Automatic electron beam deflecting circuit

摘要

Apparatus for use in conjunction with a work piece positioned on a work table and having an interface spaced from the work table which is provided for controlling the impingement of the beam from an electron beam welder upon the interface. A search unit coupled to the work table both generates a sense wave pulse along the work piece and receives an echo from the work piece interface. A timing circuit is operatively coupled with the search unit and determines the elapsed time between the generation of the sense waves pulse and the receipt of the echo from the interface so that the elapsed time is representative of the distance of the interface from the work table. In response to the elapsed time determined by the timing circuit, a control unit generates electrical signals to a deflection coil magnetically coupled with the electron welder beam to position the beam so that the beam impinges upon the work piece interface.