| 摘要 |
A security system is disclosed which includes a transmitting device and a receiving device. The transmitting device generates a uniquely coded signal on a pseudorandom time interval and is attached to a person, pet or object. The associated receiver is placed near or carried by a person wishing to monitor this person, pet or object. The monitoring person will typically be close enough that he or she is well within the range of the transmitter. If the person, pet or object with the attached RF transmitter is removed by some predetermined minimum distance from its associated RF receiver, the RF receiver will not receive the unique coded signal and will trigger an alarm. The receiver can be set to recognize several unique codes but will ignore all others. The transmitter can be set to different power levels to change the range over which the receiver will signal its alarm.
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