Since 1961 E.O.Paton Electric Welding Institute has developed not less than 10 types and has provided manufacturing more than 600 complete sets of the power electron beam welding units : gun with power supply and control system. The developed units not only meet the stringent requirements of ISO 14744 on time stability of power parameters of the electron beam (the limit deviations of U acc and I beam is less than +/-1%), but also provide the possibility of:
- pulse modulation of beam current;
- short-time transition from welding to a sharply-focused low-power probing of the welding zone for its real-time secondary electron imaging and, simultaneously, automatic guiding of the beam to the butt being welded;
- prevention of arc discharges in the welding gun and the resulting defects in the welds.

Up to 6 kW power sources use generators based on high-frequency transistor converters. called "switching". Due to a low stored energy of' up to I - 2 J/kW development of spark discharges into arc discharges is essentially impeded, when using such sources, thus preventing the operation of current protection of the power source.

General view of 60 kV, 6 kW power unit with high-frequency generator of accelerating voltage is given on the left in the photo.

In higher power sources of 60kV ,60kW (left) and 120kV,120kW (right) an electron tube is used as linear control element, which essentially improve the power source dynamic characteristics.