This analog tachometer was found in Radio Electronics from the 90s. The components used can still be found with some ease.
The LM3911 from National Semiconductor (Now Texas) is a temperature sensor that provides an output...
Found in a 1990 Electronics Handbook, this circuit causes an LED to flash when the phototransistor receives...
This circuit was obtained in a Portuguese publication in 1979. It is a simple code switch that...