ATO 1962 Junghans ATO Electronic Clock

[eskmill]

Most available ATO "electronic" battery clocks were made by KUNDO under the ATO license. Obviously Junghans made some too as a licensee of ATO.

They're at least two different versions of the electronics used in the ATO patent electronic switching clock pendulum circuit. The most commonly encountered has two windings in the brass covered solenoid along with a germanium transistor and either a capacitor or resistor.
Bryan Mumford has a schematic of the single transistor circuit available on his web site.
ATO Schematic
Additionally, some later models employ a solenoid with only a drive coil. A small printed circuit board with a two transistor circuit is external to the solenoid. I understand that the two transistor circuit is an "L-C" oscillator circuit with the solenoid winding used as the inductor. I don't have reference to the circuit diagram.

Les

 

[dennishoy]

Les,

This was an old post and therefore a late reply.....

Thank you for posting the schematic. I have just acquired a Junghans Anticlimatic clock with this arrangement, but it does not work.

Best wishes,
Dennis in Uk.

 

[dennishoy]

Good morning everybody.

Further to my previous post, I have performed some fault finding on this clock.
I disconnected the coil (red, blue, green terminals) in order to check the windings.
I have measured 2400 Ohms across one winding (blue-green terminals).
The other winding (red-blue terminals) is open circuit.
I've removed the outer layers of insulating tape and the dreaded green gunge syndrome is present on the outer layer of the winding.

The red wire is connected to the most easily accessible point i.e. the 'start' of the outer copper winding.
I have checked to see if the break was (hopefully) where the red wire connects to the copper winding, but this was not the case.

Has anyone managed to successfully rewind one of these coils by hand, please? The wire seems very fine.
What is the resistance supposed to be (red-blue terminals) ?
What is the thickness of the wire, please (SWG or AWG) ?

I was thinking of making a simple winding machine then unwinding the outer layer onto another bobbin whilst counting the turns that come off.
I'm unhappy about tackling the job because the wire is very thin.

Any thoughts or pointers would be much appreciated.

Thanks.
Dennis.

 

[eskmill]

Dennis and all. Apparently you have mis-identified a KundO transistor switched pendulum battery clock which in function appears to be nearly alike the Junghans ATO battery clock which is dry contact switched.

Dennis is replying to a thread that I replied to fully over nine years ago. The reply I made nine years ago is incorrect and wrongly assumes that Junghans produced transistor switched pendulum battery clocks; an incorrect assumption. As far as I know, Junghans never produced for sale transistor switched pendulum battery clock.

The Junghans-ATO pendulum battery clocks produced by Junghans are all dry contact switched.

The issue is confusing because ATO did license their transistor switched clock mechanism to many balance wheel battery clock makers, but, to my present knowledge, no pendulum battery clock makers.

It is commendable that you propose to rewind the two-winding sense-drive coil used in a KundO battery pendulum clock.

Few if any repairers have been successful at rewinding the fine tapped winding. Even the simple task of accessing the fine wire coil from its pressed-together brass case usually destroys the brass covering.

I personally wish I had not posted to the subject nine years ago. My information was wrong but at that time I was misinformed.

 

[dennishoy]

Good morning Les and all,
(A glorious day here in the UK - the first for several weeks).

Les, sorry, I have to disagree with your last post and suggest you were correct in your first post all those years ago.
I'm certain this item is a transistorised clock by Junghans and not KundO.
It has the Junghans logo on the main frame, if made by KundO, surely it would be stamped as such or something to the effect of being made under license?
I have attached some pictures of the clock to this post including the Junghans logo.
Perhaps this clock was not exported to the US in any quantity, but found its way to the UK by returning soldiers in Germany at that time (Cold War)?

I'll post a bit about the coil structure in my next post.

Looking forward to your comments and thoughts......

Dennis.

 

[dennishoy]

Hello again, Les and all,

This clock is electronic and I attached a picture of the module. The module is located to the rear of the clock just above and to the left of the battery holder; not underneath as in KundO clocks. The transistor is a OC33 and is hiding behind the 0.1uF capacitor; you can just see the black, glass encapsulation to the bottom left of the capacitor.

