Having played a central role in the modernization of power electronics in the 1960s, large-capacity thyristors are now handling higher voltages and currents. They evolved from the reverse-blocking thyristors with no self arc extinction capability to the self arc extinction type GTO (Gate Turn Off) thyristors that switch from on to off when negative current is applied to the gate, even in a DC circuit. However, as this requires a drive circuit whose negative current has to be a fifth of the main current, we tried to achieve faster operation by developing the GCT (Gate Commutated Turn-off) thyristor that brings low impedance to the GTO's gate.


  • Thyristors for general use are 400-12,000v/1,000A-5,000A
  • High-speed switching thyristors are 1,200-2,500V/800-1,500A
  • GTO thyristors are 2,500-6,000v/1,000A-6,000A

Lineup includes GCT Thyristor Unit (GCU)

  • Turns off only in clamp circuits
  • Reduction of turn-on time enables series-parallel connection.
  • Series of CGT thyristor units that are integrated with optimally designed gate drivers

Main Applications

High frequency changers (high voltage inverters)/DC choppers AC/DC switches/SVG (reactive power generators)/BTB (power system link devices)


a list of  thyristors functions

Data Sheets

View data sheets for Thyristors