie tubes to
display seconds and tens of seconds respectively. I use a 7420 four input
NAND gate to detect "59" which is output to the slave clock driver. The
slave clock advances when the drive solenoid releases, hence it increments
at the end of the 59th second. The output from the divider section drives
the mechanical slave clock which displays minutes and hours. I hope to
finish breadboarding the control panel tomorrow and then start boxing up the
unit. Now, I am just comparing the sound of the once per minute, 1PPM?,
click of the slave clock movement to the voice announcements from CHU.
Sure, it is a strange clock, but I like the mixture of mechanical, Nixie,
and GPS.
John WA4WDL
That mechanical mixture is music to my ears. Nicely done.
One question - what happened to your clock after the most
recent leap second, 12/31/2005 ;-)
/tvb
Hi Tom:
I've been looking at patents for secondary clocks and find that there's two
class numbers: 368/59 is Horology/Secondary and 968/548 is Horology/stepping
secondary.
Do you know what the difference is between the two top class numbers both
called Horology?
Have Fun,
Brooke Clarke
http://www.PRC68.com
http://www.pacificsites.com/~brooke/PRC68COM.shtml
http://www.precisionclock.com