| 摘要 |
PURPOSE:To eliminate a phase advancing capacitor, a changeover switch and a relay by operating an inverter for a single phase or 3 phases by switching a program contained in a microprocessor. CONSTITUTION:3-phase AC is converted to a DC voltage EDC by a converter 4 having diodes D1-D6, and smoothed by a capacitor C. A microprocessor 3 controls an inverter 1 having transistors Tr1-Tr6 through a PWM generator 2. A PWM generator 2 has switching means 7, single phase driving means 5 and 3-phase driving means 6. It is switched by a command from the microprocessor 3, and the Tr1-Tr6 are operated in a single phase motor or 3-phase mode in response to a load. A reverse switching, speed regulation are conducted by altering the program of the microprocessor 3. Thus, a phase advancing capacitor, and a switch are eliminated. |
