In the world of electronics and DIY projects, there’s always a need for innovative solutions that balance functionality with subtlety. One such solution is the Power IR LED Module, a versatile tool designed for applications requiring infrared illumination without disrupting the environment. Whether you’re working on night vision systems, wildlife monitoring, or security applications, this module offers a discreet way to observe without being noticed.
In this blog post, I want to write about the Power IR LED Module–a Kicad-based project that leverages the power of infrared LEDs for stealthy observation. We’ll explore its design, testing, and practical applications, including how it can be chained in parallel for larger projects. Additionally, we’ll discuss the second revision of this module, which introduces improvements like a status LED and photoresistor for adaptive operation.
Why Use an Infrared LED Module?
Traditional LEDs emit visible light, which can be intrusive in dark environments–whether you’re observing wildlife or testing security systems. Infrared (IR) LEDs, on the other hand, produce light outside the visible spectrum, making them ideal for stealth applications.
Infrared LEDs are available in different wavelengths, each with unique characteristics. The module I tested uses two types: one emitting at 940 nanometers, which is completely invisible to the human eye and perfect for covert observation. The other emits at 850 nanometers, a wavelength that lies on the edge of visibility–it appears as a faint red glow, just enough to be noticeable without being disruptive. This dual-wavelength approach offers flexibility depending on whether you need complete stealth or a subtle indicator.
| Wavelength | Visibility | Best Use Cases | Notes |
|---|---|---|---|
| 940nm | Completely invisible to humans | Wildlife monitoring, covert surveillance | Ideal for complete stealth. |
| 850nm | Faint red glow (barely visible) | Security systems, subtle indicators | Useful when a minimal indicator is acceptable. |
The faint glow captured with ordinary phone camera can be seen as a bright point.
The module is designed for efficiency and compatibility, working seamlessly with standard 12V power supplies, making it practical for industrial and DIY applications alike. Its scalability allows multiple modules to be chained together, either increasing coverage or brightness without overloading a single unit.
Design and Testing: From Single LED to Full Module
Before finalizing the module, I conducted thorough testing on individual infrared LEDs to ensure reliability and performance. The tests focused on voltage, current, and power output under different conditions.
Initial Testing with Single IR LEDs
I tested three SMD-type waterproof IR LEDs (likely referring to a specific package type) at varying voltages and currents:
| Voltage (V) | Current (A) | Power Output (W) |
|---|---|---|
| 1.6 | 0.689 | 1.102 |
| 1.7 | 0.827 | 1.405 |
| 1.8 | 0.953 | 1.715 |
| 1.9 | 1.047 | 1.989 |
| 2.0 | 1.107 | 2.214 |
Key Observations: At 2.0 volts, the LEDs operate at approximately 2.214 watts, which is below their maximum rated power of 3 watts. Exceeding 2.0 volts causes the LEDs to break down, leading to immediate failure. For continuous operation (without PWM modulation), a configuration with 6 LEDs per strip is recommended, producing around 1.7 volts per LED and 1.4 watts of power. This setup ensures stable performance while minimizing heat buildup.
The LED gets hot throughout prolonged use. This is best visible using infrared camera.
When the voltage is around 1.7V the temperatures are reasonable, but having a heatsink or active cooling is more than welcome.
Module Configuration
The final module consists of:
- Four strips, each containing seven IR LEDs.
- No additional resistors are required; the 12V input is divided across the LEDs.
- Each LED operates at ~1.714 volts when fully powered.
- When using PWM modulation, one LED per strip can be omitted to increase voltage per LED and increase power output per LED.
Schematic of this module can be found below.
Chaining Multiple Modules: Best Practices
When scaling up your project by chaining multiple modules together, it’s crucial to consider both electrical and mechanical aspects to ensure optimal performance and longevity. Start by ensuring that your power supply can handle the combined load; for instance, if each module consumes approximately 40 watts when fully powered, chaining n modules will require a power supply rated for at least 40n watts. Maintaining consistent voltage across all modules is equally important to avoid uneven brightness or potential damage. Using appropriate gauge wiring can minimize voltage drops over longer distances, ensuring uniform performance.
