| 摘要 |
PURPOSE:To reduce electric power consumption by collecting all of discharge and charge of a piezoelectric element by a condenser and making it possible to reutilize this collected charge for charging the piezoelectric element. CONSTITUTION:A drive unit of a piezoelectric element PZT consists of a high voltage generating unit A made of a DC-DC converter and a drive unit B of the piezoelectric element PZT and the high voltage generating unit A is furnished with a first condenser CL, a second condenser CU serially connected to a high voltage side of the first condenser CL and electric power source units 20a, 20b to respectively maintain voltage between terminals of each of the condensers CL, CU, for example, at 100V, 300V in the case when it is applied to a fuel injection valve using the piezoelectric element PZT. Additionally, it is devised to charge electric charge charged in both of the condensers CL, CU to the piezoelectric element PZT by way of switching on a switching element S1 and to charge electric charge in the piezoelectric element PZT to the first condenser CL by way of switching on a switching element S2.
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