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Timex Electronic from the junk pile


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This was sitting in my junk pile for some time. I was looking for a spare contact wire for one of my Timex Electrics, and I remembered that the Timex Electronic has a contact wire. But when I opened it up, it was a totally different beast inside.

The movement number on the dial plate is 882, which I checked up is a M87. The balance appeared fine. So I put a battery in to see if it would fire up. And it does!

After cleaning it up, it doesn't look half bad. And now I have to continue searching for a contact wire....

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Haha. If you look at the author of that post.... that was me.

The problem with the mainspring that I used was that it was magnetic. And when the drive magnet was fitted, the contact wire would deflect towards the magnet.

I'll need to find a non magnetic mainspring or hairspring.

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Do we know the dimensions and gauge of the original wire?

Given that it is relatively short, might nichrome heating wire of a suitable gauge do the trick?

Nichrome wire tends to be fairly springy, although it does have a higher resistance than copper or steel. The dimensions suggest this is probably not an issue in this case. It is also fairly hard wearing.

Depending on the type of wire you try, you may need to copper, or nickel plate the end of the wire you are soldering before you can solder it with off the shelf "electronics" multicore soft solder. Steel wire tends to fall in to the "nightmare to solder" category as it is difficult to wet particularly with lead free solder, but the solder will stick to copper very well.

I would use good old fashioned 60%/40% lead/tin solder rather than lead free as it is more likely to work, and also use a good quality flux. 

Nichrome wire is easily sourced in a variety of gauges from China via ebay or AliExpress, or from most electronics suppliers closer to home.

Edited by AndyHull
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I do have nichrome heating wire but it's too soft to be used for a spring. Probably it's the alloy composition. The commonly available 80:20 nickel chrome alloy is designed for heater coil winding, so it has to be ductile.

In dentistry, we do use nickel chrome alloys for constructing denture frameworks. Those are extremely hard and tend to be brittle. 

I think finding the right alloy would be the biggest problem. I'm currently thinking of using nickel titanium. This is an unique alloy that has memory effect, very springy but soldering it would be impossible.

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On 12/4/2020 at 11:25 PM, HectorLooi said:

soldering it would be impossible.

Try plating the end you want to solder with copper. Making  small quantity of copper acetate using white vinegar is pretty easy. You could also use copper sulphate. Solfering to copper should be easy.

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I have a Timex like this with the contact wire and if I had to replace it I would try a flattened section of hairspring from one of those clunky, open-mainspring type pin pallet alarm clocks popular years ago. The hairspring is usually plated in a gold colour so shouldn't degrade and should also solder. It will be springy and about the right size, and you wouldn't be destroying an historical item by taking one. Just a thought - good luck.

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Just an update on this watch. It worked fine on the bench but when I wear it, it stops. So I took everything apart, cleaned and oiled everything. Then it worked fine on the bench for 2 days. But when I wore it yesterday, it stopped 3 times. Each time it stopped, I noticed that I could still hear the balance ticking away. So it had to be the indexing system. 

When putting the movement together, I did notice that the indexing lever was not snapping crisply as it should. I studied the service manual and noticed that the indexing magnet was upside down. So I removed it and flipped it around. The indexing lever action improved, but it was still not as crisp as my other Timex Electric watches. I also noticed that the indexing magnet was so weak that it couldn't magnetize my screwdriver.

I suspect that the previous watch repairer must have demagnetized the movement. Now I have to bring home a powerful neodymium magnet and try to remagnetize the indexing magnet.

I remember reading recently that another member had a similar problem with his Timex. I wonder if he managed to fix it.

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3 hours ago, HectorLooi said:

Just an update on this watch. It worked fine on the bench but when I wear it, it stops. So I took everything apart, cleaned and oiled everything. Then it worked fine on the bench for 2 days. But when I wore it yesterday, it stopped 3 times. Each time it stopped, I noticed that I could still hear the balance ticking away. So it had to be the indexing system. 

When putting the movement together, I did notice that the indexing lever was not snapping crisply as it should. I studied the service manual and noticed that the indexing magnet was upside down. So I removed it and flipped it around. The indexing lever action improved, but it was still not as crisp as my other Timex Electric watches. I also noticed that the indexing magnet was so weak that it couldn't magnetize my screwdriver.

I suspect that the previous watch repairer must have demagnetized the movement. Now I have to bring home a powerful neodymium magnet and try to remagnetize the indexing magnet.

I remember reading recently that another member had a similar problem with his Timex. I wonder if he managed to fix it.

You sure it's just not the balance end float not adjusted right?........

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1 hour ago, JohnD said:

You sure it's just not the balance end float not adjusted right?........

Very sure. The balance was still running all this while. The indexing lever was just not turning the index wheel and hence the second hand doesn't move. I've been wearing it since morning and so far so good. ?

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3 hours ago, HectorLooi said:

Very sure. The balance was still running all this while. The indexing lever was just not turning the index wheel and hence the second hand doesn't move. I've been wearing it since morning and so far so good. ?

If you have the anti magnetic shield in place between the balance and the hair spring how can you see if the pallet fork is being operated by the peg on the balance? I would have thought that a combination of wear on the balance pallet drive peg and some end float on the balance could intermittently stop the, still oscillating,  balance from engaging with the pallet fork, due to differences of watch orientation when being worn, thus stopping the drive of the rest of the movement though the balance still oscillated?

