procedure and device for control of a freely selectable halvledarposition in an electric halvledarventil

摘要

A method and a device for functional testing of an optional semiconductor position (TS1, TS2, ...TSN) included in an electric semiconductor valve (V), which semiconductor valve comprises a plurality of semiconductor positions with mutually series-connected semiconductor devices (T1, T2, ...TN), wherein each of the semiconductor devices may be brought into a conducting state by being supplied with a firing pulse, whereby a first indicating signal (IP) is formed when the forward voltage exceeds a predetermined first level (U1). In each one of the semiconductor positions there is arranged a recovery protection unit (RP) which, in case of faultless function, initiates a firing pulse when the voltage across the semiconductor exceeds a predetermined second position(URP). The chosen semiconductor position is supplied alone with an activation signal (FPP) and the other semiconductor devices included in the semiconductor valve are brought into a conducting state in dependence on the firing signals (FP) supplied to the respective semiconductor positions. Said activation signal is of a first duration ( tau ), so chosen that the forward voltage across the semiconductor position during said first duration reaches a level which exceeds the second level. A firing pulse for the chosen semiconductor position and a second indicating signal are formed in dependence on said activation signal. A first function signal (a1) is formed in dependence on said second indicating signal.