The module has three connections - red, blue and green wires connecting to the coil in the left hand brass cover when viewed from the front of the clock.
The right hand brass cover is devoid of anything other than an aluminium ring to dampen the pendulum and prevent overswing.

The coil cover on this model is a simple bayonet fit like the old-style light bulbs in the Uk.
A simple twist in one direction releases the cover (unlike those damn KundO sealed units).

Under the brass cover is a layer of what appears to be metallic shielding tape and under that is a layer of tape and cord to keep the wire ends tight to the winding itself. I have removed a lot of green gunge presumably resulting from the tape disintegrating over the years. I think this is a by-product of early PVC breakdown and is acidic (and toxic !). This may simply have corroded the outer layers of the coil (hence the green gunge; copper = green), leading to a break. There was also some green gunge where the old PVC sleeving that covered the wires exiting the coil had been in contact with the main frame of the clock. I seem to recall PCBs and dioxins were used in the manufacturing process of old PVC and these materials are not pleasant.
Best to lose that old sleeving and replace it with modern safe stuff, perhaps?

This wire is very thin, but I think I can rewind it provided I can source the wire in a sensible (small) quantity.
Modern wire is much easier to work with and the insulation is better.
I will also need to make up a small hand coil winder as this task will be impossible (for me anyway!) to complete otherwise.

I intend to bring out an extra blue wire and keep the coils separate, joining them at the electronics module.
I think two thin copper wires soldered around one connecting wire in the middle of the bobbin is not a good idea and the coils should be connected externally.

This is going to take a while, but I'd like to post my progress as I go along.
Funny though it sounds, folk like Les give me confidence to complete the job, so THANKS.
It may be a total failure of course, but even that may help others.


Best wishes,
Dennis.

 

[dennishoy]

Les,

Here is a circuit (from your original post) for the later KundO clock with two transistors.

This circuit is not mine, it's from Rod Elliott's website.
The page is here.... http://sound.westhost.com/clocks/motors.html

D.

 

[eskmill]

Thank you Dennis for continuing this thread despite my error. You are obviously correct. Your photos reveal my lack of knowledge. I'm "eating crow" and embarrassed. Junghans did produce a transistor switched pendulum clock with the ATO logo....but I wonder if the ATO company actually licensed Junghans to produce the "Anti-Climatic" transistor switched pendulum clock.

The Junghans-ATO Anti-Climatic is a natural improvement and perfect progression from their older dry contact switched pendulum-battery clock. It is likely patterned after the ATO patent model. ATO is known to have produced a very few actual production models but these lack any reference to Junghans.

Given that your Anti-Climatic model's solenoid lends itself to being re-assembled, it is likely that with some "sleuthing" you might be able to replace the defective solenoid coil with one removed from a later model KundO solenoid 3-wire coil.

 

[dennishoy]

Les, this thread has woken up after several years so I'm pleased to be able to add my input. I don't think anyone should feel embarrassed and I'd like to think that we can provide a few answers to the queries that occur from time to time. I know for fact that KundO and Junghans both made clocks using a contact arrangement and later, also using a simple transistor circuit. The logos would be 100% proof of the manufacturer, especially in the 1960s. I think the German clock industries of that era can be compared with the UK car industry at that time. I'm not sure how much you know about UK cars, but there were very similar models from Austin and Morris, the only obvious differences being the radiator grilles and logos. so an '1100' of that era could be either Austin or Morris. I'm guessing the ATO idea was taken up but both KundO and Junghans firstly as an electrical contact concept, then turning to transistor technology when it became affordable to the masses. Did anyone make a valve clock, by the way?

