Smiths Clock

[mickjj]

Can someone tell me how to determine wether a clock is pos or neg earth. There is one in my car that was not wired up. also there is only one terminal on the back so I presume it justs grounds through the securing braket.

 

[64beam]

Can someone tell me how to determine wether a clock is pos or neg earth. There is one in my car that was not wired up. also there is only one terminal on the back so I presume it justs grounds through the securing braket.

Hi Mick,

If there is nothing printed/stamped on the clock, you will have to use the part number on the clock face. Be aware that even the positive ground clocks, have the positive to the frame also. Some people have also fitted positive ground clocks to negative ground cars (as long as your dash is not metal you can get them to work).

Regards, Robin.

 

[Tom H]

My Smith's clock, which I disassembled years ago was polarity independent. It uses an electric coil pulse magnet to attract the swinging/ rotating "pendulum". and as the pendulum rotates it moves an electric contact which then breaks contact as the pendulum moves, thereby interruping the current to the coil. Thus the current energizes the coil intermittently, like pushing a child on a swing. It doesn't matter what polarity , as the magnet coil produces a magnetic field regadless of polarity. The clock stopped working because the contact got "dirty". I cleaned the contacts and the clock then ran for about a year, before it quit again. Now it right only twice a day.

I don't know if that's the kind of clock you have.

Tom

 

[mickjj]

OK so I have checked the part number and it is CE2194/09 which means it is a seriesI/II clock. Now two questions:-
1) How do I bench test the clock

2) how is it wired in the dash, as I said there is only one terminal which I presume is for power so how do I ground it?

 

[puff4]

Bench test it with a simple 12v power supply.. any source will do as it requires almost no amperage. As for the ground, like most instruments the clock is grounded via the case... in situ the ground wire goes under the knurled bracket screw. When power is supplied to the unit you should hear a click, which is the spring being wound via the servo... after that you should hear the clock begin ticking, and this will continue until it runs down enough to re-energize the servo to rewind the spring again with another 'click'.

As noted earlier, what usually goes duff on these clocks is that the contacts get fouled, and the spring does not rewind.

On edit:

Here's the original manual for the Smiths Electric Clock:

http://volvo1800pictures.com/document/Smiths-Clock.pdf

And the of there's a good description of the gubbings of the clock here: http://www.jag-lovers.org/xk-lovers/library/clock_repairs.html :

The problem, as I recall it goes something like this... The stationary contact for the clock solenoid is made of a springy material which is not a good conductor, and to make it work as a contact, it was plated (I think with silver). The moving contact on the balance wheel doesn't just hit it, but "wipes" the stationary contact, ensuring that it stays clean. This works fine for a few years, until the wiping action rubs the plating off, and then no amount of cleaning will keep the clock working reliably. It would seem simple to add a transistor circuit to amplify the current and take the load off of the contact. This does work, but not always totally reliably, I think because the contact with it's plating worn off makes a very unreliable connection. There is however another small complication... The operation of the clock depends not only on the regular opening and closing of the contact, but also on the "dwell time" (just like the ignition). When the clock is running normally, the dwell automatically adjusts to allow for small variations in friction in the clock movement. If the swing of the balance wheel starts to reduce, due to increased friction or decreased battery voltage, it swings slower and the dwell time increases, increasing the length of the current pulse through the coil, and restoring the amount of swing of the balance wheel. Any electronic wizardry added to the clock should have a similar amplitude feedback mechanism. I remember an article in a British electronics magazine in the 1970s (probably Practical Electonics of about 1972) which gave details of a transistorised "dwell extender" circuit for Smiths clocks. We built one for my mother's MkII, and the clock kept running, but after a few days, we noticed that the timekeeping was not very good (it was gaining even more than it usually lost!) and ticking was louder than previously. On closer (internal) inspection, we found that the balance wheel was hitting its end stops due to the dwell of the transistorised circuit being fixed and rather excessive. These days, it would not be too hard to design an electronic circuit based on a quartz crystal to give correctly timed pulses to make the clock keep perfect time. I am not quite sure how to provide the amplitude feedback to keep the swing of the balance wheel correct. I will solve this by the time my XK150 restoration is completed, but you might have to wait another year or two (or three). - best regards. Mike Plechaty

... and here as well: http://www.volvosolutions.com/1800inst_clk_Smiths_early.html

To find one of these clocks in working order is, to say the least, exceedingly rare. This is because they suffered from a design flaw that caused 99.99999% of them to die a very premature death. Inside the clock there's a pair of tiny and delicate electrical contacts that were almost 100% prone to burning because there was too much current going through them. These contacts typically failed within a couple years of the clock being put into use thus causing almost every one of these clocks to die an untimely and premature death. This is why you can never find one that actually works unless it's been worked on or has had the guts replaced by a quartz clock or something. The good news is that once this flaw is corrected and the problem points repaired, these beautiful and charming 4 jeweled brass reminders of a bygone era will run very reliably and for a long time because the actual workings of the clock are almost always in near new condition owing to the fact that the problematic contacts caused the clocks to malfunction and fail long before they suffered any mechanical wear.

