1960s Urgos Electromechanical Clock Not Functioning

captainclock

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Hello everyone, 4 years ago I found at Goodwill a 1960s vintage Urgos Electromechanical clock that is supposed to run on 1 1.5v C Battery but when I got the clock home and went to put a battery into the clock the clock wouldn't run, and the only solid state electrconic control device in the movement is a Germanium diode.

I had ordered a NOS Germanium diode to replace the original one in there and wired the new one into the clock and tried it out and the clock still doesn't run.

Not sure what else could be wrong with this clock as its a pretty simple movement, not much in it electronically that could fail besides that diode, the only thing I could think of is that the diode is wired in wrong, but I tried to wire it in like the old one was and it still isn't working.

Anyone on here familiar with how these old German electromechanical clocks work, and what can go wrong with them and how to get them running again?

Any help would be appreciated.

Thanks,

Levi

Urgos Electromechanical Clock Front View.jpg Urgos Electromechanical Clock Rear View.jpg
 

captainclock

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No information on this clock? I was curious about how to go about making this clock work again (and no this is NOT a quartz clock it is an actual German Electromechanical movement like some of the others discussed in this forum.)
 

Tim Orr

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Good afternoon, Levi!

Please show us some pictures of the innards of the clock, including the circuitry or circuit board where you effected repairs. I am not familiar with this particular clock, but have a hunch it's one of the ubiquitous "ATO"-like clocks, that use a magnet generating a current in a coil to bias a semiconductor. You say "germanium diode." Might it have been a germanium transistor? How many leads on the component? If only two leads, are you sure the polarity is correct?

What I have seen is a balance wheel-type movement with tiny magnets on the balance wheel and adjacent coils. Otherwise, I have also seen an electromagnet that kicks a mechanical device that puts some tension on a tiny "mainspring," a "remontoire" type of movement.

Sometimes, a wire in the coil is broken, preventing the bias from occurring. Hard to say without more info.

Also, what does that label in the battery compartment say? It looks like something to the effect, "After the battery is replaced, the clock should ... " Can't read the rest.

Was the speed adjustment screw that far off-center when you got the clock? Is the works inside properly centered?

Best regards!

Tim Orr
 
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captainclock

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OK, I'll get some shots of the guts of the clock for you, it was indeed a diode as it only two leads one on each side of the component, I thought I had wired it up correctly according to how the old one was wired in but maybe that's why it wasn't working in the first place, because someone else replaced the original diode before me and wired it up wrong and what I was seeing was someone else's faulty repair work?

Hard saying as this was the first German movement like this I had come across.

German Clock Movement.jpg

As you can see there's not much to this movement except that diode.
I installed a battery in it and tested for voltage and I got voltage at the movement like I was supposed to except that the diode was seeing voltage on both sides of it when usually diodes are supposed to only see voltage on one side which tells me that either I wired the diode in wrong and when I installed the battery into it, it blew the diode open, or the diode was a bad diode from the factory (NOS Electronic Parts doesn't always mean good parts).

I hope this helps.

Thanks,

Levi
 

Tim Orr

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Good evening, Levi!

I'm not an electronics expert. That said, a diode in that location would probably, I think, be a way to protect the circuit from a battery that was accidentally installed backward. You should be able, with an ohmmeter, to check the diode to see if it is at least blocking in one direction and passing in the other. That's not a perfect test, but probably good enough for now. You should also be able to find out if it's shorted or open. And, maybe you do have it in backward. I don't know.

Is there anything at all behind that brown phenolic card to which the diode is attached? Is there a switch anywhere? The red thing on the left is pretty obviously the coil I referred to earlier. I can't see well enough to see if there are magnets on the balance wheel. Would need tighter shots and more light.

It still might be an "ATO"-like movement. But those have a switch or a transistor (acting as a switch) generally. Indeed, I wonder what the diode is there for. The battery holder makes it unlikely anyone would install the battery with the wrong polarity, so using the diode to protect the circuit from a mis-installed battery seems like overkill. Diodes also are used for arc suppression, but that would imply there must be a switch somewhere, and I can't see it (yet).

Is it possible that the diode is a later, home-brew addition by a previous owner?

What about my other questions, about the off-center nature of the regulator screw and the words on the label in the battery holder?

Best regards!

Tim
 

captainclock

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Howdy Tim, As far as I know there isn't anything behind the phenolic plate that the diode is attached to, its just got the 3 terminal studs attached to it and that's it, and there isn't any switch on the movement anywhere that I could see of, as for the coil you talked about, it isn't open as it measures around 1218 Ohms, as for the diode it is bad as it does measure open in both directions with the diode check on my Digital Multimeter.

