IGBT stands for Insulated Gate Bipolar Transistor, and as the name implies, it is more-or-less a transistor. An IGBT has 3 pins, just like a transistor, and they are Collector, Emitter, and Gate.
The first step to hooking up your IGBT is to connect the emitter to ground..
Next you connect one conductor of your load to the collector of the IGBT.
The other conductor of your load goes to your voltage source.
Next the gate is connected to your control device.
We found that our particular IGBT responded best to a gate voltage ranging from 4-6 volts (referenced to the emitter). The higher the gate voltage, the more power the IGBT will allow to flow from collector to emitter thus increasing the voltage available to the load and, in our case, increasing the brightness of our light bulb.
As mentioned in other places on this wiki, and IGBT will only be able to control positive voltages. If a negative voltage (or the negative portion of an AC signal) is sent to an IGBT it will either, depending on the type of IGBT A) pass this voltage through untouched, or B) block this voltage from passing. The particular IGBT which we used allowed this voltage to pass untouched.
DIagram of IGBT