Post your quartz clock matters here

Discussion in 'Electric Horology' started by lmester, Oct 14, 2012.

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  1. Tinker Dwight

    Tinker Dwight Registered User

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    Actually I didn't say they didn't have a Lavet motor, I said they
    had a ratchet like device to ensure they go the right way.
    Tinker Dwight
     
  2. lmester

    lmester Registered User
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    1968 quartz master clock electronics

    1968 quartz master clock electronics.

    This has been sitting in my junk box for several decades. I'll bet that this was probably one of the early clocks with solid state electronics. Does anyone here know the history of this? When was it first made? Date codes on the board show that this one was from 1968.

    This is the circuit board from a Simplex master clock. It provided drive to a 50Hz synchronous motor.

    All done with discrete components. No IC's on this board!

    Three plug in boards make up the divider chain. Each board has a five stage divider using two transistors per flip-flop.

    The round can is an OCXO (oven controlled crystal oscillator).

    The two transistors with the black heat sinks and two transformers provide the 50Hz power to run the clock motor.

    a 1.6384 MHz clock from an OCXO is divided by 2^15 to get 50Hz.

    Here are some pictures.

    The name on the board is "Quasar" A good name for a precision oscillator.

    As you can see from the scope the OCXO and divider chain are working. It's putting out a 20 ms (50Hz) waveform. Unfortunately, the the transistors on the motor drive are bad. It's not putting out the motor drive voltage. Probably why it was replaced.

    TCXOBoard 001.jpg TCXOBoard 002.jpg TCXOBoard 003.jpg TCXOBoard 011.jpg TCXOBoard 012.jpg
     
  3. Tinker Dwight

    Tinker Dwight Registered User

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    Re: 1968 quartz master clock electronics

    HP used to have a solid state frequency synthesizer.
    If had phase locked loops tuned to 1/10 the previous
    decades frequency. This way it didn't need flop dividers.
    Much more reduction in circuitry. From the your dates, I'd say
    yours used germanium power transistors. Most likely PNPs.
    Tinker Dwight
     
  4. harold bain

    harold bain Forums Administrator
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    Re: 1968 quartz master clock electronics

    Luke, these boards were used by Simplex from around the mid-60's to power their 93 and later 943 master clocks. The motors were A. W. Haydon synchonous motors, 115 volt 50 cps, .025 watts. The 93 masters used wiper boards for their contacts, while the 943 had the same contact arrangement as the IBM 91 master clocks. I recall servicing a 93 master on a great lakes ship back around 1969, the contacts not being affected by gravity making them suitable for ship life.
    I have a few of these old masters in my garage, likely would still run if fired up. They used a 12 volt DC input, with a 6 AH backup battery under charge during normal use. In the 1970's a much smaller board was used that could replace these older units. By around the early 1980's these masters were replaced with fully electronic masters.
     
  5. Movementman

    Movementman Registered User

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    #105 Movementman, Dec 28, 2014
    Last edited: Dec 28, 2014
    They are different motors that use a similar design to a Lavet motor but are more stable at a higher drive frequency and a higher speed. I have not found much on the though.

    They seem to hold up fairly well but they do get pretty noisy over time. The seem a bit more accurate than the Lavet type movements, though. They are pretty reliable even once they get noisy, but I do not see them lasting for more than a few years because of the plastic pivots, but they seem to be very hard to lubricate because these motors have almost no torque at all. I would say that they should easily last 5-10 years as long as they are taken care of. Also, some get noisy after only a few weeks and some may never get noisy, it is really hit or miss with long term problems.

    You will know when the battery gets low because the second hand will "jump" as it moves instead of being a fluid movement, although it will still keep accurate time.

    Also, the one that I am looking at right now will sometimes start in the wrong direction and run until the bent teeth grab and cause the motor to reverse, usually a second or two.
     
  6. lmester

    lmester Registered User
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    Re: 1968 quartz master clock electronics

    Thanks for the info!