Here's some better shots of the movement, yes there are magnets on the balance wheel and there are also little brass counterweights on the opposite side of the balance wheel of the magnets, the movement the way it is built looks almost like a shaded pole motor.

As for the Phenolic Board there is nothing on the back as can be seen in the picture below and the diode is for sure the only electronic component in this clock, and there is no switches either, its just a simple electromechanical movement with a diode in it (which the diode that is in there was an AA116 Diode which is a signal diode and was definitely a germanium diode).

See pictures below.

Backside of Phenolic Board.jpg Front Side of the Phenolic Board.jpg Urgos Clock Movement Balance Wheel Assembly.jpg


I hope this helps.

Thanks

-Levi
 
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Tim Orr

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Good evening, Levi!

OK, now I can see things a lot better. I no longer think this is a modern ATO-style movement. I think we just have a simple electromagnet pulling on the little magnets on the balance wheel. But, there has to be some kind of switch somewhere. Usually, the switch is actuated by the turning of the balance wheel, and might be above or below the balance wheel. It's mechanically actuated, and open until a cam of some sort closes it. It has to be there, or this will never work.

I believe the diode is a red herring. I believe it has nothing to do with anything except arc suppression. I have seen a French version that uses a capacitor for that. If the diode is open, I would expect it should have no effect on operation except that you would have no arc suppression and that could burn up the switch contacts fast.

Forgetting the battery for a moment, if you gently flip the balance wheel (Try doing it with a little artists' paintbrush – that's pretty safe. You do want to be very gentle, because if you break off one of those pivots on the balance wheel shaft, you're done), does the brown "gear" (with the funny-looking teeth) behind the balance wheel assembly turn? This is the gear that advances the time mechanism. If it doesn't move, it'll never work. There's usually a very short arm or cam on the balance wheel shaft that actuates the little brown gear. I seem to see a collar of some sort on the balance wheel shaft there. Does it have a cam or arm or something that would move that brown gear?

Timing on these is critical. The switch, wherever it is, has to close, applying power to the red coil and generating a magnetic field to pull on the little magnets, at exactly the right time. There's usually a way to adjust that timing.

You can use the meter to see if there's voltage across the coil – ever. If you flip the balance wheel, the voltage should go on and off as the wheel rocks.

So those are a few more things to check.

Best regards!

Tim
 

captainclock

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Good evening, Levi!

OK, now I can see things a lot better. I no longer think this is a modern ATO-style movement. I think we just have a simple electromagnet pulling on the little magnets on the balance wheel. But, there has to be some kind of switch somewhere. Usually, the switch is actuated by the turning of the balance wheel, and might be above or below the balance wheel. It's mechanically actuated, and open until a cam of some sort closes it. It has to be there, or this will never work.

I believe the diode is a red herring. I believe it has nothing to do with anything except arc suppression. I have seen a French version that uses a capacitor for that. If the diode is open, I would expect it should have no effect on operation except that you would have no arc suppression and that could burn up the switch contacts fast.

Forgetting the battery for a moment, if you gently flip the balance wheel (Try doing it with a little artists' paintbrush – that's pretty safe. You do want to be very gentle, because if you break off one of those pivots on the balance wheel shaft, you're done), does the brown "gear" (with the funny-looking teeth) behind the balance wheel assembly turn? This is the gear that advances the time mechanism. If it doesn't move, it'll never work. There's usually a very short arm or cam on the balance wheel shaft that actuates the little brown gear. I seem to see a collar of some sort on the balance wheel shaft there. Does it have a cam or arm or something that would move that brown gear?

Timing on these is critical. The switch, wherever it is, has to close, applying power to the red coil and generating a magnetic field to pull on the little magnets, at exactly the right time. There's usually a way to adjust that timing.

You can use the meter to see if there's voltage across the coil – ever. If you flip the balance wheel, the voltage should go on and off as the wheel rocks.

So those are a few more things to check.

Best regards!

Tim
There are a couple of switch looking contacts on the clock one of them is a hair-thin wire that is attached to the upper contact of the phenolic plate that the balance wheel hits up against (kind of like the pivot arm gear on a regular mechanical watch that goes back and forth when the balance wheel hits it) and then theres a little switch looking thing that sits ontop of that little gear you were talking about that the balance wheel is supposed to turn when it rotates to transfer the power from the balance wheel to the rest of the clock mechanism, and when I turn the balance wheel that little brown gear (I think its actually red) does not seem to want to turn, its acting almost as if maybe that gear might be stripped out because no matter how much I push the balance wheel the gear wont turn with the balance wheel.)

