| 摘要 |
<P>PROBLEM TO BE SOLVED: To switch on/off a battery power source of a sensor device by detecting an operating state of machinery in the sensor device which performs power supply by a battery and measures a state of the machinery for transmitting a signal by a radio circuit. <P>SOLUTION: The sensor device comprises: a sensor 7 for measuring the state of the machinery; the radio circuit 8 for transmitting sensor information by radio; the battery 3 for feeding the power to them; a power switch 2 for switching on/off the power supply of the battery 3, and an operation detecting means for detecting the active/inactive states of the machinery, wherein, for example, the operation detecting means is composed of a piezoelectric vibration sensor 1 to thereby detect an operation start by vibrations at an operation start of the machinery and turn on and off the power supply switch 2. <P>COPYRIGHT: (C)2008,JPO&INPIT |
