ALARM DEVICE WHICH TRACES LOCATION OF MONITORED OBJECT Russian patent published in 1997 - IPC

FIELD: radio engineering, in particular, using radio beacons for monitoring activities of children, persons of legal disability and pets. SUBSTANCE: device has transmitter and receiver. Transmitter has serial circuit of master frequency oscillator, modulator, power amplifier, and transmitting antenna. Receiver has serial circuit of receiving antenna, radio frequency amplifier, mixer, intermediate frequency amplifier, and first detector. In addition device has heterodyne, which is connected to second input of mixer, sound and visual indication units. In addition transmitter has serial circuit of first quartz low-frequency oscillator and controlled frequency divider, which output is connected to second input of modulator. In addition receiver has repeat frequency filter, second detector and threshold gate, serial circuit of amplitude clipper, signal processing unit which clock input is connected to second quartz oscillator, commutator, analog-to-digital converter, memory unit which has writing mode switch, and two- coordinate indicator. In addition device has memory control unit, which outputs are connected to address input of memory unit and synchronization input of two-coordinate indicator. Inputs of visual and audio indicators are connected to first output of signal processing unit. Input of repeat frequency filter is connected to output of first detector. Input of amplitude clipper is connected to output of intermediate frequency amplifier. Second signal input of commutator is connected to output of second detector. Output of first threshold gate is connected to control input of commutator and input of memory unit. Input of memory control unit and clock input of analog-to-digital converter are connected to second output of signal processing unit. EFFECT: increased precision of detection of time function of signal level from low-power transmitter which is located on person that moves along given route, possibility to detect correspondence between movement and given function. 2 cl, 4 dwg