Hello mcdull2k
The resistor calculator not working?
Tested it with your values.... Works correctly
the keeper saying it is 1.5V just like normal LED. I guess it was around 1.5-1.6V and therefore I get myself a tiny 5 Ohm resistor and put them all together.
Your keeper has to provide 2 values :
Forward voltage : 1.5v
Forward current : ?????
Form your resistor value, i suppose you went for about 100mA
Thats OK for SFH485 (although a bit too high already , IMO), but can be definitely to much for some led models.
So you have to ask the keeper for the forward current value.
And none of the LED light up (I tested it with a capable DC of course)
How did you check ?
If you power a 880nm IR led , you can see a very faint red glow, but if you power a 940nm IR led , you see absotuley nothing, since this wavelength is too far inside IR range and is absolutely invisible to human eyes.
About the webcams :
All webcams can perceive 880nm leds without being IR modded, but a few cams need to be IR modded to be able to perceive 940nm Leds.
About the leds :
Leds are diodes, so they're polarized. Did you mount them the correct way ?
so I remove the resistor.
LEDS ARE NO LIGHT BULBS BUT DIODES.
THEY ALWAYS NEED A CURRENT LIMITING DEVICE TO OPERATE PROPERLY
NEVER USE THEM WITHOUT A RESISTOR, YOU CAN DESTROY THEM DOING THAT
To check you leds :
If your multimeter has a diode test function :
- switch off your setup
- select diode test on your multimeter
- for each led : use your multimeter on the led leads, on both ways. You should find nothing on one way , and a low voltage (varying , about 1 to 1.5v) on the other way.
If a led doesn't react as stated, then this led is fried, and you can change it.
If your multimeter doesn't have a diode test function :
- select voltage tester on your multimeter
- power on your setup
- test the voltage drop of each component
The voltage drop should be :
- about 0.5v for the resistor
- about 1.5v for each led
if your find these values , then your setup is working.
if you don't find these values , please post each value so i can help you debug this.
cya
