atcomsystems.ca/forum Forums Other TDM Phone Systems 1A2 and Comkey Telephones & Systems KS-19175 interrupter pin out.

Starting a intercom project.

Would anyone know the pin out of the KS-19175 interrupter? Does the ST act like a switch for the interrupter so it can return to the home position? How does the ST work with the 10VAC and ground for the power source.

Thanks

I searched on the schematic drawing for the KS-19175 interrupter and didn't come up with one for just the interrupter. Might try different search engines or different verbiage. I really don't recall an SD for the interrupter, but then that was many years ago.

Thanks... Is the ST acting like a switch to activate the interrupter? Then when its deactivated it would return to home position? I looked at one of the ITT 400 card schematics and it looks like the ST would short out to the ground.

Sorry, I don't remember.

Hi, I wasn't able to locate a BSP specific to the interrupter model you gave, however most interrupters worked the same, the difference being in capacity. This link provides a ckt diagram and operation description of an interrupter from an early key system - at a minimum it explains the lead designations. It's a start (no pun) and hope it helps.

https://www.telephonecollectors.inf...10-403-i3-ktu-232a-232b-interrupter/file

My understanding is the ST ("Start") signal is an output from the interrupter's motor (the other side of the motor's coil is connected to the interrupter motor's power supply). ST is common to all the line cards, so any one (or more) of the line cards can connect that signal to MG (motor ground), which causes the interrupter's motor to run. I imagine once it starts rolling, it will continue running until all the ST closures have been released, leaving the connection open. I /believe/ a switch internal to the interrupter keeps the motor running until it completes its cycle. So I imagine there's a notched disk internally just for that purpose.

So here the interrupter is highlighted (in blue). The motor supply's hot connects directly to the motor's coil (M), and the other side of the coil is presented as "ST", all of which is highlighted in yellow. The switch closure between ST and MG is what the line card provides, shown highlighted in orange. And the motor ground (MG) is highlighted in green. The KSU's internal wiring provides whatever voltage source is needed for the interrupter.



So if your intercom circuit (mentioned in the OP) needs lamp flashing, you should be able to provide that by connecting ST to MG, and then routing LF as needed to get the lamp to flash at the ringing rate, etc.

Afraid I haven't seen an actual pinout myself of the interrupters offhand, but you can probably easily look inside one (through the clear case) to figure out which one is the motor coil, and which spinning disks do what signals. Hold Wink vs Flash vs. Ringing should be easy to spot by the pattern of notches, and the disk that makes sure the entire cycle completes should be the only one with a single notch.

According to 518-215-407, the interrupter's motor is indeed 10VAC (the above condensed schematic doesn't specify this, as it's a general diagram and would want to cover both 10VAC interrupters like the KS-19175, and 24VDC interrupters like the KS-19385).

There's also a diagram in that document (Fig 82, excerpted below) showing the interrupter's internal switch closure to MG that keeps the interrupter's motor turning until it completes a cycle; follow the "1" -> "X" -> "11" -> "MG" electrical path (shown in green).

The "ST" path is similar, and takes the ground side of the motor through the path: "(Z,Y)" -> "3" -> "J9" -> "ST" (shown in blue).

You can see the hot side of the motor's coil "M" takes a path directly to the 10 VAC power supply through the 0.5 amp fuse "F3" (shown in red):

By the way, there IS a pin-out of the various interrupters in Fig. 84 and Fig. 85 of 518-215-405.

For example Fig. 84 (excerpted here) shows the interrupter (highlighted in blue).
Pretty sure those are pin#s around the outer edge:



Note in Fig. 85 (a page or so later) there's a similar diagram, with slightly different pin#s. It's a little hard to tell which interrupter is which, but I'm pretty sure the one excerpted above is the KS-19175, based on the "(Z)" designation shown in the table in Fig. 85.

Since the interrupter was installed at the factory, I imagine they don't show it in much detail.

Thank you so much everyone for your help.
The schematics helped me so much...

Here is some info on my intercom project.

I found a Tone Commander Flashing light Unit 2000 that works in conjunction with your dial selective intercom unit and interrupter. When you buzz or ring the called station, the lamp will start to flash like a incoming call and only on the called station while the other lamps on the other phones remain solid.

I thought, how to add audible ring on the intercom line as I have a WECO Comkey 455 Tone Ringing card collecting dust. Originally, I was thinking to use the KSU interrupters ring cadence but if you are on the intercom line and a incoming call comes in on the regular line then you would hear the 455 card. So, I was looking at a second interrupter so it would only activate by the Tone Commander unit and not by the line cards.