This IR light sensor circuit was found in the July 1992 issue of Radio Electronics magazine. It is tuned for 20 kHz modulated light.
With the configuration shown in the figure, a single pulse for a counter can be obtained from a...
With calibrated RV1 it is possible to find a zener diode voltage. The integrated circuit is 0 741...
This circuit was found on an 80's Ham Radio. The transistor admits equivalent. The circuit can...