A metal detection circuit that includes a power source and a connection to
ground. At least one transmitter circuit is electrically coupled to the
power source and ground and a transmit coil is electrically coiled to the
transmitter circuit. At least one receiver coil has provided along with
an amplifier to be electrically coupled to the receiver coil. An
integrator is electrically coupled to the amplifier and a track/hold
circuit is electrically to the integrator. A filter is electrically
coupled to the track/hold circuit and an output. The circuit provides a
high amplitude, low duty cycle excitation pulse, which allows for the
sensitivity of a high level excitation signal with the power economy of a
much lower energy excitation signal. The receiver circuit collects and
conditions the signals resulting from the relatively short duration,
large amplitude excitation pulse, and goes in to hold mode during the
relatively long charge and idle periods.