| 摘要 |
A driver circuit for a piezoelectric element having capacitance C, including a DC power source, a coil having inductance L, a voltage limiter, and a first and a second switching device for charging and discharging the element, respectively. The first switching device is held on for a time not shorter than ( pi 2ROOT LC)/3 and is turned off at a first point of time before a voltage of the piezoelectric element has reached a predetermined voltage not higher than a line voltage of the power source. The voltage limiter allows the element to be charged with an energy stored in the coil after the charging by the first switching device, and prevents the element from receiving an excessive energy that causes the voltage of the element to exceed the predetermined level. The second switching device is turned on at a point of time not earlier than the first point of time, and is turned off by the time when the first switching device is turned on for a next activation of the element. |
