POSITIONING SYSTEM

摘要

A positioning system for enabling a guardian to monitor his charge within a protective zone comprises a master receiver (40) capable of being worn or carried by a monitoring person, and at least one slave transmitter (10) capable of being worn or carried by a person being monitored. The system has two modes of operation, the first activating an alarm on the master receiver when a slave transmitter being monitored moves outside a protective zone, the perimeter of which is a preset distance from the master receiver. In the second mode of operation the alarm means is actuated by the monitoring person, the output from the alarm increases in strength as the master receiver moves closer to a slave transmitter being sought.