Author Options:

How many volts is an IR LED? (from a remote)? Answered

I am trying to wire IR (Infrared) LEDs, and I need to know how many volts each one takes, they are from remote controls.



Best Answer 9 years ago

I don't know the exact voltage, but it will be low. Lower than a red LED. Probably 1.2v to 1.5v. This can be tricky to test. Rig up a circuit with an IR detector to blink a visible LED when an IR is lit. Test it with a remote control first. Then select a resistor to power the LED at 1v, then 1.2v and upward until it triggers the detector.

and how many amperes it takes each one?
because i had put 1600 mA and the led was destroyed

1600 ma = 1.6 amps and very destructive to small electronics like led's. You probably want more around 6mA. You could power it simply from a 5 volt power source and a resistor to control the incoming current. 5v/820 ohm resistor is roughly 6 ma.

A decent IR detector is a digital camera such a phone- or web-camera.

In case this isn't clear, a typical consumer digital camera can often be used to "see" whether an IR LED is on or not, although it can be somewhat faint depending on the camera.  Just look through the LCD viewfinder while the IR LED is thought to be on and you should see the chip glowing inside the epoxy housing.

When I tried this with my own camera, I initially thought that it didn't work with my TV remote control -- however it was just pretty faint.  Clearly(?) if you're using a remote control, the LED will flicker when you press a key, as opposed to driving it directly.

This works because most digital cameras (and webcams, etc.) don't fully filter out IR, even though they try to, by design.

I'm playing around with these currently and I've found that 3 volts blows em up (minimag power source) but one AA works great.

5mm IR LEDs have a forward voltage requirement of 1.2v to 1.6v DC and normally the Typical Forward Voltage to apply is 1.4v

around 2 or 3 volts. most remotes take two AA batteries, which is 3 volts (each is 1.5 volts), figure in the power drop from other things like transistors in the remote, probably like 2.5 volts