Improvements in or relating to devices to be worn on the human body to reveal the wearer's position if he is accidentally buried

Abstract

Abstract 810,730. Radio signalling. WENDT, W., WENDT, E., and WENDT, H. Feb. 16, 1956 [Feb. 16, 1955], No. 4881/56. Class 40 (5). [Also in Group XXXVIII] A tell-tale portable radio transmitter identifying the position of the wearer should he be buried in a disaster, and used in conjunction with an appropriate search receiver, comprises a wristlet case (Fig. 3, not shown) from which projects a short aerial A (Fig. 1) energized by a parallel resonant circuit LC and a three-electrode transistor Tr supplied by a battery connected at B to generate detectable HF oscillations. A temperature-sensitive semi-conductor member T has a small resistance at normal body temperature and a high resistance at lower temperatures and is arranged to diminish or suppress radiation in response to body cooling after death. A microphone UE responsive to heat pulse or lung sounds may modulate the radiated signals in life. The temperature-sensitive semiconductor may be replaced by a linear resistance (Fig. 2, not shown) so that the device responds to body sounds alone.

Inventors

No inventors recorded.

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