steam powered cell phone charger

Discussion in 'The Projects Forum' started by Jibaro, Dec 25, 2015.

  1. Jibaro

    Thread Starter New Member

    Dec 25, 2015
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    hi- i don't know a great deal about electronics, but i have coupled a model steam engine (Stuart 10H) up to a dynamo that puts out 12 volts dc at 5300 rpm at 2.3 amps.

    I picked up an analog volt meter (0-15 volts) that shows the dynamo puts out plenty of juice.

    However, when I hook it up to a USB car charger and plug a phone into it, the charge light on the phone only lights up when the voltage is around six, and the phone does not actually charge.

    I am wondering if there is some way to control the dynamo output to conform with the input expectations of the USB charger.

    Failing that, if I wire the cell phone (which is no longer used and cheap to begin with) directy to the dynamo and run it at five volts, would that work?

    I showed the guys at my local electronics store, and while they thought it was neat, they did not have any suggestions on moderating the output so the phone would charge.

    While the engine will peg the volt meter at about 3/4 throttle, at five volts, it is turning at a placid, sustainable rate.

    It sounds great!

    BTW, i am running it on compressed air.
     
  2. tcmtech

    Well-Known Member

    Nov 4, 2013
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    Is the dynamo putting out a reasonably clean DC power?

    If not that may be why the USB adapter doesn't like it.
     
  3. wayneh

    Expert

    Sep 9, 2010
    12,155
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    Am I hearing you right that your "voltage regulator" is the rpm of the motor? That's unlikely to be good enough regulation for a USB device. I forget but I think they expect 5 +-0.2v or so. And, at reduced rpm where you get 5V, you may not get much current. Finally, some USB devices won't charge unless they see certain voltages on the data pins.
     
  4. Jibaro

    Thread Starter New Member

    Dec 25, 2015
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    I believe it is- i bought a car cigarette lighter with an old fashioned bulb.

    It does not flicker at all.

    Nor does the needle on the volt meter move unless i adjust the air pressure.
     
  5. tcmtech

    Well-Known Member

    Nov 4, 2013
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    A incandescent light and a mechanical voltmeter are very poor devices for measuring electrical power fluctuations and noise. :rolleyes:

    For all we know it could be putting out AC current or DC with a ridiculously high voltage ripple and neither device would show any signs of it. :(

    My guess it that if it is a DC output it's being generated by a simple permanent magnet brushed commutator type motor/generator that has little to no filtering whatsoever on its output which means its power output is loaded with voltage ripple and commutator brush noise which will easily screw up the operation of the tiny power converter circuits found in automotive USB adapters.

    I would suggest putting a automotive radio/CB power filter block or at least a small iron core inductor and good sized capacitor in series with the dynamos output to clean up the power first before it goes to the USB adapter.
     
  6. #12

    Expert

    Nov 30, 2010
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    James Watt...meet Bill Gates.:D

    This could be incredibly cool. You might study steam engines to learn about mechanical speed regulators. Governors, that's what they were called. You might run it pretty fast and learn about voltage regulator chips. Either way, you are jumping across a couple of centuries.
     
  7. GopherT

    AAC Fanatic!

    Nov 23, 2012
    6,073
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    image.jpg Governor

    They also work on interns that are too fast - an old joke from the Clinton era.
     
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  8. #12

    Expert

    Nov 30, 2010
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    Bill Clinton, governor of Arkansas.:D

    I never did like that states' name. Kind of like Arnevada or Artexas.
    What? They ran out of coffee on the day they picked a name for the State and nobody cared?:confused:

    So, you're on an electronics site. That means you want a voltage regulator, right?
    Run the generator it at a convenient speed (Convenient means a speed you can control rather well.) and tell us about the voltage and current it can provide, including whether it's AC or DC and how much AC is mixed in with the DC. Just set the meter to measure DC voltage, and when you have that number, change the switch on the meter to AC and the meter will display the AC voltage content. You will need to connect a load resistor to use up about 1/4 of an amp. About 50 ohms @ 6 watts will do. Not convenient? How about a small light bulb that is supposed to live in a car? Maybe an 1157 tail light bulb? Or one of those ceiling lights about the size and shape of a fuse? Be sure to measure the current through the light bulb, too.

    Please find your, "Profile" page and enter something about your location. Even the country you are in will help us find parts for you.;)

    ps, you can get a digital volt meter at Harbor Freight for about $4..if you live in the U.S.
     
  9. Jibaro

    Thread Starter New Member

    Dec 25, 2015
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    Now we are getting somewhere!

    As soon as I get this translated, it is off to the electronics store.

    Thank you so much for your suggestion.
     
