We found this CMOS circuit in a 1978 publication. It allows you to use a standard calculator keyboard with 16 keys for encoding in hexadecimal.
This circuit appeared in the June 1990 issue of Radio Electronics magazine. Integrated circuits must...
Lockout shooting, due to the incidence of light, can be achieved with the circuit in the figure. In...
This circuit can function either as a crystal or galena receiver with a pre-amplifier using a FET...