| 摘要 |
PURPOSE:To interrupt operation of the captioned machine when electrical discharge is produced in an electron gun by detecting a current flowing in a circuit and voltage applied to load, and operating a high-tension interruption device in a state thereof insulated from an earth by means of optical fibers. CONSTITUTION:A high-tension main circuit of an electron beam processing machine is adapted to have a high-tension power source 1, an electron gun 2, and a high-tension interruption device 3, and adapted to interrupt operation of the electron gun 2 by making use of the high-tension interruption device 3 when electrical discharge is produced in the electron gun 2, and return it to an original state after the elapse of prescribed time for protecting the device. A control circuit 4 thereupon receives signals from a beam current detector circuit 6 disposed serially between the high-tension power source 1 and an earth and an accelerating voltage detector circuit 7 arranged parallely to the high-tension main circuit for controlling the high-tension interruption device 3 with use of optical fibers 5. Accordingly, a problem of dielectric strength of the device against the earth can be eliminated to prevent any electrical discharge form being produced in the electron gun 2 for applying the captioned machine with ease to existing processing machines. |
