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.
Obtained from a 1980s Linear Technology documentation, this circuit has a hysteresis of less than...
This grid-isolated sensor was proposed by General Electric in 1966 documentation. The circuit...
This simple circuit can be used to power a simple communication system using ordinary telephones....