Any ideas for a fun project?

Discussion in 'The Projects Forum' started by physgrad, Jul 20, 2010.

  1. physgrad

    Thread Starter New Member

    Jan 20, 2010
    I'm looking for an interesting project to work on to refresh/sharpen some of my electronics skills. I've had a basic electronics class, a semester of analog electronics, and a semester of digital electronics (pretty basic - probably about freshman/sophomore level EE classes) and would like to use some of it so I don't completely forget everything or have to think so hard and long in front of my professor when I'm debugging experiments. The area I would be most interested is probably something to do with ac electronics - filters, low noise amplifiers, etc. since those are the most common circuits needed in my particular area of research.

    AAC Fanatic!

    May 26, 2009
    Why not try to build a function generator?
  3. Wendy


    Mar 24, 2008
    Or a color organ.

    Different lights light with different audio frequencies, their intensity varies with that frequencies sound volume.

    It involves filters, and drivers. A bit complicated, but doable, and very visual.

    Have you seen this?

    LEDs, 555s, Flashers, and Light Chasers (forum edition)
  4. SgtWookie


    Jul 17, 2007
    Do you have an oscilloscope, or are you considering buying one, or considering making an audio card adapter to make an el-cheapo audio spectrum O-scope?

    If so, you might consider building this:
    A Rotating Sprocket Wheel Generator

    If you don't wish to get into programming microcontrollers, you could use the quadrature sine wave oscillator on page 4 of this PDF document (figure 8):

    Increase C1-C3 to 33nF or R1-R3 to 33k to get the frequency down to around 500Hz.

    You can then use a 555 timer circuit to gate the 4066 analog switch.

    I've worked up a schematic for this, but no time now to upload it.
    Schematic attached.

    The opamp should be a rail-to-rail CMOS or JFET input type. An LMC6484 would be a good choice.
    Last edited: Jul 21, 2010
  5. studiot

    AAC Fanatic!

    Nov 9, 2007
    Welcome to All about Circuits.

    Don't know if you actually want to build anything or just do theoretical projects and simulations.

    A very interesting, and useful learning and consolidating project is to build a multifunction instrument based on a simple audio (and perhaps radio) oscillator and amplifier.
    By building a signal injector/ tracer you have most of the modules needed to also add a component measuring bridge and filter tester/demonstrator to your instrument.
  6. davebee

    Well-Known Member

    Oct 22, 2008
    Simple radios are really fun to build.

    It practically seems magical when a fairly simple circuit starts pulling voices and music out of nothingness!
  7. Wendy


    Mar 24, 2008

    That is stage one.

    Stage two is where my Dad started telling me to turn it off so he could watch his already weak TV signals. It was whatever I happened to be what I was working on at the moment, but it usually worked for him.
  8. someonesdad

    Senior Member

    Jul 7, 2009
    How about a basic lock-in (you'll use one if you go on in physics)? Dick Capels (who sometimes visits this board) has some nice-looking projects -- see I think he's got some plans for a milliohmmeter based on similar ideas somewhere, but a quick scan didn't show it...