Night vision using infra red LED

[TS84]

can anyone tell me how to drive 20 infra red LEDs for night vision system.are there any need of driver circuit for infra red LED's?

Please help me as soon as possible......... Thank you

 

[Torben]

Nothing special needed for IR LEDs, just drive them like visible-light LEDs. That is, using current-limiting resistors.

How you hook them up will largely be determined by the supply voltage you have available.


Torben

 

[tytower]

5 leds with 100k down to 33k resistors work for me on 9 to 15Volts ,bit hot on 15 and PP on 9
Put themin any shape you want but you must parellel the 5 plus resistor all the way.

Once made one for the back window of the car with a finger salute .

 

[Boncuk]

Hi TS84,

for optimum target illumination I recommend Vishay TSAL6400 IR emitters.

They have a forward voltage of 1.35 to 1.6V and a forward current of 100mA (940nm).

Depending on your power supply you might use two LM317T wired as constant current sources to supply two clusters of 10 LEDs (in series) without the need of further current limiting resistors. (The power supply should provide at least 20VDC at 1.2A for 10 LEDs).

Boncuk