Goal: \$300, Received: \$225.00 (75%) Contribute Now
Donate whatever you can or Join the 14,000 other NAWCC members for only \$80 (plus \$10 for hard copy publications). Check it out here.

Notice: This is an old thread. The last post was 4037 days ago. If your post is not directly related to this discussion please consider making a new thread.

# Thread: International Time Recording slave clock

1. ## International Time Recording slave clock

I have an ITR weight-driven master clock. the weights are raised by an electric motor. I recently acquired an ITR slave clock and would like to connect the two. The master clock shows model 26 4 with a serial number of 313655 (the 1 is upside down). The slave clock has a patent date of July 22, 1919. On the top of the master clock are three terminals to go to the slave clock. By the terminals are letter notations O E C. The slave clock has three wires also. My question is (assuming the master clock sends the appropriate impulses): what is the connecting sequence of the three terminals to the three wires on the slave clock? I am hesitant to use trial and error in case I might damage the slave clock (assuming that it too works). Thanks for your help.
Sam

2. ## International Time Recording slave clock (By: logan)

I have an ITR weight-driven master clock. the weights are raised by an electric motor. I recently acquired an ITR slave clock and would like to connect the two. The master clock shows model 26 4 with a serial number of 313655 (the 1 is upside down). The slave clock has a patent date of July 22, 1919. On the top of the master clock are three terminals to go to the slave clock. By the terminals are letter notations O E C. The slave clock has three wires also. My question is (assuming the master clock sends the appropriate impulses): what is the connecting sequence of the three terminals to the three wires on the slave clock? I am hesitant to use trial and error in case I might damage the slave clock (assuming that it too works). Thanks for your help.
Sam

3. ## International Time Recording slave clock (By: logan)

Sam and all. There's quite a few variables that affect how and which ITR slave dial is connected to your older master clock.

The motor driving the winding gears is most likely a GE motor designed for 110 volts AC/DC and one would logically assume you have the clock connected to a 120 volt AC 60 Hz utility electrical outlet. There must exist, in addition to the power to wind the weights, a nominal 24 volts DC to operate any attached slave dials. The 24 volts DC source may be internal to the master clock or it may be an external source.

Many ITR slave clocks require 24 volts DC but some were supplied to operate in a series loop configuration of six or eight slave clocks. Singly, these would need a source voltage much less than 24 VDC.

Additionally, many ITR and IBM slave clocks as well as the master clocks were supplied with their "hourly correction feature" these generally require three wires between the master and slave to affect the hourly correction feature. However, master and slave clocks with the hourly correction feature will function in the simple non-correction mode using only two wires.

We would need more specific information about both your master and slave clocks before providing guidance specific to your needs.

Data and or photos of the insides and top of your master clock and the back side of your slave clock will help provide more specifics.

4. ## International Time Recording slave clock (By: logan)

You might find something also helpful on my webspace:

www.execpc.com/~hweiland

Please click on the IBM items. These are copies of factory instructions for various ITR-IBM-Simplex clpocks.

Henry Weiland