Senior Design Project Help! Increasing voltage

Discussion in 'General Electronics Chat' started by sulbien, Apr 11, 2012.

  1. sulbien

    Thread Starter New Member

    Apr 11, 2012
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    Hello,

    I'm doing a senior design project where we are using exhaust to turn a turbine which is coupled to a motor that we are using as a generator. At our maximum speed we are getting output of 1.02V and .53A. I would have liked to increase the voltage to above 12V so we could use it to trickle charge a car battery would this be possible to do with an electric circuit and a charge regulator? My major has very minimal exposure to electronics so any help would be greatly appreciated. If that is not possible does anyone have any ideas of a useful way to utilize my output? Thank you in advance!
     
  2. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
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    The thing to remember is that when you increase the voltage (voltage multiplier/charge pump/etc..) the amperage will go down..
    From Ohms law P=E*I (where P is watts, E=voltage, I=current)
    So basically 1V x .53A=.53W (So you basically have .53W of usable power..)
    Now if you increase that to 12V you only have .044Amps (.53W/12V=.044 Amps)
    Of course the efficiency of your voltage multiplication is not factored in there and will lower the available current a little more.
     
  3. sulbien

    Thread Starter New Member

    Apr 11, 2012
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    I figured that the amperage would go down but I was unsure of how much it would decrease. Basically my professor wants us to apply the power we are getting in some manor. If that decrease in amperage is what is necessary to obtain 12V and be able to use the power I guess that is what I will have to do. How would I go about setting up a circuit to accomplish this? Otherwise do you have an alternative way I could use this power in some fashion?
     
  4. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
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    Whats the minimum voltage your device will produce or will it always be at full speed?
    You could look into a dc/dc converter (boost) or joule thief.
     
  5. sulbien

    Thread Starter New Member

    Apr 11, 2012
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    it is just a proof of concept so we are showing the maximum so it will be at full speed.
     
  6. djsfantasi

    AAC Fanatic!

    Apr 11, 2010
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    I like McGyver's suggestion. With the voltage and current you are getting, a joule thief may be used to light an LED for example - you did say you just needed to demonstrate your output. Joule Thief Defined
     
  7. sulbien

    Thread Starter New Member

    Apr 11, 2012
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    I was hoping to have some proof of concept that it was capable of the some form of trickle charge. Do you think that would be possible even if it was very slow?
     
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  8. panic mode

    Senior Member

    Oct 10, 2011
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    then why are you doing this? why don't you do something that better matches your background, something you know?
    what possible benefit could outweigh problems of having something stuffed into the exhaust pipe?
     
  9. Adjuster

    Well-Known Member

    Dec 26, 2010
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    The ideas of energy and power, and in particular the fact that more energy cannot be created from less are basic science, well worth everybody's understanding.

    Failure to grasp this point can leave us vulnerable to falling prey to pointless crackpot schemes often touted by swindlers to make money from the ignorant. These ideas are not even allowed to be discussed on this forum

    If you come away from this project with a better understanding of energy, you will have learned something useful in itself,
    whatever else you achieve.

    Edit: Even a voltage converter of modest efficiency might let you operate two or three high- efficiency LEDs at 10 mA or so each, to make a noticeable light. You might like to note though that the engine power output may be being reduced by a greater amount due to obstruction of the exhaust system by the turbine, so the total power generated may actually be less than before the turbine was fitted.
     
    Last edited: Apr 11, 2012
  10. sulbien

    Thread Starter New Member

    Apr 11, 2012
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    The idea to prevent backflow to the engine was a wastegate valve similar to what is used in turbo chargers in many vehicles. Thank you for the ideas. As to why we decided to do this as our project unlike many majors that are given ideas for our projects we had to come up with something original from scratch. As we've learned its difficult to come up with any form of original idea without involving some form of circuitry or programming both of which we are lacking in depth experience in. Thank you for your suggestions.
     
  11. Bernard

    AAC Fanatic!

    Aug 7, 2008
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    You could charge one or more Ni-Cd AAs in series with Joule Thief, or simulate a diesel-electric train engine by running a small electric motor- some will run from a single solar cell, maybe one of these from Electronic Goldmine: G 9330, $1.25, 1/2V -6; G 18363, $1.29,1/2V; * G 18072, $2.49, 1/2V- 1 1/2V.
     
    Last edited: Apr 12, 2012
  12. WBahn

    Moderator

    Mar 31, 2012
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    I understand that you are just trying to find something to use the output for as a demo for your little turbine, but I think you want to be a bit careful to avoid creating the impression that you are claiming that generating half a watt of electrical power from an exhaust-stream turbine is in any way useful or practical. If this engine already has an electrical system, you are far better off to use the power from that.

    One way you might be able to claim a utility for such a device is to determine how much electrical power is needed to keep the engine running should the alternator fail and compare that to how much your device can deliver (and try to estimate how much it could deliver if it were optimally designed). I'm assuming, of course, that the engine is using a coil and not a mag and/or is not a diesel.

    Also, if you aren't already, be sure that you have some kind of indication of how much power the turbine is robbing from the engine.
     
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