PSU's and Speed controllers

Discussion in 'General Electronics Chat' started by KFL, Jan 3, 2013.

  1. KFL

    Thread Starter New Member

    Dec 27, 2012
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    Hi there!

    Am new to this forum and thought to take this opportunity to ask for your opinion regarding purchases of components.

    Have got hold of 2st engines:
    1: 22VDC 250W 10.5A approximately 3800RPM. (Electric wheelchair).
    2: 24VDC 30W 1.25A 240RPM. (In principle, wipers).

    I want to be able to connect them to the wall outlet (230VAC) and has therefore been recommended these two PSU's at an online store:
    1: USP-350-24 -> http://www.meanwell.com/search/usp-350/USP-350-spec.pdf
    2: S-40-24 -> http://www.meanwell.com/search/S-40/S-40-spec.pdf

    Do you think these are good options, or is there something more suitable?

    I also want to be able to regulate the speed of both engines separately (0-100%) and had therefore imagined 2pcs 24VDC speed controllers, but I have a hard time finding something suitable to both. If possible, I also see that the knobs are not attached directly to the circuit board, I prefer a cord between for easy placement in a controller.
    What do you think, is there anything to recommend?

    I am also puzzled about heat generation, everything will sit mounted in a closed "box" of approximately 30x30mm. When in use, it will be running about 1-2h per occasion.

    Right now, I will not tell you exactly what it is I'm building (some can probably be guessing what it is). :D
    For the curious, I intend to present a finished model in the end incl. drawings.
     
  2. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
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  3. KFL

    Thread Starter New Member

    Dec 27, 2012
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    Oops, yes I meant CM. I changed the unit to MM but forgot to add the zeros. :rolleyes:

    Thank for the heat rise information, very interesting!
    Will probably have to add a small fan circulating the air.

    Haha, a Battlebot is pretty close, it depends on how you look at it. :)
     
  4. KFL

    Thread Starter New Member

    Dec 27, 2012
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    I have now purchased these two power supply units named above.
    However, would really appreciate your assistance/input to find two suitable speed controls for the two above PSU->Engine combination.

    I find some cheap Chinese variants, but even though I want them to be "affordable", I would also like if they'll work for a while.

    Thanks
     
  5. KFL

    Thread Starter New Member

    Dec 27, 2012
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    No speed controls to recommend? Someone with good experience of any brand or supplier?
     
  6. BillB3857

    Senior Member

    Feb 28, 2009
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  7. KFL

    Thread Starter New Member

    Dec 27, 2012
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    Thanks for your answer! :)
    I have ordered two power supply units 230VAC->24VDC, one for each engine.
    I've also found many different speed control models on eBay/aliexpress etc, most of them manufactored in China.

    In my work we import lots of Chinese stuff (electronics).
    By my experience Chinese products makes me kinda... "skeptic".. But of course, perhaps they are not all bad.

    If someone have tried one of these Chinese controls I would be glad to hear their experience. Other wise, well they don't cost much.. ;)
     
  8. KFL

    Thread Starter New Member

    Dec 27, 2012
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    I have now ordered the 10A speed control for the biggest engine of them both.
    But I find it hard to find a speed controller for the smaller one at 1.25A.

    The speed control with lowest Amp I can find is at 3A, would that break the engine? Would be around 70W instead of the engines 30W..
     
  9. BillB3857

    Senior Member

    Feb 28, 2009
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    The motor will only take as much current as it needs. Of course if you stall the motor by overloading it mechanically, ............ but that holds true for either. The 3 amp drive should work fine. Another way to look at it is that the battery in your car can supply hundreds of amps. Why doesn't the windshield wiper motor blow up when you turn it on?
     
  10. KFL

    Thread Starter New Member

    Dec 27, 2012
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    Hello and thanks for your answer!
    That comparison with car battery was good for me, haven't reflected over that.

    Sounds good that the 3A speed controller should work fine, but now I start to think that maby the other speed controller that I ordered at 250w and 10A is to small to handle the 250W 10.5A engine. I read on a site that the speed controller should have 25% more capacity than the engine so it can handle peak currancy at startup, and when choosing speed controls always look at the stall currancy peak and not "normal load"..?

    Is that right? In that case, "doh"!
     
  11. BillB3857

    Senior Member

    Feb 28, 2009
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    Do you anticipate having your motors running at full capacity? Most applications that require speed control usually operate somewhere in the 75-90% range. It would really help to know the end use of the motor. The drive I listed the link to in the previous post has over current protection and should limit its output to safe levels.
     
  12. KFL

    Thread Starter New Member

    Dec 27, 2012
    8
    0
    My goal is to reach as much RPM out of both engines as possible, on the other hand there will be almost no resistance/hard work for the engines.
    The small engine will only rotate a small spring, and the bigger engine will create vibrations on a small plate via a thin poly.

    If you have not figured out yet its a "Sybian" that I'm building for my GF. :rolleyes:
    Se video on YouTube, search for "inside sybian" and you will get the whole picture of the mechanics and function. :)
     
    Last edited: Jan 5, 2013
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