My old composite video surveillance cameras have 6 IR LEDs built in. The LEDs are small, and are only useful up to a few feet away from the cameras. One particularly shoddy camera would overheat and shut down after being plugged in for a few minutes, so I had to disable its LEDs altogether. Eventually, I decided to explore stand-alone IR LED assemblies.
My first purchase was a weatherproof, pod-shaped InfraRed Illumination Light for Night Vision (DC 12V 500mA)pod with 48 LEDs from DealExtreme. All the LEDs are mounted directly perpendicular to the PCB, and right up against it, so the pod acts like a spotlight. That’s not very useful for illuminating a large area. Repositioning the LEDs isn’t a great option because of how recessed they are within the pod. So, I unscrewed the front of the pod and secured a piece of wax paper to the inside of the glass cover to act as a diffuser. This works fairly well, but is still not ideal. The pod gets quite warm to the touch, so warm that the wax paper has melted onto the glass. I keep an old computer fan pointed at the pod in an attempt to extend its lifespan a bit.
For more freedom to reposition the LEDs, I decided to try a bare IR LED assembly next. I chose an Infrared 35-LED Illuminator Board Plate for 6mm Lens CCTV Security Camera from DealExtreme for a mere $3.84. It is sold as a replacement for inside a security camera housing, but I intended to just stick it to the front of one of my cameras with foam tape. Thus, I only had to worry about the size of the inner circular cutout, which is listed as 18 mm. A word of warning: it’s actually 16.3 mm, so it does not fit my two oldest cameras.
To power the board, I got an AC to DC 12V 1A Power Adaptor with 5.4mm DC Plug – US Type (110~240V) from DealExtreme for $4.31. It came with a barrel connector, but the LED assembly had a small header. So, I cut off the barrel connector, unsoldered the header, and soldered the wires directly to the pads on the LED assembly.
Stock, the IR LED assembly had a beam much like the weatherproof pod. However, I was able to wet the solder on the LEDs’ legs, raise them off the PCB a bit, and bend them outward. I bent the 21 LEDs in the outer ring to approximately 20°, and 7 of the 14 LEDs in the inner ring to approximately 10° (I kept 7 in their original places to maintain good coverage directly to the front). Now the beam is a little over 45° wide, which works well for my old composite video cameras, and my new D-Link DCS-930L cameras after a modification.