| 摘要 |
PURPOSE:To set a voltage value with high accuracy, by controlling a driving motor for an electromotive transformer which operates windings split into two summetrically for the feedback correction of the fluctuation of secondary voltage of the transformer. CONSTITUTION:In a thermal device such as a welder, an AC power supply 1 is connected to a primary terminal 4 of an eletromotive transformer 16 and a load 30 is connected to a secondary terminal 5 set to a specified voltage. A welding condition code inputted to the terminal 15 is converted into an analog signal at a D/A converter 12 via a register 14 and a selector 13 and given to a control amplifier 8. The amplifier 8 reduces voltage fluctuation and makes a spedified amplification via an error amplifier 7, applies a DC voltage of both polarities to motors 2 and 2' of the same standards, drives the slider of the transformer 16 symmetrically at the same time and gives a specified voltage to the load. The amplifier 7 inputs the fluctuation voltage at the secondary of the transformer 16 via an absolute circuit 6 and an external signal from the amplifier 8 for amplification to achieve feedback correction in high speed through the motor drive. |
