Holtzer Cabot Clock from Cali Show

[Doug Rose]

A few weeks ago pictures were posted of the Cali show and a beautiful Holtzer Cabot clock was on one of the tables. Being a Boston boy, I had to have this as HC phones were made in Boston and Chicago. This clock has Boston right on the face. I contacted Gary Goff who contacted the person who had the table, but the clock was his friends. Clear? To make a long story short,  I came home from work and found it on my porch (out of the snow we 'got!!!), packed perfectly and with great care.. Anyone have a clue on how to go about attacking this? Looks like a DC power, but its just a guess. Point me in the right direction. I want this to work,,,,,HELP!!!...thanks....Doug

[LarryInMichigan]

Doug,

I do not believe that that is a clock in the normal sense.  It was probably used to receive impulses from a time service and display the time.  Check out: http://williamkapp.fortunecity.com/id41.htm. and check out the NAWCC forum:  mb.nawcc.org.

Larry

[Jim Stettler]

I agree with larry. I think it is an impulse clock.
You might check with American Time and Signal.
www.atsclock.com   1-800-789-1882

They deal with all styles of correcting clocks, They are a helpful company.



Jim

[Doug Rose]

Jim and Larry....I will check your sites that you gave me, thank you. Do you feel that I will not be able to get this to work in a normal sense?....Doug

[LarryInMichigan]

Doug,

I do not know, but I think that posting a question to the NAWCC forum would be a good idea.  The people there might be very interested in your clock and may be able to tell you what to do.

Larry

[Adam]

It's a beautiful clock, I understand your desire to get it going!

If the thing only needs a specific electrical pulse on a regular basis, it should be relatively easy to create a computer program with a relay connected via a serial port which sends the pulses to the clock from the computer on whatever regular interval (minute?) the clock responds to.

Sounds like a fun project!  :-)

[Owain]

It's a beautiful clock, I understand your desire to get it going!

If the thing only needs a specific electrical pulse on a regular basis, it should be relatively easy to create a computer program with a relay connected via a serial port which sends the pulses to the clock from the computer on whatever regular interval (minute?) the clock responds to.

Sounds like a fun project!  :-)

There are enthusiasts who've created a master clock impulse generator; a 555 timer would give you a basic pulse circuit, but perhaps not with acceptable long term consistency.

[GG]

Nice one.  Especially compared to what passes for clocks nowadays. 

I'm with Owain on this: use a 555 timer.  Run the 555 at a relatively high speed that can be calibrated against a known frequency source such as a 1004-Hz test tone or a touchtone signal.  Use dividers to break down the signal to one impulse per minute.  And then use a micro relay or opto-isolated relay to operate directly off the resulting one per minute pulse, and in turn switch power to a larger relay that in turn switches power to the clock.   

More fun to build it in hardware than to make a computer do it. 

Another way to go about this is to find a quartz or AC powered clock with a second hand, and use the second hand to interrupt an opto-osilator or photocell + LED, to trigger a relay to drive the HC clock.  Only problem with this is, a similar mechanism is used as a bomb timer, so if you're going to do this, get it built and installed & working quickly rather than leaving it on your workbench where it might be mistaken for a Very Bad Thing : - ) 

In general, relay-driven clocks are best used where you have a bunch of them all driven by the master clock signal.  Though, one place you may not want one is in your bedroom since it will make a distinct "ker-chunk!" sound every minute, that could keep you (or your partner) awake. 

[Doug Rose]

It's a beautiful clock, I understand your desire to get it going!

If the thing only needs a specific electrical pulse on a regular basis, it should be relatively easy to create a computer program with a relay connected via a serial port which sends the pulses to the clock from the computer on whatever regular interval (minute?) the clock responds to.

Sounds like a fun project!  :-)

There are enthusiasts who've created a master clock impulse generator; a 555 timer would give you a basic pulse circuit, but perhaps not with acceptable long term consistency.

"555" Timer. Where would I get one and how would I connect it? Thanks...Doug

[Owain]

There are enthusiasts who've created a master clock impulse generator; a 555 timer would give you a basic pulse circuit, but perhaps not with acceptable long term consistency.

