I have to assist in repair Simplex Clock System.
Not my area of expert...
Need some help understanding the general principles and then weak links.
My limited understanding of the system is that
There was a master clock that used to trigger a corrective pulse at 3510 hz.
This has been displaced by an Andover EMS.
Here are some photos.
So, briefly, the clock [or ems] pulls in two relays, one after the other.
First the generator is made to run and then the clock correct signal is injected into the 480v line. A DC signal on the generator field windings. This "noise" has to get around the transformers, so it is coupled down to the 110v line. There are two solenoids in each clock and when it gets a 8s pulse, the first solenoid gets the minutes to pull up to the top and a 14s pulse gets the second solenoid to get the hands to 6 o'clock.
Then signal wires have to leave the master clock and get to other buildings which have other generators. Some buildings don't have generators, apparently just the coupling devices... The three vacuum tube boxes.
Why the schematic seems so complicated to me?
There are three 3p relays, one for the generator, one for the 3510 pulse and seems like the 6000 is not used?
Two relays would fulfill my limited understanding here.
One pulls in the generator
One gives an 8s or 14s pulse.
Then the whole DC capacitor 3510 area.
There is an interlock to keep the clock correct signal from being generated without generator spinning. The is a hand key for the pulse and a switch for the generator. A rheostat to dial in the Hz...
So what's it doing or not doing?
After the xfmr unloaded in the old can there was no more automatic correct anywhere. We could connect the generator in hand and then key the clock correct and there seemed to be some appropriate movement on a test clock in the remote vault. One week has gone by and I went in there yesterday to key it by hand in the early morning try and get the clocks close to the right time. The job finally fell to me:grin: After I planned stay to watch it at 6am. The problem is that the key for the windings stopped working.
Too many open variables to troubleshoot yet:
- Gotta get a known good working clock ready as a tester. In the evening.
- Got to find the old frequency meter in the wooden box to be able to check for outputs. Looks like that thing has really gone missing.
- Got to be able to key the clock correct by hand and then see why the EMS is not reaching the same: is the clock correct relay picking at the mstr clock site? Need to be there at 0530 and keep a sharp eye for the 14s pulse.
My boss just wants me to figure it out from the schematic but I am not good at reading schematic.
Any insights would be appreciated.