| 摘要 |
<p>PROBLEM TO BE SOLVED: To operate an extendable mast and a light source on it with the same power source and simplify operations by connecting electric elements which depend on only one power system. SOLUTION: A DC voltage, preferably 12V or 24V, is fed to a control circuit board 61 from a DC power source 71 via a wire 72, and all signal processing of mast operations are conducted by the control circuit board 61. The control circuit board 61 is connected to an air compressor 33 by a wire 73, a mast is tended by an up/down-solenoid valve 35, and a mast drive motor 52 is operated to move the mast. The DC power source 71 feeds electric power to a remote control layout PC board 84 through a coiled tube 63 via the control circuit board 61, and it also feeds electric power to light sources 85, 86. The electric power is fed from only the DC power source 71, operations can be conducted by the same power source 71, and the operations can be simplified.</p> |
