| 摘要 |
A distance determination and alarm system for alarming when a wireless transmitter is either close or distant, having a wireless transmitter for transmitting an emitter signal. A wireless receiver is for receiving the emitter signal. The wireless receiver is for resolving the distance between the wireless transmitter and the wireless receiver. A proximity switch is electrically connected to the wireless receiver for selectable switching between within boundary alarm and out of boundary alarm. An alarm is electrically connected to the wireless receiver.
|
