Speed control
AssigneeKoninklijke Philips Electronics N. V.
InventorsHarry Marinus, Wilhelmus Gerardus Maria Ettes, Gaatze Bareld Bosma, Jacob Dijkstra
Life of this patent
Estimating the term…
Abstract
A motor speed control for controlling the speed of an electric induction motor by modulating the amplitude and frequency of the driving voltage. When the load increases the speed control controls the speed so as to be relatively constant with respect to the frequency of the driving voltage. Preferably, the speed control controls the amplitude of the driving voltage in proportion to the square of the frequency.
Claims20
A speed control for controlling the speed of an electric induction motor by modulating the amplitude V and frequency f of the driving voltage of the motor, characterized in that the speed control controls the amplitude V of the driving voltage in accordance with the formula V=b.fx, where x has a value greater than 1 and smaller than 3 and b is a constant.
A combination of an induction motor for driving a load having a load torque at low speeds substantially smaller than the motor torque at high speeds, and a speed control for varying the speed of the motor by modulating at least one of the amplitude and frequency of the driving voltage of the motor, characterized in that the speed control controls the frequency f of the driving voltage and controls the amplitude V of the driving voltage in accordance with the formula V=b.fx, where x has a value greater than 1 and smaller than 3 and b is a constant.
A device comprising an induction motor, a load coupled to said motor having a load torque at low speeds substantially smaller than the motor torque at high speeds, and a speed control for varying the speed of the motor by modulating at least one of the amplitude and frequency of the driving voltage of the motor, characterized in that the speed control controls the frequency f of the driving voltage and controls the amplitude V of the driving voltage in accordance with the formula V=b.fx, where x has a value greater than 1 and smaller than 3 and b is a constant.
Dependencies are inferred from the claim text.