IR on/off switch

Discussion in 'The Projects Forum' started by majhi, Oct 9, 2014.

  1. majhi

    Thread Starter Member

    Jul 2, 2014
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    Yes, I know this topic has been brought up time and time again, but I can't find any solid leads on how to go about building my project. I have a little bit of electronics knowledge, but let's just call me a newbie to play it safe. So here's the deal:

    I have an LED strip attached to a 12v (8xAA) power source. I want to be able to just turn the LEDs on and off with a transmitter/receiver setup.
    I want to build my own transmitter as well (due to project restraints).

    I was looking at this guy's schematic (http://www.instructables.com/id/How-to-make-an-IR-infrared-receiver-and-transmit/?ALLSTEPS) and it seems easy enough, but upon reading some of the threads on here, I decided to scrap the phototransistor and choose an IR receiver instead. I haven't bought the parts yet because I don't know what I'm doing (ha), so I guess what I really want to know is if this plan will work as a simple on/off.

    Thanks in advance.
     
  2. jpanhalt

    AAC Fanatic!

    Jan 18, 2008
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    By commercial IR receiver, I presume you mean something like one of the Vishay TSOP devices. Those receivers require an on/off modulated IR signal to reduce effects of IR in the environment (e.g., from fluorescent lamps) and improve range. Making your own transmitter for one is not difficult. You can use a couple of NE555 IC's or a microcontroller.

    What is your preference?

    John
     
  3. majhi

    Thread Starter Member

    Jul 2, 2014
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    Last edited by a moderator: Oct 9, 2014
  4. jpanhalt

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    Jan 18, 2008
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    Link doesn't work.

    John
     
  5. majhi

    Thread Starter Member

    Jul 2, 2014
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    Hmmm. It's TSL267-LF-ND on Digikey's website. "IC IR LIGHT-VOLT CONV SIDELOOKER"
     
  6. Brevor

    Active Member

    Apr 9, 2011
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    Thats not an IR receiver it's a light to voltage converter, you dont want to use one of those because ambient light will interfere with it. You need to use a device like John mentions in post #2.
     
  7. majhi

    Thread Starter Member

    Jul 2, 2014
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    Well shoot. So this sounds like it's getting a bit too complicated for me. That Instructable that I first posted is about my skill level, I have zero experience with ICs or microcontrollers. I wouldn't even know where to start.
     
  8. jpanhalt

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    A proper receiver has only three pins: power, ground, and signal. Here is just one of many examples: http://www.vishay.com/docs/82491/tsop382.pdf There is very little user design involved.

    The transmitter is where some design must be done. Have you ever worked with a transistor or with the NE555/LM555 IC?

    Beware that not all Instructables work as presented. Some are outright fakes.

    John
     
  9. majhi

    Thread Starter Member

    Jul 2, 2014
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    I've used transistors before, but never an IC. The TIP31 I used to convert audio to electric was just the one transistor and the wires and I was done. Is this going to be the same thing? Well, at least for the receiver.

    If so, then yes, the transmitter will be the hard part. It looks like I'll need to use a PWM setup to make the LED work at 38KHz.
     
    Last edited: Oct 9, 2014
  10. majhi

    Thread Starter Member

    Jul 2, 2014
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    Oh wait, it looks like I'd also need some resistors (or something) for the TSOP38238 because it will be driven off a 12v power supply.
     
  11. jpanhalt

    AAC Fanatic!

    Jan 18, 2008
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    The receiver will be no more difficult to hook up than TIP31 transistor.

    The transmitter can be done with two 555 IC's or a single 556 IC (which is two 555's in the same package). Here is the circuit I used in a simulation.
    IR_555.png

    Here is the simulation of the output. You will notice there the signal is repetitive clusters of peaks.
    IR_555_sim.png

    Look at that circuit, and if it is something you want to tackle, we can move on. That is just one of many similar circuits. The LED shown is an IR emitting LED.

    John
     
  12. majhi

    Thread Starter Member

    Jul 2, 2014
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    Erf, possibly. I have a limited budget (like $15) for this project at the moment...
     
  13. jpanhalt

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    Jan 18, 2008
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    The components, a bread board, and a perf board for final assembly can probably be bought for that, depending on what you have access to. Mouser has no minimum order, but there will still be shipping. Are you in the USA? Assuming the usual newbie screw-ups, however, $15 USD might be tight. About $30 should be no problem. Do you have any common components, like resistors and capacitors already available? Remember, you will have to add a section to go from the receiver signal to a switch to turn you LED's on and off.

    Have you checked Radio Shack and surplus dealers (e.g., Electronic Goldmine) for off-the-shelf remote switches? In this day, I suspect a DIY project like this will likely end up costing more.

    John
     
  14. majhi

    Thread Starter Member

    Jul 2, 2014
    49
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    I've looked on eBay and a little set-up from China is like $2. I don't know if those have the right capabilities, but maybe this is a project for next year when I can budget a little more (the project that I'm working on generally gets one modification a year).
     
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