Hello everyone,
I've collected up some test gear, averaging about 40+ years old, and am starting to tear down pieces, cleaing them up, replacing electrolytics and doing obviously needed repairs. The collected restoration links in this forum have been a great help. While I'm in there (the most dangerous restoration words... ) I was wondering about updating the AC line input with X & Y safety capacitors and MOVs? A couple dollars in parts per instrument should do it. I'm not an EE, so your feedback and advice would be appreciated.
Let me know if the following seems reasonable.
Put a MOV between line and earth ground and another between neutral and ground. The one connected to the line would be after the unit's power switch and the fuse. What specs on the MOVs would be appropriate for 120VAC residential home supply?
Put a Y2 rated safety capacitor between line and ground and another between neutral and ground. EMI line filters seem to use ceramic caps with values between 2200 - 4700 pF, so that would be my guess for appropriate size.
Put a X2 capacitor between line and neutral, also after the power switch. EMI line filters seem to use values of 0.1 uF, so use this size.
Thanks much,
Tim