This circuit was found in an American publication from the 1980s. The circuit generates pulses from light and shadow, which can be used in a tachometer circuit. The phototransistor can be of any type as well as Q2.

This circuit was found in an American publication from the 1980s. The circuit generates pulses from light and shadow, which can be used in a tachometer circuit. The phototransistor can be of any type as well as Q2.