Abstract A speed controller for a prime mover includes a permanent magnet rotor, rotated at a speed corresponding to the speed of the prime mover, and an annular stator provided with an output winding connected, through an amplifier, to a throttle or the like controlling the speed of the prime motor. The rotation of the permanent magnet rotor developes a voltage in the output winding at a first frequency corresponding to the speed of the prime mover. Speed setting means are coupled with the stator to develop, in the output winding, a voltage at a second frequency corresponding to a desired speed of the prime mover as set by the speed setting means. The output winding thus supplies to the throttle or the like a control voltage at a frequency which is the difference between the first and second frequencies. In one embodiment of the invention, the annular stator is rotatable independently of the permanent magnet rotor, by a motor whose speed is controlled in accordance with a setting of the speed setting means. In another embodiment of the invention, an input winding on the stator is supplied by an oscillator at a frequency set by the speed setting means.
A speed controller for prime movers having a control throttle comprising, in combination, a rotary magnet generator including a rotary magnet element and an annular stator element; means coupling one of said elements with the prime mover for rotation by the latter at a speed proportional to that of the prime mover to develop, in said stator element, a voltage at a first frequency corresponding to the speed of said prime mover; control means controlling the control throttle; an output winding on said stator element connected to said control means; and speed setting means operatively coupled to the other of said elements and operable to develop, in said stator element, a voltage at a second frequency corresponding to a speed set by said speed setting means; whereby to develop in said output winding a control voltage at a frequency equal to the difference between said first and second frequencies to control the throttle in accordance with any difference between the speed of said prime mover and the speed set by said speed setting means; said rotary magnet element being coupled with the prime mover; said stator element being non-rotatable; said speed setting means including means developing, in said stator element, a magnetic field rotating at a speed corresponding to the speed set by said speed setting means; said means developing said rotating magnetic field comprising a primary winding wound on said stator element and an oscillator having its output connected to said primary winding; said speed setting means controlling the frequency of said oscillator; said control means comprising frequency discriminating means connected to said output winding; and a speed setting unit connected to said frequency discriminating means.
Claim 2
Dependent Claim
277 words
A speed controller for prime movers having a control throttle comprising, in combination, a rotary magnet generator including a rotary magnet element and an annular stator element; means coupling one of said elements with the prime mover for rotation by the latter at a speed proportional to that of the prime mover to develop, in said stator element, a voltage at a first frequency corresponding to the speed of said prime mover; control means controlling the control throttle; an output winding on said stator element connected to said control means; and speed setting means operatively coupled to the other of said elements and operable to develop, in said stator element, a voltage at a second frequency corresponding to a speed set by said speed setting means; whereby to develop in said output winding a control voltage at a frequency equal to the difference between said first and second frequencies to control the throttle in accordance with any difference between the speed of said prime mover and the speed set by said speed setting means; said rotary magnet element being coupled with the prime mover; said stator element being non-rotatable; said speed setting means including means developing, in said stator element, a magnetic field rotating at a speed corresponding to the speed set by said speed setting means; said means developing said rotating magnetic field comprising a primary winding wound on said stator element and an oscillator having its output connected to said primary winding; said speed setting means controlling the frequency of said oscillator; said control means comprising frequency discriminating means connected to said output winding; and a speed setting unit connected to said frequency discriminating means.