Drive circuit for piezoelectric fuel injection device of e.g. diesel-type internal combustion engine, of vehicle, has evaluating device evaluating consumption energy or energy consumption rate based on unloading and recovery energies

摘要

The circuit has a capacitor storing energy for driving a piezoelectric device, and a loading/unloading circuit (2a) provided such that a current flows into the piezoelectric device, if the piezoelectric device is loaded by the capacitor, and the current flows from the piezoelectric device to the capacitor, if the piezoelectric device is unloaded. Evaluating devices determine loading energy/recovery energy, if the piezoelectric device is loaded/unloaded, and third evaluating device evaluates consumption energy or energy consumption rate based on the unloading and recovery energies.