Simple tone generator?

Discussion in 'General Electronics Chat' started by PartyLine4, Jan 12, 2013.

  1. PartyLine4

    Thread Starter New Member

    Jan 12, 2013
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    Ok I have looked everywhere for an easy to build tone generator and had no luck. So I am asking here if anyone could explain to me how one is designed and then built.

    I know most of the formulas for capacitors and inductors, as well as frequency.

    But how the heck do they design speaker circuits in the first place?

    I have the feeling that it is common knowledge among electronic engineers. But with the classes I have taken at my tech school, we have not learned anything about this sort of circuit design.

    So I ask you , PLEASE answer this question!

    Thanks,
     
  2. tracecom

    AAC Fanatic!

    Apr 16, 2010
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    A tone generator is simply an oscillator that operates at audio frequencies. What kind of tone do you want to generate and what purpose do you have for the tone generator?
     
  3. Wendy

    Moderator

    Mar 24, 2008
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    A simple 555 can drive a speaker almost directly. A speaker is only a type of load, it is not complicated.

    Volume 6 of the AAC book series has several example of what you are looking for.
     
  4. PartyLine4

    Thread Starter New Member

    Jan 12, 2013
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    As usual, everybody jumps the gun.

    I am trying to just make a simple 8 ohm speaker make a tone.

    It is to my limited understanding that you have to have at least 3 different items to make a speaker function.

    I don't want to use IC's, I know I will have to use a transistor somewhere probably.

    But I am in for the actual experiment and even more so how these circuits are designed and made functional.

    Has this information been lost over the years or something?
     
  5. Jaguarjoe

    Active Member

    Apr 7, 2010
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    You could try searching for "astable multivibrator". You'll get numerous hits. You mentioned you wanted to use a transistor, you'll need 2.
     
  6. WBahn

    Moderator

    Mar 31, 2012
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    How is what anyone said in any way "jumping the gun"? The first response merely pointed out that a tone generator is simply an oscillator operating in a particular frequency range and asked for some more details about what you are trying to accomplish. Your original post said that you wanted an easy to build tone generator and said nothing about not wanting to use an IC, so why should you be annoyed when the other response recommends a simple and easy to build IC-based solution? The quality of the response you get is directly proportional to the quality of the information you provide.

    You say you have looked everywhere to find an easy to build tone generator and have had no luck. Doing a Google search for "transistor tone generator" yields 1.2 million hits and brings up several images of schematics and a few lab exercises that have schematics, a bill of materials, and some theory of operation -- all on the first page of results! The first one I looked at has a tone generator using an 8 ohm speaker, two transistors, a resistor, a capacitor, and a 1.5V battery. It's simple enough that I went downstairs and threw it together and had it working in under five minutes.

    So if you can't find anything that is simple enough for you after all of the effort you have put into your search, perhaps you might help things along by being a lot more specific about what it is you are looking for that is lacking in all of the results that your extensive search efforts have turned up.
     
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  7. ScottWang

    Moderator

    Aug 23, 2012
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    Search on google as : transistor astable.

    And the circuit you want as this way:
    Transistor astable → 1uf → NPN BJT Amplifier → speaker
     
  8. JingleJoe

    Member

    Jul 23, 2011
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    As the americans say; you need to chill out, man!
    What do you have against ICs? They are more often than not the same circuits you would build with transistors, but all done for you and in a smaller space, smaller price and shorter time. Anyways if you want to learn some things and do experimentation, I found learning about voltage dividers and the operation of a 555 timer astable circuit very helpful when I started electronics.
    Whenever I want to drive a speaker and don't want complex sounds, I use a 555 timer.
     
  9. vk6zgo

    Active Member

    Jul 21, 2012
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    Normally,a "tone generator" is a circuit,or device which produces an electrical signal which is in the audio spectrum & may be used for various purposes.

    It does not imply :"An oscillator driving a loudspeaker",except perhaps among the unknowing,who seem to be prolific posters on the Internet.
    For that reason,we can surely be excused for not understanding your original question,
     
  10. SPQR

    Member

    Nov 4, 2011
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  11. bertus

    Administrator

    Apr 5, 2008
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  12. ScottWang

    Moderator

    Aug 23, 2012
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    If series in a 47Ω~220Ω resistor between two transistors on his circuit is better.
     
  13. MrChips

    Moderator

    Oct 2, 2009
    12,442
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    I'm gonna jump the gun.
    You can do it with one unijunction transistor.
    Or two Bipolar junction transistor. Google "transistor oscillator".

    Or with a PNP and NPN transistor. Google "ARRL transistor oscillator".

    Google is your friend (hate to say this).
     
  14. BillO

    Well-Known Member

    Nov 24, 2008
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    My mother always told me, "If you can't say something nice about another person, don't say anything at all about them."

    I'm not going to say anything about the OP.
     
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  15. tubeguy

    Well-Known Member

    Nov 3, 2012
    1,157
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    Also:
    Never insult your dentist until AFTER he's done drilling...
     
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  16. thatoneguy

    AAC Fanatic!

    Feb 19, 2009
    6,357
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    "Tone generator" is rather generic, leading one to think of a device that creates tones to be heard by an ear, especially when you mention "speaker" in your post.

    If you are looking for an audio frequency generator, what do you require for output impedance and amplitude, what waveform type do you want at the output?

    Don't get angry at responses because your question was sloppy.
     
  17. WBahn

    Moderator

    Mar 31, 2012
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    I may well slap my head when you answer this, but if someone asks for a simple tone generator in the context of circuits that drive speakers, what other types of circuits besides oscillators producing audio frequency tones driving a speaker should be included in the discussion?
     
  18. vk6zgo

    Active Member

    Jul 21, 2012
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    Well,gee,over the years,I have seen "tone generators" used for Telegraphy signals,tone encoded squelch systems,dial tone,time pips & many other things,but the only time I've heard the term used for something which drives a speaker is on the Internet.

    The "speaker" seemed out of context with the "tone generator" part ,so it appeared to me as if he was asking two questions.

    I guess I was led astray by the use of a term which had a real meaning other than that in which it was being used.

    My Bad,should have read his second posting!
     
  19. PartyLine4

    Thread Starter New Member

    Jan 12, 2013
    27
    0
    So from my basic understanding, the transistors can amplify a signal usually about 100 times, and resistors are used as a voltage divider in most circuits for oscillators.

    correct me please.

    I should have been more specific as to I am wishing for a mainly SIN wave generator. I just didn't want to use any ICs or anything integrated. Just standard components that I can modify.
     
  20. SPQR

    Member

    Nov 4, 2011
    379
    48
    There is a phase-shift oscillator HERE.
    HERE is another site with a tonne of stuff
     
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