Found in old documentation, this circuit uses a double gate MOSFET. The operating frequencies depend on the coil, and the indicator is a microammeter.
September 2017 - Analog Devices is making available through Mouser Electronics the Analog Devices...
Found in an Electronics Now from the 90s, this circuit appears elsewhere in this section and...
This circuit takes advantage of the inductance of the phone in the resonant circuit. The circuit is...