There is also the 'cultural differences' between our two countries and whatever was fashionable at that time in one country may or may not have been taken up in the other. For example, you had a liking for large fridge-freezers in the USA long before they became affordable over here. Large cars over here have never become popular, so can we say the same about certain clocks? Who became lazy first when not wanting to wind up a clock every week - folk in the UK or the USA? This may have instigated a flurry of purchases once an advertisement appeared in the media claiming you would never have to wind your clock again. Both countries were involved in military action in (West) Germany to keep the sides apart during the Cold War. I know for fact that a lot of servicemen brought back items from Germany after their tour of duty ended. I live in Aldershot (sign on entering the town says 'Home of the British Army') and the house clearance auctions on a Wednesday evening have regular items from Germany including old valve radios (tuning scale stations in German) and clocks. The export ban on old East German goods would not have applied if the goods first entered old West Germany, then became in the possession of servicemen returning to the UK.

I understand these clocks may still be relatively common in Germany and it would be great if the Forum members from that country could add their comments.

Les, this is becoming an interesting thread for discussion..... but it took a while didn't it?

D.

 

[dennishoy]

An update.....

I investigated further and found that there were several breaks in the top layer(s) of the winding. It seems that the products resulting from the breakdown of the old PVC insulation corrode the copper and eventually the winding may become open circuit like this one. As I unwound the top layer(s), I kept finding short pieces of wire rather than one continuous length. Eventually, after removing 234 turns, I found the start of the 'good' section of the winding which was free from corrosion.

The copper wire forming the winding was very fine; I measured 0.002" which equates to a wire thickness of 47 SWG. Considering the amount of wire removed, the actual thickness was unimportant as it is the number of turns that affects the magnetic properties of a coil of this type. The resistance was unimportant as less than 10% of the winding had been removed. I could (probably) have simply 'made off' a new connection to the shortened coil, but decided that I would try and replace the missing turns by rewinding by-hand. I dismantled an old headphone coil which gave me a source of thin wire (and not worrying about the exact gauge).

The first problem I encountered was in removing the enamel insulation from the copper without breaking the wire. I found 'Nitromors' to be the easiest method. I'm not sure if you can buy this in the US.... Nitromors is a paint stripper and there is a version available in the UK which removes enamel such as radiator paint. Wet-and-dry paper snapped the wire and a (very) hot soldering iron on it's own did nothing. I lost a few more turns on the coil during this process. I eventually soldered a new length of wire to the broken end of the old coil and insulated it with a smear of enamel after wrapping a few new turns over the old winding. I eventually managed to replace the missing turns by careful winding by-hand. It was just on the limit of my ability and it was impossible to make the turns tight for fear of snapping the wire.

The end of the coil was 'made off' to the original connection wire, then tied-off to relieve any strain before replacing the original paper protection over the winding. Finally, the resistance of the coil was measured - now 2655 Ohm instead of infinity. The brass cover was fitted to the coil and the whole assembly refitted to the clock.

Once again, a 1.5 V battery was connected and the mechanism obseved...... nothing.... which was disappointing as these clocks are normally self starting with a good-gain transistor. A gentle swing of the pendulum did not improve things so the old OC33 transistor was replaced with a 'new old stock' AC125. I selected one with a gain of at least 130 (145 in this case as indicated by my meter).

The battery was again connected and this time the pendulum moved by itself... just a little at first, then more and more until the clock was running nicely after 30-40 seconds.
The clock has been running reliably for over a week, but is losing 5 minutes over 3 days. I've adjusted the pendulum weight 'up' by one turn so perhaps that will help. We'll see.
Rewinding or repairing these coils is not impossible but just about on the limit for me personally, especially as my concentration is not too great. It would be impossible for a ham-fisted type with little patience. I would recommend you to have a go at a repair rather than throwing away the clock for the sake of a coil.

I hope that helps.
Dennis.

 

[eskmill]

Dennis. Your restoration effort is commendable. I shudder at the thought of rewinding with such fine wire....we used to call it "hair-wire" and found it on the secondary of the Ford Model T automobile vibrating ignition coils.

I and other battery clock collectors are always looking for any of the pendulum battery clocks such as ATO and the Junghans ATO but seriously, I can say that it would be my first to find a Junghans ATO pendulum battery clock with transistor switching. All that I've observed for the past ten or more years have been dry contact switching types. Admittedly, I've seen one or two with the "Anti Climatic" name but these too had dry contacts. It is possible that the transistor switched were not exported to the US and the few were "brought over."

