| 摘要 |
PURPOSE:To keep an output current in constant and control a load so that V/F is constant by a method wherein the output voltage of a power transistor circuit is reduced when the value of the output current is higher than a set value while the output voltage is increased when the value of the output current is lower than the set value. CONSTITUTION:Upon the control of an inverter for a compressor 1, a set value in accordance with a predetermined V/F pattern is read out and the set value is compared with the detected value of the output current of a power transistor module unit 2. The data of voltage is processed by the result of the comparison and the output voltage is increased when the detected output current is larger than the set value while the output voltage is reduced when the detected output current value is smaller than the set value on the contrary whereby the output current of the power transistor module unit 2 can be kept constant. Even when there is an error in the data stored in a memory unit 10, the error is corrected. |
