| 摘要 |
The invention relates to a device for power adjustment, by phase control of an alternating current, supplying an electrical user (14) and for reduction of the harmonic waves arising from the phase control, in particular, up to the region of 4 kHz, preferably in the range of the third harmonic wave, with a first circuit element (12) (TRIAC) in series with the user (14), controlled by a control device (20), for carrying out a phase control. The device is characterised in that a second circuit element (34) is provided in series wi th a resistance element (32), whereby the series circuit is arranged parallel t o the first switching element (12) and the control device (20) is embodied suc h as to control the second switching element (34) shortly before the first switching element (12) and to switch for a short duration into the conductin g state. The invention further relates to a method for reduction of harmonic waves in the region to 4 kHz, preferably the third harmonic wave, on power adjustment by means of phase control.
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