Repairing a school's Simplex Clocks (Frequency Synced)

Discussion in 'Electric Horology' started by alanwh, Dec 4, 2011.

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  1. alanwh

    alanwh Registered User

    Dec 4, 2011
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    Hello, I'm new to this forum.

    I'm a high school student and I've made it my project to repair the Simplex electric clocks at my school. They are actually rectangular and located inside a wall panel with a speaker, thermostat and phone, which I have yet to see anywhere else. They use frequency synchronization, running at 4,680hz.

    The school was built in 1976 and the original frequency generator is still in use and we have a slightly newer 2350 master clock. I'm happy to say that many of them continue to work as designed, but many have failed in a few different ways and I was wondering if someone could give me some help....

    Many of the clocks no longer synchronize. They will do the hourly and 12 hour correction if I manually close the solenoid. The ones that don't sync up still have the vacuum tubes inside. What's the best way to fix this issue? I've purchased a circuit board replacement from American Time and Signal which was successful, but for $50 each, it's out of our price range.

    The remainder of the broken clocks don't move at all. I have gotten some to start back up by spraying WD-40 into the movements and either just unplugging them and plugging them back in and/or giving one of the gears (located in the circle above the motor) a gentle push. The ones that won't exhibit a weird problem: they'll work for a while but then they will somehow jam(?). The second hand will literally be impossible to move forward with the motor or with your hand. If i turn the second hand backwards and let it go, it will work but then stop at the same place again. What causes this?

    Thanks for your help.

    I attached a picture of the wall panel and a picture of the inside of one of the regular glass clocks we have (identical mechanism). (I am aware that in the photo there is a torn wire...I found out the hard way).
     

    Attached Files:

  2. Tinker Dwight

    Tinker Dwight Registered User

    Oct 11, 2010
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    Hi
    Firstly, WD40 is not a good long term solution.
    Proper clock oil is needed. The problem now is that
    the WD40 will need to be cleaned out first.
    I'm curious about the tubes. I'd think these are
    to detect the sync tone and operate the solenoid.
    You'll need to find an old tube tester someplace.
    I can't make out the numbers but many of these
    old tubes can still be found.
    Most likely, many of the motors have failed. Replacing
    them is one option. Rebuilding them is another.
    It all depends on the amount of damage.
    I'd be curious to see a schematic of the circuit for the
    clocks.
    Where in the world are you located?
    Tinker Dwight
     
  3. harold bain

    harold bain Forums Administrator
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    Hi, kwhite, welcome to the message board. You have a monumental task with this clock system. It sounds like the transmitters are not putting out enough signal to activate the correction. The newer receivers will work with less signal than the older ones. Fixing this may be as simple as replacing the tubes in the transmitters (many of these systems had more than one transmitter). The tubes in the clocks just about never fail.
    It also sounds like many of the wall clock movements have failed due to wear. Spraying with WD40 won't compensate for wear, and will only be a temporary solution, as it will harden and make things worse.
    You can buy new movements much cheaper than new clocks (ATS).
     
  4. alanwh

    alanwh Registered User

    Dec 4, 2011
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    The tube is part of a 4 component receiver in each of the clocks. Normally they would use a third red wire for the signal to close the , but these pick up a signal/pulse over the buildings wiring (so they can be plugged in anywhere w/o any special wiring.)

    They use a type 5823 thyratron tube as an electrical switch to close the solenoid. I did find replacement tubes but they didn't fix the problem. I think it's because some don't close "enough" to put the correction arm in enough to move up.

    I used the wd40 to clean out the dust, concrete and metal shavings that built up in the movements over the years which seemed to work perfectly (it's been weeks and they still turn).

    I'd be really surprised if the motors have burnt out as the synchron motors they use are designed not to fail even if they are jammed, are still warm to the the touch. I'm almost positive there's something wrong in the movements.

    Thanks for your help. I'm located in Massachusettes.
    -> posts merged by system <-
    What should I use instead of wd40? I agree that the tubes don't burn out as they still illuminate but I'd be surprised if the signal is too weak as I can actually hear the signal generator (the generator is located in a central location in a relatively small building.
     
  5. caperace

    caperace Registered User

    Nov 1, 2006
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    Where in Massachusetts? I DON'T ADVISE A HIGH SCHOOL STUDENT TO GO NEAR A TRANSMITTER OR GENERATOR THESE UNITS ARE CONNECTED TO HIGH VOLTAGE AND THE CAPICITORS WILL HOLD A CHARGE THAT WILL MELT A SCREWDRIVER IF IT TOUCHES THE WIRES WITH THE POWER SHUT OFF.
     
