초록 ▼

A motor control chip (62) for asserting the control signals used to regulate the energization of the windings of a DC motor. The motor control chip includes a tachometer (94) that receives pulsed signals that vary with the rotation of the motor rotor and that produces a pulse width modulated tachome

A motor control chip (62) for asserting the control signals used to regulate the energization of the windings of a DC motor. The motor control chip includes a tachometer (94) that receives pulsed signals that vary with the rotation of the motor rotor and that produces a pulse width modulated tachometer signal as a function of the motor speed. A pulse width modulator (90) receives the tachometer signal and an analog signal representative of the user-selected motor speed. Based on the received input signals, the pulse width modulator produces a variable speed control signal. A forward/reverse oscillator (92) receives user-set signals indicating if the motor should be run in the forward or reverse directions or in an oscillatory pattern. Based on the received signals, the forward/reverse oscillator asserts a forward/reverse signal having an appropriate signal state or cycle. A motor decoder (98) receives the signals produced by the pulse width oscillator and the forward/reverse oscillator. The motor decoder then asserts the control signals that regulate when power switches selectively tie the motor windings to either a power source or ground.

대표청구항 ▼

[ The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:] [1.] A motor control circuit for regulating the speed of a motor having a rotor, a plurality of windings located around the rotor and configured to generate a pulsed signal representati

