Apparatus and method for starting and controlling a motor

A process for starting a motor having a starting load and for controlling the motor during a period of normal operation, the process comprising the steps of:

• initiating a start-up period having a predetermined duration upon detecting an initial application of power to the motor;
• providing for variable magnitudes of power to be selectively applied to the motor;
• applying a fixed, substantially maximum magnitude of power to a main winding of the motor during the start-up period;
• applying a fixed, substantially maximum magnitude of power to a start-up winding of the motor during the start-up period;
• applying at least one of the variable magnitudes of power to the main winding of the motor during the period of normal operation, the period of normal operation generally following the start-up period, the duration of the start-up period being at least as long as necessary for the motor to overcome the starting load thereon;
• applying substantially no power to the start-up winding of the motor during the period of normal operation;
• and
• measuring the duration Of the start-up period with a resistive-capacitive circuit and a switching circuit, the resistive-capacitive circuit having a resistor and a capacitor, the resistive-capacitive circuit also having an RC time constant, the switching circuit coupled to the resistive-capacitive circuit and having an open state and a closed state, the measuring step comprising the steps of:
• charging the capacitor through the resistor according to the RC time constant upon the initial application of power;
• and
• shifting the switching circuit from one of the open state and the closed state to the other of the open state and the closed state when the charge on the capacitor crosses from a first predetermined range to a second predetermined range.