| 摘要 |
PURPOSE:To control the stop position of a rotary plate simply by connecting conductive materials arranged at equal interval on the circumference of a circle and a conductive material on another circumference with resistance of the same value, using resistance of difference value for one of them, and detecting and counting potential difference between brushes. CONSTITUTION:On a rotary plate, n pieces of conductive members 211-21n are attached at equal spaces on the circumference, and a conductive member 22 is attached to another circumference. The members 211 and 22 are connected through a resistance 231 of a resistance value R0, and other members 212-21n and the member 22 are connected through resistances 232-23n of a resistance value R1 respectively. When the rotary plate 20 rotates, an end of the first brush 24 is brought into contact with members 211-21n successively, and the second brush 25 is always in contact with the member 22. A potential difference detecting device 26 detects potential difference according to the resistance between two brushes, and a convertor 27 converts it to digital signal of corresponding bit. A counter 28 counts the number of contact on the basis of contact of the first brush with the member 211. A discriminating device 29 stops an electric motor 30 when it is judged that an input value A corresponding to the stop position coincides with the counted value of the device 28. |
