| 摘要 |
PROBLEM TO BE SOLVED: To prevent magnetic flux produced by driving magnets from giving harmful influence upon the generator wire elements of a frequency generator pattern by a method wherein the generator wire elements which correspond to the center lines of the salient poles of an armature core are provided in the frequency generator pattern. SOLUTION: A frequency generator pattern 5 is formed on a board 10 so as to have a generator wire 5a on a wire A passing through the center of the salient pole 1a of an uppermost U-phase. The generator wires 5a are provided with opening angles of 15 deg. and the salient poles 1a are provided with opening angles of 40 deg.. Therefore, the generator wires 5a are provided on the wire which pass through the centers of the salient poles 1a at 3 positions. Those wires are the wire A, a wire B 120 deg. apart from the wire A counterclockwise and a wire C 120 deg. apart from the wire A clockwise. With this constitution, magnetic flux produced by driving poles does not give harmful influence upon the generator wires 5a, so that high frequency signals with high precision and with little pitch fluctuations can be obtained. |
