Module 3.5

Switched Mode Power Supplies Quiz

Try this quiz, based on the information you can find in Power Supplies Module 3. Submit your answers and see how many you get right. If you get any answers wrong, just follow the hints to find the right answer, and learn about Switched Mode Power Supplies as you go.

1.

Which answer from the following list is a major advantage of switched mode power supplies over series regulated supplies?

a) Switched mode supplies create smaller amplitude ripple waveforms than series regulators.
b) Switched mode supplies dissipate less power in the control element than series regulators.
c) Switched mode supplies provide better regulation at low power than series regulators.
d) Switched mode supplies work digitally, so are more efficient than series regulators.

2.

Which answer from the following list is a disadvantage of switched mode power supplies compared with series regulated supplies?

a) Switched mode supplies are less suitable for high power applications.
b) Switched mode supplies are more expensive to implement than series regulated supplies.
c) It is more difficult to prevent high frequency electrical interference in switched mode supplies.
d) Over voltage protection is not possible in switched mode power supplies.

3.

Which one of the following acts as an energy store in a DC to DC Converter?

a) The inductor.
b) The high frequency switching transistor.
c) The load.
d) The flywheel diode.

4.

Refer to Fig 3.5.1. Which of the following components is not active during the ON period of the switching waveform?

a) Tr1
b) D1
c) L1
d) C2

5.

What type of circuit is illustrated in Fig 3.5.2?

a) Buck Converter.
b) Boost Converter.
c) Buck-boost Converter.
d) Flyback Converter

6.

Which of the following is one of the main advantages of a push-pull converter compared to buck or boost DC to DC converters?

a) It works at twice the frequency of other DC to DC converters.
b) It uses pulse width modulation.
c) It provides an output voltage of twice the amplitude of the input .
d) It uses a transformer to isolate the output from the input.

7.

Which of the following statements is true of a Buck-Boost Converter?

a) The output power may be less than, or greater than the input power.
b) The output voltage is always greater than the input voltage.
c) The output current is always greater than the input current.
d) The output voltage may be less than, or greater than the input voltage.

8.

Refer to Fig. 3.5.3. What is the purpose of Tr1 and Tr2?

a) They act with Tr3 and Tr4 to form two Darlington Pair output stages.
b) They isolate the output transistors from the common ground connection.
c) They speed up the switch off time of the output transistors.
d) They integrate the square wave signals to the bases of Tr3 and Tr4.

9.

Refer to Fig. 3.5.3. What is the purpose of IC2?

a) It acts as a comparator for the current limiter.
b) It acts as an error amplifier for the current limiter.
c) It acts as a comparator for the over voltage control.
d) It acts as an error amplifier for the over voltage control.

10.

Refer to Fig. 3.5.3. What type of signal will be present at pin 4 of IC3.

a) 50kHz pulses with an amplitude proportional to the output voltage.
b) A DC voltage proportional to the output current.
c) 100kHz pulses with an amplitude proportional to the output current.
d) A DC voltage proportional to the output voltage.

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Module 3.5

Switched Mode Power Supplies Quiz

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