    I decided to do some troubleshooting and see if I could get the board working. The problem ended up being an open circuit in a connection to the transformer. The transistors were good. Very lucky because I'd probably have a hard time finding replacements.

    You said it takes a .025 watt motor. That's much less power than the ones I have . Mine are all rated at 2.5 watts. I tried one and the board couldn't provide enough power to run it. My motors are also rated for 60Hz. Running at 50Hz they'll be drawing a little more power and be running slow.

    I also trimmed the oscillator. I was surprised that I was able to get it set to the correct frequency. It's also nice and stable. Amazing for an oscillator that's getting close to 50 years old.

    Also, were quartz crystal oscillators common in master clocks? I'd think this would be overkill for most applications. Much simpler to just directly connect a synchronous motor to the power line. I have an old Cincinnati Time Recorder master clock that does this. It has a DC motor that takes over if the power fails. It keeps excellent time. I only need to set it twice a year when the time changes.

    You'd mentioned servicing one of these on a ship. Using a crystal oscillator would make sense there. Since they generate their own power the frequency may not be very stable.

    I trimmed the frequency last night. You can see from the picture that it was right on the correct frequency. I checked it tonight and it's only changed by about .3 Hz.

    QMBoard 004.jpg
     
  7. lmester

    lmester Registered User
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    Re: 1968 quartz master clock electronics

    I've been doing some research on early quartz clocks.

    The earliest ones used vacuum tube electronics. A 15 stage divider made with flip-flop circuits would be insane. 30 triode tubes would be needed. You could also use the clock to heat your house! I found that they also used PLL's like that HP frequency synthesizer. That would get it down to a reasonable number of tubes.

    At first, the quartz clock was an expensive custom designed piece of equipment. They replaced pendulum clocks for national time standards and were later replaced by atomic clocks.

    Once transistors were available, crystal oscillators were used in industrial equipment like my Simplex master clock circuit board. There were also some expensive domestic consumer clocks and watches available in the 1960's. They only became a common inexpensive consumer item when integrated circuits with the required electronics were available.


    The earliest consumer quartz clock that I've found so far is the Junghans Astro-Chron from 1967.


    Here are some pictures.

    astrochron-b.jpg astrochron-f.jpg

    This clock uses transistor flip-flops like my simplex board.

    Here is a link to a web site with detailed info on this clock. The language is German. Electronics units and schematics are standardized. You can still get a good idea of how it was designed. It has a 12.8KHz crystal oscillator feeding a ten stage divider. This feeds a 12.5Hz signal into an electromagnet impulsed balance wheel movement. This is most likely a modified ATO balance movement. The mechanics look nearly identical to some old ATO balance movements that I have.


    http://www.hwynen.de/jgh-astrochron.html



    I'm going to gather up the documents, URL's and pictures that I've found and post them on this board or possibly on the web. I'm sure others would be interested in some quartz clock history.
     
  8. harold bain

    harold bain Forums Administrator
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    Re: 1968 quartz master clock electronics

    These were used often in places that had generators for power, where frequency might not be well controlled. They did also show up in many schools. It is a 4 wire motor with a small capacitor between the windings. I would also advise, don't run it for any length of time without having a 12 volt battery connected
    These were quite common in the 1960-70's as being the latest technology from Simplex.
     
  9. flynwill

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    Re: 1968 quartz master clock electronics

    Or 15 dual triodes. I've seen 4-tube decade counters before.

    There were also some cool tubes that implemented a decade counter (or more) in a single unit:

    http://www.decadecounter.com/vta/tubepage.php?item=15

    I remember coming across some 1950's test equipment (I think it was an HP frequency counter) that utilized these years ago.
     
  10. lmester

    lmester Registered User
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    Re: 1968 quartz master clock electronics

    Right now I'm running the board from an unregulated dc power supply. I'm assuming that the battery was used for voltage regulation. I've seen some circuits that use the battery as a regulator. I should at least get it connected to a 12v regulated power supply. After spending the time to get it working it'd be a shame to have a power spike kill it.

