How to Identify Between which is IR sensor and which is reciver.....

[Pushpkant Yadav]

Hii all,

I got a IR wall sensor from my training company, and it a open loop differential amp with an op-amp and two IR things, these are look alike with a difference that one is of blue color and another one is colorless, Now I have to use these both thing on different ckt, but I am unable to identify that which is IR sensor and which is IR emitter.

Thanx in advance

 

[(*steve*)]

I'd guess that the blue one is the receiver.

The blue or sometimes brown colouring is more opaque at shorter wavelengths, thus making the device less sensitive to ambient light.

The transmitter doesn't need special colouring, so it is just clear.

NOTE: This is a guess

 

[daddles]

Measure them with the diode function of a DMM and get the forward voltage and polarity. Then connect them up to that voltage with a DC power supply (set the current limit low so you don't accidentally damage anything). The sensor will probably stay with pretty low currents; the emitter will probably behave like a conducting diode. Once you think you have the emitter, connect the other device across a voltmeter and see if you get a reasonable output voltage with the thing unbiased (I'm assuming it's a photodiode...).

 

[KJ6EAD]

Manufacturers sometimes tint the emitter, not the detector.

 

[duke37]

Could you use a TV zapper to check which one is the receiver?

 

[(*steve*)]

If the receiver is a phototransistor rather than a photodiode, then or will not look like a diode junction (to a multimeter with a diode test function).

If you measure the resistance it will be high in both directions. I diode will have a resistance in one direction that is substantially lower in one direction than the other.

If they are both diodes, then both will act as receivers, but only one will emit light when forward biased. With a couple of mA through them, only one should show up as "bright" when viewed through a video camera with IR sensitivity (a lot are).

 

[rann]

i f you want to know which is IR sensor and which is reciver
you have to go to electronics market then ask him( which is IR sensor and which is reciver) ha ha ha
it is funny
by the way i did that few times (but whith another parts) and i got some good results

 

[rann]

ok
maybe you can do what (daddles) i am not sure but a mobile phone camera can detect IR so when you connect it to dc try to use it