Chapter Overview

Electronic circuits need energy to work. In most cases, this energy is provided by a circuit called the power supply. A power supply failure will affect all of the other circuits. The supply is a key part of any electronic system. Power supplies use rectifier diodes to convert alternating current to direct current. They may also use zener diodes as voltage regulators. This chapter covers the circuits that use diodes in these ways. This chapter also discusses component-level troubleshooting. Knowing what each part of a circuit does and how the circuit functions allows technicians to find faulty components.

This chapter will help you to:

1. Identify the common rectifier circuits and explain how they work.

2. Recognize various filter configurations and list their characteristics.

3. Measure and calculate power-supply ripple percentage and voltage regulation.

4. Predict and measure dc output voltage for filtered and unfiltered power supplies.

5. Troubleshoot common power-supply problems.

6. Select replacement parts for power supplies.

Study Outline

4-1 The Power-Supply System

4-2 Rectification

4-3 Full-Wave Rectification

4-4 Conversion of RMS Values to Average Values

4-5 Filters

4-6 Voltage Multipliers

4-7 Ripple and Regulation

4-8 Zener Regulators

4-9 Troubleshooting

4-10 Replacement Parts