American Clock Company Chicago 1889

[TQ60]

We picked this clock up years ago and forgot about it.

Found while looking for something else.

Electric by maybe a couple 1.5 volt ign batteries.

Mercury pendulum with a built in level.

Seems well made but very dirty so some cleanup is needed.

The Pendulum suspension is missing th e coupling between rod and suspension, but good thing is previous owner attached with wire.

it seems to work but will need cleaning.

Serial number D7994
Patent date Nov. 21,1899

Anyone have one of these or some history on them?

 

[Tim Orr]

Good afternoon!

I have one someplace that is similar to yours, but has a conventional pendulum (not mercury) and no level. Mine has no bezel or glass, and looks as though it never had either.

I have heard that these were "premiums" awarded to newspaper carriers, but perhaps someone else can verify.

Best regards!

Tim Orr

 

[TQ60]

Today we cleaned it up.

It was dusty but otherwise not bad.

Used a 5 volt wall wart and the winding is great.

The level is needed as it is very picky.
The escapement was not working well, but simple adjustment there.

The suspension is the last puzzle, we just used some wire for now but it seems that there should be more due to the amount of holes.

May need to do more searching, maybe a patent search.

On the bottom of the ornamental feet are adjustable insert feet.

One is loose so repairs needed, will do that when we do the casework.

During first testing it would only run for a short time, seems to be doing well now.

This also is a clever layout.

The back is nailed in place, but the movement attaches to the dial and is smaller diameter.

The dial attaches to front via screw plates attached to from.

One can open the top, remove pendulum then remove clock like a Service module for service or replacement without needing access to back.

 

[Tim Orr]

Good evening!

Not sure I'd run this for long on a 5v wall wart. Unregulated, those warts can easily deliver 6v or more. Could accelerate the frying of the switch contacts.

Chances are, no more than 3v was used originally, and being dry cells, probably pretty much right on the nose 3v. I'd bet that once it's cleaned and serviced, 3v will be just fine. There's another thread here about "American" clocks, a reprise of a very very old thread.

You had said in your original posting that it has a mercury pendulum. Does it really?

Best regards!

Tim Orr

 

[TQ60]

The pendulum has a liquid inside and is very heavy for the size.

The wall wart was just for testing and not long term.

It is a switching type so 5 volts out.

Coil worked very well, the "running voltage" during the time of load may be less depending on the load of the coils.

Original was pair of 1.5 volt batteries so about 3 volts.

We have some flat pack Lithium batteries removed from communications radios, 3400 MHr.

They should be close to 3 volts, 3.4 or so maybe.

Pondering either using larger capacity battery or possible use of super-cap as some have suggested.

One thought to limit current is to combine a larger capacity battery for longer run time with a super-cap isolated by a resistor to limit the current to that stored in the capacitor.

One thought was to add a relay or transistor switch to isolate the current from the switch, but then it would not be "original".

A relay can be added later if it fails, that can be for someone down the road.

For now goal is to get it running properly.

 

[Ingulphus]

These clocks were made with agate pallets and mercury filled pendulums. They require 3 volts DC but need a higher amperage to reset the weight that powers the movement; more than regular batteries. When I had one, I used air alkaline batteries that look like dry cells and fit inside the case. I bought mine from McMaster-Carr the price has increased since then, but they lasted me quite a while, and are closer to the original
cells.

As I remember, there was a thin suspension spring that connected the time regulator to the pendulum rod, but it's been about ten years since I had the clock (and regret selling it), so I may be wrong.
.

 

[TQ60]

The brain ever stops...

The thought of protecting the coil switch had been bouncing in there for some time, then this morning the light went off.

This has NOT been tested, just sketched it now.

It is based on VERY OLD automotive stereo external audio power boosters that used the current drain of the radio to turn on the Amp.

Really simple, a diode is added to the path, current through diode turns on transistor that activates a relay.

How to protect the switch WITHOUT modification?

This is all external to the original connections.

We need minimal current during "turn on", and if possible, zero current for "turn off".

We start with the diode and transistor, but add a resistor to limit the current.

This PREVENTS the coils from working, but does allow very small current through the switch to be seen by the transistor.

The transistor is not likely able to drive the relay, but we need to do something else here so we add another transistor.

First transistor senses the current from the coil and turns on the second transistor.

Second transistor turns on a relay.

