Motor control circuit

A motor controller for applying energization signals to a motor, the motor having a magnetized rotor and a plurality of windings that surround the rotor, the windings being configured to be selectively connected to either a power source or ground so as to cause the energization of the windings, said motor controller including:

• a motor monitor connected to the motor for generating a MOTOR-SPEED sensor representative of the speed of the rotor;
• a speed controller connected to a user-actuated speed switch, said speed controller configured to generate a USER-SPEED signal in response to the actuation of the speed switch that is representative of a user-selected speed for the rotor;
• an energization controller connected to the motor for selectively connecting the windings to a power source or ground, to said motor monitor for receiving said MOTOR-SPEED signal, to said speed controller for receiving said USER-SPEED signal, said motor controller being configured to:
• connect the windings to the power source or ground in response to said MOTOR-SPEED signal and said USER-SPEED signal so as to actuate the rotor;
• to connect the windings to the power source or ground to cause the deceleration of the rotor in response to a BRAKE-ENABLE signal;
• and when said MOTOR-SPEED signal and said USER-SPEED signal indicate the rotor is exceeding the user-selected speed by a given amount, to assert a BRAKE-TRIGGER signal;
• and
• a brake controller connected to said motor monitor for receiving said MOTOR-SPEED signal and to said energization controller for receiving said BRAKE-TRIGGER signal, said brake controller being configured to assert said BRAKE-ENABLE signal to said energization controller when said BRAKE-TRIGGER signal is asserted and said MOTOR-SPEED signal indicates the rotor is moving and after said MOTOR-SPEED signal indicates the rotor has stopped moving, to negate the assertion of said BRAKE-ENABLE signal regardless of the state of said BRAKE-TRIGGER signal.

A motor controller for a motor having a magnetized rotor and a plurality of windings that surround the rotor, the windings being configured to be selectively connected to either a power source or ground so as to cause the energization of the windings, said motor controller including:

• a motor monitor connected to said motor for generating a MOTOR-SPEED signal representative of the speed of the rotor;
• a speed controller connected to a user-actuated speed switch, said speed controller being configured to generate a USER-SPEED signal in response to an actuation of said speed switch that is representative of a user-selected speed for said rotor;
• an energization controller connected to the motor for selectively connecting the windings to the power source or ground, to said motor monitor for receiving said MOTOR-SPEED signal, to said speed controller for receiving said USER-SPEED signal, said energization controller being configured to:
• connect the windings to the power source or said ground in response to said MOTOR-SPEED signal and said USER-SPEED signal so as to actuate the rotor;
• to connect the windings to the power source or ground to cause the deceleration of said rotor in response to a BRAKE-ENABLE signal;
• amplify any difference between said USER-SPEED signal and said MOTOR-SPEED signal to produce an ERROR signal;
• and compare said ERROR signal to a fixed signal and when said comparison indicates that said MOTOR-SPEED signal exceeds said USER-SPEED signal, to assert a BRAKE-TRIGGER signal;
• and
• a brake controller connected to said energization controller for receiving said BRAKE-TRIGGER signal, said brake controller being configured to assert said BRAKE-ENABLE signal to said motor controller when said BRAKE-TRIGGER signal is asserted.

A motor control circuit for a motor configured to be rotated in a forward direction and in a reverse direction at variable speeds in response to the application of selected energization signals thereto, said motor control circuit including:

• a current sensor connected to the motor to monitor current drawn by the motor, said current sensor being configured to generate a variable CUR+ signal representative of the current drawn by the motor wherein said CUR+ signal is based on an adjustable volts/amp ratio established by said current sensor based on a current sensor control signal;
• a motor controller connected to the motor for applying energization signals thereto, and to said current sensor for receiving said CUR+ signal, said motor controller being configured to apply energization signals to the motor to cause said motor to rotate at a selected speed in response to the application of a speed signal applied thereto and in response to said CUR+ signal and in a specific direction in response to the application of a FORWARD/REVERSE signal thereto, wherein when said FORWARD/REVERSE signal is in a FORWARD/REVERSE state, said motor controller causes the motor to rotate in the forward direction and when said FORWARD/REVERSE signal is in a FORWARD/REVERSE state, said motor controller causes the motor to rotate in the reverse direction;
• and
• a direction controller connected to user-set direction switches for receiving said direction commands and being configured to generate said FORWARD/REVERSE signal for forwarding to said motor controller in response to setting of the direction switches and connected to said current sensor for generating said current sensor control signal, wherein when said direction signals indicate said motor is to be driven in oscillatory rotation, said direction controller cyclically transitions said FORWARD/REVERSE signal between the FORWARD/REVERSE signal state and the FORWARD/REVERSE signal state and, with each said state transition of said FORWARD/REVERSE signal, said direction controller asserts said current sensor control signal to cause said current sensor to momentarily base said CUR+ signal on a first volts/amp ratio and to subsequently base said CUR+ signal on a second volts/amp ratio.