Application of MOSFET Solid State High Frequency Power Supply in Pipe Welding
According to the comparison of solid state high frequency power supply and electron tube high frequency pipe welding power supply, it could be concluded that solid state high frequency power supply is more efficiency, more security, longer life-span and will replace electron tube high frequency pipe welding power supply in not very long time in this field. In this paper, a solid state high frequency pipe welding power supply using MOSFET as the inverter switch components is designed, its operating principle is analyzed, the key technique of section of rectifier and inverter is discussed and the load adaptability, frequency tracking, output power are explained in detail. From the simulation and experiment, it can be seen that the designed method is reasonable and the whole device is high efficiency
Specifics of Pulsed Arc Welding Power Supply Performance Based On A Transistor Switch
Specifics of designing a pulsed arc welding power supply device are presented in the paper. Electronic components for managing large current was analyzed. Strengths and shortcomings of power supply circuits based on thyristor, bipolar transistor and MOSFET are outlined. As a base unit for pulsed arc welding was chosen MOSFET transistor, which is easy to manage. Measures to protect a transistor are given. As for the transistor control device is a microcontroller Arduino which has a low cost and adequate performance of the work. Bead transfer principle is to change the voltage on the arc in the formation of beads on the wire end. Microcontroller controls transistor when the arc voltage reaches the threshold voltage. Thus there is a separation and transfer of beads without splashing. Control strategies tested on a real device and presented. The error in the operation of the device is less than 25 us, it can be used controlling drop transfer at high frequencies (up to 1300 Hz).
Far-field dispersal modeling for fuel-air-explosive devices
A computer model for simulating the explosive dispersal of a fuel agent in the far-field regime is described and is applied to a wide variety of initial conditions to judge their effect upon the resulting fuel/air cloud. This work was directed toward modeling the dispersal process associated with Fuel-Air-Explosives devices. The far-field dispersal regime is taken to be that time after the initial burster charge detonation in which the shock forces no longer dominate the flow field and initial canister and fuel mass breakup has occurred. The model was applied to a low vapor pressure fuel, a high vapor pressure fuel and a solid fuel. A strong dependence of the final cloud characteristics upon the initial droplet size distribution was demonstrated. The predicted fuel-air clouds were highly non-uniform in concentration. 18 refs., 86 figs., 4 tabs.