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Semiconductors & Devices



Having played a central role in the modernization of power electronics in the 1960s, large capacity thyristors are now handling higher voltages and currents. In the 1980's, it evolved from a reverse blocking thyristor without self turn off function to GTO(Gate Turn off) thyristor that switches from ON to OFF state by applying a negative gate signal even in a DC circuit. Furthermore, the GCT (Gate Commutated Turn off) thyristor which inherited the basic structure of the GTO thyristor and greatly reduced the impedance of the gate realized high speed operation and high turn off performance. We line up high power products such as GCT thyristors, GTO thyristors and Ultra high voltage thyristor which have long experience in the field.

  • GCT thyristors are 6,000-6,500V/400-6,000A
  • GTO thyristors are 2,500-4,500V/1,000A-4,000A
  • Ultra high voltage thyristor is 12,000V/1,500A

Features of SGCT thyristor unit

In particular, the SGCT (Symmetrical Gate Commutated Turn off) thyristor unit is a reverse voltage blocking type GCT thyristor. By combining optimally designed gate drivers, excellent SGCT thyristor’s performance is realized and contributing to shortening system design period.

  • Realization of high voltage reverse blocking type: Rated voltage: forward/6,500 V, reverse/6,500 V.
  • It inherits the low on-voltage characteristic which is the feature of thyristors.
  • Suitable for high voltage circuit breaker, current source inverter applications.

Main Applications

High voltage inverter / Frequency changers / SVG (Static Var Generator) / BTB (Back-to-Back) / AC/DC switches / Traction propulsion system


Product Rating current Rating voltage
2.5kV 4.5kV 5.0kV 6.0kV 6.5kV 12kV
GCT SGCT Thyristor Unit 400A          
GCT Thyristor 6000A          
GTO Thyristor 1000A          
Thyristor 1500A          

Data Sheets

View data sheets for Thyristors