Control loop measures weld-spot temperature to regulate focus current. Square-wave generator modulates current in electron-beam focus coil so that focal point is varied between points slightly above and below surface of weld. Sensor detects intensity of light emitted by weld, proportional to fourth power of temperature at hottest part of weld spot. Sensor signal is detected by chopper demodulator synchronized by square-wave generator, to determine whether average position of focal point is higher than, coincident with, or lower than optimum point; and focus coil current is adjusted accordingly.
Controlling Electron-Beam-Weld Focus
NASA Tech Briefs ; 6 , 3
1982-12-01
Sonstige
Keine Angabe
Englisch
Controlling the Focus in Electron-Beam Welders
NTRS | 1984
|Portable electron beam weld chamber
NTRS | 1972
|