| 摘要 |
PCT No. PCT/SE90/00730 Sec. 371 Date Jul. 13, 1992 Sec. 102(e) Date Jul. 13, 1992 PCT Filed Nov. 12, 1990 PCT Pub. No. WO91/07237 PCT Pub. Date May 30, 1991.This invention relates to an arrangement for driving a high-frequency oscillating tool arrangement (1) which includes, inter alia, a device (1a) whose form changes with a change in voltage, utilizing an electric drive circuit (2) constructed to generate alternating voltage which can be connected to the device and the frequency of which is adapted, through a first control circuit (7), to a value (C1, L1) which momentarily corresponds to the resonance frequency of the reactive element which varies during a working operation. The first control circuit (7) is constructed to control momentary frequency in dependence on momentary phase difference between the current and voltage values of the alternating voltage. A second control circuit (4) is intended to control an inductive element (12) included in an oscillation circuit having a capacitive element (C2) corresponding, inter alia, to the form-changing device, such that the inductive element (C2) will obtain a value (1a) which corresponds to resonance for the prevailing alternating voltage frequency.
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