And yes this movement does work I just confirmed it because when I was spinning around the balance wheel the balance wheel was defaulting to one side or the other of the electromagnet coil when it would stop and when I removed the battery out of the clock the balance wheel jumped back to being "centered" in the middle of the electromagnet coil instead of being on one side or the other.

I have the two aforementioned switch contacts marked on the picture below.

Urgos Clock Movement Balance Wheel Assembly.jpg
 
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praezis

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The contact, a wire, is visible here:
p2.jpg

You should test the coil here:
p1.jpg

It will have several 100 ... 2000 Ohms if ok.
The diode is for contact protection against back EMF, the clock will run without diode, too. Tim already mentioned that.

Also test, if there is electrical link between contact and balance wheel when both touch.

Frank
 

captainclock

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The contact, a wire, is visible here:
View attachment 594973

You should test the coil here:
View attachment 594972

It will have several 100 ... 2000 Ohms if ok.
The diode is for contact protection against back EMF, the clock will run without diode, too. Tim already mentioned that.

Also test, if there is electrical link between contact and balance wheel when both touch.

Frank
I did mention in a previous post that the coil has 1218 ohms on it, and it didn't test open, so the coil is working, I did notice that the top contact was bent and wasn't making contact with the balance wheel, which I then bent it back so that it now makes contact with the balance wheel again but it still doesn't stay running, but I can confirm that the coil is working because when the balance wheel stops running from being push started by hand the balance wheel magnets will stop on either the left or right side of the coil depending on which side of the contact switch the balance wheel lands on, also the red gear that is supposed to rotate with the little spring under the balance wheel when that spring touches red gear wont turn properly, and it also wont turn the gear behind it that it is attached to which is supposed to trip the other contact switch for the movement (the switch contact that looks like a pawl lever, that would raise and lower in reference to the position of the teeth of the gear that the lever is riding ontop of).
 

Tim Orr

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Good evening, Levi!

Not sure what to say now. I just can't see things clearly enough. I suspect a total teardown is in order, with lots and lots of photos taken during the process. That the coil reads 1218 ohms doesn't actually mean it's "working," just that it's not open. That's a lot of resistance for a single dry cell. The current would only be about 1 ma. Doesn't seem like enough to do the job of powering the balance wheel and clock mechanism to me.

We don't know if the upper wire should contact the wheel or not. Do we? Might just be adding drag to the system.

I still suggest putting your voltmeter across the coil, then rotating the balance wheel back and forth with the battery installed. Use the points Frank suggests for your meter and put it on a low scale. If there's no voltage across the coil, that's one thing. If it goes on and off depending on the position of the balance wheel, that's another – and promising – indication. If there's voltage there all the time, that's indication that whatever switch there is, is not opening when it should.

That the red (brown) ratchet-like wheel doesn't turn is crucial. You must figure out why and fix that. Is it frozen? Can you move it with a toothpick or something? What moves it? We can't see in the photos what or how it would be moved. That collar on the balance wheel staff looks to be in the perfect position to carry a pin or blade to move the red (brown) wheel. Is there anything sticking out of that collar that could actuate that wheel? Is there a hole or slot where something might have once been but has since been broken off or fallen out?

It looks as though this clock doesn't have a seconds hand. True?

Best regards!

Tim
 

captainclock

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No, there is no second hand on this clock, I have about 10 electromechanical clocks in my collection and none of them have second hands.
As for that red gear, the balance wheel has a little spring metal bar mounted to the underside of it that kicks that red gear into movement, and that red gear does move when that little spring bar under the balance wheel touches it but only when the balance wheel starts slowing down, when it is going at full speed after it is being jump started by hand the gear doesn't move with the balance wheel.

As for those switch contacts I'm not sure what to say about those. This movement may very well be beyond repair at this point but I'm not sure. I do have an extra electromechanical movement laying around that I could install in here, it just wouldn't be original, unless I searched ebay for another movement like this to install in this clock.
 

Tim Orr

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Good evening, Levi!

The red gear must advance every single time the balance wheel swings. It it doesn't, there's something wrong. There are systems, using pendulums and devices called a Hipp Toggle, that swing multiple times before finally activating. But that's just pendulums, and what is tripped is a switch, not a gear.

Not sure what you mean by a "spring bar," since I can't see it, but the device needs to move the red gear when it passes it in one direction, but does not move it when it returns the other direction. Speed should not matter.

This is one of those deals where we really must understand what is supposed to happen before we can make it happen. It may be difficult to get this thing back to life, or even impossible. Finding another identical movement is likely to be a big challenge.

