We found this circuit in an Electronic Engineering of the 90s. The circuit can be implemented with any logic and next to the diagram the truth table for the indications is given.
This circuit was obtained from a Popular Electronics of 1994. The magazine no longer exists in its...
The basis of this circuit is a National Semiconductor operational amplifier that functions as a...
This circuit is from an 1977 American publication. The coil consists of 30 + 70 turns of 28 AWG...