Stephen J Sanders

US Patent:

45448663, Oct 1, 1985

Filed:

Jun 28, 1984

Appl. No.:

6/625697

Inventors:

Richard R. Clemmons - Roscoe IL
Darrel E. Zimmer - Rockford IL
Stephen H. Sanders - Rockford IL

Assignee:

Amerock Corporation - Rockford IL

International Classification:

H02P 308

US Classification:

318 54

Abstract:

A window operating system includes a motor control circuit for controlling the operation of direct current permanent magnet motors mounted on window operators associated with each window. Each of the motors on each of the windows is connected to the control circuit only by a pair of wires which both power the motor and provide information to the control circuit as to the status of motor operation. The status of motor operation is determined by monitoring the back electromagnetic force expressed by the motors. To help differentiate back electromagnetic force from supply voltage supplied to the motors, the motors are supplied with full rectified alternating current power, rather than simple direct current, so that the presence or absence of zero voltage between half waves of the voltage expressed across the motors can be monitored to determine the absence or presence of back electromotive force during those time periods. A reversible connector is used to connect the motor to the control circuit so that the polarity of motor operation can be reversed by reversal of the connector relative to its mating receptacle.