Build Your Own: 1.3-22V Adjustable Power Supply Circuit

Description

Is a stable, adaptable voltage necessary for your project’s needs? This Adjustable Power Supply is compact, straightforward to assemble, and capable of generating a consistently regulated voltage within a range of 1.3V to 22V, supporting currents up to 1A. This circuit originates from SiliconChip Magazine

Numerous preset-voltage integrated circuits, or IC regulators, are commercially available, often offered with outputs of 5V, 6V, 8V, 9V, 12V, and 15V. However, if a specific voltage requirement doesn’t align with standard options, or if the ability to modify this output voltage is desired, an adjustable regulator presents the ideal solution – one that can be configured to deliver the precise voltage required.

This Adjustable Power Supply incorporates a small printed circuit board and employs a 3-terminal regulator. The design minimizes extraneous components, consisting only of three diodes, three capacitors, a resistor, and a trimpot utilized to set the output voltage provided by the regulator. The circuit is based on the LM317T adjustable voltage regulator. D1 provides protection against reverse polarity connections while P1 enables adjustments to the output voltage.

LM317T Adjustable Voltage Regulator

The LM317T is a versatile, three-terminal adjustable voltage regulator. It’s a popular choice for creating custom voltage sources. This integrated circuit continuously monitors the feedback voltage and adjusts its internal current to maintain a stable output, regardless of variations in input voltage or load current. It’s typically employed in applications needing a precise and adaptable DC voltage source. It operates from an input voltage ranging from 3.0V to 35V and can supply currents up to 1.5A. The regulator incorporates a thermal shutdown protection mechanism, which disables the device if it overheats, preventing damage and ensuring reliable operation. The feedback network utilizes a resistive divider to provide a precise voltage reference for regulation.

Integrated Circuits in Detail

Integrated circuits (ICs) are complex electronic circuits miniaturized onto a single semiconductor chip. They are essential components in modern electronics, offering increased efficiency, reduced size, and improved reliability compared to discrete components. In this project, the LM317T is a prime example; it exemplifies the power and flexibility offered by IC technology. Other common IC regulators include the 7805 and 7808, each with specific features and characteristics depending on the application. The versatility of IC regulators allows for efficient design and construction of customized power supplies and voltage control systems

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