This relay provides battery power to the clock, bypassing the transistor.

This turns off the relay providing the full current.

A "hold" capacitor is added to the second transistor so the relay will stay on for long enough to "fire" the coils.

The trick is to have the size such that it only is on for the time it takes to fire the coils to toss the weight up and not hold them.

We think the hold time should be very short, the goal is to have the relay release before the switch opens.

If we can time it well there will be very little current through the switch

We could add a diode connected to the coils, there is a screw on the switchso easy to restore.

This diode can go back to battery to capture some of the ringing from the coil field collapse.

First photo is without diode for capture, second is edited one with diode, moved after "DUH" moment, I wrong place...

This is all external to the clock, except for the diode.

Not sure if it will work, looks good on paper though.

 

[TQ60]

Here is the battery, 2 cells in series for 7.5 volts, will remove and do parallel, 3.4 amp hr each so should be good for 6 Amp or more parallel.

 

[Jmeechie]

Hi,
These clocks as previously stated, we’re powered by 3 volts DC and honestly require a low milliampere as they were powered by 2 number 6 batteries. I have several of these clocks and the biggest issues are the unique pendulum/suspension assembly and the fact that the weight arms are not synchronous or side by side, but rather staggered so it only throws 1 weight arm at a time every roughly 12 minutes. I’ve attached a picture of a complete upper assembly. Yes, the bob were either mercury or solid and you should be able to tell if mercury filled by giving it a shake and you should feel it sloshing around. The spring is 0.003” thick.
I strongly recommend not connecting all that amperage to the clock as again 3 volts and only milliamperes is all needed to drive this clock. 2 D cell batteries in series will run one or these clocks for several years!
Cheers,
James

 

[TQ60]

Thanks for the thickness, the rest we can figure out from the photos.

If you could measure the length and width of the spring it would help.

Distance between the closest holes as well, that would save us from translating from photos.

Having more current available does not matter, the coils will draw what they will based on their resistance.

We are guessing maybe 60 ma, not much and this should not stress the switch.

inrush current may be higher, and there could be arcing during make and break that causes the damage.

There are a few posts stating that the weak point of these are the contacts fail.

The Lithium battery should be close enough to the pair of ignition batteries so the current should be very close.

The circuit works by only connecting the battery directly to the coils after the switch has made its connection and opening the circuit before the switch opens up.

This transfers the arcing to the relay, away from the internal switch, without modifying the clock.

We may not be able to find a relay that works on 3 volts, so maybe a transistor.

It is just something to play with for fun that may improve battery life while reducing strain on the clock, without modifying it.

 

[Jmeechie]

Here’s the spring spec
Thickness 0.004” (apologies for earlier error at 0.003”)
Total length 1.050”
Width 0.190
Centre to centre inner holes 0.625
Total length of pendulum assy 9” 1/4

The only issue is these coil packs were made with a resistor wired in across the coils to control arcing and American Clock Co was one of the few, personally, that got it right and controlled the arc. Wear and discoloration (tarnish/dirt) is the biggest issue with the contacts. I have to kindly disagree with over powering the coils, several issues will result as I’ve repaired and restored numerous Electro Mechanical clocks for 35+ years and seen people apply everything up to 110v ac! The coil cores will start to become heavily magnetized, stronger magnetic field will slam the weight arms causing excessive damage and wear to pivots, weights and gears, amperage consideration is more important vs voltage as the old #6 dry cells were only good for around 1.4 volts and minimal amperage and the arc was created by the coil field collapsing when the contacts open. Modern batteries, let alone lithium batteries are capable of dumping larger amounts of amperage and volts and I’ve found with these specific clocks they’ll run happily on 3 volts from 2 C or D cells in series for several years. These clocks suffer from miss adjusted stops and excessive power supply and being allowed to slam the weight arms against the stop constantly! Again, trying to rewind both arms at the same time is the usual problem people have with these clocks failing to rewind and needing more power! The arms must be staggered for correct running and rewinding.
Here’s a link of one of my clocks rewinding. Sorry for the out of beat.


Cheers,
James

 

[TQ60]

We assumed the weights needed to be offset, the switch in ours looks new.

Thanks for the measurements, we just need to get some material, timesavers has some 12 packs for $3.00, maybe order some, need to see what else we can fine in the catalog.

We have not checked resistance yet, have read posts stating 5 to 6 ohms maybe.

