LED IR (Infrared) Illuminator
DIY 24-LED Infrared (IR) Spotlight Illuminator
One question we receive a lot is about building an IR Illuminator. An IR Illuminator allows a camera to see in total darkness. Infrared light can be useful for security applications, or maybe you want to watch the night activities of the local wildlife.
The IR Illuminator uses our LED SpotLight PCB, which holds a total of 24 LEDs on a circular PCB. The board contains 24 individual IR LEDs that do all of the work, along with eight current limiting resistors. Assembly time for the kit by a novice builder is about 30 minutes total assembly time.
850nm or 940nm IR LEDs?
When you build your system, you need to decide what frequency of LEDs to install on the board. There are two standard frequencies available, one at 940nm and the other at 850nm. The most commonly used frequency is the 850nm model. Although the 940nm model is more desired for covert operations.
850nm LEDs produce a very slight red glow when operating, which is visible to the human eye. 940nm models produce no visible light to the eye.
The Parts In Your LED IR Illuminator
Your first step is to identify and collect the parts necessary to build the system.
Shown to the right are all the parts that are required.
Once assembled, the power to the circuit is needed. We have set up this unit to run on 12v DC at about 160mA (0.160A). To operate at other voltages, you must select the correct value of a dropping resistor (of which there are eight).
First LEDs to Install
Once you have all the parts, the first step is to become familiar with the PCB. It is set up with 24 LEDs in total, 18 around the outside, and another 8 on the inside (the LEDs are labeled D1 to D24). Resistors go on the board at positions R1 to R8, which are between the inner and outer rows of LEDs. Finally, apply power to the board just below D24, where you will see the Positive and Negative solder pads. In the very center of the PCB is a single hole. The hole can be enlarged for mounting or even further to fit around a camera lens.
The simplest way to begin the install is to insert and solder into the board the inner row of LEDs. These are located at D3, D6, D8, D12, D14, D17, D19, and D22. Keep in mind that LEDs are polarity sensitive, so ensure that you align the flat on the LED with the flat on the solder mask on the board. After you have soldered in the first 8 LEDs, trim the leads.
Install Second Set of LEDs
Now you should install and solder in the LEDs at D1, D2, D4, D5, D7, D9, D10, D11, D13, D15, D16, D18, D20, D21, D22, and D23. When installing the LEDs, try to keep them flat against the board.
Install The Resistors
The last step is for the installation of the eight current limiting resistors which go at positions R1 to R8. The resistors will stand on their ends for this project. Unlike the LEDs, the resistors are not polarity sensitive to install any way you want.
Once the assembly of the board is complete, you can apply power leads to the power input terminals.
We have seen these units mounted in many different types of housing, including PCV plumbing end caps.
When you power up your system, you may notice a slight glow to the LEDs. For 850nm LED models, you will see a slight red glow. The 940nm models do not have any glow that is visible to the human eye.
The LED IR Illuminator is based on our LED Spotlight board. For additional information, visit the LED Spotlight page.
Good luck with your build, and you are sure to receive many years of service from your IR Illuminator display.