    The heater for the crystal oven requires AC voltage for operation. It uses an SCR for switching. Do you know what voltage the heater was designed to use? I tried 6VAC and it didn't get hot enough to go into regulation. I'm now running it on 12VAC and it's maintaining temperature.

    Also, this must have been a top of the line master clock. Right now my board is running about .015 second per day or 5.7 seconds per year slow. Amazing for 1960's technology. I could probably get it adjusted more accurately if I wanted to spend the time on it. It has a nice system for trimming the oscillator frequency. There are two trim capacitors. One for coarse adjustment and one for fine.
     
  11. lmester

    lmester Registered User
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    Re: 1968 quartz master clock electronics

    It looks like flip flop circuits were not commonly used until transistors were available.

    The earliest quartz clock that I've found used a phase locked loop circuit. It had four triodes.

    Here is a link to the document:https://archive.org/details/bellsystemtechni27amerrich The Bell System Technical Journal.

    The article on quartz clocks starts on page 510. Page 538 has the schematic of the first quartz clock. It's some interesting reading.
     
  12. harold bain

    harold bain Forums Administrator
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    Re: 1968 quartz master clock electronics

    We didn't do much with these in the field, as it was too easy to just swap them out when there were problems, then ship them back to head office. I might have a schematic around somewhere for these, but it will take a bit of looking. Don't know what the voltage would have been for the heater, but 12 volts is likely, as it could be taken from the AC side of the charger. Running without the battery would show about 14 volts charging voltage, which we always assumed would be bad for the circuitry if used that way for any length of time. Any time a battery died, unplugging it would be the test to see if the board is good, but if we left it in that condition to keep the system running, we would bring a spare board with us when we changed the battery, just in case. I'll have a look around tomorrow to see what I might have in the way of schematics.
     
  13. eskmill

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    Re: 1968 quartz master clock electronics

    Thanks Luke and Harold for bringing up the subject of the Simplex quartz master time piece. There's one under my bench that I would like to spend some time with although, years ago, I did "fiddle" with it long enough to see the motor run the hands.

    I notice that the oscillator has a three-terminal thermostat connected to a solid state device in the board. What I do not have, like Luke, is knowledge of the service voltages and their external connections.

    I'd like to enclose the timepiece in a steel box of the '60's era.

    My very best, Les
     
  14. Tinker Dwight

    Tinker Dwight Registered User

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    Re: 1968 quartz master clock electronics

    These transistor circuits were more forgiving for over/under voltage
    then later IC would be. It is more an issue of better regulation
    of the frequency of the oscillator then damage to the circuit.
    The amount it is off is about 1 part in 10^-7. With a crystal oven,
    it should do better than 10^-8. If the frequency counter you're
    using is not calibrated recently, it can be that or more off.
    WWV signal is still broadcast but without some special circuits,
    it wouldn't be of much direct use to the clock. I have use it
    to calibrate frequency counters. With a scope and XY inputs,
    one can do reasonable.
    Tinker Dwight
     
  15. lmester

    lmester Registered User
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    Re: 1968 quartz master clock electronics

    Les,

    The device on the board is an SCR. It switches power to the heating element. The gate of the SCR is driven by a mechanical click type thermostat switch in the oscillator.

    Look at my post #102. The first picture is of the bottom of the board. The connector is on the right. Counting from the top of the connector here are the connections.

    1 Clock motor
    2 Clock motor
    3 Oscillator power supply ground.
    4 Heater power supply (12VAC ??)
    5 Heater power supply (12VAC ??)
    6 Oscillator power supply +12VDC


    To get the board running you only need to connect +12V to terminal 6 and ground to terminal 3.

    Warning! The clock motor outputs have high voltage on them when the board is running.

    The board will run without the heater but accuracy will be poor.

    Because of the SCR switch, the heater power supply requires AC. I had to guess at the heater voltage. 6VAC was too low to run the heater. It's running at about a 25% duty cycle with 12VAC applied.

