Regulated and Switching Power Supplies

Uninterruptible Power Supply (UPS) – Block Diagram and its Workings: Uninterruptible Power Supply (UPS) – Most of us take the mains ac supply for granted and use it almost casually without giving the slightest thought to its inherent shortcomings and the danger posed to sophisticated and sensitive electronic instruments/equipment’s. For ordinary household appliances such as …

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Constant Voltage Transformer (CVT) – Construction and Working Principle: With the popularization of PCs, the constant voltage transformers (CVTs) have also become equally popular. The Constant Voltage Transformer is simply a magnetic transformer of a special construction that has a capacitor connected across the secondary winding of the transformer. In an ordinary transformer, the primary …

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Switch Mode Power Supply (SMPS) or Switching Regulators: Switch Mode Power Supply (SMPS) – The regulated power supplies described earlier were basically linear voltage regulators. A linear voltage regulator possesses many limitations: The input transformer is bulky and is a very expensive component in the whole regulated power supply since it is used at low …

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What is Dual Power Supply? -Circuit Diagram and its Workings? Many discrete and ICs need bipolar (dual power supply or ± V) supplies. This can be easily accomplished with two three-terminal regulators, as illustrated in Fig. 43.39. Opposite-phase ac is provided by the transformer’s secondary and a grounded center tap. The single full-wave bridge converts …

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What is Current Boosting in Voltage Regulator? Current Boosting in Voltage Regulator – IC723 regulator is limited to provide a maximum current of 140 mA. To increase its current capacity, we add a transistor Q by connecting its collector to pin 11, base to pin 10, and emitter to pin 2, as shown in Fig. …

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LM340 Series Voltage Regulator: This LM340 Series Voltage Regulator is typical of the three-terminal voltage regulators. The block diagram is shown in Fig. 43.27. The built-in reference voltage Vref drives the noninverting input of an op-amp. The operational amplifier consists of several stages of voltage gain. Because of the high gain of the op-amp, the …

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Adjustable Voltage Regulators: Sometimes variable voltage is required and under such a situation adjustable voltage regulators is used. A number of IC regulators, like LM317, LM338, and LM350, are adjustable regulators. They have maximum load currents from 0.10 to 1.5 A. For example, the LM 317 is a three-terminal positive voltage regulator, which can be …

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Fixed Negative Voltage Regulator: As we have seen many times previously, positive and negative regulated power supply voltages are often required. In response, many manufacturers have developed negative three-terminal regulators. They offer the same types of features and protection as are found in positive voltage regulators. The 7900 series of fixed output negative voltage regulators …

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