  10. Jibaro

    Thread Starter New Member

    Dec 25, 2015
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    I had a model steam engine when i was in the sixth grade. One day, i was showing it off to a classmate and my bedroom window came crashing down right on the boiler. That was about 1965 or so. It wasn't until three or four years ago that i got another one, a gift from my wife. Since then, i have picked up a few more,

    My father was a steam boiler guy- NROTC grad from Worcester Polytech In mechanical engineering and a Lt. JG in the Pacific theater. He later worked for a company that sold metering devices to power plants and paper mills for the most part. After that he worked for the local electric company, first as a project manager and later as their manager of fuels. He bought bunker fuel and coal by the bargeful.

    So I have always had at least a passing interest in steam powered electric generation. Hopefully i can figure this out and get a working model. I just love the sound of them and I am piping the compressed air into my living room. Initially just to have the Stuart chugging away while i did the crossword puzzle, but
    I have aimed a little higher now. Luckily my wife is very patient.

    BTW, I am in Boston , MA.
     
    Last edited: Jan 1, 2016
  11. BR-549

    Well-Known Member

    Sep 22, 2013
    2,006
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    Most of us get our power the same way. Steam.

    Before deciding what needs to be done, let's have a look at that dynamo datasheet or link.

    I was very impressed with your prime mover. Must see dynamo.

    Let's see the tail end.
     
  12. Jibaro

    Thread Starter New Member

    Dec 25, 2015
    10
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    If you google "mini-castings dynamo for Stuart DYN-1" you should get an ebay hit of exactly what I have: a fully machined casting kit that needs a little paint and assembly. Any specs I am aware of are on the exploded view photograph.

    Per GopherT's suggestion, I picked up a meter at Harbor Freight. After I selected the meter, I wandered over to the metal workng section and somebody else was staring wistfully at a brake. We struck up a conversation, he saw the meter in my hand, and handed me a coupon for a free meter same as the one in my hand, as long as you made another purchase. They played me like a fiddle; I bought three things I didn't need that came to three times what the meter would have cost me if I bought it outright!

    Anyway, that is downstarirs and I haven't messed with it yet. I did get a digital ammeter just the the volt meter.

    I will scope out the CB radio filters next.

    Happy New Year!
     
  13. #12

    Expert

    Nov 30, 2010
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    The Harbor Freight meter has ranges for volts and amps. I think you have a, "forest for the trees" problem.:D

    Just a thought. Can you imagine how many Chinese engineers are spinning in their graves at the idea you would use an air compressor to drive a steam engine to charge a cell phone after they gave the best years of their lives to get the cell phone to run on a kiss and a promise?:D
     
  14. BR-549

    Well-Known Member

    Sep 22, 2013
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    Have you got a friend with a scope? That dynamo is rated at 10 VDC, 10 watts at 5300 rpm.
    Which is 1 amp at 10 volts at 5300 rpm.

    You might consider an old auto generator(junk yard maybe) or a small auto alternator.

    I might be wrong, but I think your dynamo is noisy. A scope will tell.

    I don't believe your dynamo is sufficient for a reliable 5 volt charger.
     
  15. #12

    Expert

    Nov 30, 2010
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    It is as reliable as the compressed air supply...if nothing mechanical breaks.
    Ten volts with a capability of one amp is sufficient to charge many small batteries. I guess the doubt is about the cell phone's internal charger circuit. Will it require the 2 amp maximum rating for USB ports in order to function properly?
     
  16. BR-549

    Well-Known Member

    Sep 22, 2013
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    Only until someone sees a vacant usb charger and plugs a heavier load to it.
     
  17. Jibaro

    Thread Starter New Member

    Dec 25, 2015
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    The automobile alternator is for the the "built-in" version. I have a PMResearch engine number 4 that puts out 1/4 HP and weighs 40 pounds. This setup fits in a little wooden box about a foot wide.
     
  18. tcmtech

    Well-Known Member

    Nov 4, 2013
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    From what I can see online the DYN-1 dynamos are a very basic two pole four brush permanent magnet generator which to be honest is a design that is going to have loads of voltage ripple in its output.

    Sending its output through a diode and a big capacitor would do a world of wonder on cleaning up the voltage ripple.

    That said one of the smoothest DC generators I have ever worked with are the DC drive motors from commercial copier machines.

    Stop by your local office equipment repair shop and ask for a few junk copier motors. Odds are if you give them a good story and promise not to fix anything to resell they will probably give you a few old trade in machines just to see them go someplace other than their dumpster. ;)
     
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  19. WBahn

    Moderator

    Mar 31, 2012
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    No, a bunch of pirates sailed up the Mississippi looking for a place to retire and thought they had settled in Kansas. When the government came by to record their deed, he asked for the address and they replied, "Arrrgh-Kansas." Since they were actually in unclaimed territory, the government simply recorded the response as the name of the new territory.
     
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  20. Jibaro

    Thread Starter New Member

    Dec 25, 2015
    10
    0
    I
    I will take a look, thank you.

    I ordered a voltage regulator yesterday- another site had a thread with a similar issue (the details of which escape me right now)

    The regulator is coming from a place called pololu which looks to be devoted to sumo robots. It costs all of fifteen bucks.

    Years ago, a guy whose nickname was "Pululu" used to work for me.
     
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