    The heater takes nearly an amp with 12VAC applied. Make sure your power supply can handle that.

    There are two gold plated test pins on the top of the board. These provide the oscillator frequency that goes into the divider chain. There is also a pot on the board. It is on the output of the divider chain. It adjusts the signal level going into the motor drive circuit.
     
  16. harold bain

    harold bain Forums Administrator
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    Re: 1968 quartz master clock electronics

    Looking through my service manual, no schematic, but some interesting information. The whole board was called a "Quasar unit". It was designed to provide 115VAC, 50 CPS (regulated) to the drive motor. Uses a 3.2768 MHZ crystal and an oven to keep the crystal heated to 75 degrees C or 167 F., controlled by a thermostatically controlled SCR. When power is applied to the Quasar unit (recified ac during normal operation and standby battery during power failures), the crystal generates a low voltage high frequency signal which is fed through frequency divider boards. Each board contains 5 flip-flop circuits to ensure accurate frequency reduction. From the last board, the signal is applied through a potentiometer, a wave shaper circuit, a presignal amplifier circuit, and an output transformer. The three divider boards are constructed identically, but are not interchangeable. The signal from the output transformer is applied directly to the motor.
    Service hints:
    If the power is off for 24 hours, the oven will also be off, and the clock will gain 7-8 seconds.
    If the clock runs slow, make certain all contacts have an RC network to suppress any transients that may affect the Quasar unit.
    These units came with a metal cover to keep any RF noise away from the circuit boards and prevents any physical damage to the boards.
    A fully charged battery will be at 14 volts DC. Adjust the output so that at 12 volts DC, it is 100VAC. 12.5 volts, 106 VDC, 13 volts, 108 VAC, 13.5 volts, 110 VAC, and 14 volts, 115VAC.

    I recall these metal boxes that came with the circuit boards were often removed by servicemen over the years, with no ill effects.
     
  17. Peixian

    Peixian Registered User

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    thanks for your sharing information.
     
  18. Dave T

    Dave T Registered User
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    Trying to make something out of nothing! A (friend)? asked me to take a look at this Chinese plastic quartz anniversary clock. the clock works, the Westminster chime works, but the pendulum does not. The following pictures are looking at the bottom of the clock where the pendulum is activated by a hairspring which has detached from the lever that pulls the pendulum around for each cycle. The little white lever on the left is working properly and driven by the clock mechanism. But the end of the hairspring is detached. Not sure if the lever it attached to is broken off or not. I've never seen another to compare it to.
    I'm trying to figure out a way to re-attach the hairspring end.
    And the other problem is... how to I remove the plastic back cover. I'm tempted to pry it off, but not sure if I'll break it. Does it pry off?
    Any help, thoughts, experience by others greatly appreciated.
    Anniversary Quartz hairspring pendulum1.jpg Anniversary Quartz hairspring pendulum.jpg
     
  19. Tinker Dwight

    Tinker Dwight Registered User

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    Just epoxy the hair spring back on.
    Tinker Dwight
     
  20. John Arrowood

    John Arrowood Registered User
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    I have 3 quartz clocks with receivers for the NIST time signals and one of them is consistently 3 minutes ahead of the other two. One is one of those 'shine on the ceiling' kind, one is just a digital alarm, and the fast one is in a model that detects outside and inside temps and does something with barometric pressure that I haven't bothered to learn about. They have been like this for months.
     
  21. Dave T

    Dave T Registered User
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    Hmmm! Good idea. What have we got to lose? :p
     
  22. Cheezhead

    Cheezhead Registered User
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    #122 Cheezhead, Feb 27, 2017
    Last edited: Feb 27, 2017
    Re: Nine Year Quartz Clock Battery?