With 3 volts available the current should be around 1/2 Amp for the short period.

As long as the voltage is kept at the 3 volt range there should be minimal risk of overcurrent.

If it gets stuck it could be a problem i suppose.

Agree that higher voltage clearly can be an issue.

The ignition batteries can put out a lot of current, back in the day they were used for glow plugs and other high current loads.

Not to worried about overdriveing the coils, their resistance will limit the current they draw.

Did not notice a resistor in ours, something to check out next time we are tinkering.

 

[Jmeechie]

5 to 6 ohms is correct total for the pair measuring each coils then adding together. The resistor is tucked in between the 2 coils on one side.
I’ve seen lower and slightly higher with no ill effects on performance.
Cheers,
James

 

[TQ60]

We ordered the suspension material earlier in the week, only 3 bucks for 12.

To avoid the minimum order charge we stocked up on 400 day suspensions, have a few to tinker with.

Will be next weekend to continue.

 

[Ralph]

Good afternoon!

I have one someplace that is similar to yours, but has a conventional pendulum (not mercury) and no level. Mine has no bezel or glass, and looks as though it never had either.

I have heard that these were "premiums" awarded to newspaper carriers, but perhaps someone else can verify.

Best regards!

Tim Orr

Tim,

You may have sold me the clock you mentioned, at a regional in Denver a few years ago. The subject clock looks familiar. The one I got from you, is gone so I can’t verify it is the same model.

Ralph

 

[TQ60]

So we wanted to tinker, have not received the parts yet, but the electronics part does not need anything...

First rule, KISS, Keep it SIMPLE.

Second rule, use what we had.

Third rule, zero modifications to the clock.

First, using a relay would be bad, not easy to find one that operates on 3 volts, plus, it draws energy, so out with it.

We like the design of this clock, the whole thing can be easily removed while attached to the dial!

There are no resistors or other devices in the clock, just 2 coils.

the switch connects the coil return to clock case through a pivot, so current needs to be such to reduce and inrush.

We used our small bench supply for testing, only good for 500 mA, so perfect.

coils ohm out at 6 ohms total.

operating current measured at 3 VDC about 350 mA, less than .5 amps that it should be, so ammeter may be off a bit, old supply.

Next, we looked at our kit of parts, there was a bag of small transistors, foud one for testing, using clip leads to bypass the switch We can just fire the coils.

We used the ohmeter in diode test mode to turn on the transistor, not enough gain in the unit.

Dug through our estate sale stuff ND found some very old, new, Delco power transistors from very old car radio, germanium so will operate with less drive.

Used a 10k series resistance between the positive supply and creation to the clock, so when the switch closes the current is maybe 1 mA.

The transistor is PNP, so the emitter connects to the supply side of the resistor, and the collector connects to the clock side.

The base connects also to the clock side.

Current through the resistor as well as the EB junction turns on the transistor bypassing the resistor, allowing almost full current.

We then located and added a 50k pot in series with the creation to the base.

This allows us to adjust the gain resulting in adjusting the current.

We could adjust the voltage to 12 volts and current from zero to well above the 350 at 3 volts.

Our battery is just above 3 volts so this will allow us to control the current.

The biggest benefit of this is controlling the "make contact" event.

The 10k resistor limits the current to lesstgan 1 mA when it connects, almost impossible to arc.

AFTER the switch is closed, the coil load turns on the transistor, the current is still small so switch should be happy.

We tried adding a diode to capture the collapsing energy, not enough there to measure anything, since adding the diode would require modifying the clock, it will not be used.

The diagram is stupid simple.

Photo of the parts.

Will create some mounting arrangement on another day.

 

[Jmeechie]

Here’s pictures of one of my movements awaiting restoration showing the resistor tucked neatly under/between the coils on the lower side. I wouldn’t worry at all about controlling arcing at the switch with these clocks as they got it right. I did a rebound of all my running American Clock Co clocks and have 4 running happily for 2+ years with no arcing or fouling at the contacts.
As long as you’re suppling 3 - 3.4 volts around 300 mA you should be in great shape.
Ive experimented with resistors, diodes, capacitors and have found the least viable option is diodes (Zener or fast) as they tend to cause the coils to hesitate the immediate release required. Depending on the clock this causes issues with resetting the mechanism.
Cheers,
James

 

[TQ60]

Yours may be a later model than ours maybe?

