Adjustable Voltage Regulator Circuit Using LM317

The schematic shown above represents a simple adjustable voltage regulator circuit built around the LM317, a popular linear voltage regulator IC. This circuit is commonly used in electronic projects to derive a stable and adjustable output voltage from a higher, unregulated DC input.

Key Components:

  • U1 - LM317: A 3-terminal adjustable voltage regulator. It allows for output voltage adjustment from 1.25V to about 37V, given a suitable input.

  • RP1 - Variable Resistor (Potentiometer): Used to adjust the output voltage.

  • R1 (100Ω): Works in conjunction with RP1 to set the output voltage using the formula:

  • C1 (0.1µF): Input bypass capacitor to improve stability and filter noise.

  • C2 (1µF): Output bypass capacitor for transient response and further noise filtering.

  • U2 (Connector - Input): DC voltage input connector.

  • U5 (Connector - Output): Regulated DC voltage output connector.


How the Circuit Works:

  1. DC Input is supplied at connector U2.

  2. C1 filters any high-frequency noise from the input.

  3. The LM317 regulates the input voltage based on the resistive divider formed by R1 and RP1.

  4. RP1 can be adjusted to change the output voltage.

  5. C2 ensures stability at the output and suppresses voltage spikes.

  6. The regulated output voltage is available at connector U5.


Applications:

  • DIY power supply units

  • Battery chargers

  • Voltage control circuits for embedded systems

  • Educational projects to understand voltage regulation


Conclusion:

This LM317-based voltage regulator circuit is an essential tool for hobbyists and engineers alike. Its simplicity, reliability, and flexibility make it an excellent choice for powering a variety of low-current electronic devices with a custom-set voltage.


Comments

Post a Comment

Popular posts from this blog

Malaysia’s AI Boom: Trends, Innovations, and Adoption

Malaysia has rapidly embraced the global wave of generative AI and automation tools. ChatGPT and related AI platforms have surged in popularity among students and professionals, and 84% of Malaysian knowledge workers now use AI at work to boost productivity. According to Prime Minister Anwar Ibrahim, the launch of Malaysia’s new National AI Office in December 2024 was “another historical moment in our digital transformation journey”. The government is pursuing an ambitious AI strategy – including an AI Talent Roadmap (2024–2030) , a Malaysia-AI Consortium, and a five-year AI Technology Action Plan – aimed at positioning Malaysia as a regional hub for generative AI. Government Strategy and Initiatives In late 2024, Malaysia’s cabinet approved a National AI Office (NAIO) to coordinate policy, ethics and regulation for AI, with support from tech giants like Amazon, Google and Microsoft. The NAIO’s first-year goals include a code of ethics, a regulatory framework, and an AI acti...
Read more