Optoelectronics – Free preview!

Questions

  • 1

    Ras Bongo Natty Tafari

    Are the other modules coming out?

    • Ian Juby

      All total I will have five modules, producing them over the next year or so. I’m already working on the second module (digital electronics) but it takes time. I just came back from vacation and got called back right to work as well, so time is an issue there.

  • 1

    Jacob

    Hi Mr. Ian .
    So could an infrared LED be used to project a shape in the sky and keep its shape. https://www.youtube.com/watch?v=_CRWE-L45k . I don’t know if I am getting a little to far ahead of my self.
    Jacob 🙂

    • Ian Juby

      Hmm… the youtube link didn’t copy over right, but I probably have an idea of what you’re getting at: Sort of the “Batman signal light”? 🙂 You can use LED’s for that, but you’d have to focus it through a lens because LED light diffuses so fast. Also, infrared is not visible to the human eye, so you’d need infrared night vision to see it. But yes – it could be done. 🙂

  • 0

  • 1

    Jacob

    OK try this link https://www.youtube.com/watch?v=0Ztp4ej5Q_4
    Jacob

    • Ian Juby

      Oohh – you mean the purple circle thingie? Hmmm… Ya, it could be done – but it would be tricky. They do similar things by spinning LED’s in a circle and timing when to turn the LED’s on and off, like this: https://www.youtube.com/watch?v=uVL9V1wNoVg But you can do similar pattern formations with lasers and moving mirrors – usually they just have two mirrors that you can rotate at different speeds, and the mirrors are on subtle angles so they “wobble”. You bounce the laser off of one mirror on to the other, and then on to the wall. Even a cheap laser pointer does pretty good. Then you get different patterns by simply varying the rotation speed of the mirrors, like this: https://www.youtube.com/watch?v=8P5gmY0thl0
      That’s cool you’re thinking of stuff to build because that’s what’ll challenge you to learn things. 🙂

  • 1

    Jacob

    Thanks Ian I will try that.
    Also my friend has a BIG bass from an old stereo system and put a mirror on it.

    good job with the course.
    Jacob

    • Ian Juby

      Ah yes – I was going to mention that, but obviously youse guys thought of it already: A lot of speakers have mirrored domes or cones and you can reflect lasers off of them. 🙂

  • 4

    i took part a nightlight that i think had a cds cell. how do i know how much power it puts out

    Krystal Wawrzyniak

    should i just buy one or should i figer this one out

    • Krystal Wawrzyniak

      i think it was a cds cell at least.
      it reads the same when i put the pins of the multi meader in the air and on the the pins of what i think is the cds cell
      HELP!!

      • Ian Juby

        Hi Krystal!
        Can you post a picture of the CDS cell? And can you post a picture of your multimeter while trying to read the photocell? You have the meter on resistance, right?

    • Krystal Wawrzyniak

      so i had it in volts. when i change it to resisance it is the same on both pins. if i have the positive on the left pin and the negitive on the leftit reads the same is it does reversed.

      • Ian Juby

        Okay, yes it should do that if measuring resistance. Now what should happen to cause it to change is the amount of light hitting the sensor’s face. How it changes will depend on the sensor, but most likely the resistance will go down with more light and resistance will go up in the dark. Polarity doesn’t matter because technically it is a resistor.

    • Krystal Wawrzyniak

      i will try to take a picture.

    • Krystal Wawrzyniak

      i need help building the break beam burgler alarm system but i am aving trouble with connecting pin 1 on the left to negative and a capaciter. could you post a picture of the whole circute?

  • 0

    Krystal Wawrzyniak

    i want to build the burgiler system but the cds cell ( or what i think is a cds cell) i got from a nightlight that turns on when the light is off is reading the same when i but the prongs of the multi meader in the air as when ey are toughing. HELP!!

  • 0

    help

    Krystal Wawrzyniak

    i will try to take a picture.

  • 2

    ll

    Krystal Wawrzyniak

    i need help building the break beam burgler alarm system but i am having trouble with connecting pin 1 on the left to negative and a capaciter. could you post a picture of the whole circute?

    • Ian Juby

      Already done! 😀 Look up, to the right of the video lesson, you’ll see two PDF files you can download. One for the break-beam burglar alarm and one for the photophone (telephone communicating with light). Pick whichever one you want, or both, and you’ll have the entire circuit diagram.

    • Krystal Wawrzyniak

      I mean a picture of the circuit itself not the schematic

      • Ian Juby

        I don’t have a picture, only the schematic. I didn’t build that circuit for the lesson. I added it later and never showed even a close up of the circuit. Pictures of the circuits are usually less than informative. I get people to post pictures while trying to troubleshoot things because I know what to look for. But oftentimes I still can’t make out where the wires are even going. You really have to go by the schematic.