In article <jk4qkp$c9i$1@speranza.aioe.org>,
"garyr" <garyr@fidalgo.net> writes:
>There was an article in Scientific American, sometime in the 80's I think,
>about using electronics to drive or synchronize a pendulum clock. I believe
>it described using a solenoid to nudge the pendulum at the appropriate
>intervals.
A Venerable Clock Is Made Highly Accurate By Equipping It
with Quarts-Crystal Works
by C. L. Stong
September, 1974
--
These are my opinions, not necessarily my employer's. I hate spam.
Reply by whit3rd●March 18, 20122012-03-18
On Friday, March 16, 2012 9:02:05 PM UTC-7, Bill M wrote:
> I just installed a quartz battery movement into a wall clock that once had a
> mechanical movement. I lost the pendulum capability and I'd like to find a
> simple circuit that would move the pendulum with the same speed as in a
> normal clock. I'd like to use the same pendulum the clock used before I
> replaced the movement, which is 3" diameter bob and 12" long.
Well, there are quartz movements that wag pendulums (maybe you can
just buy one and use a link... like a rubber band...)
A 12" pendulum with ALL THE WEIGHT AT THE END has a natural period
of sqrt(g/L)/(2*pi) = 0.9 seconds
so, with a little fiddling (maybe tune the pendulum) it should
work with a movement that makes a 1 Hz pendulum output.
Reply by garyr●March 18, 20122012-03-18
There was an article in Scientific American, sometime in the 80's I think,
about using electronics to drive or synchronize a pendulum clock. I believe
it described using a solenoid to nudge the pendulum at the appropriate
intervals.
"Bill M" <bm@map.net> wrote in message news:jk21ki$n64$2@dont-email.me...
>
> "Jasen Betts" <jasen@xnet.co.nz> wrote in message
> news:jk1dgi$uj7$1@reversiblemaps.ath.cx...
>>
>> they don't get much simpler than this:
>>
>> http://www.norkro.com/webpages/quartz2.htm
>>
>> --
>
> I agree, that's cheap alright but the problem is that I already have a
> chiming electronic quartz movement installed and I just need a pendulum
> only
> driver. The hand shafts would only serve to take up too much space since
> I
> already have hands on the current movement.
>
> Bill
>
Reply by Jamie●March 17, 20122012-03-17
Bill M wrote:
> I just installed a quartz battery movement into a wall clock that once
> had a mechanical movement. I lost the pendulum capability and I'd like
> to find a simple circuit that would move the pendulum with the same
> speed as in a normal clock. I'd like to use the same pendulum the clock
> used before I replaced the movement, which is 3" diameter bob and 12"
> long. The circuit would be best powered from a single or double C or D
> batteries. Anyone have any ideas or links?
>
> Thank you,
> Bill
Find you're self a small DC motor that can support the weight of the
pendulum or a helper support for it on the end of the shaft.
Use a 9 Volt battery instead and a 555 timer that turns on the motor
for a short burst.. Also at the same time, you can have a reverse
polarity detector to determine when the motor is at the end of the back
travel. When no voltage is detected, the timer will then be on for a
short time, so that it will pull it back again.
The Back motion of the motor generated energy can be used to hold down
the RESET pin on the 555 timer. The timer will be a one shot set up,
once the timer is done with its short duration, nothing will happen
until enough voltage gets back generated to pull the reset pin or you
actually pull the pendulum to get it started.
Once you get this in motion, you won't need much to maintain it.
THe timer can handle up to 200 ma output, but I wouldn't push it that
hard, you really shouldn't need that much any way depending on your demand.
If you really need a C/D cell operation, I guess one could implement a
2/3 transistor version of a monostable oscillator where the back
energy of the motor resets the cycle and starts it over again. That
would be an
interesting idea.
Jamie
Reply by Bill M●March 17, 20122012-03-17
"Jasen Betts" <jasen@xnet.co.nz> wrote in message
news:jk1dgi$uj7$1@reversiblemaps.ath.cx...
I agree, that's cheap alright but the problem is that I already have a
chiming electronic quartz movement installed and I just need a pendulum only
driver. The hand shafts would only serve to take up too much space since I
already have hands on the current movement.
Bill
Reply by Bill M●March 17, 20122012-03-17
"Jasen Betts" <jasen@xnet.co.nz> wrote in message
news:jk1dgi$uj7$1@reversiblemaps.ath.cx...
> On 2012-03-17, Bill M <bm@map.net> wrote:
>> I just installed a quartz battery movement into a wall clock that once
>> had a
>> mechanical movement. I lost the pendulum capability and I'd like to find
>> a
>> simple circuit that would move the pendulum with the same speed as in a
>> normal clock. I'd like to use the same pendulum the clock used before I
>> replaced the movement, which is 3" diameter bob and 12" long. The
>> circuit
>> would be best powered from a single or double C or D batteries. Anyone
>> have
>> any ideas or links?
>
> they don't get much simpler than this:
>
> http://www.norkro.com/webpages/quartz2.htm
I agree, that's cheap alright but the problem is that I already have a
chiming electronic quartz movement installed and I just need a pendulum only
driver. The hand shafts would only serve to take up too much space since I
already have hands on the current movement.
Bill
Reply by Jasen Betts●March 17, 20122012-03-17
On 2012-03-17, Bill M <bm@map.net> wrote:
> I just installed a quartz battery movement into a wall clock that once had a
> mechanical movement. I lost the pendulum capability and I'd like to find a
> simple circuit that would move the pendulum with the same speed as in a
> normal clock. I'd like to use the same pendulum the clock used before I
> replaced the movement, which is 3" diameter bob and 12" long. The circuit
> would be best powered from a single or double C or D batteries. Anyone have
> any ideas or links?
they don't get much simpler than this:
http://www.norkro.com/webpages/quartz2.htm
--
⚂⚃ 100% natural
--- Posted via news://freenews.netfront.net/ - Complaints to news@netfront.net ---
Reply by Bill M●March 17, 20122012-03-17
I just installed a quartz battery movement into a wall clock that once had a
mechanical movement. I lost the pendulum capability and I'd like to find a
simple circuit that would move the pendulum with the same speed as in a
normal clock. I'd like to use the same pendulum the clock used before I
replaced the movement, which is 3" diameter bob and 12" long. The circuit
would be best powered from a single or double C or D batteries. Anyone have
any ideas or links?
Thank you,
Bill