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Check the values for IR emitter and phototransistor used for IR detection

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saurav_sdpl

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I am using a IR emmitter and phototransistor for IR detection.

IR light is emitted via a12V supply and 1.2K registance.
Where as The collector registance of phototransistor is 6.2K biased with 12V supply.

Plz check whether these values are correct for the proper operation.

The reflecting surface i am using is lighting tape used in cars, cut in a triangular shape.

when i am moving the module from the top to bottom of surface i am not able to achieve any variation in voltage sensed by phototransistor.

Wat modifications i should do to overcome this problem
 

fishkiller

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Re: sensor

Hi,
Some help ...
For the transmitter you have 12V and 1.2k:
The driving current is 10mA, I think you can increase this value and mostly you have to work in pulse mode.
Check on the data sheet of the transmitter what kind of pulse current you can have (50mA / 10ms for example could be acceptable).
If you have pulse current it became easy to separate the signal from the sun light on the receiver by using a simple capacitor.

For the receiver, check the typical value of resistor on the datasheet, it depends off the component used.
Connect a capacitor on the collector then amplify the signal with an AOP or a transistor and detect the alternative signal.

Sorry for my english
A+
_________________
www.benito-design.fr
Perhaps you can work
 

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