This circuit of a 1964 Electronic Design uses a photodiode from the time. Modern equivalent can be used. The standby current is 1.2 mA.
Found in a 90s documentation, this switch that is also sensitive enough to operate capacitively uses...
This circuit was found in an integrated circuit manual from the 1980s. The circuit can be designed...
This powerful and sophisticated power supply was found in a 1998 publication. The circuit must...