| 摘要 |
PROBLEM TO BE SOLVED: To provide a sine wave converter with filtering function which has a function corresponding to an active filter for normally maintaining the sine wave waveform of a power supply circuit. SOLUTION: A sine wave converter with a filtering function converts a sine wave input from the predetermined AC power supply circuit 1 into a preset DC voltage. In this case, the filtering function is provided also to detect any one of the high frequency harmonic elements or current elements of a delay current element from a load current or both of these current elements and to generate a high frequency harmonic element control signal, corresponding to these current elements, in order to maintain the AC power supply circuit current to the sine wave by adding the high frequency harmonic element to the sine wave converter control signal. This filtering function includes a load current detecting function 21, a harmonic detecting function 22 to detect the harmonic included in the load current detected by the load current detecting function 21 as the harmonic control signal of a predetermined shape an the addition of the harmonic control signal detected by the harmonics detecting function 22 to the sine wave converter control signal as the compensating signal. |
