The Paton Welding Journal, 2011, #5, 24-27 pages
SIMULATION OF THE EFFECT OF HIGH-VOLTAGE CABLES ON CURRENT RIPPLE IN WELDING GUNS WITH AUTOMATIC BIAS
O.K. NAZARENKO, V.A. MATVEJCHUK and V.V. GALUSHKA
E.O. Paton Electric Welding Institute, NASU, Kiev, Ukraine
The mechanism of formation of current ripple in welding electron guns with automatic bias caused by ripple of the cathode bombardment current is studied by using computer mathematical simulation. It is shown that when using the coaxial high-voltage cable the ripple of the cathode bombardment current does not affect the ripple of the beam current. In case of a multi-core cable or four separate single-core high-voltage cables the ripple of the cathode bombardment current causes the ripple of the beam current because of the parasitic capacitance currents flowing through the beam current control circuit. To decrease the beam current ripple factor to 0.05, the cathode bombardment current ripple factor at a frequency of 20 kHz should not exceed 0.05 either.
electron beam welding, high-voltage cable, distributed capacitances, electron gun, triode emission system, automatic bias, cathode bombardment current ripple, beam current ripple
1. ISO 14744-1: Welding Д acceptance inspection of electron beam welding machines. Pt 1: Principles and acceptance conditions.
2. Rolf, M. Strahlstromsteuerung fuer eine Elektronenstrahlschweissmachine. Pat. 24 60 424 Deutsche. Int. Cl. H 01 J 37/24. Publ. March 17, 1977.
3. Nazarenko, O.K., Lanbin, V.S. (2007) Investigation of high voltage control circuits of welding electron beam current. The Paton Welding J., 5, 17-20.
4. Amelina, M.A., Amelin, S.A. (2007) Circuit simulation software Micro-Cap 8. Moscow: Gor. Liniya Telekom.
5. Koren, N. (1996) Improved vacuum-tube models for SPICE simulation. Glass Audio, 8(5).