AC-AC conversion - TRIAC and phase control

The AC to AC converters are more complicated than the AC to DC converters because AC conversion requires change of voltage, frequency and bipolar voltage blocking capabilities, which usually requires complex device topologies. Converters that have the same fundamental input and output frequencies are called ‘‘AC controllers’’ and the conversion is from a fixed voltage fixed frequency to a variable voltage fixed frequency (as applications light dimmers and control of single-phase AC motors that are typically used in home appliances). Converters, which convert a fixed voltage fixed frequency to variable voltage variable frequency, are called “Cycloconverters”; they are used in high power applications driving induction and synchronous motors, usually phase-controlled and traditionally use thyristors due to their ease of phase commutation. Another way of achieving AC/AC conversion is by using AC/DC and DC/AC through an intermediate DC link. De Lorenzo, also here, has available two trainers: one allows the study of the light dimmer (using DIAC and TRIAC) with fault simulation and one to study in deep the TRIAC and the controlled AC/AC converters. They are dedicated to high schools and first years of university.