For those still interested in the 10 MHz to 32 KHz divider issue, I
offer the PIC source to a tested divider that runs in an 8-pin DIP
package device:
http://www.ni6e.com/time/10M32K.html
Regards,
Peter
Tom Van Baak wrote:
Since synchronization is more important than jitter in this
A 10 MHz clock into a PIC gives a 400 ns/instruction time.
To produce 32.768 kHz you flip an output pin put every 38
instructions, except that 9632 times per second you make
it 39 instructions instead.
To figure out those sorts of ratios for static frequency dividers,
Allan Herriman has
Hi John:
All the quartz clocks I've taken apart have a single coil, for example see:
http://www.prc68.com/I/QuartzClk.shtml
The drive to that coil is bi-polar and is from a single AA cell, so the driver
IC must use an H-bridge. If you want to drive a clock like this at 1 PPS from
a 10 MHz
Hi Brooke,
The drive for the coils is really not very critical. All you need is
a cmos inverter and a couple of capacitors:
~1PPS--[o---+[o---|(-+
~| |
~| MOTOR
~| |
~
Chuck Harris wrote:
Hi Brooke,
The drive for the coils is really not very critical. All you need is
a cmos inverter and a couple of capacitors:
~1PPS--[o---+[o---|(-+
~| |
~| MOTOR
~|
- Original Message -
From: Brooke Clarke [EMAIL PROTECTED]
To: Discussion of precise time and frequency measurement time-nuts@febo.com
Sent: Thursday, September 04, 2008 12:25 PM
Subject: Re: [time-nuts] How to get 32.768KHz from 10MHz.
Hi John:
All the quartz clocks I've taken apart have
Max Skop wrote:
How does one get a 32.768KHz signal from our 10MHz reference.
There does not appear to be a nice divide ratio to do this.
With a locked 32.768KHz signal one could lock the oscillator of any of the
cheap (low cost) LCD clocks that are available with nice big digits,
Only the clockwork and the coils. All the clocks will be wired
in parallel.
Traditionally, such systems had all the slave coils in series.
I suspect you will find that the better way; less room for weirdness.
Otherwise, I like it!
Tom Frank
___
On Wed, 23 Jul 2008 15:22:08 -0700, Jim Lux [EMAIL PROTECTED] wrote:
At 03:01 PM 7/23/2008, Mike S wrote:
You're missing the point. The application is to drive a common, readily
available consumer clock. Simple and cheap. It can be done with a
single $1 PIC. You could spend $20 or $100 and not
At 04:22 PM 7/28/2008, you wrote:
On Wed, 23 Jul 2008 15:22:08 -0700, Jim Lux [EMAIL PROTECTED] wrote:
Based on the clocks I've taken apart, dividing the 10MHz down to 1 Hz
is probably your best bet, rather than trying to hit 32768. However,
I don't know of a non-programmable single chip
FYI,
Quartz analogue clocks almost universally use a bipolar motor, a two
pole
magnetic circuit with the minimum reluctance axis displaced from the
direction
of the energised field.
When activated the 2 pole magnetic rotor aligns with the magnetic
field, when the field collapses,
the
At 05:04 PM 7/28/2008, you wrote:
FYI,
Quartz analogue clocks almost universally use a bipolar motor, a two
pole
magnetic circuit with the minimum reluctance axis displaced from the
direction
of the energised field.
When activated the 2 pole magnetic rotor aligns with the magnetic
field, when the
How does one get a 32.768KHz signal from our 10MHz reference.
There does not appear to be a nice divide ratio to do this.
With a locked 32.768KHz signal one could lock the oscillator of any of the
cheap (low cost) LCD clocks that are available with nice big digits,
temperature sensors and
At 09:09 AM 7/23/2008 , Max Skop wrote:
How does one get a 32.768KHz signal from our 10MHz reference.
There does not appear to be a nice divide ratio to do this.
