Design of Thyristor Digital Trigger Circuit Based on Microcontroller Unit

In the current paper, a kind of thyristor digital trigger circuit, based on 8-bit microcontroller unit, is designed. The circuit can be used to trigger the three-phase full-controlled-bridge rectifier circuits. It adopts single phase voltage as the synchronization signal; 6-channel trigger pulses from it are very symmetrical and the pulses can be shifted within a cycle of a sine wave from 0 degree to 180 degree. The circuit consists of a microcontroller unit, a keyboard, a LED display, synchronization shift phase module and trigger pulses output module and so on. Its structure is simple; its performance is high stable and reliable; its anti-interference ability is strong and its operation is easy. The hardware structure of the trigger circuit and its principle are the emphasis of this paper and especially the process of generating of the trigger pulses has a detailed description.