8)
The IGBT(Insulated Gate Bipolar Transistor) like it name sound, have a two transistor structure, MOS-FET + bipolar, and is controlled on MOS-FET gate terminal. So, I supose that your drive circuit is the circuit for driving the IGBT gate.
Usually the control circuit for a bridge or half bridge is designate for control eatch IGBT through a gate drive circuit.
The power supply, I supose, is for this control circuit and all gate drive circuits.
The gate drive circuit for IGBT is very similar with one for MOS-FET.
Bellow is a gate drive circuit designated to drive a IRF740 MOS-FET from a half bridge of a switching DC source.
[/img]