Help IR Detector / Emitter

Hello all,

I want to create this circuit but I don't know wich parts to use :

The input voltage will be 5V, so can you tell me :

  • witch IR LED and phototransistor référence I must buy ?
  • witch resistance I must use instead of the 270ohms ?

Thanks a lot for your help.

REGARDS.

Why do you want that LED in the sensor? That will prevent you from attaching it to an arduino.

There are many IR LEDs and photo transistors you can use, look at your local supplier.
Once you know the parts you are using you can work out the values.

Grumpy_Mike:
Why do you want that LED in the sensor? That will prevent you from attaching it to an arduino.

There are many IR LEDs and photo transistors you can use, look at your local supplier.
Once you know the parts you are using you can work out the values.

Hello, Thanks for your reply...

Yesterday I went to see my local supplier but the only sell electronic parts and they don't help me to realise this schema. So they sold me an IR led and a photo transistor but I don't know the références and I test them but it don't works...

It's for this reason I need your help...to buy the correct parts to realise this.

I want use a led just to view if the result is correct. After I want to connect this to an arduino (in second time).

On internet, I found this parts :
Emitter : http://www.selectronic.fr/diode-emettrice-lte5208-cqy89a-lte4208c-ir333.html
Detector : http://www.selectronic.fr/phototransistor-bpx95c.html

these parts are compatible?
In case yes, can you help me to know witch resistor must I buy ?

Sorry for my poor english and i'm beginner in electronic...

REGARDS.

Ok get the ir emitter working first. Use the 5V from the arduino not 9V as this maks things easier. Wire up the IR emitter and look with a digital camera at the diode. You will see it light up white. If you don't then swap the two wires over.
Next wire up the transistor as you have it but to 5V maker the resistor 100K or something like that and do not put the led in. Put a wire from the transistor / resistor junction and run a simple button sketch.
Put the emitter and photo transistor facing each other with a very small gap. You should see the output from the button sketch change when you put a piece of card between the two.
Good luck.

Grumpy_Mike:
Ok get the ir emitter working first. Use the 5V from the arduino not 9V as this maks things easier. Wire up the IR emitter and look with a digital camera at the diode. You will see it light up white. If you don't then swap the two wires over.
Next wire up the transistor as you have it but to 5V maker the resistor 100K or something like that and do not put the led in. Put a wire from the transistor / resistor junction and run a simple button sketch.
Put the emitter and photo transistor facing each other with a very small gap. You should see the output from the button sketch change when you put a piece of card between the two.
Good luck.

I've just connected the IR led directly on the +5v but I kill it...
I must buy an other one....

I've just connected the IR led directly on the +5v but I kill it

Lesson 1 you always need some current limiting device with an LED, the simplest of which is a resistor.
http://www.thebox.myzen.co.uk/Tutorial/LEDs.html

Grumpy_Mike:

I've just connected the IR led directly on the +5v but I kill it

Lesson 1 you always need some current limiting device with an LED, the simplest of which is a resistor.
http://www.thebox.myzen.co.uk/Tutorial/LEDs.html

Thanks for your reply...the next time I'll take care...