| 摘要 |
PURPOSE:To operate a load such as a motor in a high efficiency by controlling a voltage reference signal on the basis of the specific waveform, thereby equalizing the peak value of the voltage between output lines always to that of the input voltage. CONSTITUTION:A frequency command 1 is converted by a V/F converter 2 to a pulse train, which is counted by a counter 3. The output of the counter 3 is inputted to ROMs 4a-4c, addressed by the counted value outputted from the counter 3, and a function value is outputted. The function value is inputted to a multiplication type D/A converters 5a-5c, and multiplied by the output from the frequency instruction unit 1. The outputs of the converters 5a-5c are compared with the output of a triangular wave generator 7, and an output for controlling the inverter is lead. The inverter can be controlled to output a voltage between the lines of the peak value equal to the input DC power source voltage by setting the function values from ROMs 4a-5c to the prescribed value. |