Thermal management is another critical factor when chaining modules closely together, as this can lead to increased heat buildup. It’s essential to provide adequate spacing between modules to allow for proper heat dissipation. Passive cooling solutions like heatsinks or active cooling methods should be considered if necessary, especially in high-density setups. Additionally, PWM (Pulse Width Modulation) modulation is highly recommended for applications where the module runs continuously. This technique allows for dynamic control of brightness and significantly reduces heat buildup, ensuring longevity and stability.
Mechanical mounting also plays a significant role in the stability and performance of chained modules. Using mounting brackets or spacers can secure multiple modules together while maintaining alignment and ensuring sufficient space for heat dissipation. It’s also important to securely fasten all modules to the surface or enclosure to prevent vibrations, which can be particularly problematic in applications like FPV setups where stability is crucial.
For a practical example, consider setting up a wildlife monitoring system that requires coverage over a large area. You might chain four modules together to achieve a wider field of view. In this scenario, ensure your power supply is rated for at least 160 watts (4 modules * 40 watts each). Additionally, mount the modules with sufficient spacing and use passive cooling if needed to manage heat effectively.
To prevent overheating, PWM (Pulse Width Modulation) is recommended for applications where the module runs continuously. This allows for dynamic control of brightness and reduces heat buildup, ensuring longevity and stability.
Ready Module: Features and Connectivity
The Power IR LED Module is designed for ease of use and scalability:
Key Features:
The module features input and output connectors that allow it to be chained with other modules, enabling extended coverage or higher brightness as needed. When fully powered (with no PWM modulation), the module consumes approximately 40 watts, making it suitable for applications requiring sustained operation.
The module is roughly 91mm x 84mm in size, making it compact enough for various installations while still providing substantial infrared illumination. You may notice that the LED package has a thermal pad on the bottom side, which helps dissipate heat generated during operation. Additionally, there are four M4 mounting holes located at each corner of the PCB, allowing for secure attachment to different surfaces or enclosures.
Second Revision: Improvements and Adaptations
After a while I realized that some additional features are needed. I was inspired by another IR LED module which I saw online.
Above image shows a small IR LED module that is dedicated for CCTV applications. It is quite small but it uses 5mm through-hole IR LEDs which are not as powerful as SMD ones that I used in my own design. However, it has two additional features that I found quite useful, so I decided to implement them in the second revision of my Power IR LED Module.
- Status LED: A small visible LED with a resistor indicates whether the module is powered on, providing a quick visual check without relying on infrared detection.
- Photoresistor for Adaptive Operation: The photoresistor measures ambient light levels, allowing the module to activate only in low-light conditions–such as nighttime or overcast weather. This feature is particularly useful for battery-powered applications where energy conservation is critical, ensuring the module operates efficiently without unnecessary power drain.
As it can be seen in the schematic below, these additions enhance the module’s usability and adaptability compared to the first revision.
Practical Applications
The Power IR LED Module is suitable for a wide range of applications, from wildlife monitoring to security systems and FPV (First-Person View, but with a stretch since it is quite big) setups. Its ability to provide infrared illumination without visible light interference makes it ideal for covert observation or situations where subtle lighting is required.
Whether you’re building a custom night vision system, enhancing your drone’s visibility in low-light conditions, or developing an environmental sensor, this module offers the flexibility and performance needed to bring your project to life.
Getting the Project Files
Production Footprint (Gerber Files)
For those interested in manufacturing this module, the production footprint is available for download. This includes all necessary design files to send to a PCB factory, ensuring you can produce high-quality modules tailored to your needs.
Additional files (for Supporters only)
Supporters can access the full project, including:
- Libraries for the IR LED used in the project (which are not commonly found in standard packages).
- Footprint definitions and schematic files.
- Additional code or firmware if applicable.
The files for the first revision can be found here:
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- Power IR LED Module Rev. 1 – project files
IR_LED_array.zip
- Power IR LED Module Rev. 2 – project files
IR_LED_array_v2.zip
Conclusion
The Power IR LED Module is a powerful yet stealthy solution for projects requiring infrared illumination without intruding on the environment. Its design, scalability, and adaptability make it a valuable tool for hobbyists, engineers, and DIY enthusiasts alike. Whether you’re building a wildlife monitoring system or enhancing your FPV drone’s night vision, this module offers flexibility and efficiency.
I hope you found this blog post informative and inspiring! If you’ve used this module in your projects or have ideas for improvement, share them in the comments below. Your feedback helps me refine my work, so consider supporting me by buying a coffee–it goes a long way in keeping this content ad-free and high-quality.