What kind of sensor is this?

Hello there,

I have generator that sends and recieves signal with sensor. Sensor looks like led, but it doesn't emmit any light.
I will post photo and my question is: can you help me indentify this sensor?

I tried to upload photo, but it is too large.
So I uploaded to this url:

That's definitely a LED - probably an infra-red one if nothing is visible.

Try looking at it through a digital camera / phone camera, they can often pick up some IR light and show if something is emitting - check with a TV remote first to see if you can see that, and if so then try it on the generator one.

Yep infra red led.
Also measure the foward voltage.

dr pepper said:

Yep infra red led.
Also measure the foward voltage.

Click to expand...

Some multimeters will measure the forward voltage. It often called diode test with a diode symbol. The forward voltage of an LED is closely related to its colour.
IR (infra-red) around 1 V
Red around 1.8 V
All other colours have higher voltages.
You can usually see an LED glow when it's forward voltage is being measured, and it works in the visible range. For an IR LED, you need to use a digital camera.

As previously stated: likely an IR LED - an emitter if this part of the device commands the other, not a sensor per se.

Works exactly like a visible spectrum LED, but the wavelength is too short for the naked human eye to perceive. Also previously stated, depending on the filtering, most digital imaging devices will "see" the output as dim white light.

The output will almost certainly be modulated as opposed to continuous - likely at .. was it 38KHz? And (I may be giving away my age), an AM radio in close proximity will likely pick up this modulation as a high pitched "bee" - although this is only barely useful as a go/no-go determination as to whether a remote is working or not.

The March Muppet said:

As previously stated: likely an IR LED - an emitter if this part of the device commands the other, not a sensor per se.

Works exactly like a visible spectrum LED, but the wavelength is too short for the naked human eye to perceive.

Click to expand...

Infra-Red is longer wavelength than is visible by the human eye. It's UV (Ultra-violet) that is shorter wavelength than visible.

You can get UV LEDs, but they aren't used for remote controls.

Whoops .. Xmas eve with momma's home brewed 'nog. Of course you're correct.