Wire Feed-Rate Controller

摘要

An electronic wire feed-rate controller has been developed at Sandia Laboratories, Livermore for remotely controlling the rate and direction of the wire intersecting an electron beam during cold-wire welding operations. This is accomplished by regulating pulses to a high-speed stepping motor attached to a mechanism (located within the vacuum chamber) which propels wire into the beam path. Metallic parts are thus joined by the resultant molten wire. The design permits programming by front-panel switches for wire speed, start-time delay, rate of change of wire speed for starting and stopping (linear up-slope and down-slope time), and automatic retract time. Wire speed may also be controlled by a remote computer. Each of these parameters is explained in specifications listed in the next section. Although especially developed for welding applications within a vacuum, its use can be considered for other applications where precise motor control is required. The instrument's output is compatible with any 4-phase unipolar stepping motor requiring 5 amperes or less per phase. Maximum pulse rate is 10 kHz. The solid state design utilizes integrated circuits of the complementary metal-oxide-semiconductor family (CMOS) mounted on plug-in printed wiring cards. A photograph of the controller is shown. Detailed drawings are given. (ERA citation 03:048482)