Abstract: A personal safety device controlled by a microprocessor which responds to commands, such as activation and deactivation commands. The microprocessor acts to control sound emitted from two separate speakers. The sound is controlled through digital outputs of the microprocessor such that the sound emitted by the first speaker has a first sinusoidal component sin(a) and the sound emitted by the second speaker has a second sinusoidal component sin(b) yielding a complex tone when perceived by a human ear. The personal safety device further allows for coded deactivation thereby rendering it difficult for a third-party without knowledge of the code, such as a would-be attacker, to deactivate the device. Further, the personal safety device provides a detection circuit for detecting a low battery condition. Finally, a method for operating the device is disclosed.

Abstract: A personal safety device controlled by a microprocessor which responds to commands, such as activation and deactivation commands. The microprocessor acts to control sound emitted from two separate speakers. The sound is controlled through digital outputs of the microprocessor such that the sound emitted by the first speaker has a first sinusoidal component sin(a) and the sound emitted by the second speaker has a second sinusoidal component sin(b) yielding a complex tone when perceived by a human ear. The personal safety device further allows for coded deactivation thereby rendering it difficult for a third-party without knowledge of the code, such as a would-be attacker, to deactivate the device. Further, the personal safety device provides a detection circuit for detecting a low battery condition. Finally, a method for operating the device is disclosed.