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.
Intended for use with signals from tape recorder pickups, this circuit was found in the December 1972...
In the figure we have the configuration of a voltage regulator with 3 transistors. The components depend...
This circuit was found in an 80s documentation. The integrated circuit used is from that time,...