Thanks everyone for the prompt and numerous responses. It was really an
academic question. He was curious what the division was for 4.194304 MHz
to get it to 1pps.
Bill
On 9/11/2020 5:50 PM, paul swed wrote:
I went looking for the clock and found nothing. But like the rest
discovered
Hi Tom
But Bill called out a 4 pole motor. Most of what I have seen are simple
single coil clocks.
Wondering how his comment changes the discussion.
But Bill actually didn't ask for a driver circuit just the divider ratio.
Regards
Paul
On Fri, Sep 11, 2020 at 6:43 PM Tom Van Baak wrote:
> Paul,
Paul,
I'll open the Omega Quartz Chronometer and trace the circuit if you're
curious. Many of these 70's stepper / analog clocks used Patek Philippe
movements, the classic one you see in vintage Austron, Tracor, Sulzer,
and, of course, hp time / frequency standards with the /001 clock option
Hi
If it was a custom chip, then the motor driver “stuff” would be integrated into
the
IC. That was indeed the case back in the 1970’s when I was designing this sort
of thing. Those chips were pretty hard to dig up, even back then. Unless you
wanted
to buy >10K pcs a month, they really didn’t
It may be that he's looking for info on how to drive the stepper motor(s),
such as
pulse sequences etc.
Dana
On Fri, Sep 11, 2020 at 2:59 PM Graham / KE9H wrote:
> 2^22 = 4,194,304
> So divide by two, 22 times in a row to get to 1 Hz.
> --- Graham
>
>
> On Fri, Sep 11, 2020 at 12:42 PM Bill S
I went looking for the clock and found nothing. But like the rest
discovered the divider ratio to 1Hz. But does the conversation stop at that
point? Since Bill said the motor was 4 pole wouldn't there be 1 more
divider to .5 Hz with the Q and /Q essentially across the coil. Add
protection diodes
2^22 = 4,194,304
So divide by two, 22 times in a row to get to 1 Hz.
--- Graham
On Fri, Sep 11, 2020 at 12:42 PM Bill S wrote:
> A friend has acquired a Chelsea Clock Company Chronoquartz which was
> probably made in the 70's. He has measured the oscillator frequency at
> approximately
Isn't the 4 MHz crystal near the sweet spot for one of the cuts? A dim
memory at best :-)
DJ
On 2020-09-11 11:57, Tom Van Baak wrote:
Bill,
4194304 Hz = 2^22 Hz so 22 flip-flops gets you down to 1 Hz. The
binary divider is s similar to how the Seiko Beta 21 was designed. See
[1] for an
s.febo.com"
> Subject: [time-nuts] Chelsea Chronoquartz dividers
>
> A friend has acquired a Chelsea Clock Company Chronoquartz which was
> probably made in the 70's. He has measured the oscillator frequency at
> approximately 4.194304 MHz. He wanted to know what arrangement o
HINT: 2^22 = 4194304
On 2020-09-11 11:30, Bill S wrote:
A friend has acquired a Chelsea Clock Company Chronoquartz which was
probably made in the 70's. He has measured the oscillator frequency at
approximately 4.194304 MHz. He wanted to know what arrangement of
dividers they used to run the 4
Bill,
4194304 Hz = 2^22 Hz so 22 flip-flops gets you down to 1 Hz. The binary
divider is s similar to how the Seiko Beta 21 was designed. See [1] for
an example of a clock that uses this frequency.
What's nice about the Omega Ships Chronometer shown there is that it has
a LEMO 1PPS output
Hi
Well …. 4.19304 = 2^22
I’d bet they used a bunch of divide by 2 ( or 2^N ) parts. :)
At some point they went from electronic division to driving gears. Is that what
he’s looking for?
or is he after the brand / model of divider chip? It’s quite possible that they
used a custom part,
even
A friend has acquired a Chelsea Clock Company Chronoquartz which was
probably made in the 70's. He has measured the oscillator frequency at
approximately 4.194304 MHz. He wanted to know what arrangement of
dividers they used to run the 4 pole stepper motor to step seconds.
Anybody know?
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