Research Of Digital AC Voltage Controller Technology For LS-WEDM

Low-Speed Wire Electro-Discharge Machine ( LS-WEDM ) has higher machining efficiency and better surface quality, which meets the higher requirement to precision modules and precision parts of IT, Home Appliances, Automobile, Aeronautics and Astronautics, Military industry, mould industry and so on. The high efficiency pulse generator is one of the core components of LS-WEDM, whose voltage could be digitized adjustment to meet different machining condition.The recent research on the pulse generator of LS-WEDM in oversea and domestic are generally analyzed, basing on the reading to the related Chinese and foreign literature. Aiming at silicon controlled rectifier voltage controller has much disadvantage: slow power factor, low dynamic response speed and rich outputting low sub-harmonic. A new digital and higher efficiency system of AC-Chopping PWM voltage controller is designed. The begin and end phase of driving signals can be adjusted, avoiding the voltage out of controlling and protecting the power switch tube; and the system needn't zero dead-time, which improves the efficiency of voltage.The hardware and software of the system of voltage controller are designed. The programmable counter 8254 is the core component of the control board that can digitally adjust the pulse-width and periodic of riving signals to change the output voltage through signal chip computer modular and keyboards/displays modular. And the power amplifier board, adopting push-pull converter of MOS, drivers better to power switch tube IGBT.Making unit debug with hardware and software, includes changing pulse-width and pulse period to measure the different output voltage, making the curves about pulse-width and pulse period to analyze the influencing factors.