摘要 |
An apparatus for detecting a low impedance load on an output of a driver circuit electrically connected to a coil of a fluid dispensing gun. The driver circuit provides a plurality of output signals to the coil in response to respective drive signals. Each drive signal has a waveform commanding the dispensing gun to open, and the waveform has a higher magnitude initial peak period followed by a lower magnitude hold period. A feedback circuit provides a difference signal as a function of a difference between each drive signal and a feedback of a corresponding output signal. A diagnostic circuit is connected to the driver circuit and provides an error signal representing a low impedance error as a function of the difference signal crossing a threshold signal magnitude during an occurrence of the peak period of the drive signal.
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