Question 1

What is an Insulated Gate Bipolar Transistor (IGBT), and what advantages does the IGBT provide over both power MOSFET and traditional BJT devices?


Question 2

Complete the schematic diagram showing an equivalent circuit for an N-channel IGBT, using an N-channel E-type MOSFET and a PNP bipolar transistor:


Question 3

The equivalent circuit for an IGBT - comprised of a MOSFET coupled to a BJT - bears resemblance to a couple of other BJT circuits you may have seen before:

Which of these two paired-BJT circuits most resembles the IGBT equivalent circuit, in terms of what two terminals the control signal voltage must be applied between to turn the device on?


Question 4

Draw a complete schematic diagram showing how this IGBT can be used to control a DC motor, at the command of the toggle switch:

Note: the DC power supply voltage is 240 VDC, and the IGBT’s maximum gate-to-emitter control voltage is 20 volts!


Question 5

Examine the schematic diagram for this photographic strobe light control system:

Explain its operation, and explain why an IGBT is a good transistor type for this application.


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