Patent ID: 6717383
Filing Date: 2004-04-06
Classification: A01K,B05B,F04D

Abstract:
An apparatus for providing a variable flow of liquid, comprising:a. an AC permanent magnet synchronous motor pump controller comprising a programmable micro-controller with means generating AC pulse switching signals applied to said motor pump for varying the flow rate of said motor pump over an extended range of flow rates in accordance with said AC pulse switching signals, further comprising means setting the frequency of said AC pulse switching signals for obtaining a given speed of said motor pump, wherein said speed is synchronous to said frequency for all realizable speeds of said motor pump, and further comprising means setting the pulse width of said AC pulse switching signals in relation to said frequency for a given motor speed in order to maintain constant and continuous flow for any given realizable speed of said motor pump; and b. an output switching circuit incorporated into said controller, for generating said AC pulse switching signals and for driving said motor pump in direct synchronization with the frequency of said AC pulse switching signals.