MOS Controlled Thyristor Precaution
- MCT works as a gate controlled device if its current is less than a value called peak controllable current. If we try to turn off the MCT when current through it is higher than its rated peak controllable current, then the MCT may get destroyed. Hence for higher values of currents, we should turn off the MCT just like the conventional SCR.
- We should use a wider turn off gate pulse if the MCT is to be turned off at higher currents. In many applications a continuous gate pulse should be applied over the entire on/off period to avoid ambiguity.
Important Features of MOS Controlled Thyristor (MCT)
- MCT has a low forward on state voltage drop.
- It has a short turn on time typically 0.4 µS.
- It also has a short turn off time (1.95 µS typically).
- Typical voltage and current ratings : 500 V and 300 A.
- Low switching. loss due to shorter turn on and turn off delays.
- The blocking capacity of MCT is lower than that of SCR.
- High input impedance due to MOS gate structure.
- The gate driving circuit of MCT is simple.
- It is easy to parallel MCTS for carrying higher currents.