Abstract: A brushless motor includes a minimum number of parts and is assembled easily. A molded, substantially annular plastic permanent magnet on a rotor is magnetized in axially opposite directions alternatively such that a plurality of pairs of S and N poles are formed alternatively. The substantially annular permanent magnet includes an annular portion associated with air-core coils provided on a stator for generating a driving torque for the rotor and associated with a frequency signal generating circuit pattern provided on the stator for generating an electric signal indicative of a rotor speed and a protruded portion protruding from an outer peripheral side surface of the annular portion and associated with a rotor position detecting means provided on the stator for generating an electric signal indicative of a rotor position. A boundary line between an S and N pole of one of the plural pole pairs passes through the protruded portion.

Abstract: The stator comprises three phase driving coils and an electric commutator for controlling current to the driving coils. The rotor comprises permanent magnets which are alternately magnetized in N polarity and S polarity. Driving torque is generated corresponding to the current flowing through the driving coils and the permanent magnets. On the surface of the permanent magnet facing to the driving coils, two non-magnetizing portions are provided in each permanent magnet having either N or S polarity.

Abstract: In the transmission of measurement data from a rotating body to a stationary receiver, a rotary signal transmitter mounted on a rotating shaft employs a printed circuit. A printed circuit board assembly for the rotary transmitter has a plurality of evenly circumferentially distributed printed circuit boards which have their electronic components facing radially inwardly so as to resist damage due to centrifugal force resulting when the shaft and boards rotate. Connecting wires connect the assembly to a temperature sensor and the signal corresponding to the temperature is transmitted via a light-emitting element to a light-sensitive element of the receiver. Another arrangement employs rotationally balanced printed circuit discs extending radially. Multiplexing means may also be provided.