| 摘要 |
PURPOSE:To realize the reduction of cost and miniaturization and thinning of a polyphase brushless motor by preventing problems due to leakage flux and decreasing the number of component parts. CONSTITUTION:The number N of the poles of the driving magnets 1 of a rotor 4 is made smaller than that P of the poles of an FG magnets 2 in order to obtain the rotational-position detecting signal Q of a polyphase brushless motor while N/2 and P/2 are set in the relationship of a prime number. An electromagnetic rotating machine is composed of a first field detecting means 12 for detecting the field change of the driving magnets 1, a first comparator binary- coding an output signal from the means 12, a second field detecting means 7a for detecting the field change of the FG magnets 2, a second comparator binary-coding an output signal from the means 7a, and a latch circuit using an output from the first comparator as a clock input and an output signal from the second comparator as a data input. An output signal from the latch circuit is employed as the rotational-position detecting signal, thus omitting an exclusive rotational-position detecting element. |
