Page 249 - Concise Encyclopedia of Robotics

Power Supply
utility outlet consists of alternating current (AC) at about 117 V. Most
electronic equipment requires direct current (DC). Figure 1 is a block
diagram showing the stages in a typical DC power supply. The stages
include a transformer, a rectifier, a filter, and a voltage regulator.
Trans-
Regulator
former
AC input Rectifier Filter DC output
Power supply—Fig. 1
The transformer
Power-supply transformers are available in two types: the step-down trans-
former that converts AC to a lower voltage, and the step-up transformer
that converts AC to a higher voltage. These are illustrated schematically
in Fig. 2.
Most solid-state electronic devices, such as robot controllers and small
robot motors,need only a few volts.The power supplies for such equipment
use step-down power transformers. The physical size of the transformer
depends on the current.

Step-down transformer

Input Output

Step-up transformer

Input Output

Power supply—Fig. 2

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