| 摘要 |
PURPOSE:To detect the generation of cracking immediately by arranging a power source circuit and a detection circuit on a rotor. CONSTITUTION:While a disc 1 is rotating, a fine current from a dry cell 7 is supplied to a loop 2 as shown by the arrow (e). As the resistance value of a resistor R1 is so set that the collector voltage of a transistor 8 can be small sufficiently, a light emitting diode 10 is OFF. Now when the disc 1 cracks, the loop 2 corresponding to the affected part is cut off and the supply of the fine current is stopped, causing a rise in the potential at the point 13 and the collector voltage of the transistor 8 to emit light with the light emitting diode 10. Thus, when this light signal (f) is set in linkage with a shutter release of a camera using an additional photoelectric device or the like, a picture can be taken almost the moment cracking takes place. |
