All items tagged with switch and phone (13)

1-01-1994 | The switching unit described here is capable of controlling up to seven mains-powered loads with the aid of commands received via telephon...

1-12-1991 | Rectifying the buzzer signal on a telephone line results in a voltage that may be used to switch one or more loads, for instance, a light...

1-07-1985 | elektor July/august 1985 Microphones, unfortunately, produce onlyasmallsignalandthey,therefore, require a special pre-amplifier to boost the...