AN440 QII和QIII可控硅触发与电源正极

AN440 QII和QIII可控硅触发与电源正极

AN440
Application note

QII and QIII TRIAC triggering with positive power supply

Introduction
New TRIACs with high commutation and dv/dt performances are now available on the
market.
Generally these TRIACs can be triggered only in the first three quadrants (case of
Snubberless, logic level and Snubberless high temperature TRIACs) as shown in
Figure 1.
This paper describes a trigger circuit supplying a negative gate current for quadrants II and
III implemented in a system using a positive power supply.
Withou