I'm trying to figure out a way to deal with a ground loop problem I have at home, this is 60hz mains hum that comes out of speakers, even when nothing is connected to the device besides power cable. I ...

Electro-Sensors, Inc. announces the ST420, a loop-powered, stainless steel analog shaft tachometer. The ST420 requires no user calibration, providing a dependable shaft speed monitoring solution right ...