Again Dennis. Good work with steady hands and determination.

 

[dennishoy]

Les, you are probably correct about the type not being exported to the US (at least in any quantity).
Likewise in the UK, I have never seen several of the clocks shown in this section which are to be had for just a few $ in the US.
Similarly, a quick look through 'ebay.de' shows more collectible battery clocks from manufacturers such as Hettich on offer in Germany which I have nevver seem in the UK. I am of the opinion that certain mopdels were not exported to some countries in any number.

Back on topic.... the single transistor Junghans 'Anti-Climatic' type seems to have the plastic electronics box crudely fixed to the backplate of the clock. It looks as though this was the natural progression of the direct conntact type. It would have been easier to take an exisiting design and 'stick on' a small compartment to carry the electronics. You won't get two transistors in this design so that must have bene of different construction.

Dennis.

 

[dennishoy]

Now corrected for losing 2 minutes/day by winding the pendulum weight upwards by one-and-a-half turns.
This clock is an excellent timekeeper.

Dennis.

 

[Wynen]

Some facts about the history of the transistorized Kundo and Junghans-ATO clocks:

Junghans was the license holder for ATO clocks in Germany since about 1930. In 1953/1954 Hatot presented a transistorized version of the ATO pendulum clock. There was always an excellent corporation between Hatot in Paris (i.E. Marius Lavet and Jacques Dietsch) and Junghans in Schramberg (i.E. Günther Glaser) and Dr. Glaser did a lot of research before starting a “mass-“production of this type of clock. So it was up to Kundo (named Kieninger & Obergfell until 1956) to start selling the first transistorized Clock from mass-production in 1956. Junghans followed in 1957.

There was a long patent litigation between Kundo and Junghans, not because of the electrical part of the clock (the operating principle is somewhat different) but because of the mechanical parts (the pawl mechanism really looks identical). The action was dismissed in 1960, when Kundo agreed to pay license fees. In the same year the production of ATO clocks by Junghans was stopped but Kundo continued until the early 1970s.

The "anticlimatic" term concerns the research done by Junghans to compensate for temperature changes. Dr. Glaser was especially afraid of the temperature dependency of the used germanium transistors so I'm astonished of "anticlimatic" clocks with mechanical contacts. Please have a look at the German patent 1.208.699. Unfortunately, I didn't find a US or GB equivalent.

Best Regards from good old Germany
Hartmut

 

[dennishoy]

Hartmut, very many thanks for the interesting information. I have a couple of questions for you.
Am I right in assuming all the clocks for export to the UK/US were made in what used to be called West Germany and not the GDR? The UK had an import ban on items made in the GDR.
Were similar designs manufactured in the GDR under different makers names and exported to Russia, Hungary, Poland etc.?
I have seen clocks with the names Elfema, Geratewerke (Leipzig?) and Senug (Dresden?) whilst on holiday in Germany after the reunification. The quality looked very good.

Best wishes from Dennis in sunny and warm UK.

 

[jerry2222]

Hartmut, very many thanks for the interesting information. I have a couple of questions for you.
Am I right in assuming all the clocks for export to the UK/US were made in what used to be called West Germany and not the GDR? The UK had an import ban on items made in the GDR.
Were similar designs manufactured in the GDR under different makers names and exported to Russia, Hungary, Poland etc.?
I have seen clocks with the names Elfema, Geratewerke (Leipzig?) and Senug (Dresden?) whilst on holiday in Germany after the reunification. The quality looked very good.

Best wishes from Dennis in sunny and warm UK.

I found this transistor for Sale now on EBAY ...a electrical engineer has re created new circuit boards ..$50.00 usa

jerry5839@aol.com

 

[phred01]

I found this transistor for Sale now on EBAY ...a electrical engineer has re created new circuit boards ..$50.00 usa

jerry5839@aol.com

could u please give a link