Hopper spreader with back EMF control and hopper system speed control
AssigneeSno-Way International, Inc.
InventorsRobert N. Gamble, II, Terry Wendorff
Life of this patent
Estimating the term…
Abstract
A method of controlling a DC motor that includes the step of providing a pulse-width modulation (PWM) signal to the DC motor. The PWM signal provides a voltage to operate the DC motor. The method also includes the steps of measuring a voltage generated by the DC motor when the PWM signal is off. In more particular embodiments, the method includes measuring a current being supplied to the DC motor when the PWM signal is off. The method may further require determining a motor speed of the DC motor based on the measured voltage. The method further includes controlling the DC motor to maintain a relatively constant motor speed with varying loads on the DC motor.
Claims21
A method of controlling a DC motor of a hopper spreader, the method comprising the steps of:
- providing a pulse-width modulated (PWM) signal to operate the DC motor of the hopper spreader;
- measuring a voltage generated by the DC motor of the hopper spreader when the PWM signal is turned off;
- determining a motor speed of the DC motor of the hopper spreader based on the measured voltage;
- measuring current supplied to the DC motor when the PWM signal is turned off;
- controlling the DC motor of the hopper spreader to maintain a relatively constant motor speed which corresponds to a desired motor speed setting, the relatively constant motor speed being maintained with varying loads placed on the DC motor;
- wherein the voltage and current measurements occur within 3 milliseconds of each other.
A method of controlling a DC motor of a hopper spreader, the method comprising the steps of:
- providing a pulse-width modulated (PWM) signal to operate the DC motor of the hopper spreader;
- measuring a voltage generated by the DC motor of the hopper spreader when the PWM signal is turned off;
- determining a motor speed of the DC motor of the hopper spreader based on the measured voltage;
- controlling the DC motor of the hopper spreader to maintain a relatively constant motor speed which corresponds to a desired motor speed setting, the relatively constant motor speed being maintained with varying loads placed on the DC motor;
- providing a second pulse-width modulated (PWM) signal to operate a second DC motor;
- measuring a voltage generated by the second DC motor when the second PWM signal is turned off;
- and
- automatically activating a light when the measured voltage indicates that the second DC motor is operating.
A method of controlling a DC motor of a hopper spreader, the method comprising the steps of:
- providing a pulse-width modulated (PWM) signal to operate the DC motor of the hopper spreader;
- measuring a voltage generated by the DC motor of the hopper spreader when the PWM signal is turned off;
- determining a motor speed of the DC motor of the hopper spreader based on the measured voltage;
- controlling the DC motor of the hopper spreader to maintain a relatively constant motor speed which corresponds to a desired motor speed setting, the relatively constant motor speed being maintained with varying loads placed on the DC motor;
- determining a material flow rate through an auger, with an electric motor, by measuring a voltage from the auger's electric motor when a PWM supply voltage to the electric motor is turned off;
- and
- automatically activating a wetting system if the material flow rate is above a first threshold value, and automatically deactivating the wetting system if the material flow rate is below a second threshold value.
A motor control system configured to vary a motor speed of one or more DC motors, the system comprising:
- a microprocessor coupled to the one or more DC motors, the microprocessor configured to supply a pulse-width-modulated (PWM) signal to the one or more DC motors, the PWM signal providing a voltage to operate the one or more DC motors;
- wherein the microprocessor is configured to measure an electric current supplied to the one or more DC motors, and being further configured to measure a voltage generated by the one or more DC motors when the PWM signal is turned off;
- wherein the microprocessor is configured to determine a motor speed of the one or more DC motors based on the measured voltage, and further configured to control the motor speed to maintain a relatively constant motor speed with varying loads placed on the one or more DC motors;
- and
- wherein the microprocessor is configured to measure the voltage and measure the current within three milliseconds of each other.
A motor control system configured to vary a motor speed of one or more DC motors, the system comprising:
- a microprocessor coupled to the one or more DC motors, the microprocessor configured to supply a pulse-width-modulated (PWM) signal to the one or more DC motors, the PWM signal providing a voltage to operate the one or more DC motors;
- wherein the microprocessor is configured to measure an electric current supplied to the one or more DC motors, and being further configured to measure a voltage generated by the one or more DC motors when the PWM signal is turned off;
- wherein the microprocessor is configured to determine a motor speed of the one or more DC motors based on the measured voltage, and further configured to control the motor speed to maintain a relatively constant motor speed with varying loads placed on the one or more DC motors;
- and
- wherein the microprocessor is configured to determine a material flow rate through an auger, having an electric motor, by measuring a voltage from the auger's electric motor when a PWM supply voltage to the electric motor is turned off, and further configured to automatically activate a wetting system if the material flow rate is above a first threshold value, and automatically deactivate the wetting system if the material flow rate is below a second threshold value.
Dependencies are inferred from the claim text.