Reference
JL-AD3W-HT-V3 – Everything You Need to Know About This AC-DC Power Supply Module
A compact, mains-connected switch-mode power module that converts AC directly into a regulated 5V DC output, popular in low-cost embedded electronics. This guide covers its electrical specs, pinout, output filtering, and the mains-safety rules that come with using bare board-mount SMPS hardware.
The JL-AD3W-HT-V3 is a compact AC-to-DC power supply module commonly found in low-cost embedded electronics, IoT devices, and DIY projects. It converts mains voltage directly into a regulated low-voltage DC output, typically 5 V, making it a popular alternative to bulky wall adapters or external power bricks. This article covers the JL-AD3W-HT-V3 as a hardware component: what it is, how it works, electrical characteristics, pinout, usage guidelines, and important safety considerations.
What Is the JL-AD3W-HT-V3?
The JL-AD3W-HT-V3 is a small switch-mode power supply (SMPS) module designed to be mounted directly onto a PCB or wired into an enclosure. It accepts AC mains voltage and provides a low-voltage DC output suitable for powering microcontrollers, sensors, and small electronic circuits.
Unlike complete power adapters, this module has no external enclosure, exposes mains-connected pads, and is intended for internal use only inside insulated products.
Typical Electrical Specifications
Exact specifications may vary slightly depending on manufacturer and batch, but the most commonly observed parameters are:
| Parameter | Typical Value |
|---|---|
| Input Voltage | 100–240 VAC, 50/60 Hz |
| Output Voltage | 5 V DC |
| Max Output Power | ~3 W to 3.5 W |
| Max Output Current | ~0.6–0.7 A |
| Topology | Isolated switch-mode power supply |
| Efficiency | Moderate (budget SMPS design) |
These modules are usually not precision-regulated laboratory supplies. Output voltage may sag slightly under load.
How the Module Works
Internally, the JL-AD3W-HT-V3 uses a switching stage with transformer isolation to convert high-voltage AC into low-voltage DC. The typical stages include:
- AC rectification
- High-voltage DC filtering
- High-frequency switching circuit
- Transformer isolation
- Secondary rectification and smoothing
Because it is a low-cost SMPS, output ripple and EMI noise are higher than on premium power modules.
Pinout and Connections
Most JL-AD3W-HT-V3 boards expose four pads or pins.
AC Input Side
- L, Live (Line)
- N, Neutral
DC Output Side
- +V, +5 V DC output
- GND, Ground
Critical safety note: the AC side is connected directly to mains voltage. Always ensure proper insulation, adequate creepage distance, and no exposed copper when powered.
Typical Use Cases
The JL-AD3W-HT-V3 is commonly used to power microcontroller boards (Arduino, ESP-based designs), sensor hubs, low-power IoT devices, small relay or control boards, and USB-powered circuits (internally wired).
It is not suitable for high-current loads, safety-critical medical or industrial equipment, or exposed/user-accessible electronics.
Output Filtering & Stability
Because this is a budget power module, additional filtering is strongly recommended. Common improvements: a 470–1000 µF electrolytic capacitor on the output, a 100 nF ceramic capacitor close to the load, and a ferrite bead or LC filter for noise-sensitive circuits. This is especially important when powering RF modules, ADCs, audio circuits, or precision sensors.
Thermal Behavior
Under moderate load, the JL-AD3W-HT-V3 can become noticeably warm. Best practices: do not operate continuously at maximum power, ensure airflow or thermal dissipation, and avoid enclosing it tightly in plastic without ventilation.
Safety Considerations (Very Important)
This module operates directly from mains voltage. Always mount it inside a fully enclosed, non-conductive housing, maintain isolation distances on your PCB, avoid touching or probing while powered, and disconnect mains before soldering or testing.
Do not assume regulatory certification, reinforced isolation, or consumer-grade safety compliance.
Common Mistakes
- Treating it like a low-voltage module
- Exposed AC pads in open projects
- No output filtering
- Powering loads close to or above rated current
- Using it in handheld or user-accessible devices
Conclusion
The JL-AD3W-HT-V3 is a compact, low-cost AC-DC power supply module suitable for embedded and DIY projects where space and cost matter. When used correctly, with proper insulation, filtering, and realistic load expectations, it can be a practical solution for powering low-voltage electronics directly from mains power.
However, it should always be treated with respect: this is mains-connected hardware, not a beginner-safe component.