main terminal 1 (MT1) (of a bidirectional triode thyristor)

The main terminal intended by the thyristor manufacturer to conduct the control current in addition to the principal current.

NOTE Some bidirectional triode thyristors are completely symmetrical, e.g., SBS thyristors. For these, the choice for the manufacturer is arbitrary, and the user can return the control circuit to whichever main terminal will provide the required polarity of gate current.