© Dr. Steve Rapp
Tuned Radio Circuits
There are two possible designs: single radio
circuit, and two radio circuits.
When in operation, an electromagnetic field is
produced by the circuit. If an object enters this
field, it detunes the circuit, causing the current
through the circuit to change.
In two radio circuit devices, both circuits start out
tuned to the same frequency, and a difference
detector is connected to both circuits.
Metal detectors can be designed to use either of
these two methods.