This circuit was found in an EDN from the 90s. The circuit employs a double 555 and uses the courtesy light switches of the car as sensors.
This circuit was found the Optoelectronics Sourcebook by Texas Instruments. Any phototransistor...
This traditional photodiode amplifier configuration uses an operational one that is no longer...
Figure bellow shows how one of the two separated counters found inside the 4518 is used as a...