The sensor of this circuit is a photodiode. Equivalent operations can be used, and the instrument can be replaced by the lower current range of a standard multimeter.
This circuit is from Mullard 1969 documentation. The circuit operates at a relatively high supply...
This circuit was found in the September 1984 issue of Radio Electronics magazine. The circuit has...
This circuit is regulated by zener and provides a voltage of 9 V. The circuit is from a Radio...