20V 4A AC-DC Switching Power Supply Module | 85-240V Step-Down
20V 4A AC-DC Switching Power Supply Module | 85-240V Step-Down
20V 4A Switching Power Supply Board — Reliable AC-DC Step-Down Conversion
This compact switching power supply module converts wide-range AC mains input (85–240V) to a stable 20V DC output at up to 4A, making it an excellent choice for DIY electronics projects, industrial automation, LED drivers, and embedded systems. Built-in overload and overvoltage protection safeguard both the module and your connected devices.
Key Features
- Universal AC Input: Accepts AC 85–240V — compatible with mains supplies worldwide.
- Stable 20V DC Output: Delivers a clean, regulated 20V at up to 4A (max 80W).
- Switching Design: High-efficiency switch-mode architecture minimizes heat generation and energy loss compared to linear regulators.
- Overload Protection: Automatically limits current to protect your load and the module itself.
- Overvoltage Protection: Shuts down output if voltage exceeds safe thresholds, preventing damage to sensitive components.
- Compact Form Factor: At just 109 × 51 × 34 mm, it fits easily into enclosures and project builds.
- Rated Capacity: <40VA (EU LVD compliant — low voltage: below 50V AC or 75V DC).
- No High-Concern Chemicals: Manufactured without restricted hazardous substances.
Technical Specifications
| Input Voltage | AC 85–240V |
| Output Voltage | 20V DC |
| Output Current | 4A (max) |
| Rated Capacity | <40VA |
| Dimensions | 109 × 51 × 34 mm |
| Protection | Overload & Overvoltage |
| Topology | Switch-Mode (AC-DC) |
What's in the Box
- 1 × 20V 4A Switching Power Supply Module
Made in Mainland China.
Note: Due to lighting and screen differences, the item's color may appear slightly different from product photos. Please allow 1–10 mm tolerance due to manual measurement.
For guidance on electrical safety standards relevant to power supply modules, refer to the OSHA Electrical Safety resources and the NIST Electronics & Electrical Engineering resources.
Frequently Asked Questions
Q: What input voltage range does this switching power supply module support?
A: The module accepts a wide AC input range of 85V to 240V, making it compatible with mains supplies across North America, Europe, Asia, and most other regions worldwide — no manual voltage selection required.
Q: What is the maximum power output of this 20V AC-DC power supply board?
A: With a 20V output voltage and a maximum 4A output current, this module can deliver up to 80W of power. It is rated at <40VA under EU LVD guidelines, ensuring compliance with low-voltage safety standards.
Q: How does the overload and overvoltage protection work?
A: The built-in overload protection automatically throttles or cuts the output current if the connected load draws more than the rated 4A, preventing the module from overheating or failing. The overvoltage protection circuit monitors the output rail and shuts down the module if the voltage rises above a safe threshold, protecting your connected electronics from damage.
Q: Is this power supply module suitable for DIY and embedded electronics projects?
A: Yes — the compact 109 × 51 × 34 mm board design, screw-terminal connections, and universal input range make it well-suited for DIY builds, LED driver systems, industrial control boards, Arduino/Raspberry Pi power rails, and other custom electronics enclosures where a stable regulated 20V DC supply is needed.