An improved TRIAC model for computer-aided analysis and design

A triac model is developed using current and voltage sources. The use of the triac instead of two antiparallel thyristors eliminates the memory problems with small computers, especially PCs, concerning the circuits containing several SCRs. The on-state characteristic is simulated with a series connection of constant resistance and polynomial voltage controlled variable resistance. The reverse recovery time is defined by a simple PC combination. The model is tested on the demo version of PSPICE and can be easily improved for other versions of SPICE. The device can be fired by positive as well as negative gate pulses. The disc can be easily simulated by small modifications of the triac model. The static and dynamic characteristics are presented.<>