Standard ElectricTime CO Master Bell Clock? Question Please

[popeye]

I bought this today and figured it was the Standard Electric Time Co Master Clock. WHen I go there it looks smaller and bottom different. He said was a clock in the school that rang the bells.
Does anyone know the model of this clock, age, and history. I have yet to see this clock on the internet.

Some questions on getting this to run. I do have a 24V adapter. Wondering which wires connect to the adapter. On the top of the clock there are letters R & M-figure that might be the connections? I have pictures of the movement wires and the top connections. Advice and info would be appreciated.
Also, I never had this type of pendulum. I think one of the pictures shows that the pendulum is crooked and not straight. How can you make it straight? I see a small screw near the top bar, does that do it?

Lastly, the wood almost looks fake, it is too shiny with no texture. Any ideas if wood and if so what wood it could be?

Again, info and advice on wiring to get this to run would be appreciated.
Thanks as always!

 

[neighmond]

Pretty clock! Mercury pendulum and al!

It probably had a separate cabinet somewhere nearby with slave controls and the bell programmer.

It looks like birch or maybe gumwood on the case. That was a real popular wood in schools around here come 1930 or thereabouts.

 

[eskmill]

I suspect that the SET master clock in Popeye's photos is a model RA-2. It used 24 Volts DC to maintain the master clock movement but the control of slave clocks required both the 24 Volts DC to advance but hourly correction required both 24 Volts DC and about 42 Volts AC superimposed on the two wire slave clock circuit if I am correct.

This opposed to the RA-3 system that required three wires to each slave clock for hourly correction.

The wood case has some pieces that have the appearance of oak while some more straight grained wood pieces may be fruitwood.

SET is known to have supplied fake mercury pendulums as well as true Hg temperature compensated pendulums. The fakes are just plain nickel plated steel of the type used in Ford automobile rear axles. Only careful dimension and displacement measurements will reveal Hg or just plain nickel plated steel.

 

[popeye]

I suspect that the SET master clock in Popeye's photos is a model RA-2. It used 24 Volts DC to maintain the master clock movement but the control of slave clocks required both the 24 Volts DC to advance but hourly correction required both 24 Volts DC and about 42 Volts AC superimposed on the two wire slave clock circuit if I am correct.

This opposed to the RA-3 system that required three wires to each slave clock for hourly correction.

The wood case has some pieces that have the appearance of oak while some more straight grained wood pieces may be fruitwood.

SET is known to have supplied fake mercury pendulums as well as true Hg temperature compensated pendulums. The fakes are just plain nickel plated steel of the type used in Ford automobile rear axles. Only careful dimension and displacement measurements will reveal Hg or just plain nickel plated steel.

Thanks-Question-any possibility of showing the connection to adapter for just clock winding? I tried the r and m connection and no luck. I connected to the two screws on the bottom left and clicks up. Could you please direct?
Thanks.

 

[Ingulphus]

On my SETCO, the first connection on the top of the case (the one all the way to the left) is the common; one of the others will be for the minute winding cycle. You can use a continuity tester to figure out which it is. The switches at the bottom of the case don't connect to the movement.

 

[popeye]

Thanks are you talking about the one with "w" or "m" above it as the first?

 

[harold bain]

Popeye, you need two things. A set of contacts (switch) that makes contact once a minute for just a few seconds. Then using this switch, it needs to be wired up to the wind magnet in series, just like a simple light circuit. A continuity checker (ohmeter) is needed to find this switch. You have had plenty of electric master clocks, your knowledge of electric circuits should be increasing over the years. Blindly hooking up your power supply is more likely to get you onto a short circuit, destroying your power supply.

 

[eskmill]

Popeye and all. The Standard Electric Time Co. Master Clocks are built to order and now two are exactly alike. In the field, they've been serviced and rewired by both SET technicians and school personnel and few have their wiring diagrams.

In the clock at issue, there must have been another cabinet to contain the school/factory bell program tape mechanism and a separate DC and AC power supplies.

In the simplified diagram below, trace the DC source connects to the winding electromagnets via the oscillating contact on the verge arbor when it contacts the rotating contact on the escape wheel arbor. The DC source connects to the movement mounting casting then to the movement plates and the finger that rubs on the escape wheel arbor. The other half of the circuit is a common that connects to the common of the winding electromagnets. The shunt resistor quenches any arc from the electromagnets when the circuit opens. The oscillating and rotating contacts have precious metal contacts. Wipe or burnish these contacts but do not file or sandpaper the precious metal.

The oscillating and rotating contacts take care and patience to adjust but once set, it's the system the designer made the circuit. Would-be technicians have substituted the bell control contacts to energize the wind electromagnets but the timing and length of the impulse cannot be as precise as with the oscillating circuit.

 

[popeye]

Popeye and all. The Standard Electric Time Co. Master Clocks are built to order and now two are exactly alike. In the field, they've been serviced and rewired by both SET technicians and school personnel and few have their wiring diagrams.

In the clock at issue, there must have been another cabinet to contain the school/factory bell program tape mechanism and a separate DC and AC power supplies.

In the simplified diagram below, trace the DC source connects to the winding electromagnets via the oscillating contact on the verge arbor when it contacts the rotating contact on the escape wheel arbor. The DC source connects to the movement mounting casting then to the movement plates and the finger that rubs on the escape wheel arbor. The other half of the circuit is a common that connects to the common of the winding electromagnets. The shunt resistor quenches any arc from the electromagnets when the circuit opens. The oscillating and rotating contacts have precious metal contacts. Wipe or burnish these contacts but do not file or sandpaper the precious metal.

The oscillating and rotating contacts take care and patience to adjust but once set, it's the system the designer made the circuit. Would-be technicians have substituted the bell control contacts to energize the wind electromagnets but the timing and length of the impulse cannot be as precise as with the oscillating circuit.

Again, thanks. I was able to hook up the adapter with the top connections. Runs great.
Ekmill-thank you for your expertise. Nice to have support like this!
Much appreciated!

 

[John Sidlauskas]

For your inquiry for adding bells, this was probably of a larger install, since usually most bell circuit relays were installed with the clock, right above the movement on either side, I see that the wire that would have gone from the movement to the top of the case is missing, that most likely was the program machine, another guess is that since it was not there maybe it was disconnected. The program machine controls the bells, it's how they are programmed. My program machine runs with the rewind coils.