This article summarizes the hardware organization and working principles of the thyristor zeropassage trigger capacity control circuit which have a singlechip as its main body.

The shift trigger pulse of the thyristor trigger circuit with integration amplifier is generated by comparing directly principle of three-phase AC and shift-phase control voltage.

This article describes the design and debugging of three phase and six pulse thyristor trigger board based on TC787. The performance and application information of TC787 are also mentioned.