Agilent Technologies manual Overview of Agilent E3632A Operation, 141

Chapter 7 Tutorial

Overview of Agilent E3632A Operation

Overview of Agilent E3632A Operation

Series regulated power supplies were introduced many years ago and are still used extensively today. The basic design technique, which has not changed over the years, consists of placing a control element in series with the rectifier and load device. Figure 7-1shows a simplified schematic of a series regulated supply with the series element depicted as a variable resistor. Feedback control circuits continuously monitor the output and adjust the series resistance to maintain a constant output voltage. Because the variable resistance of Figure 7-1is actually one or more power transistor operating in the linear (class A) mode, supplies with this type of regulator are often called linear power supplies. Linear power supplies have many advantages and usually provide the simplest most effective means of satisfying high performance and low power requirements.

Figure 7-1. Diagram of Simple Series Power Supply with Tap Selection

To keep the voltage across the series resistance low, some supplies use preregulation before the rectifier bridge. Figure 7-1shows a controlled transformer tap as used in the Agilent E3632A. This is one of several techniques using semiconductors for preregulation to reduce the power dissipated across the series element.

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