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US 4,242,626 AGranted
AC Motor drive
AssigneeJet Spray Cooler, Inc.
InventorThomas A. O. Gross
Life of this patent
Estimating the term…
Abstract
The drive circuit operates a shaded pole motor having in the disclosed embodiment three windings of turns N, N/2 and N/2. The control is basically two-speed control with the lower speed operation being adjustable by means of the drive circuit and with the high speed operation being directly from the AC line. The drive circuit includes a clock, frequency adjustment means, power inverters and unilateral means for limiting power consumption.
Claims11
A motor drive circuit for driving the windings of an AC motor comprising;
- clock means,
- first and second semiconductor switch means each having at least a control electrode and first and second output electrodes,
- means responsive to said clock means for generating cyclic signals for controlling the control electrodes respectively, of the semiconductor switch means,
- load impedance means,
- DC source means including means coupling to one side of the load impedance means and means coupling to the windings,
- first and second unilateral conducting means coupling respectively, from the first output electrode of the first and second semiconductor switch means to the other side of the load impedance means.
- and means coupling the semiconductor switch means to the motor windings.
4 more elements
A system for controlling an AC motor having a plurality of windings comprising;
- means for providing complementary drive signals,
- means for receiving an AC drive voltage,
- switch means having two modes in one mode coupling the complementary drive signals to a series connection of the windings, and in the other mode coupling the AC drive voltage to a parallel connection of the windings.
Dependencies are inferred from the claim text.