Synchronize old IBM clock

I've never done this but I believe you just need to inject the 3510 Hz signal to the AC line via a capacitor. You might also need to have protection for your circuit's output since spikes from the AC line might fry your components. Diodes might be sufficient for this.

At 6 minutes to the hour, turn the clock so rhat the 9 is up, for 6 seconds. To set the hour, leave the 9 up for 15 seconds, at 6 minutes to 6. The clock solenoid will think it got it's signal.

RichH

9

try to use LM567 as a carrier of frequency of 500k at modulation of 3.510k.

capacitor are two of 102/1500v

There are commercially available devices that are used to send telephone signals through the AC wires in your house to an extension phone in a different room. Perhaps you could use the transmitter portion to couple the 3510 Hz signal into the AC line? It should already have surge protection and noise filters built into it. Don't reinvent the wheel if you don't have to.... UNLESS, that is what gives you great joy in life! 3510 Hz is an audible frequency, so a simple audio amplifier should be able to boost the signal to an appropriate level.

Good luck & have fun!

The 3510 hz is used to set and co-ordinate all of the clocks in a building or campus, such as a school, courthouse, factory, or campus. It triggers a mechanical drive through a solenoid, which after a 6 second pulse at 6 minutes to the hour, runs the minute hand around to 5 minutes to the hour, if it's not there. At 6 minutes to 6 the pulse is 12 or 15 seconds to allow the clock action to catch the second stage of the setting mechanism, resetting the time to 6:00 both hour and minute hands. The mechanisms tend to wear out quite often (5 year life, replacement clocks are their main business) At the school High School I ran, I disabled hourlies from 6 PM to 6 AM, and also the 6 PM diurnal.

The clocks you have were probably from the pile of not working clocks that were replaced. In the 80's, those clocks were $125, I'd bet that they are currently $400. I had a room full of dead ones when I got there, and out of the 128 clocks we had, 25 to 30 we would accumulate every year. I only stayed 4 years, so I can't verify that the failure rate dropped from the un-needed reset cycles.

RichH

Hello - sorry to hop on an old thread, but I bought an old school clock like the one mentioned above, and now would like to provide power to it and use it in my kitchen. Is there any way to do this? I'm willing to learn but know nothing about electrical circuits. Thank you! Nathan