Found in documentation from the 1980s, this circuit uses components from that time. The circuit is used in process control. The power supply is double.
This circuit was obtained from an English magazine from 1979, but it can be easily assembled today...
Found in a 1991 Hobbyst Handbook, this circuit monitors both battery and alternator voltage. The set...
This simple circuit detects when a conductive liquid reaches the sensors. The circuit has no...