  6. alanwh

    alanwh Registered User

    Dec 4, 2011
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    I was not planning on touching the generator myself (it is in fact connected to the main 480v line. That's what the building electricians are for.
     
  7. harold bain

    harold bain Forums Administrator
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    To properly clean the movements, they need to be removed from the clock, and cleaned out with paint thinner or something similar. If you are going to spray it with anything, get some Slick 50 "One Lube", which will be much less damaging than WD40.
    What usually wears out is the correction ratchet. Where it's arbor goes through the movement plate will have an elongated hole. This will eventually jam the movement and likely chew some teeth off the intermediate gear that is connected to the back plate. These motors do fail (nothing lasts forever).
    Since you have a motor generator instead of a transmitter, the correction signal is probably as good as it ever was.
    I hope you are getting some supervision from a shop teacher, or someone who knows his way around electricity.
     
  8. caperace

    caperace Registered User

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    I live in Mass, where are you, my e mail is lanejim@verizon.net, I may be able to help you.

    Jim
     
  9. alanwh

    alanwh Registered User

    Dec 4, 2011
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    Just in case anyone was wondering (many expressed concerns over me doing this)... I did not start doing this clock project blindly. I do in fact have knowledge about electricity and electrical safety and someone gave me detailed instructions about testing them before I started (though the wd-40 was my idea; apparently very incorrect). The school calls me "Mr. Fix It" as I do similar repairs with the lighting system in the theatre, the computers and the phone system. Unfortunately, there's no shop teacher or electricians that have to time to do "low priority" stuff like the clocks and the school is basically out of money. That's why I posted here, as I'm stuck past being able to replace the receivers or attempting to grease/free the movementS.

    Does it make any sense for the solenoids in the clocks not being strong enough to move the arm far enough? The solenoid closes when its supposed to, but it won''t actually do anything in terms of moving the correction arm up with the gears unless I'm the one closing it or pushing up slightly more with a pen.

    Thanks for everyones help!
     
  10. harold bain

    harold bain Forums Administrator
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    The solenoid probably needs to be adjusted so there is a very small gap at the bottom when it pulls in. Also the segment that rides up the ratchet gear may be worn, so it won't ride up to unlock the correction.
    Unfortunately many school boards are caught in a situation where there is no money for frivolous things like clocks:rolleyes:.
     
  11. skruft

    skruft Registered User
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    Bravo! This is a wonderful project and I'm glad you are undertaking it in a safe way.

    As noted, we have members in Massachusetts who should be willing to help.

    I know little of these particular clocks but believe there are both tube and solid state receivers. Also I think these clocks often come up as surplus on eBay and the like, often for low prices. I will look and see if I have any clocks or parts around. One question someone could answer is, are the Simplex wire-controlled clocks, or some of them, the same as these except for the receivers, so that you could substitute ones with good movements.

    Also - if you did not already mention it, tell us all about the system. How many of these slave clocks are in the system,and are they all corrected this way or are some wired? What are the two master clocks doing?
     
  12. harold bain

    harold bain Forums Administrator
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    Skruft, the only difference between the wired sync clocks and these electronic clocks is the soleniod, and the receiver. The movements are identical. I didn't notice any mention of two master clocks.
     
  13. alanwh

    alanwh Registered User

    Dec 4, 2011
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    We have one 2350 Master Clock (not original, digital, circa 1980s), that controls the clocks (and the bells that go through the PA system).

    Harold bain is correct in that our clocks are identical to any other simplex clock (even though they are rectangular and made of steel to go inside a panel, they are identical to the regular glass circular ones that we also have), the only difference being that they have a tube or PC board receiver in them.

    Bit more of an explanation on how the system works: Most Simplex/IBM clocks would use a 3rd red wire thats connected to the master clock to trigger the solenoid to run the correction cycle. At my school there is instead a special signal generator located in the electrical room between the main power lines from the outside and the building transformer and distribution panels that provide power to the whole building. The generator injects a 4680hz pulse into the regular 60hz 120 volt electrical wires in the building when triggered to do so by the master clock, which the clocks receive and closer the solenoid. The benefit of this system is that you can plug any of these simplex clocks into any outlet in the building and they will work and set themselves.

    The school has ~ 60 slave clocks (~55 of them being located in the panels, ~5 of the regular circular, glass ones that you usually see). ~20 of them work correctly, another 20 work but don’t sync, and the remainder don’t work at all.

    Simplex no longer makes these frequency synchronized clocks and recommended that the school switch to their newer model clocks in the late 90s, but that would have required a total overhaul of the wiring in each of the classrooms and all new clocks, something that was way out of budget.

    American Time & Signal still makes the receivers (in circuit board form) and even the signal generators (now silicon/solid state).
     
