The invention relates to an experimental tester with an automatic switching device, which comprises an adjustable
single phase current output unit, an analog breaker unit, a three-phase
alternate current and
voltage output unit, an auxiliary
relay, a central proceeding unit and a computer. The analog breaker unit comprises three independent analog breakers and operation power sources; each analog breaker circuit
beaker is provided with corresponding
tripping and switching instruction input port, a
tripping and switching setting port and an output normally-closed contact port or normally-
open contact port; normally-open contacts of two control switches and three analog breakers form
voltage which is output; a common end of the
central processing unit is connected with the operational power source; the output end of the
central processing unit is respectively connected with the
tripping and switching setting port of each analog breaker; a
voltage control end of the
central processing unit is respectively connected with the input ends of the two control switches and the auxiliary
relay; and the central
processing unit is connected with the computer, can generate various signals required by the experiment, and has the characteristics of simple structure, convenient operation and improvement on the working efficiency of the experiment.