Using 940nm "bulb" as illuminator ?

[stephanovich 0]

I`ve been using a 940nm camera which has good night vision up to around 10 metres but then seems to drop off rapidly...I`ve looked at some illuminators but to me they seem way over-priced...I have ordered a 36 led 940nm "bulb" (the inner ring of leds around a lens) and intend to use that as an illuminator,placed at a distance of 10 metres from my camera...and which to me has the added benefit of not looking like a device that needs to be avoided along with being a fraction of the price.

 

Has anyone used an illuminator and how efficient are they ?

 

Or can anybody foresee any problems I may encounter ?

 

I would appreciate the advice...

 

Thanks,stephanovich

[PaulsonLaw 0]

I saw those replacement rings for WAY less as well! Let me know how that works!

[stephanovich 0]

I saw those replacement rings for WAY less as well! Let me know how that works!

 

Hi...

 

I thought I`d come back and let you know about this...

 

I now have several of these 940nm illuminator bulbs that cost around £4 - £ 5 each...they took a while to arrive from the far east but they have been well worth the wait...just one of the things illuminates brightly and using them all in a configuration when I need them gives a very bright area indeed...of course,I needed to make up a decent waterproof casing for them but if I`d bought these as complete encased items from the places I see them advertised,I guess they would have set me back about £150 at least (and been easily visible)...I paid just over £15 for the lot.

[PaulsonLaw 0]

How hard was the connections? Do they come w/ a pigtail?

[mike_va 0]

Once you get above that many LED's on a single board (or possibly enclosure) you may have some thermal/lifetime issues. You may want to try adding a small fan like CNB does in their MIR. Note also that as the temp goes up the forward voltage changes, and unless you are using a constant current source the current will be higher. Also can help mitigate against a failed short unit in the string causing higher current draw.

 

One easy way around that is picking up an old HP lab supply and using the constant current feature.

 

Depending on the rating etc of the parts you may not end up with a 10 year solution unless the thermal design is thoughtfully addressed - but then again this may not be the goal.

 

Good luck and nice to hear about your experiment.

[stephanovich 0]

How hard was the connections? Do they come w/ a pigtail?

 

 

The connections couldn`t have been simpler...they came with pigtails...in fact the hardest thing was finding something to house them in...I tried several methods and used the right size hole saws to cut holes in various items and things...I experimented with several types...from electrical enclosures/hollowing out round type electrical junction boxes are just two of different things I tried out...my rear garden is not very big,maybe 50ft max,but they gave a good enough light to satisfy the police with recognition...this all came about as I had a worse than useless 940nm camera with internal leds.

[stephanovich 0]

Once you get above that many LED's on a single board (or possibly enclosure) you may have some thermal/lifetime issues. You may want to try adding a small fan like CNB does in their MIR. Note also that as the temp goes up the forward voltage changes, and unless you are using a constant current source the current will be higher. Also can help mitigate against a failed short unit in the string causing higher current draw.

 

One easy way around that is picking up an old HP lab supply and using the constant current feature.

 

Depending on the rating etc of the parts you may not end up with a 10 year solution unless the thermal design is thoughtfully addressed - but then again this may not be the goal.

 

Good luck and nice to hear about your experiment.

 

 

 

 

I have to say that I only understand some of what you`re saying but what I do undertand I`ll bear in mind...I`ve only been using cctv for about 4 months max,from initially getting the usual 850nm stuff,which is good,to getting useless 940nm cameras...I`ve also messed around with some pcb cameras and lenses and been opening up the cameras etc and taught myself a little but,obviously,you don`t learn a huge amount in such a short time.

 

As far as the illuminator thing goes,I`ve only housed each bulb separately (48 led ring bulbs) so haven`t encountered the difficulties you`ve pointed out...but I do want to learn about the high powered leds and for that I will need to learn the type of thing you speak of...little by little and I hope to get there !!

 

Thanks