My goal is to implement digitally-controlled reverse-phase-control (dimming) of 120V/60Hz AC power, using IGBTs as the switching device and a micro-controller to control them. The reason I am using IGBTs instead of TRIACs is because TRIACs cannot realize reverse-phase-control. IGBTs can, and can be turned off slowly, reducing current spikes and thus reducing EMI - which is a requirement for my application. Anyways I will probably use this thread to pose a number of questions as I continue to develop my device. Short disclaimer: this forum will not let me include URLs in to this post until I have posted more, so please bare with me for the time being: I can only include part numbers, without links to their respective data-sheets. So, to start off: While phase control is my ultimate goal, for now I would like to be able to just switch the AC on and off. I have the AC side of the switching circuit already worked out, I just need some help with the gate drive circuitry. The IGBTs that I have in my possession are the irg4rc10u To provide the typical +/- 15 volts to drive the gates, I have opto-coupled DC/DC converters. The ones I have are the VASD1-S5-D15-SIP series. Though the DC/DC devices are opto-coupled, would I still need an opto-coupled IGBT driver such as the HCPL-J312, or can I drive the IGBTs directly from the DC/DC converters?