Connect with us

simple tone generator

Discussion in 'General Electronics Discussion' started by 12vdc, Dec 21, 2014.

Scroll to continue with content
  1. 12vdc


    Apr 13, 2011
    would like to generate 10hz to 80hz 500 mv output to test woofers (with an amp)
    Looking for a simple circuit.
  2. KrisBlueNZ

    KrisBlueNZ Sadly passed away in 2015

    Nov 28, 2011
    Simplest option: create a .WAV file with a waveform editor such as Audacity and download it onto a smartphone or an iPad.

    Edit: I meant iPod, not iPad!
    Last edited: Jan 12, 2015
  3. 12vdc


    Apr 13, 2011
    well, I don't know where you are from but those of us living in 1980 only have a soldering iron, solder (the real stuff with lead) and a bag of caps and resistors. My phone has a dial on it and ..... I want a small prject box with a power switch and a pot to vary the freq.
  4. davenn

    davenn Moderator

    Sep 5, 2009
    We are from the rest of the world where even in 3rd world countries, everyone has a cellphone

    so you are telling me Canada is worse than 3rd world ? surely you jest

  5. KrisBlueNZ

    KrisBlueNZ Sadly passed away in 2015

    Nov 28, 2011
    OK. Ironically, that makes things more difficult! In that case, your simplest option would be an XR2206. They're no longer manufactured, but you can get them on eBay. You can also get kits based on them.
    hevans1944 likes this.
  6. hevans1944

    hevans1944 Hop - AC8NS

    Jun 21, 2012
    If you are "testing" woofers, you probably want a nice sinusoidal output with almost zero harmonic distortion and good amplitude stability as a function of frequency. What you need is a Wien bridge oscillator, said bridge having been developed by Max Wien in 1891. If you can find one, the Hewlett-Packard 200CD audio signal generator is an excellent choice. Or, if you want to roll your own, I have attached the original schematic from William Hewlett's 1939 U.S. Patent. If you can find the parts you need (a dual-ganged capacitor or dual-ganged resistors) the Wien bridge oscillator is simple to build... oh, you will also need a small incandescent light bulb whose filament is used to provide negative feedback for amplitude stability.

    If you follow the "roll your own" link above, Ramon describes a 1 kHz to 10 kHz oscillator. It will take some design effort to lower the range to 10 Hz to 100 Hz (probably need two incandescent lamps wired in series), but his circuit only uses one potentiometer and NO variable capacitors.

    Attached Files:

    Last edited: Dec 22, 2014
    KrisBlueNZ likes this.
  7. 12vdc


    Apr 13, 2011
    Hmmm....the Wien Bridge is interesting (thanks for link) I was hoping for something less complicated (intimidating). Looks like a cheap mp3 player and some tone files is the easiest.
    Last edited by a moderator: Jan 12, 2015
    hevans1944 and KrisBlueNZ like this.
  8. LvW


    Apr 12, 2014
    12vdc - in case you are interested in linear (harmonic) oscillators I would not recommend to restrict yourself from the beginning to the WIEN type oscillator only. There are many other oscillator topologies which could meet your requirements. This applies, in particular, to the tuning capabilities which are not so comfortable for WIEN oscillators (dual gang pots necessary).
Ask a Question
Want to reply to this thread or ask your own question?
You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.
Electronics Point Logo
Continue to site
Quote of the day