END OF MOTION DETECTION CIRCUIT FOR DIESEL ENGINES

摘要

A detection circuit for a diesel injection valve includes a first threshold, a first comparator for receiving a BEMF signal from the valve and compare the BEMF signal to the first threshold, a filter for filtering the BEMF signal thereby providing a filtered BEMF signal, a second threshold, and a second comparator for comparing a difference between the BEMF signal and the filtered BEMF signal to the second threshold, indicating an end of motion of the valve. An output of the first comparator and an output of the second comparator are joined to define an output signal. The output signal is activated only when the BEMF signal is above the first threshold and when the difference between the BEMF signal and the filtered BEMF signal is greater than the second threshold.

主权项

1. A detection circuit for detecting end of motion of a diesel injection valve, the valve having a first coil for opening the valve and a second coil for closing the valve, the detection circuit comprising:
a first threshold, a first comparator constructed and arranged to receive a back electromotive feedback (BEMF) signal from the valve and compare the BEMF signal to the first threshold, a filter constructed and arranged to filter the BEMF signal thereby providing a filtered BEMF signal, a second threshold, and a second comparator constructed and arranged to compare a difference between the BEMF signal and the filtered BEMF signal to the second threshold, indicating an end of motion of the valve, wherein an output of the first comparator and an output of the second comparator are joined to define an output signal and wherein, the output signal is activated only when the BEMF signal is above the first threshold and when the difference between the BEMF signal and the filtered BEMF signal is greater than the second threshold.