[ The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:] [1.] A motor control circuit for regulating the speed of a motor having a rotor, a plurality of windings located around the rotor and configured to generate a pulsed signal representative of the rotational position of the rotor, said circuit comprising:a tachometer for receiving the pulsed signal from the motor and producing a pulse width modulated TACHOMETER signal having an on duty cycle that is proportional to the frequency at which the pulsed signal is generated;,a pulse width modulator for receiving the TACHOMETER signal and a USER.sub.-- SPEED signal representative of a user-selected speed, said pulse width modulator configured to generated a pulse width modulated SPEED.sub.-- CONTROL.sub.PWM signal that has an on-duty cycle proportional to the difference between an integral of the TACHOMETER signal and the USER.sub.-- SPEED signal; anda motor driver for receiving the pulsed signal from the motor and the SPEED.sub.-- CONTROL.sub.PWM signal for producing a plurality of HIGH.sub.-- SIDE.sub.-- CONTROL signals, each HIGH.sub.-- SIDE.sub.-- CONTROL signal being asserted to cause a separate one of the motor windings to be connected to a power source, and a plurality of LOW.sub.-- SIDE.sub.-- CONTROL signals, each LOW.sub.-- SIDE.sub.-- CONTROL signal being asserted to cause a separate one of the motor windings to be connected to ground, wherein the motor driver sequentially asserts the HIGH.sub.-- SIDE.sub.-- CONTROL signals and the LOW.sub.-- SIDE.sub.-- CONTROL signals as a function of the pulsed signal and the on-duty cycle of the SPEED.sub.-- CONTROL.sub.PWM signal. [6.] A direction control oscillator for generating motor control signals indicating if a motor rotor should operate in a forward state, a reverse state or oscillate between the forward and reverse states, said direction control oscillator including:a first logic circuit connected to receive a first user-generated direction signal indicating that the motor should operate in the forward state and a second user-generated direction signal indicating that the motor should operate in the reverse state, said first logic circuit configured to generate a MOTOR.sub.-- ENABLE signal when either the first user-generated direction signal or the second user-generated direction signal is received;a second logic circuit connected to receive the first user-generated direction signal and the second user-generated direction signal, said second logic circuit configured to generate a FORWARD/REVERSE signal wherein: when only the first user-generated direction signal is received, a FORWARD/REVERSE state signal is generated; when only the second user-generated signal is received, a FORWARD/REVERSE state signal is generated; and, when both the first and second user-generated direction signals are received, the FORWARD/REVERSE signal is cyclically transitioned between the FORWARD/REVERSE state signal and the FORWARD/REVERSE state signal; anda third logic circuit connected to receive the first and second user-generated direction signals and the MOTOR.sub.-- ENABLE signal, said third logic circuit configured to selectively forward the MOTOR.sub.-- ENABLE signal or a MOTOR.sub.-- ENABLE signal, wherein, when both the first and second user-generated direction signal are received, after each state transition of the FORWARD/REVERSE signal, said third logic circuit forwards the MOTOR.sub.-- ENABLE signal for a select period of time before forwarding the MOTOR.sub.-- ENABLE signal. [14.] An integrated circuit for regulating the operation of a motor having a variable speed rotor, a plurality of windings that are selectively tied to a power source or ground, wherein the motor generates at least one pulsed signal representative of the rotational position of the rotor, said integrated circuit comprising:a tachometer for receiving the pulsed signal from the motor said tachometer including:a current source;a switch array for selectively tieing a first capacitor to said current source or ground, wherein said switch array is configured to tie the capacitor to the current source for a fixed period of time after each pulsed signal is received; anda first pulse generator connected to the first capacitor for producing TACHOMETER.sub.PWM pulses as a function of the voltage across the capacitor; a pulse width modulator including:an amplifier having a first input to which integrated TACHOMETER.sub.PWM pulses are applied, a second input to which an analog, user-set USER.sub.-- SPEED signal is applied, said amplifier producing a SPEED.sub.-- CONTROL signal as a function of the difference between the USER.sub.-- SPEED signal and the integrated TACHOMETER.sub.PWM pulses; anda second pulse generator connected to the amplifier for receiving the SPEED.sub.-- CONTROL signal, said second pulse generator configured to produce a pulsed SPEED.sub.-- CONTROL.sub.PWM signal, wherein the SPEED.sub.-- CONTROL.sub.PWM signal has an on duty-cycle proportional to the magnitude of the SPEED.sub.-- CONTROL signal; anda motor driver responsive to the SPEED.sub.-- CONTROL.sub.PWM signal and the pulsed signal from the motor for sequentially asserting HIGH.sub.-- SIDE.sub.-- CONTROL signals to tie the windings of the motor to a power source and variable on duty-cycle LOW.sub.-- SIDE.sub.-- CONTROL signals to tie the windings of the motor to ground, wherein, said motor driver sequentially asserts the HIGH.sub.-- SIDE.sub.-- CONTROL and the LOW.sub.-- SIDE.sub.-- CONTROL signals as a function of the pulsed signal and varies the on duty-cycle of the LOW.sub.-- SIDE.sub.-- CONTROL signals as a function of the on duty-cycle of the SPEED.sub.-- CONTROL.sub.PWM signal. The integrated circuit of claim 14, further including:a forward/reverse controller for receiving a user-set forward signal when the motor is to be run in a forward direction and a user-set reverse signal when the motor is to be run in a reverse direction, wherein, said forward/reverse controller is configured to assert a MOTOR.sub.-- ENABLE signal when either the forward signal or the reverse signal is received and a FORWARD/REVERSE signal, the FORWARD/REVERSE signal being in a FORWARD/REVERSE signal state when the forward signal is received and in a FORWARD/REVERSE signal state when the reverse signal is received; andwherein said motor driver receives the MOTOR.sub.-- ENABLE signal and the FORWARD/REVERSE signal and is further configured to inhibit assertion of the HIGH.sub.-- SIDE.sub.-- CONTROL signals when a MOTOR.sub.-- ENABLE signal is received and further regulates the sequence in which the HIGH.sub.-- SIDE.sub.-- CONTROL and the LOW.sub.-- SIDE.sub.-- CONTROL signals are asserted as a function of the state of the FORWARD/REVERSE signal. The integrated circuit of claim 15, wherein said forward/reverse controller is configured so that, when both the user-set forward signal and the user-set reverse signal are received, said forward/reverse controller causes the FORWARD/REVERSE signal to cyclically transition between the FORWARD/REVERSE signal state and the FORWARD/REVERSE signal state. An integrated circuit for regulating the operation of a motor having a rotor and a plurality of windings that are selectively tied to a power source or ground, said integrated circuit comprising:a pulse width modulator for receiving a signal representative of the speed of the motor rotor and an analog, user-set USER.sub.-- SPEED signal, said pulse width modulator configured to produce a pulse width modulated SPEED.sub.-- CONTROL.sub.PWM signal that has an on duty-cycle that varies as a function of the speed of the motor and the USER.sub.-- SPEED signal;a forward/reverse controller for receiving a user-set forward signal when the motor is to be run in a forward direction and a user-set reverse signal when the motor is to be run in a reverse direction, wherein, said forward/reverse controller is configured to assert a MOTOR.sub.-- ENABLE signal when either the forward signal or the reverse signal is received and a FORWARD/REVERSE signal, the FORWARD/REVERSE signal being in a FORWARD/REVERSE signal state when the forward signal is received and in a FORWARD/REVERSE signal state when the reverse signal is received and, wherein:when both the user-set forward signal and the user-set reverse signal are received, said forward/reverse controller causes the FORWARD/REVERSE signal to cyclically transition between the FORWARD/REVERSE signal state and the FORWARD/REVERSE signal state; andsaid forward/reverse controller is further configured to receive a motor speed signal indicating if the motor rotor is turning and, when both the user-set forward signal and the user-set reverses signal are received, with each signal state transition of the FORWARD/REVERSE signal, said forward reverse controller asserts a MOTOR.sub.-- ENABLED signal until the rotor speed signal indicates that the motor rotor has stopped turning; anda motor driver responsive to the SPEED.sub.-- CONTROL.sub.PWM signal and a signal representative of the rotational position of the motor rotor for sequentially asserting HIGH.sub.-- SIDE.sub.-- CONTROL signals to tie the windings of the motor to a power source and LOW.sub.-- SIDE.sub.-- CONTROL signals that have a variable on duty-cycle to tie the windings of the motor to ground, wherein, said motor driver sequentially asserts the HIGH.sub.-- SIDE.sub.-- CONTROL and the LOW.sub.-- SIDE.sub.-- CONTROL signals as a function of the rotational position of the motor rotor and varies the on duty-cycle of the LOW.sub.-- SIDE.sub.-- CONTROL signals as a function of the on duty-cycle of the SPEED.sub.-- CONTROL.sub.PWM signal and wherein said motor driver receives the MOTOR.sub.-- ENABLE signal and the FORWARD/REVERSE signal and is further configured to inhibit assertion of the HIGH.sub.-- SIDE.sub.-- CONTROL signals when a MOTOR.sub.-- ENABLE signal is received and further regulates the sequence in which the HIGH.sub.-- SIDE.sub.-- CONTROL and the LOW.sub.-- SIDE.sub.-- CONTROL signals are asserted as a function of the state of the FORWARD/REVERSE signal. The integrated circuit of claim 17, further including a tachometer circuit for receiving the signals representative of the rotational position of the rotor for generating a TACHOMETER signal representative of motor speed and, wherein, said pulse width modulator receives the TACHOMETER signal as the signal representative of the speed of the motor. The integrated circuit of claim 18, wherein: said tachometer circuit includes:a current source;a switch array for selectively tieing a first capacitor to said current source or ground, wherein said switch array is configured to tie the capacitor to the current source for a fixed period of time after each signal representative of motor rotor position is received; anda first pulse generator connected to the first capacitor for producing TACHOMETER.sub.PWM pulses as a function of the voltage across the capacitor; andsaid pulse width modulator receives the TACHOMETER.sub.PWM pulses as the TACHOMETER signal.