A deactivator for deactivating label-style EAS devices is claimed. The
preferred embodiment, of which, employs a microprocessor unit to control
two transceiver coils, and a deactivation coil in series with a
capacitor. The two transceiver coils are essentially two flat figure
eights arranged concentrically but rotated through some angle with
respect to each other. The transceiver coils are operated alternatively,
first transmitting an interrogation signal and then listening for a
response. When an EAS device is detected, the microprocessor unit drives
the capacitor and deactivation coil at the system's resonant frequency to
generate a high amplitude magnetic field then shifts the frequency of the
driving current away from the resonant frequency to attenuate the
magnetic field. A field sensor or current sensor provides feedback to the
microprocessor to determine the resonant frequency of the system during a
frequency sweep.