Detector for person buried in e.g. snow avalanche - has transmitting dipole aerial woven in sleeves of over-garment and connected to Hartley oscillator

摘要

The person to be detected wears clothing contg. an oscillator circuit and a dipole aerial. The dipole aerial(9, 10) is pref. woven into the sleeves of an overgarment such as an anorak. The oscillating circuit is an Hartley oscillator in which the battery has been replaced by a capacitor(2). An exterior transmitter receiver emits a signal which is detected by the oscillator's resonant circuit(L3C4). The resonant circuit (L3C4) being tuned to the external transmitter frequency. Variations to the Hartley oscillator can be made so as to indicate body temp. of the buried person. The signal received from the external transmitter receiver triggers the Hartley oscillator which sends out a signal which is picked up by the external receiver.