Music box

Discussion in 'The Projects Forum' started by Quillion, Aug 12, 2009.

  1. Quillion

    Thread Starter Member

    Jul 18, 2009
    10
    0
    Ok so my brother bought some tiny ipod thing(really not ipod fan), and it had this tiny cute box, in which my small breadboard fits perfectly.
    So I want to make a light sensitive music (more like annoyance) box.
    Any ideas or suggestions on how I should do it?
    This is my plan, but I am pretty bad at this.
    So in general what I want is that the more light hits the photoresistor the louder piezo speaker starts to sound. And when there is almost no light you can barely hear it.
    I am planning to use 555 chip, but if there is anything better to use please tell me. It does not have to contain 555 chip, I just want some kind of idea that will work.
     
  2. jj_alukkas

    Well-Known Member

    Jan 8, 2009
    751
    5
    No need for a 555, transistors will do it I guess.
     
  3. Quillion

    Thread Starter Member

    Jul 18, 2009
    10
    0
    How exactly would you use transistor?
    And what kind of transistor will you use?
    The problem I have been having is making piezo make noise. If I just directly connect it to the battery it makes no noise, so I end up using 555 chip.
    So how should I connect transistor to it to make it work?
     
  4. jj_alukkas

    Well-Known Member

    Jan 8, 2009
    751
    5
    A low gain pre-amp circuit with an LDR replacing the input resistor might work.

    A single BC547 or 2N3904 transistor based circuit is enough. You could find one easily online and do some experimentation. I am not used to LDR's, so I dont know its Rmin and Rmax.
     
  5. Quillion

    Thread Starter Member

    Jul 18, 2009
    10
    0
    I am sorry for sounding very stupid, but how would you connect it to piezo so it would buzz. Can you please provide some rough explanation as to where I connect base, collector and emitter
     
  6. jj_alukkas

    Well-Known Member

    Jan 8, 2009
    751
    5
    [​IMG]

    This is a preamp ckt. If you can measure the LDR's resistance at max and minimum light, you can calculate the dividing resistor and place those 2 instead of the 10 k variable in this ckt. Then you will get variable output. By why do you need to run a piezeo?? A normal small speaker will work on this ckt. For piezo, you might need a capacitor in series with the output.
     
  7. Quillion

    Thread Starter Member

    Jul 18, 2009
    10
    0
    I can't get my hands on any speakers, whenever I ordered (3 times already) it came to me broken(I tried from different websites), it was back in time when I was planning to make motorcycle sounding thingie with capacitors and a potentiometer, so I simply decided to stick with piezo, since I got a store nearby that sells them 90 cents each
     
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