53results about How to "Suppress voltage drop" patented technology

The invention provides a motor driving apparatus that supplies energy to a motor so that the peak of the input current from a power supply to the motor can also be suppressed when particularly large energy is needed during the second half period of motor acceleration. A motor driving apparatus 1 having a converter 2, which receives AC voltage and converts it to DC power, and an inverter 3, which receives the DC power and converts it to AC power, includes a charge / discharge control circuit 7 and a capacitor 8 connected in parallel to a link section between the converter 2 and the inverter 3, and energy stored in the capacitor C8 is charged and discharged at arbitrary timing by the charge / discharge control circuit 7.

The invention provides a liquid ejecting head, a liquid ejecting head unit, and a liquid ejecting apparatus, which can suppress a crosstalk between piezoelectric elements and through a partition wall, as well as a voltage drop, thereby suppressing deviation of ink droplet landing position and stabilizing liquid ejection characteristic, thus contributing to improving printing quality. The piezoelectric element includes a first electrode serving as an individual electrode, a piezoelectric layer, and a second electrode serving as a common electrode is attached on a face of a flow path substrate via a vibrating plate. A piezoelectric active portion defined by the first electrode and the second electrode serving as a substantial driver of the piezoelectric element is provided in a region opposing the pressure chamber. An opening formed by removing the second electrode and the piezoelectric layer is provided in a region of the piezoelectric element opposing the partition wall. A wiring electrode and the second electrode provided on the flow path substrate are connected via a common lead electrode provided on the piezoelectric active portion, and the common lead electrode is provided at least on the partition wall inside the opening.

A characteristic selection / current upper limit value calculation section 64 selects a cranking upper limit characteristic map MP2 in the case where a cranking state is detected by a cranking state supposition section 63, and selects a non-cranking upper limit characteristic map MP1 in the case where the cranking state is not detected. Upper limit limitation on a current caused to pass through a motor 20 is relaxed in a cranking upper limit characteristic as compared with a non-cranking upper limit characteristic. Consequently, it is possible to prevent excessive current limitation during cranking.