  14. harold bain

    harold bain Forums Administrator
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    Seems strange that the master clock supplied in 1976 needed replacing in the 1980's. It was probably a model 943. These were pretty trouble free, except for the bell programmer, which would have been a tough fix for any but an experienced repairman.
    At 35 years old, the slave clocks are reaching the end of their useful life, considering no one ever does any preventive maintenance on these. They would last a lot longer with occasional lubrication (keep in mind that WD40 is not a lubricant, it's a water dispersant).
     
  15. alanwh

    alanwh Registered User

    Dec 4, 2011
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    Harold bain your response reminded me: all of the clocks were serviced in both 1988 and 1995 by simplex. Most, if not all, do not have movements from 1976.
     
  16. caperace

    caperace Registered User

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    The tube type take about 1v signal to fire the tube where as the Pc receiver only needs about 1/4v signal.
     
  17. harold bain

    harold bain Forums Administrator
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    The motors are date coded, and would usually be replaced along with the movement, so it should be possible to tell which are original movements.
    If you are mechanically inclined enough to remove the movements, strip them, and clean them properly, you will have a better chance of keeping them running. In the process you will learn why they are failing, and which key parts are wearing out.
     
  18. alanwh

    alanwh Registered User

    Dec 4, 2011
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    I took a look around today and could not find any movements that were original, they all have “’88” scratched into them. I have no idea why every single one was replaced, but I can tell you that Simplex probably did these the same time the “new” master clock was installed. The school had some sort of contract with them as they also installed and managed our fire alarm system up until the late 90s. Likewise, I can’t find any motors that were from 1976 and on the plus side, I can’t find any broken ones.

    The head custodian told me that Simplex wanted to replace all the clocks with non-frequency ones and after they said that and merged with Grinell, the school no longer worked with them. The school hasn’t made nay sort of communication with Simplex since 1998. (The only reason I know that is because our address changed in ’98 and Simplex had no record of that).

    I did take one of the broken clock’s movements apart. Here’s what I found: none of the gears appeared to be worn down. However, they appeared to be misaligned and covered in gunk. What’s the best way to clean these and put them back together?

    Thanks
     
  19. harold bain

    harold bain Forums Administrator
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    Soak them in paint thinner overnight then brush them off. The gears can't be misaligned unless there is wear/broken pieces.
     
  20. caperace

    caperace Registered User

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    Are you saying that all the motors are working, but the clocks are not keeping the correct time? Simplex took the fall for a lot of things, customer when the have money problems always want to blame someone other than themselves, school systems have a lot of people between the custodian and the superintendent of schools and the sales and service reps had to deal with them all and each had a different story. Some school system were well run and budgeted for the clock systems and others just took a chance they would have money to repair or replace their equipment, which in most cases thay did not have. In the middle of the school year when the equipment failed and there was no money who was the bad guy? My experience with 38 years at Simplex pre Grinelle (Tyco) was that it was a Family owned business and their name and reputation meant quite a lot.
    Those movements were a vendor item and sometimes there were defects, the metal was soft and the plates were worn at the pivot points, in some cases all the movements were replaced.
     
  21. harold bain

    harold bain Forums Administrator
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    Jim, these Hansen movements from the 1950-60's were much better quality than they were in the 1980-90's. I always oiled these clocks and movements before installing them, and this really extended their run time before breaking down. Also a dab of grease on the ratchet arbor kept the arbor from tunnelling into the plate.
     
  22. alanwh

    alanwh Registered User

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    Mare clarification:

    The school has 60 clocks from about 1976. Though the clocks are original today, here’s two thing that Simplex did for maintenance purposes:
    -Late 80s: replaced all the movements in all the clocks.
    -1995: replaced some receivers in the clocks with PC board receivers.

    The new master clock was installed at the same time time as the new movements. I can only deduce that maybe a failure with the master clock caused all the clocks to stay in their correction cycle for an extended period and ruined the movements. I believe it was right about then too that the transformer outside the building exploded and a lot of the electrical equipment inside the school was damaged which may have damaged either the clocks or the master clock.

    Jim, I don’t think the school blamed Simplex for anything. To my knowledge they had a great relationship with them, especially as a local company. I believe it was in the late 90s Simplex stopped manufacturing the PC boards for the clocks and recommended that my school switch to their newer models. With the building’s layout, that wasn’t really feasible and would have cost tens of thousands of dollars, which is why they stopped servicing them.

