Patent ID: 9618947
Date: 2017-04-11
CPC Classifications: G05D

Claim:
1. A method comprising: receiving a voltage-representation signal that is proportional to a voltage across a heater component; generating a magnified voltage-representation signal by determining a difference between a voltage baseline offset reference value, which represents a minimum operating voltage of the heater component, and the voltage-representation signal; receiving a current-representation signal that is proportional to an electrical current passing through the heater component; generating a magnified current-representation signal by determining a difference between a current baseline offset reference value, which represents a minimum operating current of the heater component, and the current-representation signal; pulse width modulating the magnified current-representation signal to generate a resistance-representation signal that is proportional to an amount of modulation that makes the magnified current-representation signal approximately equal to the magnified voltage-representation signal, the pulse width modulating comprises comparing the error signal to an output of a periodic signal generator and applying a result of the comparing to the magnified current-representation signal; and integrating a difference of the resistance-representation signal and the magnified voltage-representation signal to provide an error signal, wherein the pulse width modulating comprises comparing the error signal to an output of a periodic signal generator and applying a result of the comparing to the magnified current-representation signal.