This circuit was obtained in a 1982 English magazine. The purpose of this circuit is to interface signals other than TTL circuits with TTL inputs. The transistor can be a BC548, 2N2222 or any equivalent.
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...