This circuit is from a Radio Electronics magazine from August 1990. The indicator module is of a common type at the time.
Circuits similar to this appear elsewhere in this section. The transistors can be BC549 (low...
Indicated to be used at the sensor input of a PC, this circuit was found in an English...
July 2017 - Mouser Electronics announced the availability of Littelfuse's GEN2 series Schottky...