With a locked 32.768KHz signal one could lock the oscillator of any of
the cheap (low cost) LCD clocks that are available with nice big
At 10:09 AM 7/23/2008, Max Skop wrote...
How does one get a 32.768KHz signal from our 10MHz reference.
There does not appear to be a nice divide ratio to do this.
I've thought about this too. It seems the simple way would be to clock
a PIC with the 10 MHz, then use loops to produce the 32768 Hz.
, 625000/2048, 312500/1024, 156250/512, and 78125/256.
John WA4WDL
- Original Message -
From: Max Skop [EMAIL PROTECTED]
To: time-nuts@febo.com
Sent: Wednesday, July 23, 2008 10:09 AM
Subject: [time-nuts] How to get 32.768KHz from 10MHz.
How does one get a 32.768KHz signal from our 10MHz
]time-nuts@febo.com
Sent: Wednesday, July 23, 2008 10:09 AM
Subject: [time-nuts] How to get 32.768KHz from 10MHz.
How does one get a 32.768KHz signal from our 10MHz reference.
There does not appear to be a nice divide ratio to do this.
With a locked 32.768KHz signal one could lock the oscillator
Problem is one period of 32768 is not a multiple of 100nS (one period of 10
MHz) so that won't work. Maybe there is a common denominator and it may be
possible to generate an average 32768 periods over one second, even though all
periods may not be equal.
Didier KO4BB
Mike S [EMAIL
At 07:09 AM 7/23/2008, Max Skop wrote:
How does one get a 32.768KHz signal from our 10MHz reference.
There does not appear to be a nice divide ratio to do this.
With a locked 32.768KHz signal one could lock the oscillator of any
of the cheap (low cost) LCD clocks that are available with nice big
Since synchronization is more important than jitter in this
application it's easy to generate 32 kHz from 10 MHz.
A 10 MHz clock into a PIC gives a 400 ns/instruction time.
To produce 32.768 kHz you flip an output pin put every 38
instructions, except that 9632 times per second you make
it 39
At 11:56 AM 7/23/2008, Didier Juges wrote...
Problem is one period of 32768 is not a multiple of 100nS (one period
of 10 MHz) so that won't work.
As long as both periods are rational numbers, it doesn't matter, and it
can work. For this purpose (display for humans), it doesn't matter if
some
Max,
You are a mild case
I also got bitten by the bug: Now I have 4 HP10811, two rubidiums,
two cesiums, T-Bolt and I am seriously considering making my own Cesium.
A visit to Las Vegas could turn to be cheaper fun than this..
Predrag
At 16:09 23.7.2008, you wrote:
How does
I see I'm coming to the party late, on the heels of Mike and Tom, but here's
some additional from playing with the numbers during lunch.
A mix of 30.4 us and 31.2 us periods (76 and 78 pic instr loops) in the
ratio of 1747 to 301 does it -- 32768Hz with a few percent fm-ing. With just
the two
] How to get 32.768KHz from 10MHz.
How does one get a 32.768KHz signal from our 10MHz reference.
There does not appear to be a nice divide ratio to do this.
With a locked 32.768KHz signal one could lock the oscillator of any of
the cheap (low cost) LCD clocks that are available with nice big
Correction - freq is high (*lead* builds up) for 53msec.
Ed
snip abt 200usec of lag accumulates
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions
Since synchronization is more important than jitter in this
application it's easy to generate 32 kHz from 10 MHz.
A 10 MHz clock into a PIC gives a 400 ns/instruction time.
To produce 32.768 kHz you flip an output pin put every 38
instructions, except that 9632 times per second you make
At 04:17 PM 7/23/2008, Tom Van Baak wrote...
I just prototyped this PIC algorithm and it works perfectly:
Exactly 10 MHz in gives exactly 32.768 kHz out.
TPIWWSC.
(This Post Is Worthless Without Source Code)
:-)
___
time-nuts mailing list --
Start:
NOP
NOP
NOP
...
