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CHAPTER 3
POWER SUPPLIES
LEARNING OBJECTIVES
Upon completion of this chapter you will be able to:
1. Identify the various sections of a power supply.
2. State the purpose of each section of a power supply.
3. Describe the operation of the power supply from both the whole unit standpoint and from the
subunit standpoint.
4. Describe the purpose of the various types of rectifier circuits used in power supplies.
5. Describe the purpose of the various types of filter circuits used in power supplies.
6. Describe the operation of the various voltage and current regulators in a power supply.
7. Trace the flow of ac and dc in a power supply, from the ac input to the dc output on a schematic
diagram.
8. Identify faulty components through visual checks.
9. Identify problems within specific areas of a power supply by using a logical isolation method of
troubleshooting.
10. Apply safety precautions when working with electronic power supplies.
INTRODUCTION
In the early part of this century when electronics was first introduced, most electronic equipment was
powered by batteries. While the use of batteries allowed the equipment to be portable (to some degree), it
also placed several limitations on how the equipment could be used. Because of their general inefficiency,
batteries had to be either replaced frequently or, if they were rechargeable, kept near a battery charger.
Thus, the advantage of having portable equipment was more than offset by the need to replace or recharge
the batteries frequently.
Users of electronic equipment needed a power supply that was reliable, convenient, and cost
effective. Since batteries failed to satisfy these requirements, the "electronic power supply" was
developed.
In today's Navy, all electronic equipment, both ashore and on board ship, require some type of power
supply. Therefore, this chapter is of extreme importance to you. We will discuss the sections and
individual components of the power supply and their purposes within the power supply. We will also
discuss troubleshooting of each section and its components.
