High-voltage pulse rise time decreasing using transmission coaxial and spiral lines with ferrite

This article presents the results of a study of the formation of a short rise time of a powerful nanosecond 410 kV pulse. Ferrite filled coaxial transmission lines with standard inner conductor and construction in the form of a spiral are designed. The sharpening of the pulse occurs due to the appearance of an electromagnetic shock wave in the ferrite. The value of the rise time at the level of 0.1 - 0.9 has been decreased from 4.5 to 2.5 ns.

Energy parameters of the vehicle electromagnetic shock absorber

The creation of an electromagnetic shock absorber system is necessary taking into account such parameters of the vehicle and operating conditions as the quality of the roadway, the grades, and the weight and size of the vehicle. A mathematical simulation model of the vehicle was developed to determine energy indicators in various road sections. The MATLAB Simulink programming environment was chosen to create the most practical and functional simulation model. A number of experiments were carried out using various parameters of the vehicle, types of roadways and driving cycles. Simulation results allow obtaining basic characteristics of electromagnetic damper of the selected vehicle, on the basis of which a linear electromagnetic damper shock absorber will be calculated. System energy efficiency was determined when using a vehicle on roads having a different road surface evenness index.

DETECTION OF ADHESION-FREE AREAS AND EXFOLIATIONS IN MULTILAYER STRUCTURES BY THE ACOUSTIC-TOPOGRAPHIC METHOD

Physical the bases of acoustic-topographic method of defektoskopiya of multilayer structures are briefly covered. Installation for implementation of acoustic-topographic method in two options is developed and mounted: with the magnetostrictive activator and with the electromagnetic (shock) activator. By pilot studies it is established that at control by acoustic-topographic method of brazed and welded structures sensitivity of control significantly (in 2–3 times) is higher, than at control by other methods of defektoskopiya. It is established also that the zone of control of multilayer glued structures is much less, than at control of brazed and welded structures. It is shown that the greatest thickness of the upper leaf of structure at which control by acoustic-topographic method with sufficient sensitivity is still possible, is equal to about 1 mm, at control of structures with thickness of the upper leaf initiation of elastic oscillations it is reasonable to carry out over 1 mm in the shock way. Repeated control with change of point of input of ultrasonic oscillations is in certain cases necessary for specification of picture of distribution of powder near initial point of input of oscillations.