Chapter 27: Power Supplies
MULTIPLE CHOICE
1. When selecting a transformer, its ____ is the first concern.
a.
primary power rating
c.
secondary voltage and current ratings
b.
frequency
d.
power-handling capability
2. With a ____ rectifier, the frequency of the pulses is the same as the input frequency.
a.
filter
c.
bridge
b.
full-wave
d.
half-wave
3. The basic ____ rectifier circuit requires two diodes and a center-tapped transformer.
a.
half-wave
c.
bridge
b.
full-wave
d.
filter
4. With a full-wave rectifier, the ripple frequency is ____ the input frequency.
a.
half
c.
thrice
b.
twice
d.
quadruple
5. The diodes in half-wave and full-wave rectifiers should be operated at ____ of their rated value to
allow for changes in the input voltage.
a.
20%
c.
60%
b.
40%
d.
80%
6. A ____ provides constant output regardless of load and input voltage changes.
a.
voltage multiplier
c.
voltage regulator
b.
rectifier
d.
filter circuit
7. Circuits that are capable of producing higher DC voltages without the benefit of a transformer are
called ____.
a.
voltage multipliers
c.
over-voltage protection circuits
b.
rectifiers
d.
filter circuits
8. A ____ is a circuit designed for over-voltage protection.
a.
fuse
c.
circuit breaker
b.
varistor
d.
crowbar
9. To protect circuits against excessive transient voltage, a ____ is used.
a.
fuse
c.
varistor
b.
crowbar
d.
circuit breaker
10. A ____ is a device that fails when an overload occurs.
a.
varistor
c.
crowbar
b.
fuse
d.
circuit breaker
COMPLETION
1. The function of the ____________________ circuit is to convert the incoming AC voltage to a DC
voltage.
2. A bridge rectifier is a type of ____________________ rectifier because it operates on both half-cycles
of the input sine wave.
3. The ____________________ converts the pulsating DC voltage to a smooth DC voltage.
SHORT ANSWER
1. Discuss the advantages and disadvantages of the full-wave rectifier.
2. Discuss the two basic types of voltage regulators.
