This circuit with unijunction transistors was found in a documentation from the 80's. The trigger times of the SCRs depend on the capacitors and are adjusted in the 5M (4M7) potentiometers.
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...