NOP
flip_bit
NOP
NOP
NOP
...
flip_bit
JUMP Start
(details omitted for clarity)
:-)
Didier KO4BB
Mike S [EMAIL PROTECTED] wrote:
At 04:17 PM 7/23/2008, Tom Van Baak wrote...
I just prototyped this PIC algorithm and it works perfectly:
Exactly 10 MHz in gives
Another approach is to divide the 10MHz by 5^7 (78125) and then use an
injection locked multiplier chain to generate 32768 Hz from the
resultant 128Hz output.
It may even be possible to do the 256x multiplication using a single
injection locked 32768Hz injection locked multiplier.
When designed
At 05:42 PM 7/23/2008, Bruce Griffiths wrote...
Another approach is to divide the 10MHz by 5^7 (78125) and then use an
injection locked multiplier chain to generate 32768 Hz from the
resultant 128Hz output.
It may even be possible to do the 256x multiplication using a single
injection locked
At 03:01 PM 7/23/2008, Mike S wrote:
At 05:42 PM 7/23/2008, Bruce Griffiths wrote...
Another approach is to divide the 10MHz by 5^7 (78125) and then use an
injection locked multiplier chain to generate 32768 Hz from the
resultant 128Hz output.
It may even be possible to do the 256x
Mike S,
I think you missed the point ! One does not ask the question How does
one get a 32.768KHz signal from our 10MHz reference ? and not expect
it to cost both in terms of money and effort. There was no statement
of doing it cheap, re-read the original Email.
A more practical offshoot of this concept is to subsample the
32 kHz oscillator at 128 Hz (ie a sampling phase detector) and use a slow
loop to tune the 32768 kHz oscillator. The biggest problem here is that
you have to have a tunable oscillator. Attempting to get around
this by injection
An oscillator can be injection locked to at frequency that is a rational
number (M/N where M, N are integers ) multiplier of the injection frequency.
Thus, in principle, a 32768Hz oscillator can be injection locked
directly to a 10MHz signal (32768Hz = (256/78125)*10MHz) without
requiring any
Rick Karlquist wrote:
A more practical offshoot of this concept is to subsample the
32 kHz oscillator at 128 Hz (ie a sampling phase detector) and use a slow
loop to tune the 32768 kHz oscillator. The biggest problem here is that
you have to have a tunable oscillator. Attempting to get
Bruce Griffiths wrote:
An oscillator can be injection locked to at frequency that is a rational
number (M/N where M, N are integers ) multiplier of the injection frequency.
Thus, in principle, a 32768Hz oscillator can be injection locked
directly to a 10MHz signal (32768Hz =
At 04:17 PM 7/23/2008, Tom Van Baak wrote...
I just prototyped this PIC algorithm and it works perfectly:
Exactly 10 MHz in gives exactly 32.768 kHz out.
TPIWWSC.
(This Post Is Worthless Without Source Code)
:-)
Hi Mike,
Yeah, I thought I provided enough information in that posting so
In response to Jim Lux's email I checked out the NASA tech brief.
According to them to run a sidereal clock you should set the frequency to
32,859.27577 Hz.
Now the length of the sidereal day is 23:56:4.091 seconds. This is
23.934469722 hours. That is, the sidereal clock must cover 24 hours on
Quoting Tom Van Baak [EMAIL PROTECTED], on Wed 23 Jul 2008 06:27:30 PM PDT:
The result will be a $1, 8-pin, single-chip, 10 MHz to 32 kHz, low
(not zero) jitter frequency divider, suitable for driving cheap digital
or analog clock and watch movements from a 10 MHz source.
Extra credit for the
Quoting Jim Palfreyman [EMAIL PROTECTED], on Wed 23 Jul 2008
09:11:32 PM PDT:
In response to Jim Lux's email I checked out the NASA tech brief.
According to them to run a sidereal clock you should set the frequency to
32,859.27577 Hz.
Now the length of the sidereal day is 23:56:4.091
40 matches
Mail list logo
