Found in a 1964 Electronic Design this circuit compares two signals by providing the inverse of the algebraic sum of their frequencies. The circuit can be made with modern equivalent transistors.
This configurable CMOS configuration for frequencies up to a few megahertz was obtained in an...
In the figure we have the way to implement a NO OR or NOR gate with an operational amplifier. The...
This input circuit for meters, which can also be used as a shield, is intended for operation with...