Old phones with dials can be used in a simple home intercom system, as this circuit from Popular Electronics from the 90's shows.
This circuit was found in an American 1980s documentation. Dual FETs can be replaced by single...
August 2016 - It can be obtained from Mouser Electronics the new single controller LCD S1D13L04 from...
Found in an 80's Hands On Electronics, this circuit turns on a light when it gets dark and goes...