摘要 |
To provide a rotation detecting device compact in structure and operable on its own electric power generating function and capable of detecting the number of revolution of a vehicle wheel even at an extremely low speed rotation of the vehicle wheel, and also an anti-skid braking system utilizing such rotation detecting device, the rotation detecting device includes an electric power generator 4, at least one magnetic sensor 23 and an electric power supply circuit 24. The electric power generator 4 in turn includes a stator 17 and a rotor 18 in the form of a multi-pole magnet having a plurality of opposite magnetic poles alternating in a direction circumferentially of the rotor 18. The magnetic sensor 23 is mounted on either the stator 17 or a support member 1 for supporting the stator 17 and is operable to detect the magnetic poles on the rotor 18. The electric power supply circuit 24 is a circuit in which the electric power generated by the electric power generator 4 is utilized as an electric power source of the magnetic sensor 23. The stator 17 is has a wireless transmitting device 5A mounted thereon for transmitting a detection signal from the magnetic sensor 23. Even this wireless transmitting device 5A utilizes the electric power generated by the electric power generator 4 as an electric power source therefor.
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