Design Project: DC Voltage Regulator

Discrete Semiconductor Devices and Circuits

PDF Version
  • Question 1

    It may seem difficult to even start on a project such as this, with no schematic diagram provided. Identify a few different sources of information where you might find sample voltage regulator circuits, to begin your design from.

    Why do you suppose your instructor decided to challenge you with a project such as this, with no schematic diagram to follow and plenty of things to potentially go wrong?

    Reveal answer
  • Question 2

    When designing a project such as this, it is a good idea to “prototype” the circuit before soldering components together, where they will be more difficult to replace, exchange, and reconfigure. Explain how you intend to prototype your circuit prior to assembling it in its final form.

    Reveal answer
  • Question 3

    Your circuit will no doubt use a zener diode to establish the reference voltage. The zener diode circuit itself (including the series “dropping” resistor) is incapable of supplying high current to a load. How, then, does your circuit manage to supply at least 2 amps to the load, when using a zener voltage reference?

    Reveal answer
  • Question 4

    Make a rough calculation of the power your circuit’s final output transistor(s) must dissipate when carrying the full 2 amps of current. Will the power dissipation be greatest at maximum voltage (20 volts) output or minimum voltage (3 volts) output? Explain why.

    Reveal answer
  • Question 5

    The best regulator designs use feedback to ensure “tight” regulation of voltage over a wide range of load currents. Explain what this “feedback” is, and how it works to improve voltage regulation.

    Reveal answer