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US 4,600,917 AGranted
Gate-turn-off thyristor failure detecting circuit
AssigneeTokyo Shibaura Denki Kabushiki Kaisha
InventorsNagataka Seki, Shunichi Koike, Yukio Watanabe
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Abstract
A gate-turn-off thyristor failure detecting circuit includes a detector which detects an off-gate signal for a gate-turn-off thyristor and a current level detector which compares the signal with a predetermined value and produces an output signal indicative of the failure of the gate-turn-off thyristor.
Claims8
A gate-turn-off thyristor failure detecting circuit comprising:
- an off-gate signal source;
- a pulse amplifier connected to said off-gate signal source for amplifying the off-gate signal;
- a pulse transformer having primary and secondary windings, said primary winding being connected to said pulse amplifier;
- a gate pulse synthesizing circuit for producing a gate pulse which is applied to a gate of the gate-turn-off thyristor, said gate pulse synthesizing circuit being connected to said secondary winding of said pulse transformer;
- means for detecting a signal flowing through said primary winding of said pulse transformer;
- and
- means for comparing the output signal from said detecting means with a predetermined value to produce an output signal from said comparing means indicative of the failure of the gate-turn-off thyristor.
4 more elements
A gate-turn-off thyristor failure detecting circuit for detecting the failure of one or more units in a plurality of interconnected gate-turn-off thyristors, the circuit comprising:
- an off-gate signal source;
- a plurality of pulse amplifiers each connected to said off-gate signal source for amplifying the off-gate signal;
- a plurality of pulse tansformers each having primary and secondary windings, each of said primary windings being connected to a different one of said pulse amplifiers;
- a plurality of gate pulse synthesizing circuits each for producing a gate pulse which is applied to a gate of a different one of the interconnected gate-turn-off thyristors, each of said gate pulse synthesizing circuits being connected to the secondary winding of a different one of said pulse transformers;
- a plurality of means for detecting a signal flowing through said primary winding of a different one of said pulse transformers;
- and
- means connected with each of said plurality of detecting means for comparing the output signals from said plurality of detecting means with a predetermined value to produce an output signal from said comparing means indicative of the failure of one or more gate-turn-off thyristors.
4 more elements
Dependencies are inferred from the claim text.