AnsweredAssumed Answered

Block 60 Hz siginal

Question asked by mech11 on Jan 3, 2018
Latest reply on Mar 19, 2018 by jonathan.falco

I have a medical office call box/light system that is older probably 20 year old and they moved the main panel that the Drs see to know when there are patients waiting and since they moved it, it is intermittently not working. The system uses a siginal that is transmitted over the AC connection/plug.

I am new to oscilloscopes but purchased one to see if I could observe if the siginal is too weak in the new location (it’s about 250 feet from where it was originally) or if it’s getting too much interference.

I have found that the system needs to be on its own circuit and have a 2700 UH choke installed on the circuit feed but that’s about all I can come up with since apparently the manufacture has gone out of business. They do still have a website but only very limited information and no schematics.

My problem seems to be when I look at the pattern all I can identify is the 60hz siginal and don’t see any changes when energizing one of the boxes and would like to know if anyone has any suggestions for blocking out the 120V 60Hz siginal so I can see the siginal that is used to operate these boxes over the 120V line. I believe I need a high pass filter but not sure what components I would need to achieve blocking the unwanted siginal but still be able to pass the triggering siginal I am looking for to identify the problem.

Thanks in advance for any help you may be able to provide.