Electrical apparatus and a limiting method

摘要

An electrical apparatus for limiting the peak voltage across a recttifying member (23) of a current valve arranged in a circuit having a substantial inductance (24) and having at least one controllable semiconductor device (22) and at least one said rectifying member (23) connected in anti-parallel therewith when the rectifying member is turning off, comprises means (28, 29) adapted to control the semiconductor device so as to increase the conductivity thereof during turning off of the rectifying member.