ECE 421 Power Supply: Voltage Regulation and Transformers

What is the primary function of a regulator circuit in a power supply?

To maintain a constant DC voltage despite variations in the input line voltage or load (correct)
To filter out fluctuations in the DC voltage
To convert AC voltage to DC voltage
To increase the DC voltage output

What is the purpose of a transformer in a power supply?

To convert DC voltage to AC voltage
To change AC voltages based on the turns ratio between the primary and secondary (correct)
To filter out ripples in the DC voltage
To regulate the output voltage

What is the process of converting alternating current (AC) to direct current (DC)?

Regulation
Transformation
Filration
Rectification (correct)

What is the output of a half-wave rectifier?

A pulsating DC voltage with one non-alternating polarity (D) Signup and view all the answers

What is the function of a filter in a power supply?

To eliminate fluctuations in the rectified voltage (D) Signup and view all the answers

What is a load in a power supply circuit?

A circuit or device that operates from the power supply voltage and current (B) Signup and view all the answers

What is the no-load output DC voltage of an ideal half-wave rectifier for a sinusoidal input voltage?

Vdc = Vpeak / π (B) Signup and view all the answers

What is the main advantage of a full-wave rectifier compared to a half-wave rectifier?

Higher average output voltage (A) Signup and view all the answers

What is the configuration of a center-tapped full-wave rectifier?

Two diodes connected to the secondary of a center-tapped transformer (A) Signup and view all the answers

What is the main difference between a center-tapped full-wave rectifier and a bridge full-wave rectifier?

Transformer turns ratio (D) Signup and view all the answers

What is the definition of rectifier efficiency?

Ratio of DC output power to AC input power (A) Signup and view all the answers

What is the purpose of a full-wave rectifier?

To convert AC to pulsating DC with a constant polarity (C) Signup and view all the answers

What is the main reason for the efficiency of ideal rectifiers being less than 100%?

The presence of AC power in the output (C) Signup and view all the answers

What is the maximum efficiency of a half-wave rectifier?

40.53% (D) Signup and view all the answers

How do smoothing circuits improve the efficiency of rectifiers?

By reducing the ripple and AC content (A) Signup and view all the answers

What is the benefit of using three-phase rectifiers over single-phase rectifiers?

They have inherently smaller ripple and higher efficiency (C) Signup and view all the answers

What is the arrangement of the four diodes in a bridge rectifier?

In series pairs (B) Signup and view all the answers

What is the primary cause of efficiency reduction in rectifiers?

Losses in the transformer windings (C) Signup and view all the answers

What is the main advantage of a full-wave rectifier over a half-wave rectifier?

It produces less ripple in the output (A) Signup and view all the answers

What is the minimum number of diodes required for a half-wave rectifier in a three-phase supply?

3 (C) Signup and view all the answers

What is the main purpose of the center-tap in a full-wave rectifier circuit?

To complete the circuit and allow current to flow (B) Signup and view all the answers

Which type of rectifier makes use of four diodes in a bridge arrangement?

Bridge rectifier (A) Signup and view all the answers

What is the main disadvantage of half-wave rectifiers?

They produce more ripple than full-wave rectifiers (C) Signup and view all the answers

What is the output of a rectifier circuit?

Unidirectional pulsating current (D) Signup and view all the answers

What is the recommended capacitance value of a smoothing capacitor in a DC power supply circuit?

100uF or more (B) Signup and view all the answers

What is the minimum Working Voltage of a smoothing capacitor in a DC power supply circuit?

Higher than the no-load output value of the rectifier (B) Signup and view all the answers

What types of voltage can a regulator IC unit provide?

Either fixed positive or negative voltage, or an adjustably set voltage (D) Signup and view all the answers

What is the range of load currents that a regulator IC unit can operate with?

Hundreds of milliamperes to tens of amperes (B) Signup and view all the answers

What is the purpose of the third terminal in a fixed voltage regulator IC unit?

To connect to ground (D) Signup and view all the answers

What determines the amount of ripple in the output voltage of a DC power supply circuit?

The capacitance value of the capacitor (D) Signup and view all the answers