초록 ▼

A system includes a motor for producing motion when current is supplied to the motor and a motor controller coupled to the motor for receiving a motor current signal indicative of the current supplied to the motor. The motor controller has an analog-to-digital converter for converting the motor curr

A system includes a motor for producing motion when current is supplied to the motor and a motor controller coupled to the motor for receiving a motor current signal indicative of the current supplied to the motor. The motor controller has an analog-to-digital converter for converting the motor current signal to a sampled motor current signal. The motor controller is operable to detect pulses in the sampled motor current signal, count the detected pulses to generate a first pulse count, and determine a run parameter for the motor based on the first pulse count. A method for controlling a motor includes counting a first plurality of pulses in a motor current signal produced while the motor is activated to generate a first pulse count. A second plurality of pulses is counted in the motor current signal produced while the motor is deactivated to generate a second pulse count. A run parameter for the motor is determined based on the first and second pulse counts.

대표청구항 ▼

I claim: 1. A system, comprising: a motor for producing motion when current is supplied to the motor; and a motor controller coupled to the motor for receiving a motor current signal indicative of at least one of motor current and voltage and having an analog-to-digital converter for converting the

I claim: 1. A system, comprising: a motor for producing motion when current is supplied to the motor; and a motor controller coupled to the motor for receiving a motor current signal indicative of at least one of motor current and voltage and having an analog-to-digital converter for converting the motor signal to a sampled motor signal, the motor controller being operable to detect pulses in the sampled motor signal while current is supplied to the motor, count the detected pulses to generate a first pulse count, and determine a run parameter for the motor based on the first pulse count. 2. The system of claim 1, wherein the motor controller is further operable to stop the supply current to the motor responsive to the first pulse count equaling a run pulse count. 3. The system of claim 1, wherein the motor controller is further operable to count the pulses in the sampled motor current signal while the supply of current to the motor is deactivated to generate a second pulse count, and determine the run parameter for the motor based on the first and second pulse counts. 4. The system of claim 3, wherein the motor controller is further operable to stop the supply of current to the motor responsive to the first pulse count equaling a run pulse count, and the run parameter comprises the run pulse count. 5. The system of claim 4, wherein the motor controller is further operable to subtract the second pulse count from a total pulse count to generate the run pulse count. 6. The system of claim 3, wherein the motor controller is further operable to stop the supply of current to the motor after a run time parameter has elapsed and update the run time parameter based on the first and second pulse counts. 7. The system of claim 6, wherein the motor controller is further operable to count a subset of the pulses in the sampled motor signal over a first time interval after the motor is deactivated to determine a pulse rate and update the run time parameter based on the first and second pulse counts and the pulse rate. 8. The system of claim 6, wherein the motor controller is further operable to identify a low pulse signal interval responsive to determining that the sampled motor signal has dropped below a predetermined threshold, count a subset of the pulses in the sampled motor signal over a first time interval after the motor is deactivated to determine a pulse rate, approximate a third pulse count occurring in the low pulse signal interval based on the determined pulse rate, and determine the run parameter based on the first, second, and third pulse counts. 9. The system of claim 8, wherein the motor controller is further operable to subtract the first, second, and third pulse counts from a required pulse count to generate a pulse error value, divide the pulse error value by the determined pulse rate to generate a time adjustment factor, and update the run time parameter based on the time adjustment factor. 10. The system of claim 1, wherein the motor controller is further operable to generate a reference signal based on the sampled motor signal, compare the reference signal to the sampled motor signal, and detect pulses in the sampled motor signal responsive to the motor signal being less than the reference signal by a predetermined threshold. 11. The system of claim 1, further comprising: a switch connected to control the current supplied to the motor and connected to be controlled by the motor controller; and a first resistor connected to generate a first component of the motor signal while current is supplied to the motor, and the analog-to-digital converter is coupled to the first resistor to receive the first component of the motor signal. 12. The system of claim 11, further comprising: a second resistor coupled to generate a second component of the motor signal while current is not supplied to the motor, and the analog-to-digital converter is coupled to the first and second resistors to receive the first and second components of the motor signal. 13. The system of claim 11, further comprising a low pass filter coupled between the first resistor and the analog-to-digital converter. 14. An apparatus for controlling activation of a motor, comprising: an analog-to-digital converter connected to sample a motor signal indicative of at least one of motor current and voltage; and a processing device programmed with instructions that, when executed, perform a method for controlling the motor, the method comprising: detecting pulses in the sampled motor signal while the motor is activated; counting the pulses to generate a first pulse count; and determining a run parameter for the motor based on the first pulse count. 15. The apparatus of claim 14, wherein the analog-to-digital converter and the processing device are formed on the same integrated circuit. 16. The apparatus of claim 14, wherein determining the run parameter in the method further comprises producing a signal for deactivating the motor responsive to the first pulse count equaling a run pulse count. 17. The apparatus of claim 14, which includes a switch for activating and deactivating the motor, and the method performed by the processing device further comprises: counting the pulses in the sampled motor signal while the motor is deactivated to generate a second pulse count; and determining the run parameter for the motor based on the first and second pulse counts. 