Injector driving device
AssigneeDenso Corporation
InventorHiroki NAMBU
Life of this patent
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Abstract
An injector driving device includes a control circuit of a booster circuit that charges a capacitor by repeatedly switching a booster switch ON/OFF during a voltage boost control to cause a reverse voltage in a coil, and stops the voltage boost control upon determining that a capacitor voltage has reached a corrected target value. The control circuit detects a peak value of the capacitor voltage during an OFF period of the boost switch. The control circuit also detects a capacitor voltage as an ON value during the subsequent ON period of the booster switch. A difference between the peak voltage and the ON value of the capacitor is calculated, and a post-correction target value is set by adding the difference to a reference value of a target value.
Claims6
An injector driving device comprising:
- a booster circuit to drive an injector, the booster circuit including:
- a coil having a first end and a second end, a power source voltage supplied to the coil via the first end;
- a switching element having a first output terminal and a second output terminal, the first and second output terminals of the switching element connected in series between the second end of the coil and a reference potential that is lower than the power source voltage, where the first output terminal of the switching element is connected to the second end of the coil and the second output terminal of the switching element is connected to the reference potential;
- a diode having an anode and a cathode, the anode of the diode connected between the second end of the coil and the first output terminal of the switching element;
- and
- a capacitor having a positive terminal and a negative terminal, the capacitor connected in series between the cathode of the diode and the reference potential, where the positive terminal of the capacitor is connected to the cathode of the diode and the negative terminal of the capacitor is connected to the reference potential;
- a controller (i) configured to perform a voltage boost control to charge the capacitor by repeatedly switching the switching element ON and OFF to cause a reverse voltage in the coil, and (ii) further configured to stop the voltage boost control upon determining that a capacitor voltage at the positive terminal of the capacitor has reached a corrected target value that is greater than the power source voltage;
- and
- a corrector configured to detect a physical value that is correlated with an equivalent-series-resistance (ESR) value of the capacitor, and to correct the target value to the corrected target value that is a greater value when the detected physical value increases.
Dependencies are inferred from the claim text.