 

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1 hour ago, JohnD said:

If you have the anti magnetic shield in place between the balance and the hair spring how can you see if the pallet fork is being operated by the peg on the balance? I would have thought that a combination of wear on the balance pallet drive peg and some end float on the balance could intermittently stop the, still oscillating,  balance from engaging with the pallet fork, due to differences of watch orientation when being worn, thus stopping the drive of the rest of the movement though the balance still oscillated?

 

But I must say that your hypothesis sounds so much more plausible and convincing than mine. ?

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12 minutes ago, HectorLooi said:

Nice collection. Do you have one with a M87 movement?

How do you deal with broken contact wires?

Sadly the only M87 movement I managed to get was badly packed by the seller and the ceramic circuit board arrived in two pieces... As for the contact wires I have been lucky enough to purchase some new old stock complete circuits from an eBay seller in Egypt and have not had to resort to replacing missing/damaged contact wires....Having extensively 'scratched the Timex Electric/Electronic itch' in the earlier part of this year I haven't had much to do with them recently, current itch being scratched is A/C mains powered synchronous clocks from the early 1930's to the late 1950's....?

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That sounds just like me. I just fixed a Smiths Morpeth electric clock last night.

I am also weaning off my Timex Electrics. Recently 2 of my favorite ones stopped working because the contact wires broke. 

I now looking for a Jefferson mystery clock but a 230V 50Hz version costs almost twice that of a 110V version.

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4 hours ago, HectorLooi said:

That sounds just like me. I just fixed a Smiths Morpeth electric clock last night.

I am also weaning off my Timex Electrics. Recently 2 of my favorite ones stopped working because the contact wires broke. 

I now looking for a Jefferson mystery clock but a 230V 50Hz version costs almost twice that of a 110V version.

Have you seen THESE? Not cheap but I think you can run more than one clock off of them.....

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2 hours ago, JohnD said:

Have you seen THESE? Not cheap but I think you can run more than one clock off of them.....

Interesting. I've never seen that before. I wonder if there is a 230V 50Hz conditioner to regulate the accuracy of the 50Hz. I noticed that all my AC clocks tend to run fast, even the digital ones that count the AC pulses.

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On 12/10/2020 at 11:38 AM, HectorLooi said:

Interesting. I've never seen that before. I wonder if there is a 230V 50Hz conditioner to regulate the accuracy of the 50Hz. I noticed that all my AC clocks tend to run fast, even the digital ones that count the AC pulses.

Quote

50-60Hz Frequency Convertor

How it works

The AC mains at 50Hz is transformed down to 24vAC via a plug in transformer commonly used in CCTV systems.
The Frequency Converter then reduces this to 9vAC and samples it to produce a lagging frequency at 60Hz. The 60Hz output goes through filtering to give as clean and accurate output as possible. The sampling and adjustment is done by a microcontroller and some fast switching transistors.
This is then transformed up from 9vAC to 115vAC at 60Hz to supply the USA clock.

Therefore the output and so the clock will accurately reflect the mains it is connected to.

There are other simpler and or better ways to do this, but this method will produce 60 Hz as accurately as the clock requires.

Quote

The GB mains frequency is nominally 50Hz. National Grid is obliged by its licence commitments to control the frequency within ±1% of 50Hz so it can fluctuate between 49.5Hz to 50.5Hz. However the normal operational limits are 49.8Hz to 50.2Hz.

A simple microcotroller solution could provide 60Hz with the accuracy of the microcontroller quartz crystal, which is typically parts per million or better, much more accurate than sampling the 50Hz.

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10 minutes ago, HectorLooi said:

How about those 12/24V DC to 110V pure sine wave inverters designed for transforming solar power banks to mains outputs. Are they of sufficient accuracy for power synchronous clocks?

That would depend on how pure the pure sine wave is. I have an inverter for the car that claims to produce 240 V at 50Hz "pure" sine wave, but it is actually very noisy. It works OK to power a laptop power supply, but I don't think it qualifies as "pure". You would need to see the spec. of the inverter.

You could produce a fairly clean 60Hz sine wave from a 555 timer IC and an LC tank circuit and get accuracy of 1% or so.
Couple this with a driver transistor and a transformer and you could in theory drive your clock from batteries. 

 

Edited by AndyHull
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1 hour ago, AndyHull said:

You could produce a fairly clean 60Hz sine wave from a 555 timer IC and an LC tank circuit and get accuracy of 1% or so.
Couple this with a driver transistor and a transformer and you could in theory drive your clock from batteries. 

 

Hmmm..... that's food for thought. 

I could buy a spoilt synchronous clock and recoil it to run at maybe 6 or 12V then power it from a 555.

I've also been toying with the idea of building my own pulsynetic master clock with the pendulum drive parts from a quartz pendulum clock and making slave clocks from modified quartz clocks.

I could have all the clocks in my house synchronized to the second. ?

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http://www.learningaboutelectronics.com/Articles/Sine-wave-generator-circuit-with-a-555-timer.php

Full details of a 555 sine wave generator.

image.png.caf6398fadb245ea68de500c8852eea3.png

You would need to experiment with the components to get your 50 or 60 Hz, and you would also need to drive a transformer to produce your 110V or whatever your clock requires (a mains transformer run backwards with a suitable transistor and limiting resistor might be all you need, but don't quote me on that).

Bear in mind that the output would be 110 or 240 V AC, and might give you a bit of a whack if you are not careful.

 

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