Best regards!

Tim
 

captainclock

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I figured it out and got it going, that little wire that went to the balance wheel that we referred to as one of the switch contacts was bent and so I straightened it out and so now its working as it should.

Should I get a new diode to put into that movement for arc supression or will it be fine without it?
 

Tim Orr

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Good afternoon, Levi!

Glad you had success! Arc suppression is generally a good thing. Without it, contacts can erode or weld. Another diode would be good. It certainly does not need to be a hard-to-find thing. Most garden-variety diodes would work. Someone else reading this can probably advise an appropriate value. I think most would advise something rated for at least 10x the operating voltage, or about 15 volts.

If you have demonstrated that it is working, you could shut it down until you have a diode.

Best regards!

Tim
 

captainclock

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i have some 1N4007 diodes which are rated for about 1000v would that be satifactory? Also I've noticed that this clock runs about 2 hours ahead within a half hour to an hour, and I've adjusted the speed adjustment and it doesn't seem to be helping much, although it does say on the clock that one division of the adjustment screw equals one minute a week, which seems pretty liberal for a speed adjustment on an electromechanical movement (most of the electromechanical movements I have have the adjustment increments marked at 5 seconds/day.)
 

Tim Orr

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Good afternoon, Levi!

I am not an electronics expert. 1N4007 sounds like it would be fine to me. Someone else might have a comment on it. Make sure you're wired across the coil.

If you're gaining 2 hours in a half-hour to hour, you have a serious mechanical problem somewhere. No rate-adjustment system is going to be able to correct that out. You might have something slipping in the works, or somehow, the little red gear may be advancing multiple teeth with each swing of the balance wheel. I have no idea what that advance mechanism actually looks like, so can't be helpful. It could even be the hour hand slipping on its cannon. Gonna have to make a deeper dive into the mechanics. Glad you got the thing to run!

Best regards!

Tim
 

captainclock

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I put the diode back in that I had in there previously, I just happened to retest it and it wasn't actually damaged, I was just measuring the rest of the circuitry with it which made it measure funky.
Anyways I think that diode was a current limiting device on this clock because someone on another forum I had asked about this clock in said that this diode was more than likely used to cut the 1.5 volts of the battery down to about .5-.7 volts so that the movement wouldn't run away speed wise, because as soon as I put that diode back into the clock the movement slowed down significantly to the point that it seems to be running more accurately now.
 

Tim Orr

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Good evening, Levi!

This is an interesting idea. Not exactly what most people would call a "current limiting" device. What's happening is that the diode's forward voltage drop effectively reduces the battery voltage to about 0.9 to 1.05 volts. That might "kick" the balance wheel less. Interestingly, though, in a mechanical escapement timepiece, decreasing the excursion of the balance wheel often speeds the rate up, by causing an advance to take place more often. We'll have to see, because, of course, we don't have a conventional escapement here.

Also, in order for this voltage reduction to take place, the diode would have to be forward-biased and in series with the coil. Is it? You should be able to tell with your meter, by lifting one leg of the diode off the coil and metering the voltage between the diode and the other end of the battery. And, in this configuration, the diode would not provide any arc suppression at all. I would guess that sooner or later, that could be a problem.

Good luck!

Best regards!

Tim
 

captainclock

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Good evening, Levi!

This is an interesting idea. Not exactly what most people would call a "current limiting" device. What's happening is that the diode's forward voltage drop effectively reduces the battery voltage to about 0.9 to 1.05 volts. That might "kick" the balance wheel less. Interestingly, though, in a mechanical escapement timepiece, decreasing the excursion of the balance wheel often speeds the rate up, by causing an advance to take place more often. We'll have to see, because, of course, we don't have a conventional escapement here.

Also, in order for this voltage reduction to take place, the diode would have to be forward-biased and in series with the coil. Is it? You should be able to tell with your meter, by lifting one leg of the diode off the coil and metering the voltage between the diode and the other end of the battery. And, in this configuration, the diode would not provide any arc suppression at all. I would guess that sooner or later, that could be a problem.

Good luck!

Best regards!

Tim
I believe it is in series with the coil because the diode is wired in on only one side of the coil, the other side is wired in with the (-) terminal of the battery compartment.

