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IR on 208c cheap hong kong cam

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i got a cheap cam off ebay, about 30 bucks. i've mounted it to a fun lil RC tank that i'll be driving around the back yard. it has 6 LEDS but there isn't anything coming from them. i took the cam apart and tested the leds and there is NO voltage across them. HOWEVER, there are cameras just like it that DO have functional IR.

Does anyone have experience with small IR night vision cams? I bet there is an easy way to enable these lil LEDS on my cam

using my nikon digital i checked to see if there was any IR light coming from the leds. and there was nothing. but the nikon could see the light from a tv remote. AND the wireless cam could see the light from the remote also.

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i guess what i'm hoping for is some help getting better low light quality. i know it has the ability to see in very low light, i am just having a hard time getting everything out of it. If anyone has the version of this cam with functional IR leds i would REALLY appriciate some hi res pics of the PCB so i could see any differences in the wiring

thanks again

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Edited by gt3guru

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From what I could see, the IR LED's are wired in series. So, that means that you must apply the correct minimum voltage before they will come on. And, you may not find any voltage across many of them in this situation. So, what is the camera rated at and what EXACT voltage are you using? For example, if it is a 12VDC camera and you are applying 11V, the LED's may not come on at all.

Some power the LED's full time. Some have a photo transistor that turn them on when it gets dark. Others use a dedicated wire. If you need to, trace the copper traces to see where they go. At a minimum,it will be LED's and a resistor or two.

The IR LED's used on these cheap cameras are rarely invisible. In the dark, they often have a red tint to them. So, you should be able to see them with the naked eye.

Keep in mind that IR LED's do not "improve" the camera's performance. They are just flashlight beams. And like a flashlight, you can only see what is illuminated. These LED's are usually not very strong, so don't expect a miracle.

For best nighttime performance, use a good monochrome CCD with 0.005 lux or better.

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3 ir leds shouldn't require more than 2v a piece or 6volts total, i measured 6.5 coming in and nothing across any of the LEDS. as soon as i can steal my bros meter again i'm going to try and find where i'm guessing a surface mount resister is suppose to go and see if my theory is correct.

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If all 6 LED's are in series then it will take more then 6.5VDC. From the photo, it is hard to see how they are strung together. My experience with these sort of cheap imports is that they tend to be designed for 12VDC. Your camera's docs will tell you what you need to know.

If power is not present then I suspect you should look at the indicated place (marked in red in photo below). If I was an LED power entry wire, that is where I think I would probably go. But, it all really deserves an up close and personal PCB review to determine what is going on.

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my guess is the 2 banks of 3 are seperate. if u look at the upper left corner there is a similar spot that looks like the one u highlighted thats a good candidate for a resistor. i'll try applying voltage to the leds to see if they light when i get home. then see if that voltage is available somewhere on the board.

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Word of caution: Don't apply a voltage without the proper series current limit resistor in the LED circuit. The first recommended task is to trace the LED path and draw a schematic of what you find. Then use that info to help determine what is needed for safe operation.

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sadly, it looks like one of the leds is dead, 5 leds have very low resistance, around 20. but one is about 1500 ohms. is it possible to tell what voltage is needed by reading resistance?

i'm guessing 2v is whats needed by looking at data sheets of other IR leds of this size, minimum of 1.7

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Is it possible to tell what voltage is needed by reading resistance?
No. But a meter with a diode function can do that if the Vf is low enough.

I'm guessing 2v is whats needed by looking at data sheets of other IR leds of this size, minimum of 1.7
I would start with that. The current limit resistor(s) should be chosen to allow 25mA max. In case you need assistance, the RC-CAM LED info page will help you choose the correct resistor value.

Once they are lit, you can measure their true Vf to see how close your guess was.

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Hi!

I got the "same" model, 208c. BUT my LEDs are NO LEDs at all but only dummies!

I was very sad when I saw this. I tried with external IR-LEDs and found that the sensivity of the camera to the IR is less than usefull, so I will have to buy another, better one, with CCD sensor like in a Webcam. Those are more sensitive to IR, I have tried with standard webcam and some ultrabright IR-LEDs and got a Nightvisioncam out of it.

Greets,

Marcus

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Hello again!

I got myself another one of these cheap cameras.

Funny thing is that this one totally differs from my first model. This one is much more sensitive to IR. The other one I have ISNT sensitive to IR at all but with the new one you can view in the dark IF the LEDs work.

As I can see now the LEDs in my new model are real ones BUT they are NOT connectet and are there only for "better design looking" or "impress thieves".

Also they are soldered in random way with they cathode/anode respectively.

So either make sure that they work and are all in correct order (but then you have problem that your camera MUST NOT HAVE ABOVE 5 VOLTS but you need MORE than 5 Volt for lighting the LEDs. So you must connect separate 8V/12V power with adequate pre-resistor for LEDs.

Some of these cams seem to have this separate power cable. One 5V for the cam and one 8/12V for the LEDs.

So with some time AND MUCH CARE it is possible to make them work.

By the way, they are only 3mm type LED. I discovered this after I bought myself new 5mm ones...

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