Patent ID: 7857413

Claim:
A system for monitoring characteristics of a voltage signal provided to a PZT capacitor of a print head comprising: a digital driver circuit adapted to generate and transmit a signal indicating a nominal slew rate; a probe circuit coupled to the capacitor for measuring a firing pulse voltage signal provided to the capacitor; a comparator coupled to the digital driver and the probe circuit adapted to compare a measured slew rate as determined from the measured firing pulse voltage signal with the nominal slew rate and to generate a difference signal indicating a difference in magnitude between the measured slew rate and the nominal slew rate; an analog driver circuit coupled to the comparator adapted to adjust the slew rate of the voltage signal provided to the capacitor in response to the difference signal received from the comparator; and an analog/digital converter coupled to the probe circuit adapted to sample the firing pulse voltage signal output from the probe circuit and to provide a digital output signal for diagnostic purposes.