Hi guys, I am back with Part-2 of IR Illuminator (Infrared) Instructable. If you haven't seen Part-1 then CLICK HERE.

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A simple IR Illuminator Circuit to aid the night vision of CCTV Cameras. IR Illuminator Night Vision, as the name suggests, is the ability to see at night i.e. at low-light. As humans lack (or have very poor) night vision, we make use of technological ways i.e. cameras with special features. Although developed for military usage, the night vision technology, and the corresponding equipment are becoming easily available to normal public use.

The above image shows the IR Illuminator The Night Vision technology, as a part of Enhanced Vision Systems, is a part of the aircraft security system, which aids the pilot in surrounding awareness to avoid crashes.

Step 1: Fabricated Board From LionCircuits

In the above image, you can see the fabricated board by Lioncircuits. They are of very good quality.

Let’s starts with the assembly of this board.

Step 2: Components Assembled Board

The above figure shows all components are assembled on the PCB Board. I have used a 12 v adapter for input supply, All the future discussion of IR Illuminators refers only to active IR Sources, unless otherwise specified. So, coming to the uses of IR Illuminators, one of the main applications of Night Vision Technology. Usually, they are fitted around the camera lens so that the camera captures the objects as they reflect the IR Radiation emitted by the IR Illuminators. If your home or office has CCTV Cameras for security purposes, then chances are that is definitely has an integrated IR Illuminator in the form of an array of IR LEDs.

Step 3: Working

The above image shows the working of IR illuminatorThe circuit can be divided into three parts: the light sensor, the relay driver and the IR Illuminator. The combination of 100KΩ Potentiometer and LDR act as a potential divider and along with the Darlington Pair, they help in sensing the ambient light.

As the intensity of light falling on the LDR decreases, its resistance changes and the relay gets activated with the help of its driving transistor.

When the relay gets activated, the IR LEDs get a path to the ground and start to glow. The 100KΩ POT can be used to adjust the sensitivity of the lighting conditions.

Coming to the IR LEDs, they are 5mm Infrared LEDs with a forward voltage of 1.2V and a forward current of 20mA. A series of 5 IR LEDs are connected with a current limiting 330Ω resistor.

Six such combinations are connected in parallel to form an IR Illuminator array of 30 LEDs. You can easily add more LEDs but make sure that the power supply has enough juice to provide sufficient current.