20V 4A AC-DC Switching Power Supply Module | Step-Down Board
20V 4A AC-DC Switching Power Supply Module | Step-Down Board
20V 4A Switching Power Supply Board — Reliable AC-DC Step-Down Module
This compact 20V 4A AC-DC switching power supply board is engineered for electronics hobbyists, engineers, and DIY builders who need a dependable step-down power module. It accepts a wide universal AC input range of 85–240V and delivers a steady, regulated 20V DC output at up to 4A — making it ideal for powering embedded systems, custom electronics builds, automation projects, and a wide range of electronic devices.
Built-in overload and overvoltage protection safeguard both the module and your connected equipment, giving you peace of mind during long-running or high-demand applications. The compact form factor (109 × 51 × 34 mm) makes it easy to integrate into enclosures and PCB assemblies.
Key Features
- Universal AC Input: Accepts AC 85V–240V — compatible worldwide
- Regulated DC Output: Stable 20V at up to 4A (rated capacity <40VA)
- Overload Protection: Automatically shuts down to prevent damage under excessive load
- Overvoltage Protection: Guards your connected devices against voltage spikes
- Switching Design: High-efficiency switching topology for minimal heat generation
- Compact Size: 109 × 51 × 34 mm — easy to mount or integrate into custom builds
- Low Voltage Classification: Output below 50V AC / 75V DC for enhanced safety compliance
Specifications
| Input Voltage | AC 85V – 240V |
| Output Voltage | 20V DC |
| Output Current | 4A |
| Rated Capacity | <40VA |
| Dimensions | 109 × 51 × 34 mm |
| Protection | Overload & Overvoltage |
What's in the Box
- 1× 20V 4A AC-DC Switching Power Supply Module
Made in Mainland China.
For more information on electrical safety standards for low-voltage power supplies, visit the U.S. Consumer Product Safety Commission (CPSC) Electrical Safety resource.
Note: Due to manual measurement, dimensions may vary by ±1–10 mm. Slight color differences may occur due to lighting and screen settings.
Frequently Asked Questions
Q: What input voltage range does this switching power supply module support?
A: This AC-DC power supply module supports a universal input voltage range of AC 85V to 240V, making it compatible with standard electrical outlets in North America, Europe, Asia, and most other regions worldwide.
Q: What devices can I power with this 20V 4A step-down power module?
A: This module is well-suited for DIY electronics projects, embedded systems, custom automation builds, LED drivers, and any device requiring a stable 20V DC power source drawing up to 4A. Always verify your device's power requirements before connecting.
Q: How do the overload and overvoltage protection features work?
A: The built-in overload protection automatically interrupts output if the current draw exceeds the module's rated capacity, preventing overheating or damage. The overvoltage protection monitors the output and shuts down the module if voltage rises above safe thresholds, protecting your connected equipment.
Q: Is this power supply module safe to use for long-duration projects?
A: Yes — the switching design operates at high efficiency, minimizing heat buildup compared to linear regulators. Combined with built-in overload and overvoltage protection, it is designed for sustained operation. Always ensure adequate ventilation around the module during use.