Description
The STEVAL-ILD005V1 evaluation board implements a simple and cost-effective MOSbased reverse phase cut dimming solution for analog wall dimmers using a pair of STF17N62K3 power MOSFETs controlled by a triple 3-input NOR gate to effectively dim either resistive or capacitive lighting loads (i.e. halogen lamps, electronic low voltage transformers and various dimmable CFL/LED lamps). The AC analog control dimming technique employed allows for both on/off power switching and up/down dimming functions through a single linear rotary potentiometer equipped with a mechanical switch which opens the circuit at minimum setting. Control of the board is achieved using a triple 3-input NOR gate (pin-to-pin compatible with a ST's HCF4025BE 14-lead dual in-line CMOS gate logic device in plastic SO-14 micropackage) which acts as a gate driving voltage signal source, performs zero crossing detection and timing through the use of a few other passive components and diodes.