A ground fault detection circuit includes an AC power supply and a plurality of resonance circuits. The reel includes a small disk at one end rotatably mounted to an eyebolt for suspension by hook from an overhead structure and a large thick circular disk at a second end. When it is determined by the restart determining unit to restart the vehicle drive source, the switching valve control unit is started so as to supply the oil pressure accumulated in the accumulator to the hydraulic servo. The optical members are mounted in the sliding assembly. A controlling method for the discharge lamp system is also disclosed herein. A collimator array is further provided having a lens array with aligned attached optical fibers.