To effectively prevent a walking crane from coming into accidental contact with a high-voltage electric wire by providing a stator sending a radio signal between a rectifying filter circuit and a radio transmitter, and receiving the radio signal sent from the radio transmitter, thereby generating an alarm signal.
An amplifier 20 converts or amplifies AC from a trolley 10 to output AC voltage. A rectifying filter circuit 30 rectifies and filters the AC voltage from the amplifier 20 to output DC voltage. A stator 40 is inserted between the rectifying filter circuit 30 and a radio transmitter 50, and the radio transmitter 50 sends the radio signal when the DC voltage from the rectifying filter circuit 30 exceeds a predetermined value. A radio receiver 60 receives the radio signal so that an alarm 70 may generate an alarm signal. The alarm signal is outputted automatically if a trolley approaches a high-voltage electric wire, thus it is possible to prevent a crane effectively from coming into contact with the high-voltage electric wire.
| JPS5828810 | [Title of the Invention] Earth detector |
SO BUNGEN
YO SEIHATSU
GO KEIZUI
GAN SEYU
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