    [​IMG]

    This is a preliminary update to my post #53 speculating that a lithium AA cell might power my small German travel alarm clock for 9 years. The lithium battery, installed on Feb 20, 2012, at 5 years on February 20, 2017 was still powering the clock as of today, February 27, 2017. I did not check the initial voltage of the battery but I recently checked two new Ultimate AA lithium batteries to get an average voltage of 1.833 volts dc open circuit. The 5 year old battery in the clock presently measures 1.758 vdc oc.

    According to a graph on Energizer's web site, http://data.energizer.com/PDFs/lithiuml91l92_appman.pdf , a new Ultimate Lithium cell has an open circuit voltage of 1.8 vdc that immediately drops to about 1.72 vdc with an applied 1 ma. load. The graph shows a lithium battery depleted down to 1.4 volts as having a sharp voltage dropoff after that. It seems fair to believe that the clock will run for a while after 1.4 volts because the clock will still run at 1.35 vdc as determined with a nearly depleted alkaline cell.

    The meter that I used was a Velleman DMM that some time ago I was able to compare to a Beckman DMM that had been calibration checked against a standard traceable to NIST. Using the two volt dc scale the 20 dollar Velleman meter showed good accuracy as it measured only 0.4% higher voltage than the Beckman. It is possible, of course, that the Beckman meter was not perfectly accurate as is so with any meter. This is the best that I can do regarding voltage accuracy without spending some money to have my Velleman DVM850BL checked at a scientific instrument calibration facility.

    Conclusion: At 1.758 vdc oc, the Ultimate Lithium AA battery voltage is still very near the voltage when new so it appears possible as of now that the battery will continue to run the clock to 9 years. Time will tell, so to speak.
     

    Attached Files:

  23. Tinker Dwight

    Tinker Dwight Registered User

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    Re: Nine Year Quartz Clock Battery?

    I would say it should continue to run for several more years.
    Thanks for the update.
    Tinker Dwight
     
  24. lmester

    lmester Registered User
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    Re: Nine Year Quartz Clock Battery?



    From page 3 of the energizer Document A good battery has an OCV of >1.74v. A dead battery is <1.70v. At 1.758V you definitely have some life left in the battery.

    That 1mA discharge graph (Fig. 14) has a sharp voltage drop to 1.6v at about 60% depleted (2000 hours). You could put a 1mA load on the battery and let the voltage stabilize. If the voltage is above 1.6V you'll know that you've not yet reached the 60% discharged point.

    You already have 5 years from the battery. If it's not yet down to 60% discharge, you'll have a lot of life left! Assuming that you just reached 60%, it'll still take about 3 more years to drain it.

    I'll be waiting patiently for your report on when the battery finally dies zzz

    The Energizer lithium has about 3Ah capacity with a low drain load. Alkaline varies from about 2-3Ah. Not a huge difference in capacity. I'd expect that the extra battery life will come mostly from the lower self discharge rate and lower internal resistance of the lithium.

    One thing that's on my to-do list is to measure the power use of a quartz clock. I now have the instruments needed to do this. This would allow me to estimate the battery life. I'll know how much power the clock uses. With the self discharge rate and capacity of the battery I should be able to get a reasonable estimate.
     
  25. mountaintimer

    mountaintimer Registered User
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    Re: Nine Year Quartz Clock Battery?

    I found these two non-functional quartz anniversary clocks in a thrift shop a week or so back. I now have both in working condition.

    The Schatz square head, That was very easy to get running again after cleaning the badly corroded battery compartment:
    [​IMG]
    The B 8825 Bulova "Festivity", which came with all the parts, but the suspension spring had either broken off of the top hanger, or had slipped out of it.
    I was able to remove the hanger pin, but still could not get the two tiny brass squares apart. Instead, I opted to try a top hanger from a kit that I purchased from Timesavers a couple of years ago when I was tinkering with German 400 day clocks.
    After a couple of length adjustments on the suspension spring I was able to get it functioning correctly:
    [​IMG]

    The Hermle movement is basically like this one that was posted in a Westclox by Cheezhead in post #18 of this thread, except the fork is brass instead of clear plastic.
    [​IMG]
    Ron
     

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