Patent ID: 6013991
Filing Date: 2000-01-11
Classification: A61B,H01H,H02P,H03K,Y10S

Abstract:
A motor controller for applying energization signals to 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 speed control circuit connected to a user-set speed switch that monitors the state of the speed switch and that generates a USER-SPEED signal representative of a user-set speed for the motor;a direction control circuit responsive to a user-set direction signal that generates a FORWARD/REVERSE signal, wherein depending on the state of the user-set direction signal, said direction controller generates a FORWARD/REVERSE signal, a FORWARD/REVERSE signal or a signal that oscillates between the FORWARD/REVERSE signal and the FORWARD/REVERSE signal;an energization circuit for receiving the FORWARD/REVERSE signal from the direction control circuit and said USER-SPEED signal from said speed control circuit and that is connected to a power source and the motor, wherein said energization circuit is configured to apply energization signals from the power source to the motor to cause said motor to rotate at a specific speed in response to said USER-SPEED 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 said motor to rotate in the forward direction and when said FORWARD/REVERSE signal is in a FORWARD/REVERSE state, said motor controller causes said motor to rotate in the reverse direction; anda speed override circuit connected to said direction circuit, that receives the user-set direction signals and that is connected to said energization circuit for controlling the application of energization signals by said energization circuit to the motor, wherein, when said FORWARD/REVERSE signal transitions between the FORWARD/REVERSE and the FORWARD/REVERSE signal states, said speed override circuit causes said energization circuit for a period of time to apply zero-speed energization signals to the motor equivalent to those applied when a zero-speed USER-SPEED signal is received regardless of the state of the USER-SPEED signal.