This circuit was obtained in a documentation from the 70s. The operational amplifiers used are uncommon today. Modern equivalent types can be tried out.
This circuit activates an output, which can be a lock, only when a card containing the programmed code...
August 2017 - Texas Instruments is announcing the availability by Mouser Electronics of its new...
This circuit was obtained in a Popular Electronics of 1991. The magazine no longer exists, but the...