 

[Tom H]

Kevin, The two excerpts you posted describe very well the Smith's clock I have. But it seems to me this does not match the description YOU wrote. In the clock that I and the articles describe there is no "spring being wound". The magnet coil pulses the swinging swinging pendulum about once per second. Yes there is a spring that returns the pendulum after each pulse, but that's not what I understand from your description. Your description seems to describe something that is a combination of a standard mechanical wind up clock with an electric motor rewind. That might be a later attempt to overcome the design flaw in the clock- where the contacts open and close once per second and therefore wear out quickly. Maybe your clock rewinds once a minute (??) so the contacts last longer, but still the contacts wear out.

Or did I misread your description?

And in either case, I think he could test with 12 v applied. And if it is from a SI or SII, it is not likely to have any transistors in it and should be polarity independent. And if it was for a SI or SII , that would mean it surely was designed for Pos earth (i.e. Neg applied to power terminal)


Tom

 

[mickjj]

OK so I did abench test and no luck. So a couple of more questions. On the back there is what looks like a fuseable link that is broken(see photo)is that an obvious answer to the problem?


My other question is how do you remove the body case and glass with the time adjusters on the front?

 

[Ken Ellis]

mickjj,
If you succeed in disassembly, would it be possible to do a hi-res scan of just the clock face? (If you weren't going to take the hands off, then never mind.) I have a non-car clock I'd like a correct-looking face for and I'm too lazy to create it from scratch...

Thanks,
Ken

 

[chard]

Take the clock to a watch/clock repairers they will fit a quartz movement and save you all the hassel

 

[Tom H]

Mick, It's been 20+ yeas since I tookk miine apart. But from the front this looks exactly like the non -operating clock I have and once fixed - for a half year. I dont recall having troubel disassembling it. My guess is that the bezel comes forward and the 2 adjusters stay right in place. Note that even the time reseting stem is skinny enough to fit through the shaft hole.

I can't tell what you are referring to as "fusible link' - photo too small.

I see 4 screws on the rear (looking at your photo, not my clock). Located at 1 O'clock, 5 O'clock , 7 O'Clock, and 11 O'clock positions . It looks like the one at 11 is a brown phenolic insulator with a screw in the middle. I think this is the power input ( + 12) . Right? Which of the screws seem to be simply screws holding the assembly to the case - no insulating washer.?

At 6 O'clock I see something- it looks like a metal tab stiking thru the rear of the case. Is that what it is? Or is it some device that you think looks like a fuse? I cannot make it out.

Regardless, as you will see in the replies by me and Puff4, your problem is 99.99% likely to be a bad contact in the pulse coil circuit. It is a design flaw . When you take it apart you will see the contact, a thin wire that contacts a skinny rod . I forget which part moves, the rod or the wire , but if you put some contact cleaner or maybe just clean with alchohol the contact area where the two parts touch. Then apply 12 V to the power terminal and you might see it run for a few minutes. But it will not run for more than 6 months tops unless you replate the contacts with "unobtainium" !!!!

Tom

 

[AlpineIan]

I wrote an article documenting all of the clocks by part number used on Sunbeam Alpines and the series they were used in. It's available on this site in issue #1 of the Alpine Marque. Look on page 37.

http://www.sunbeamalpine.org/alpine_marque/issue_1.pdf

 

[Alpine 1789]

Take the clock to a watch/clock repairers they will fit a quartz movement and save you all the hassel

This thread reminds me that I never posted about my experience with Michael Eck (www.jaguarclock.com). I didn't post this last year because I wanted to make sure the clock worked more than 6 months or so, and then I forgot all about it until I started reading this discussion.

I found Michael about a year and a half ago when I was surfing for info on repairing Smith's clocks. He specializes in Jaguar clocks, but Smiths is Smiths and I exchanged emails with him and a couple of other people who I also found with the same search. What I liked about Michael was the fact that he didn't actual alter the clock by putting in a quartz movement. There is quite a bit of information about what he does on his website. Tom H: this will probably make more sense to you than anyone, and may give you some ideas on how you could do this yourself. Also, here's what he wrote to me in one of our early emails:

It's not really a conversion. I don't remove or replace any of your original mechanism, so your valuable and rare clock remains intact. What I do is install a crystal-controlled computer chip that controls the original clock mechanism and forces it to keep accurate time. Your clock looks original because it IS original. You can even remove my circuit and restore your clock to its original configuration if you want. No one else in the world uses this technique. Other vendors rip out your clock's guts and hot-glue a dimestore clock mechanism inside, which usually is set with something besides your original time set stem. Some vendors will simply clean the clock, but that doesn't address the fact that these clocks never ran well when they were new. My technique overcomes the inherent problems with the clock design by using 21st century technology. If your clock originally ran on 12 volts it will still run on 12 volts, with either positive or negative ground.

