A device, operated by an electric current, and causing by its operation abrupt changes in an electrical circuit (making or breaking the circuit, changing of the circuit connections, or variation in the circuit characteristics).
"My Wife’s sister had many old 33 LPs that had seen better days. On one of her visits to our house she asked if I could try and record some of her albums to cassette tapes as the LPs were really becoming worn and scratched. I recorded a few of the old albums, but gave up because the quality of the tapes was not any better than the LPs. My ..."