| 摘要 |
PROBLEM TO BE SOLVED: To prevent a valuables holding person or a person under treatment from getting away from the controllable range, where a protector exists, by composing a receiver unit of a reception circuit controller for controlling a reception circuit into reception enable state and a sound generator or a vibrator to be driven by an alarm control signal. SOLUTION: Synchronously with the transmission time of transmitter unit, a reception circuit 32 is turned into the reception enable state. A pulse signal received through an antenna 31 is identified by the reception circuit 32 and a pulse and alarm controller circuit 33. When the received pulse signal is proper, a reception circuit controller 35 closes the reception circuit 32 at suitable time and the pulse signal to be next transmitted is waited. When the reception circuit 32 can not receive the transmitted pulse signal once or continuously several times, according to a signal from the alarm control circuit 33, sounds or vibrations are generated by driving a sound generator or vibrator 36 and the alarm is applied to the holder of receiver unit. |