    Here’s a better explanation of my current problems:
    -20 clocks work perfectly and sync correctly.
    -30 of them have completely stopped. I thought it was motor failure, but its because the gears in the movements seem to have stopped/jammed. Compressed air, grease, and a push with a screwdriver got these clocks back up and running (seemingly permanently) and I’m still working on them.
    -The remainder no longer sync up but turn just fine. They either exhibit one of two problems: The solenoid closes when triggered, but does not make enough contact with the gears to initiate a correction cycle. Or, the solenoid doesn’t close at all or long enough. This is either as a result of receiver failure or the generator is failing.

    Jim recommended that I use a test clock to see if they aren’t triggering due to the generator not sending out a strong enough signal, which is something I’m working on. Another thing he recommended was replacing a part of the solenoid and adjusting its position on the clock. I’ll let everyone know how this turns out.

    The only remaining problem I can’t solve is how to reassemble one of the movements. I disassembled one of the movements to a clock that I know was already broken, but I can’t get the gears back into place.

    Thanks everyone!
    -> posts merged by system <-
    I forgot one thing: about 5 of them exhibit a weird problem: They appear to work just fine, until the second hand reaches the “12” on the clock. The second hand will stop and be impossible to move forward (even if you physically try to move the second hand forward). If I turn the clock backwards and plug it back in, it will work just fine, until the second hand reaches the 12.
     
  23. harold bain

    harold bain Forums Administrator
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    You are going to have to learn how these clocks work by watching one that does, and comparing it to those that don't. There is a little brass spring on the bottom of the lever that rides on the smooth disc beside the ratchet wheel. This stops the second hand to sync it during correction. Either the spring is bent, or the clock is still in correction. Forcing the second hand past this just bends that spring piece.
    To put them back together you will need a spring hook. It looks like a dental tool formed into a hook. This is to put the three springs back in place AFTER you have the gears assembled and the plate back on.
     
  24. caperace

    caperace Registered User

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    #24 caperace, Dec 9, 2011
    Last edited: Dec 9, 2011
    The master clock would not fail and keep the clocks in correction, what might have happened was that someone turned on the generator switch and then held the sync switch on for longer than 12 seconds, this might cause the sector to hang up if they were not adjusted correctly, but would not cause any harm to the clocks. If the transformer caused damage to the system the power company or the school insurance would be liable and the service contract if they had one would not cover the repair. Therefore a replacement would be the best recommendation. The classroom panels were not a shelf item they would have to be made special and would take some time. In order to get the system up and running, rebuilding the panels would be suggested and the movements along with the receivers would be replaced. The pc type receivers would be used as the tube type were not available. The correction coils probably would not be replaced, but the sectors would be replaced, the reason for this is the adjustments could be time consuming.The other reason for using the pc receivers is they fire on a lot less signal. If they had a motor generator and not a signal transmitter or mini generator, they would have had a field engineer come from headquarters to service the generator as this was not something most offices would tackle on their own. The generator control panel would have been serviced and relays etc. replaced at this time.
    With that said!
    Are the 20 clock that are working are they in the same area or scattered throught out the building?
    There are 30 you feel you can repair by cleaning.
    That leaves about 10 that need to be trouble shot.

    Get a good receiver and use that to trouble shoot for bad receivers.
    I think if you short between terminals 2 and 7 on the tube base with a screwdriver you can fire the tube. Some one can correct me if I'm wrong. The pot on the pc type receivers can be turned up and down, but you would need a signal generator to do these adjustments, you could try turning them in one direction or the other to see if you are turning it up or down, but remember sometimes if you turn it up or down to far you might not fire the receiver all, so don't go all the way in either direction.

    This should be enough to get you started, maybe some of the others can add to the list.
     
  25. harold bain

    harold bain Forums Administrator
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    #25 harold bain, Dec 9, 2011
    Last edited: Dec 9, 2011
    Jim, I've serviced the large motor generators a few times. About all they ever needed was new roller bearings, which was a relatively easy job.
    Yes, the tube contacts can be shorted to simulate correction. I don't recall which terminals either. I've also found moving the two coils closer together increases sensitivity, and they pick on lower signal voltage. The gap at the bottom of the correction solenoid is critical as well. Should be minimal, but there does need to be a gap. These clocks are difficult to work on without a signal generator and a signal level meter to simulate correction, and test how much signal is being received by the clock.
    One of the school boards I serviced in the 1970's had 20 of these systems, some IBM, some Simplex. They had upgraded older high schools with electronics to save the cost of hard wiring for impulse or wired sync clocks, going back to when IBM had the contract.
     
  26. JustaUser

    JustaUser New Member

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    FWIW: Here's the schematic to an IBM Slave Clock (circa 1960s?) that I came across and thought I would append here as a reference for someone else, since the previous posted pictures resemble the circuit board (pictures 1 and 2 of original post):

    IBM Clock Schematic.png
     
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