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Tsop fails on extreme lighting intensities!

24Volts

Mar 21, 2010
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Hello,

I am using the Tsop4838 ir sensor and I am
able to sense objects at different distances.

I then tried to detect those same objects but
with a flash light directed right on the tsop sensor.

To my dismay, the sensor completely died off
producing NO signal at all!!!!

Is this normal? I thought this part was able to
distinguish any disturbances such as Dc lighting,
sunlight ect... from its 38khz signal ???

Has anyone experienced these disturbances
with this sensor ?

PS... For now I have not provided the details
of the optical signal I am using.... as I was only
interested to know if I am the only one experiencing
these issues. However if relevant, I can provide
all the signal details should we think that this
sensor really can work under intense lighting conditions
such as dc lighting or sunlight.

thanks for all feedback
r
 

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
Moderator
Jan 21, 2010
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TSOP is also the abbreviation for a type of surface mount package -- so this subject can seem very weird to someone not familiar with the confusingly similarly named range of sensors...

If you point a flashlight at the sensor (and I'm guessing it had an incandescent bulb, not a LED) then you will saturate the sensor making it very insensitive to the small signal it's looking for.

These sensors can handle a small amount of ambient light (actually a lot of ambient light, but a small amount of ambient IR).

The simple answer is to get a LED torch, or stop pointing it at the sensor.
 

24Volts

Mar 21, 2010
164
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Hi Steve,

Ooops, I am sorry.... I should of put the whole part number
for the thread's title.... I will make sure of that next time.

These sensors can handle a small amount of ambient light (actually a lot of ambient light, but a small amount of ambient IR).

Well you see, my project may be exposed to direct
sunlight. So if it's a sunny day, the tsop4838 may require
to still detect objects even though it is exposed to a huge
sunbeam !!!

Thus the reason I was testing it with a flashlight. If it fails
with a flash light, we can just image how bad it would be
with the sun!!!!

Having said this, according to you, should these devices
be capable of working even in direct sunlight????

thanks for your reply!
r
 
Last edited:

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
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The only way it would be able to operate in direct sunlight is that it is not in sunlight.

If you can't shield it from *direct* sunlight, you may not have a happy time.
 

24Volts

Mar 21, 2010
164
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Hi Steve,

But does this mean that no sensor in this world
can work under the powerful rays of our sun??

r
 

CocaCola

Apr 7, 2012
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But does this mean that no sensor in this world
can work under the powerful rays of our sun??

The sun is a LARGE full spectrum light source, it will easily wipe or at least interfere with any low power modulated IR light source... You can even experience this in your house with IR remotes if you have a lot of windows and direct sun light...

This is also why things like garage door sensors are funneled down a pipe and focused so that they are shielded from ambient light...

I have one of those IR controlled helicopters (Syma S107) great little flier in the house, but FORGET about it outside during the day it simply will not work... BTW I have flown it just fine at night outside, but it has to be a very calm day...

End game if you want to use it outside make it very directional and shielded or go to radio frequencies vs light...
 
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