| 摘要 |
PURPOSE:To realize low power consumption and low heating and besides to prevent needless displacement of a piezoelectric element by a method wherein electric charges accumulated in the piezoelectric element are effectively returned to a power source, and the electric charges remaining in the piezoelectric element are effectively released in non-excitation. CONSTITUTION:In the case where, for instance, the invention is applied to a driving circuit of a piezoelectric actuator of a dot printer, a circuit as given in the figure is formed, a control circuit 55 intercepts a transistor (Tr)2 by indication of drive, and makes Tr1 conduct. After accumulating enough charges in a piezoelectric element P, Tr1 is intercepted, and Tr3 is made to conduct. A current made to flow to a coil 53 is damped, the stand by Tr3 is intercepted for displacement time necessary for printing, and Tr2 is made to conduct. Though charges accumulated in the element P flow through a closed loop, consumption as heat hardly exists. All electric energy accumulated in the element P is accumulated in a coil L as magnetic energy adjacent to the coil 53 after specific time. When Tr2 is intercepted at this instant, all the accumulated electric energy is returned to a dc power source 51 via a diode D1 by action of the coil 53. |
