Relays are electromechanical devices that use a magnetic solenoid to actual a switch. When current is passed through the solenoid coil, it produces a magnetic field. The magnetic field is strengthened ...

The CPC1390G is a 4-pin, single pole and normally open solid state relay that has input to output isolation of 5000 Vrms. It has a blocking voltage of 400 Vp and does not generate EMI or RFI ...

Over on YouTube [DENKI OTAKU] runs us through how a 4-pin MOSFET works and what the extra Kelvin source pin does. A typical MOSFET might come in a 3-pin TO-247 package, but there are 4-pin variants ...