Project Hub /Basic Analog & Power Electronics/Power Supplies & Voltage Regulators/Mini AC-DC Converter Module With Selectable Output Voltage

Advanced

ANALOG / DISCRETE

Project Specific

3 – 6 Hours

Partial Kit

Mini AC-DC Converter Module With Selectable Output Voltage

A compact and efficient miniature AC-DC converter module with selectable output voltage designed for IoT devices and smart appliances.

Originally published on ElectronicsForU

View original tutorial

Parts You'll Need

This project is sourced from another site, not written by us — this list is our best match of their components against what we stock, not a verified bill of materials. Always check the original blog (linked above) for the actual parts list before buying.

MB102 Adjustable Breadboard Power Supply Module (3.3V & 5V) for Arduino & Raspberry Pi Rs. 139.00
LM2596 Step Down DC-DC Buck Converter Rs. 99.00
10pcs - 220 ohm 1/4 W Resistor Set Rs. 39.00
400 Points Mini Solderless Prototype PCB Breadboard High Quality Rs. 89.00
Jumper Wire 10 Pin Male To Male 20cm Rs. 45.00
Jumper Wire 10 Pin Male To Female 20cm Rs. 45.00

Selected: Rs. 0.00

This list includes a generic resistor set as a placeholder — it is not matched to the exact value or part number this circuit needs. The correct one is specified on the original source page linked above; check it before buying.

We don't carry yet: Voltage Regulator IC (7805 / LM317 / 1117)
Capacitors
Inductors / Coils / Ferrite
Header Pins / Terminals / Connectors
Thyristor / SCR / Triac / Varistor / Fuse

Browse all components

How It Works

The Mini AC-DC Converter Module is designed to transform high-voltage alternating current (AC) from mains power into regulated direct current (DC) levels suitable for low-voltage electronics. The primary power conversion starts with the LD05-23B05R2 AC-DC converter module, which safely steps down and rectifies wide-range AC input voltage into a stable intermediate DC rail. To handle specific voltage requirements, the circuit incorporates multiple downstream regulation stages connected via a 2-pin screw terminal (U2) and a WJ124-3.81-4P connector for input and output interfacing. The PAM2305DGFADJ buck converter works in conjunction with a 4.7µH inductor (L1) and various filtering components to efficiently step down voltages using high-frequency switching. Specifically, a feedback network composed of a 500kΩ resistor (R1) and a 120kΩ resistor (R2) sets the target output configuration for the adjustable regulator. Additionally, an ME6217C33M5G 3.3V linear regulator provides a secondary fixed low-voltage rail. To ensure stability, suppress high-frequency noise, and smooth out voltage ripples, a network of 10µF capacitors (C1, C2, C3, C4) and a 100pF capacitor (C5) are strategically distributed across the input and output stages of the regulation circuits.

Why Build This

Design and analyze compact switched-mode power supplies suitable for space-constrained IoT devices and smart home appliances.

Gain practical experience implementing multi-stage power conversion from high-voltage AC mains down to stable 3.3V and adjustable DC logic levels.

Evaluate the interplay between linear regulators, adjustable buck converters, and passive filtering networks for efficient power management.

Real-World Application

Powering IoT devices, smart home appliances, and small electronics that require compact and efficient multi-voltage power solutions.

Skills You'll Learn

AC-DC power conversion

switch-mode buck regulation

linear voltage regulation

passive filtering design

feedback resistor network calculation

schematic layout for power electronics

Safety Precautions

Exercise extreme caution when working with mains AC voltage (85V-264V AC) to avoid electric shock.

Technology Tags

AC-DC CONVERSION

POWER ELECTRONICS

BUCK CONVERTER

VOLTAGE REGULATION

IOT POWER SUPPLY

PCB DESIGN

Frequently Asked Questions

What is the purpose of the LD05-23B05R2 module?

The LD05-23B05R2 acts as the primary AC-DC converter, stepping down and rectifying high-voltage mains AC into a usable primary DC voltage.

How does the circuit provide multiple output voltages?

It uses a combination of the ME6217C33M5G fixed 3.3V regulator and the PAM2305DGFADJ adjustable buck converter, whose output is tuned using the R1 (500kΩ) and R2 (120kΩ) resistor divider network.

What role do the capacitors (C1 through C5) play in the circuit?

The 10µF capacitors (C1, C2, C3, C4) provide bulk filtering and voltage smoothing across the power rails, while the 100pF capacitor (C5) helps bypass high-frequency noise.

Gallery

This page is part of Kitkraft's Project Hub — a curated collection of electronics & robotics projects gathered from the maker community to help students and hobbyists discover and learn to build. Kitkraft does not claim authorship of the original project, and makes no representation as to the accuracy, completeness or safety of third-party source material. The summary and "How It Works" explanation above are AI-generated, rewritten with reference to the original tutorial — not a reproduction of it. Full credit and a direct link to the original source are provided above. If you're the original creator and have a concern about how your work is represented here, please contact us and we'll address it promptly.

Kitkraft Project Hub — curated from the maker community, credited at the source.

PRJ-01258