| 摘要 |
A counter, for example a counter-speedometer for automobile vehicles, comprising a motion take-off actuating a signal emitter and a receiving unit comprising a rotary magnet which drives, by the effect of Foucault's currents, a non-magnetic movable element integral with an index and subjected to the action of a return spring, a rotating field generator driving in synchronism said rotary magnet and supplied with power by said signal emitter, wherein the rotating field generator is constituted by at least one stator winding having at least one core terminating in pole pieces which encompass therebetween the rotary magnet and the non-magnetic element, said non-magnetic element being a disc rotating coaxially with the rotary magnet which is constituted by at least one elementary magnet oriented axially, and said pole pieces being disposed in such manner that the lines of force therebetween are also parallel to said common axis. |