 

[TQ60]

Here is photo of our coils, the wire looks to go coil to coil.

The power supply is a just for fun thing, the design was simplified as we worked with the unit.

Found a small wood box the put it in, working on layout now.

If the pulse for firing the coils is 1/2 second long, the charge should last 5 to 7 years.

 

[Jmeechie]

Interesting, I have a Pneumatic Clock Co clock which was the predecessor to American Clock Co and the movement as I recall does have the resistor. I will need to check the movement to double the presence of the resistor. Getty patented the movement and as I recall with the resistor in the coils.
I‘ll pull that and photograph the points the resistor ties into. Here’s a view of one of mine from the same perspective.
Cheers,
James

 

[TQ60]

We never looked at the other side, there could be one on opposite side, it just looks the wires are all on one side.

With your unit with the resistor, is in in series with or parallel to the coils?

Received our parts today so will work on pendulum this weekend.

 

[Jmeechie]

Interesting, I have a Pneumatic Clock Co clock which was the predecessor to American Clock Co and the movement as I recall does have the resistor. I will need to check the movement to double the presence of the resistor. Getty patented the movement and as I recall with the resistor.
i looked at several of my clocks and they all have resistors. If memory serves there 150 ohms resistors wired in parallel. On the opposite side where the power wires connect (red insulation) they brought a loop out of the end cap to solder the resistor in. I hope my drawing makes sense.
Cheers,
James

 

[TQ60]

The drawing looks like the resistor is between the midpoint to end, parallel to the right coil.

I can see the resistor sinking the collapsing magnetic energy as diodes in solid state or vacuum tube were not invented yet.

We had not looked real close to the other side of the coils when we were tinkering with it, focusing on cleaning general dirt and with the wires on One side just did not look at the other.

150 ohms parallel to 3 ohms would not change the load much.

It is interesting how sharp folks were back in the day.

 

[TQ60]

Today we repaired the pendulum, used a staking tool we picked up years ago to punch the holes.

Coukd not find a suitable wire, used brass that was a bit small, same as punched hole but smaller than rod.

Then soldered it and cleaned it up.

Fit together well.

The clock is very picky, the beat is critical as is lever and anchor.

We finally got it going, it still needs the anchor to pendulum strap straightened out a bit, that will be later.

Been running all afternoon so good.

Removed the 4 feet so we could epoxy the adjustable feet inserts back in, we now know that the posts are secured with screws under the feet, need to tear down the case for re-gluing.

 

[TQ60]

We looked at the back side of the coils and there is something there.

Likely a resistor, there looks like some wires coming out of the ends of the coils, not sure how the made resistors in or around 1900, it could be a chunk of carbon rod maybe.

With the wires going into the ends of the coils their connection point could be anywhere.

I would guess it is at the active ends, just connected internally, I do not wish to know enough to look inside, it works so it is good.

 

[TQ60]

We finished the power supply/battery unit this morning.

Using the what we had rule, we did not want to order a project box, also did not want to order a socket for the TO3 transistor so mounting to metal would be a problem.

We found a nice wood box, tight fit but was able to get everything mounted.

The fuse holder was just a bit log, modified to fit.

There is a current loop to allow ammeter to be used to measure current.

The pot was a locking type, bonus points.

It was a tight fit, not our best wiring job, but it will get the job done, and all parts were "in stock"...

We first adjusted the current with the output shorted at 350 mA.

Then attached the positive to the positive connection then touched the ground to the coil connection, pulled but not optimum.

We set to volts while still connected to coil and adjusted to 3 VDC, current right at 0.5 amps, 500 mA, solid pull.

We lowered the adjustment to 450 mA, about 2.8 volts.

While we had the movement out we removed the anchor and straightened out the bridge (connects to pendulum) , and carefully set the beat using the center shaft as a guide.

Put back together, the pendulumswing is more than it was before and in beat.

We will see how it keeps time.

Need to make the wires better, just temporary for now.

Fits nice inside.

The pulse is very short, but using 1/5 second dwell time, the battery should last 6 to 7 years on a charge, battery is 2 3400 mA units in parallel, 3.7 volts.

We added a power plug, coax one from something, added a 1K resistor to the current loop connection so we can check charge current.

A 12 VDC wall wart charges at 10 mA, so it can be plugged in to charge, trickle charge rate so Lithium should be safe.