I sent him my SV clock and $85 (it looks like he's raised his prices to $100 since then) last spring (March 1999) and got the clock back within a few weeks. It has worked almost flawlessly ever since. I say almost because I have found that if I cut the power to the clock it will sometimes not start right back up unless I jiggle it a bit. I imagine he would have taken care of this niggle if I had let him know about it earlier, but it never seemed worth the effort. I never bothered putting the mounting bracket back on (the clock is a tight fit in the wooden dashboard) and I just rotate it a bit to restart it if needed. Otehr than that, I am very happy to have a working clock and consider it money well spent. I will definitely send my S3 clock to him when I get closer to putting that car back together.

 

[Tom H]

Wow, Looks hard to beat. I read all the testimonials on his website.

So Jim, I think you owe us an apology for not reporting this sooner

Intersting to me that his solution does not seem to include any repair or mod to the contacts except likely som cleaning. One of phatt4's posts showed a similar fix, just using a transistor to amplify the current thru the contacts, thus reducing the required current level thru them. It looks like Mike's solution takes it a step further and adds quartz timing self adjust for more accuracy.

Interesting that simply reducing the current thru the contacts seems in both cases to solve the contact issue. I had suspected the contacts failed because the plating at the actual contact area wore off from the constant wiping action, metal on metal over 100 million times per year! In my previous repair of mine I simply cleaned and lubed the contacts and it worked - for about 6 months. I see from reading Mike's notes, and I believe him, that this simple cleaning is all that is needed to make it work, but reducing the current is needed to make the repair last.

There is one other point to consider. Most people do not know but a contact can also fail if the signal going thru it is too SMALL. See :
http://www.patentstorm.us/patents/4491797/description.html

This is not a problem here because the voltage is 12 volts , usually enough to overcome any oxide on the contacts, plus the wiping action of the contacts tends to self clean.

Which leads to me to my next point. I suspect these clocks will always have a tendency to need a jiggle to start. Without power, the pendulum stops. It stops with the contact closed, so whenpower is applied it should allow current to flow and start ticking. But while off, the contacts have oxidezed slightly, so the tiny contact area- picture the contact area or surface if you lay 2 needles across each other - is no longer truly in contact due to oxide layer. A slight jiggle starts the pendulum, gets the contacts wiping , and all is right in the world. It might be only teh movement of the car over normal road that might get it started again. Next time you remove power,it might be a good experiment to not grab teh clock and wiggle but simply drive the car and see if that is enough "jiggle"

Thanks for the great find.

Tom

 

[Alpine 1789]

So Jim, I think you owe us an apology for not reporting this sooner

I apologize. But, in my defense, I didn't want to post something right away, only to have my clock stop working after 6 months. But, I never intended to wait 18 months. It just slipped my rapidly deteriorating mind.

Next time you remove power,it might be a good experiment to not grab teh clock and wiggle but simply drive the car and see if that is enough "jiggle"

Will do. Given that I keep the clock running by having the battery cutoff switch bypassed with a 4 amp fuse that blows if do anything wrong (like turn the key to the start position with the lights on and the switch off), this is not a terribly infrequent occurrence. (see previous comment about "my rapidly deteriorating mind".) In fact, I recently bought 100 4 amp fuses on eBay for $10, because I was spending too much buying them four at a time at AutoZone.

 

[Rootes 66]

Jim
Next time you have cause to start the clock, just push in the hand adjust knob for a couple of seconds that opens the contacts and sets the balance wheel in motion.
Pete

 

[Alpine 1789]

Jim
Next time you have cause to start the clock, just push in the hand adjust knob for a couple of seconds that opens the contacts and sets the balance wheel in motion.
Pete

Is that any different than pushing in the knob and setting the time? I've certainly done that, and on the occasions when it was stuck (which, I forgot to mention earlier, is not every time it loses power) that did not help.

 

[Jimjordan2]

Does anyone recognize this clock? CE3130/00. I don't see it listed anywhere for Sunbeam. Says Feed Lead Negative.

 

[Jimjordan2]

Date Stamp

 

[alpine_64]

Wasnt used in series alpine or Tigers.

I have one of these too. I uses its guts and put the face of a correct clock that wasnt working in it...voila..working clock

 

[Warren]

Does anyone have a guy who can fix the clocks.
Jaguar clock guy doesn't respond to emails anymore boohoo