1N6264 IR sensor question

Discussion in 'The Projects Forum' started by tron, Dec 6, 2009.

  1. tron

    Thread Starter Member

    Apr 20, 2009
    22
    0
    hello

    i am working on a project and need some help in regards to ir sensors. it is lap counter system and we are using the 1N6264 ir sensor. now do we need to power the reveiver or only the diode itself? would the receiver just have to sit acros from the ir beam to reflect it back or would it have to have a voltage connected to it?

    thanks
     
  2. tron

    Thread Starter Member

    Apr 20, 2009
    22
    0
    here is a picture of what we have so far

    [​IMG]
     
  3. eng1ne

    Member

    Dec 4, 2009
    97
    3
    Supply some details of the receiver you are using.
     
  4. Ron H

    AAC Fanatic!

    Apr 14, 2005
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    What are you using for a receiver?
    I hope you are using a current limiting resistor in series with the 1N6264.
     
  5. tron

    Thread Starter Member

    Apr 20, 2009
    22
    0
    the receiver doesnt have any identification on it, it was one that was handed to us whe we asked for an ir emitter and receiver.

    we are not using a current limiting resistor because the fpga we are using has resistors in series with the pins. however what size of a resistor would be good?
     
  6. Ron H

    AAC Fanatic!

    Apr 14, 2005
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    It's pretty hard to know (for me, anyhow) how to hook up a receiver if you don't have some information (a datasheet would be best) about it. Where did you get it?
    IN6264 is rated at 100mA max continuous current. I would probably start out with no more than 50mA. You might get by with a lot less (e.g., 10 or 20mA) The forward voltage vs current curves are in the datasheet.
     
  7. eng1ne

    Member

    Dec 4, 2009
    97
    3
    What supply voltage do you have?

    Making a reliable circuit will be difficult without knowing much about the receiver!
     
  8. tron

    Thread Starter Member

    Apr 20, 2009
    22
    0
    thats the problem im having, since the receiver has no markings on it we cannot find any datasheet with it. would it be helpful if i uploaded a very detailed picture of the receiver?
     
  9. Ron H

    AAC Fanatic!

    Apr 14, 2005
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    It wouldn't hurt. I hope it will be in better focus than the first picture you posted!
    Again I ask: Where did you get the receiver?
     
  10. tron

    Thread Starter Member

    Apr 20, 2009
    22
    0
    the receiver was given to us by our department supply room. ill upload a more detailed picture as soon as i can.
     
  11. Ron H

    AAC Fanatic!

    Apr 14, 2005
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    I think most IR receivers are designed to receive on/off modulation of a 38kHz IR carrier. Are you planning to drive the 1N6264 with a 38kHz square wave?
     
  12. tron

    Thread Starter Member

    Apr 20, 2009
    22
    0
    firs of all thank you for all the help. i will ask my partner what the frequency of the square wave is as soon as i can. until then here is a picture of the receiver we are using

    [​IMG]

    thanks again!
     
  13. hgmjr

    Moderator

    Jan 28, 2005
    9,030
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    What you have for a receiver is a light dependent resistor (LDR). I don't have any experience with illuminating an LDR with an IR light source.

    hgmjr
     
  14. Ron H

    AAC Fanatic!

    Apr 14, 2005
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    Your IR emitter will not work with your receiver (a simple Cadmium Sulfide LDR). See the attachment. The top line is from the 1N6264 datasheet. The CDS spectral response graph is from a CdS LDR datasheet. I added the 1N6264 emission line to the graph. Notice that the LDR has no sensitivity at the 940nm wavelength of the 1N6264.
    Your simplest detector would probably be a phototransistor which matches the emission wavelength of the 1N6264. This would require some additional circuit design to make a receiver from it. You can get ready-made 38kHz receivers (Google) from various sources. Radio Shack has one, but I haven't used it.
     
  15. tron

    Thread Starter Member

    Apr 20, 2009
    22
    0
    wow, thank you so so much for all of that detailed information what you said makes total sense! in regards to the 38khz receiver from radioshack, would we need to design an additional circuit? would we just simply need to power the module?

    thanks again!
     
  16. tron

    Thread Starter Member

    Apr 20, 2009
    22
    0
    quick find just now i tried to piece some information from the internet and i came up with this possible solution:

    could i just make this emitter circuit:
    http://www.trainelectronics.com/artcles/PulsedIR/images/555schematic.gif

    and use this receiver circuit (with the 38khz receiver module you posted ron):
    http://1.bp.blogspot.com/_CnJWaZjqjGY/SZlqt72eM2I/AAAAAAAAATE/EAOVfSsh538/s1600/bitmapSchematic.png

    im sorry if im asking a lot of dumb questions but this really has me and my group stumped :( thanks for your patience!
     
  17. Ron H

    AAC Fanatic!

    Apr 14, 2005
    7,050
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    That looks like it should work. You should probably shield the IR source and receiver from direct light.
    A beam break system will probably be easier to do than beam reflection, if you can do it. Reflection may be very lossy unless you are counting laps of a mirror.:D
    Keep in mind that I have never used these components, so I could be violating my avatar, as it were. :eek:
    (In other words, this may be BS).
    I'm just an old retired EE with lots of experience.
     
  18. tron

    Thread Starter Member

    Apr 20, 2009
    22
    0
    haha no problem at all, i really appreciate all of your help :) ill def keep you guys updated as to what happens tomorrow!
     
  19. tron

    Thread Starter Member

    Apr 20, 2009
    22
    0
    Hello:

    We are having problems with our receiver circuit :( when we check the 'out' pin on the receiver, we are getting a constant 5V out of it. do you guys see any problem? also i am including a schematic of our transmitter and receiver.

    transmitter (the resistor short is fixed). we get an ir beam out of it (when looked at under a camera phone, we see a purple light)
    [​IMG]

    receiver
    [​IMG]
     
  20. tron

    Thread Starter Member

    Apr 20, 2009
    22
    0
    hello

    we just hooked this up to an oscilloscope and the swuare wave coming out of pin 3 on the 555 timer is nowhere a 50% duty cycle, its more like 90% :(
     
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