18. The apparatus of claim 17, wherein the method performed by the processing device further comprises producing a signal for deactivating the motor responsive to the first pulse count equaling a run pulse count, and determining the run parameter in the method further comprises determining the run pulse count for a subsequent activation of the motor. 19. The apparatus of claim 18, wherein determining the run pulse count in the method further comprises subtracting the second pulse count from a total pulse count to generate the run pulse count. 20. The apparatus of claim 17, wherein the method performed by the processing device further comprises deactivating the motor after a run time parameter has elapsed, and determining the run parameter in the method further comprises updating the run time parameter based on the first and second pulse counts. 21. The apparatus of claim 20, wherein the method performed by the processing device further comprises counting a subset of the pulses in the sampled motor signal over a first time interval after the motor is deactivated to determine a pulse rate, and determining the run parameter in the method further comprises updating the run time parameter based on the first and second pulse counts and the pulse rate. 22. The apparatus of claim 20, wherein the method performed by the processing device further comprises: identifying a low pulse signal interval responsive to determining that the sampled motor signal has dropped below a predetermined threshold; counting a subset of the pulses in the sampled motor current signal over a first time interval after the motor is deactivated to determine a pulse rate; approximating a third pulse count occurring in the low pulse signal interval based on the determined pulse rate; and determining the run parameter based on the first, second, and third pulse counts. 23. The apparatus of claim 22, wherein determining the run parameter in the method further comprises: subtracting the first, second, and third pulse counts from a required pulse count to generate a pulse error value; dividing the pulse error value by the determined pulse rate to generate a time adjustment factor; and updating the run time parameter based on the time adjustment factor. 24. The apparatus of claim 14, wherein detecting the pulses in the method further comprises: generating a reference signal based on the sampled motor signal; comparing the reference signal to the sampled motor signal; and detecting a pulse responsive to the motor signal being less than the reference signal by a predetermined threshold. 25. A method for controlling a motor, comprising: counting a first plurality of pulses in a motor signal indicative of at least one of motor current and motor voltage produced while the motor is activated to generate a first pulse count; counting a second plurality of pulses in the motor current signal produced while the motor is deactivated to generate a second pulse count; and determining a run parameter for the motor based on the first and second pulse counts. 26. The method of claim 25, further comprising deactivating the motor responsive to the first pulse count equaling a run pulse count, and wherein determining the run parameter further comprises updating the run pulse count based on the first and second pulse counts. 27. The method of claim 26, wherein updating the run pulse count further comprises subtracting the second pulse count from a total pulse count to generate the run pulse count. 28. The method of claim 25, further comprising deactivating the motor after a run time parameter has elapsed, and wherein determining the run parameter further comprises updating the run time parameter based on the first and second pulse counts. 29. The method of claim 28, further comprising: identifying a low pulse signal interval responsive to determining that the motor signal has dropped below a predetermined threshold; counting a subset of the pulses in the second plurality of pulses to determine a pulse rate; and determining the run parameter by updating the run time parameter based on the first and second pulse counts and the pulse rate. 30. The method of claim 28, further comprising: identifying a low pulse signal interval responsive to determining that the motor signal has dropped below a predetermined threshold; counting a subset of the pulses in the motor signal over a first time interval after the motor is deactivated to determine a pulse rate; approximating a third pulse count occurring in the low pulse signal interval based on the determined pulse rate; and determining the run parameter based on the first, second, and third pulse counts. 31. The method of claim 30, wherein determining the run parameter further comprises: subtracting the first, second, and third pulse counts from a required pulse count to generate a pulse error value; dividing the pulse error value by the determined pulse rate to generate a time adjustment factor; and updating the run time parameter based on the time adjustment factor. 32. The method of claim 25, wherein counting the first and second plurality of pulses further comprises: generating a reference signal based on the motor signal; comparing the reference signal to the motor signal; and detecting a pulse responsive to the motor signal being less than the reference signal by a predetermined threshold. 33. A method for controlling a motor, comprising: counting a first plurality of pulses in a motor signal indicative of at least one of motor current and voltage produced while the motor is activated to generate a first measure of motor travel; counting a second plurality of pulses in the motor signal produced while the motor is deactivated to generate a second measure of motor travel; and identifying a low pulse signal interval while the motor is activated responsive to determining that the motor signal has dropped below a predetermined threshold; counting a subset of the pulses in the second plurality of pulses to determine a pulse rate; determining a third measure of motor travel during the low pulse signal interval based on the determined pulse rate; and determining a run time parameter for the motor based on the first, second, and third measures of motor travel. 34. The method of claim 33, wherein determining the third measure of motor travel further comprises approximating a number of pulses occurring in the motor signal during the low pulse signal interval based on the determined pulse rate. 35. A paper toweling dispenser, comprising: a roll of paper toweling; a motor coupled to the roll; and a motor controller coupled to the motor and having an analog-to-digital converter operable to receive a motor signal indicative of at least one of motor current and voltage and generate a sampled motor signal, the motor controller being operable to detect pulses in the sampled motor signal while the motor is activated, count the pulses to generate a first pulse count, and determine a run parameter for the motor based on the first pulse count.