Also in the antique fan world a single diode is wired in series with one side of the power plug to help slow down an AC/DC Universal Motor Fan by taking the full AC Sine Wave and Cutting it in half so that the motor only sees half of the AC Sine Wave thus cutting the speed of the motor down, so in that sense the diode it is being used as a current limiting device, same as what's being accomplished in this clock's movement.

the only problem is that now the clock doesn't seem to want to stay running properly since I've put that diode back in, before I put that diode in the balance wheel was running so fast that the movement had gained almost 2 hours in about an hour's time, and now since I put the diode back in the clock is running slow enough to the point that the movement acts almost like it doesn't have enough speed to keep the clock running correctly (the red gear stops moving after about 10 minuites which then makes it so that the hands no longer advance forward anymore).

I've tried readjusting the balance wheel's setscrew on the bottom of the balance wheel I'll get it really close to working but then the movement stops all together some reason.
 

Tim Orr

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Good evening, Levi!

The situation is a bit different with AC, as in your fans. There, you're lopping off half of each cycle (rectifying). Because you're dealing with a sine wave, you're getting about 0.7x the voltage and getting a pulsating DC-like voltage (every other half-cycle). Again, though, most people would say you're limiting the voltage. Current-limiting is usually a job for resistors. Of course, where Ohm's Law is operating, limiting the voltage would limit the current too. But in a DC circuit, you can limit the current without limiting the voltage.

At about 0.9 to 1.05 volts, you have even less power (about a third less), and that may be part of why the clock keeps stopping. Could also be mechanical resistances from the red gear through to the hands. And, of course, you no longer have any arc suppression.

If you had a DC supply for your fans, you'd be back to the 0.6x to 0.7x voltage with the diode, but it would be non-pulsating DC running the fan, and yes, that would still slow it down.

Long ago, you could buy in hardware stores a thing about the size of a quarter that you dropped into a light socket before screwing in the bulb. It contained a simple diode, which ended up in series with the lamp filament, and effectively dropped the voltage by about 30 percent and converted it to pulsating DC. Since incandescent lamps last much longer when underpowered, they lasted practically forever. It was sold as a way to economize on light bulbs and power. I haven't seen any of those in years. Made the lamps more warm in color too.

There are some who say that AC is harder on lamp filaments because it's pulsing.

I knew a fellow in school who built a radio with a full-wave filtered DC supply to run the tube filaments. He claimed the tubes would last forever and that it greatly reduced hum in the output. Never heard a demonstration, but he was convinced it would work.

Best regards!

Tim
 
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captainclock

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Good evening, Levi!

The situation is a bit different with AC, as in your fans. There, you're lopping off half of each cycle (rectifying). Because you're dealing with a sine wave, you're getting about 0.7x the voltage and getting a pulsating DC-like voltage (every other half-cycle). Again, though, most people would say you're limiting the voltage. Current-limiting is usually a job for resistors. Of course, where Ohm's Law is operating, limiting the voltage would limit the current too. But in a DC circuit, you can limit the current without limiting the voltage.

At about 0.9 to 1.05 volts, you have even less power (about a third less), and that may be part of why the clock keeps stopping. Could also be mechanical resistances from the red gear through to the hands. And, of course, you no longer have any arc suppression.

If you had a DC supply for your fans, you'd be back to the 0.6x to 0.7x voltage with the diode, but it would be non-pulsating DC running the fan, and yes, that would still slow it down.

Long ago, you could buy in hardware stores a thing about the size of a quarter that you dropped into a light socket before screwing in the bulb. It contained a simple diode, which ended up in series with the lamp filament, and effectively dropped the voltage by about 30 percent and converted it to pulsating DC. Since incandescent lamps last much longer when underpowered, they lasted practically forever. It was sold as a way to economize on light bulbs and power. I haven't seen any of those in years. Made the lamps more warm in color too.

There are some who say that AC is harder on lamp filaments because it's pulsing.

I knew a fellow in school who built a radio with a full-wave filtered DC supply to run the tube filaments. He claimed the tubes would last forever and that it greatly reduced hum in the output. Never heard a demonstration, but he was convinced it would work.

Best regards!

Tim
Well that diode was in that clock from the factory as when I had gotten the clock the solder around the diode looked factory (it was tarnished looking), so I don't think it was a later addition to the clock mechanism.
plus the original Diode that was in there was an AA116 Germanium Diode and the one that's in there now is a NOS 1N34A Germanium Diode which from my understanding is a direct substitute or at least a close direct substitute to the AA116 Germanium diode which according to what I've been able to find out the AAxxx designation for Germanium diodes is unique to German Germanium Diodes wheras American made ones used the 1Nxxx designator.

I just think that maybe I just don't have the balance wheel setscrew adjusted correctly because the balance wheel keeps losing contact with the red gear and I think its because the Balance Wheel Height adjustment still isn't right which I need to get that adjustment correct in order for the balance wheel to keep in contact with the red gear.
 

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