"555" Timer. Where would I get one and how would I connect it? Thanks...Doug

A 555 is the type number for an integrated circuit (IC) 555 chip at Radio Shack. You'd have to design and build a circuit from scratch.

I tried googling but my google-magic wasn't working last night. This has already been done - there are electric clock enthusiasts who have designed and built these circuits already for the purpose of driving slave clocks.

BMumford is a manufacturer of such a device, but currently unavailable. Don't know if they'd release the circuit. Here is useful info on electromechanical clock circuits and operation.

[Wallphone]

Doug, I found this site a few weeks ago while looking for something else and I thought that you and others might find it to be interesting. > http://www.youtube.com/watch?v=VoItGdTjV04 < Check out some of the other videos from Xenon53827 and others to get a better idea of how your clock works.
Here is just about everything you need to know about 555 Timers. > http://bit.ly/hg4cSk <
Doug Pav

[Doug Rose]

thanks Doug....this is going to be much more than I thought it was going to be. I appreciate it....thanks....other Doug

[Bill]

The people at NAWCC are very good. I have queried them on a couple different clocks, and they have responded in great detail, even though I am not a member.

I think they will call this a "slave clock" - same as an impulse clock. Tons of them were used in schools and factories at one time - I remember them in the eleementary school I attended. A single high-accuracy master clock was located in the head office of the facility. It generated pulses at a given interval (they differed), which were distributed over a pair of wires to all of the slave clocks. Since they had no timekeeping mechanism, the slave clocks were very cheap to make, and many of them could be installed.

Thirty years ago, I salvaged a half dozen IBM slave clocks from an old New England textile mill that was being refurbed. They were in beautiful oak cases. I sold 3, still have 3. I found a matching master clock in an antique mall once, but the price was well over $1000. Though I coveted it, that price was well out of my range.

Assuming that yours is a slave clock, you can buy an crystal-controlled impulser online for not too much money. Some impulsers require a wall-wart for power - some hold batteries, so you don't have an ugly cord hanging down.  Being an electroniker, I built a few crystal-controlled impulsers for my IBMs, but 20 years ago, the circuitry was pretty complex, and I eventually discarded them. I don't think you will be satisfied with the accuracy of a 555-based timer, and it requires a lot of circuitry as well.

Bill

[Adam]

Since they had no timekeeping mechanism, the slave clocks were very cheap to make, and many of them could be installed.

Those qualities about the slave clocks are true, but I think the overriding reason these were installed is because they were installed in places where a standardized institutional time was imperative, for example, in a large school where all the classes have to start and stop at exactly the same time, and in factories where work shifts must all start and stop at the same time.

You said:

A single high-accuracy master clock was located in the head office

The master clock could be high-accuracy, but that wasn't its main quality in these systems.  It was more important for all the clocks in the system to have the same time, as opposed to them having exactly the correct time.

[Doug Rose]

The people at NAWCC are very good. I have queried them on a couple different clocks, and they have responded in great detail, even though I am not a member.

I think they will call this a "slave clock" - same as an impulse clock. Tons of them were used in schools and factories at one time - I remember them in the eleementary school I attended. A single high-accuracy master clock was located in the head office of the facility. It generated pulses at a given interval (they differed), which were distributed over a pair of wires to all of the slave clocks. Since they had no timekeeping mechanism, the slave clocks were very cheap to make, and many of them could be installed.

Thirty years ago, I salvaged a half dozen IBM slave clocks from an old New England textile mill that was being refurbed. They were in beautiful oak cases. I sold 3, still have 3. I found a matching master clock in an antique mall once, but the price was well over $1000. Though I coveted it, that price was well out of my range.

Assuming that yours is a slave clock, you can buy an crystal-controlled impulser online for not too much money. Some impulsers require a wall-wart for power - some hold batteries, so you don't have an ugly cord hanging down.  Being an electroniker, I built a few crystal-controlled impulsers for my IBMs, but 20 years ago, the circuitry was pretty complex, and I eventually discarded them. I don't think you will be satisfied with the accuracy of a 555-based timer, and it requires a lot of circuitry as well.

Bill

Bill...I think I flumaxed them as well. Gary Goff has a big slave clock collection and said he might know someone who can build an inexpensive Master Clock. ....Doug