Is There Such

Discussion in 'The Projects Forum' started by george0039, Jul 20, 2013.

  1. george0039

    Thread Starter Active Member

    Oct 15, 2008
    126
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    Hello

    I have a audio circuit that has an audio file in it of a helicopter main motor starting up. I would like to know is there a circuit that is a motor driver that can be sync up to the audio board? That way as the sound of the main helicopter motor start, then so does the little brushed motor. As the sound intensifies, like the motor is speeding up then so would the brushed motor.

    Is that possible OR is there a Single board that I could download a sound effect file into and it would also control a small brushed motor?

    Any links to one would be great!

    Thanks

    George
     
  2. Ramussons

    Active Member

    May 3, 2013
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    One way would be to have a voltage controlled voltage regulator feeding your motor. The control voltage will be derived by rectifying the output of your sound.

    Louder sound => higher voltage to the motor.

    Ramesh
     
  3. george0039

    Thread Starter Active Member

    Oct 15, 2008
    126
    5

    Hi

    Would that have any effect on the audio playback, in terms of lowering the audio volume? Is it possible for you to show me a circuit that could do that?

    Thanks

    George
     
  4. george0039

    Thread Starter Active Member

    Oct 15, 2008
    126
    5
    Hello Again

    If anyone has a working circuit that would do what I had posted then please lets see it.

    Thanks

    George
     
  5. wayneh

    Expert

    Sep 9, 2010
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    You need to define the behavior of the motor. Would a slow ramp up in rpm work? The sound file is like a clock, and you can determine for each time interval what rpm you want. Once you know that rpm-vs-time profile, someone here can probably come up with a clever way to implement it.
     
  6. djsfantasi

    AAC Fanatic!

    Apr 11, 2010
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    Do you know what the audio signal looks like. Does it ramp up in a similar manner that you want the rotors too?
    I have a circuit that feeds an ADC on a micro controller, which is used by software to control a servo. Depending on the audio waveform, it will output a 0-4vdc signal. This could be used/modified to control your rotor.
    Look at http://forum.allaboutcircuits.com/showthread.php?t=44738
     
  7. george0039

    Thread Starter Active Member

    Oct 15, 2008
    126
    5
    Hi

    Yes the sound ramps up. Just like the areal helicopter motor in the shut down position you hear it winding up towards full speed.

    I would like the dc motor to do the same BUT my space for the electronic board is not great, I need to know the size of the circuit board for this to see if it will fit.

    George
     
  8. djsfantasi

    AAC Fanatic!

    Apr 11, 2010
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    I have the PCB somewhere. I'll see if I can find it. Small as in less than 1" square.
     
  9. george0039

    Thread Starter Active Member

    Oct 15, 2008
    126
    5
    Hi

    If your circuit board can do what I`m after, I would be interested in seeing it.

    George
     
  10. george0039

    Thread Starter Active Member

    Oct 15, 2008
    126
    5
    Hi djsfantasi

    Any luck finding that circuit for me?

    George
     
    SgtWookie likes this.
  11. djsfantasi

    AAC Fanatic!

    Apr 11, 2010
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  12. wayneh

    Expert

    Sep 9, 2010
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    I think the easiest way does not require any "synch" with the audio. If you know the audio ramps up in, say, 5 seconds, and it's always the same, then you just need to ramp up the rpm over 5 seconds. You could use PWM to control the motor speed, and then you need a way to ramp up the duty cycle of the PWM from 0 to 100% over 5 seconds.

    I'm not fluent in this area but I've seen voltage-controlled PWM circuits here lately, and I know a simple op-amp circuit can give you a linear voltage ramp. That's probably where I'd start, until somebody comes by with a more elegant solution.
     
  13. george0039

    Thread Starter Active Member

    Oct 15, 2008
    126
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    Hello Again

    Well I want to Thank all for your help so far. Since I am new to this I still need to look at circuits to know what you mean and if I can even attempt to put one together on a DIY solder experimentor`s board.

    Any Help with the design circuit would be Great!

    Thanks

    George
     
  14. wayneh

    Expert

    Sep 9, 2010
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    Start with building yourself a PWM motor controller using the 555 timer IC, since you'll need this no matter what other solution you choose. There's plenty of info on this at this site. Look for Bill's MOSFET drivers. I can never remember where to find it, but it's here somewhere. ;)

    [here is what I was thinking of]
     
    Last edited: Jul 26, 2013
  15. Bernard

    AAC Fanatic!

    Aug 7, 2008
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    Add audioto DC ramp to Sgt. Wookie's PWM. Add a driver to match motor.
     
    Last edited: Jul 26, 2013
  16. george0039

    Thread Starter Active Member

    Oct 15, 2008
    126
    5
    Hello Bernard

    Thank you for the circuit help.

    Since I am still new to this I will ask SgtWookie if he sees this to describe his circuit since I don`t see the pin. numbers for either I.C or are they the same one? The Circuit is the one posted by Bernard above.

    Also my audio circuit is from electronics123.com, it has been programmed with the sound file so I need to know how to connect it to this circuit so that I still have sound as well as powering the small DC motor, 3-5v 1A max.

    I hope the included information is enough for you to help me better understand what I have to do to get both circuits to work together.

    Thanks

    George
     
  17. george0039

    Thread Starter Active Member

    Oct 15, 2008
    126
    5
    Hello Again

    I sent SgtWookie an email to bring this post to his attention and my need of his help.

    The rest of this post will be in public.

    George
     
  18. SgtWookie

    Expert

    Jul 17, 2007
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    I have been travelling out East (MI and upstate NY) for over a week; today is the National Museum of the USAF in Dayton OH. I won't get home until late tonight, and will have a great many things to do when I get home.

    No, that circuit won't work for you as-is. No, I don't have time to work on it.
     
  19. Bernard

    AAC Fanatic!

    Aug 7, 2008
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    George, did you look up data sheet on LM2903? LM393 same function & pinout. U1a-1 = out; U1a-2 = - in; U1a-3 = + in; U1b-6 = - in; -5 = + in, -7 = out; VCC= 8; Gnd = 4. Connect DC ramp to ref, U1b-5; pot[ 10k or 100k]. is used for testing & not part of circuit. Make R3 a 100k +- pot for testing, then replace with fixed R, same with VR1, stay on low side, say 2 kHz. More later.
     
  20. wayneh

    Expert

    Sep 9, 2010
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    It's worth noting that this circuit is similar to the one in Bill's Fig 10.4 that I linked above. It uses less parts because it uses the comparator as the oscillator instead of a 555, but the idea is the same: Feed a sawtooth waveform to a comparator, and adjust the reference voltage on the other pin to change the duty cycle of the output.

    By controlling the reference voltage, you control the duty cycle and thereby the speed of the motor. From there you just need a way to ramp the reference voltage, and that's pretty easy.

    You might want to use a quad op-amp. Two of the amps could serve the role of the two comparators in Sarge's circuit. A third one could provide the slow ramp, see here for an example.
     
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