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Capacitor?

Discussion in 'General Electronics Discussion' started by thorpenny, Jul 26, 2011.

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  1. thorpenny

    thorpenny

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    0
    Jul 21, 2011
    Hello I am trying to build a circuit controlled by a PIR sensor and I have found that the battery pack that I intended to use does not provide enough amps to power my dc motor in order for it to turn the base of a spring powered party popper. The only thing that I have that provides enough amperage is a series of 3 12v gel cell batteries. Since I want the whole thing to be relatively portable, I was wondering if a capacitor with a high pulse would feed enough power to the motor for a short period of time, just long enough to turn the base of the party popper. If I am misguided in this pursuit, any suggestions as to where I should turn would be appreciated. Thank you.
     
  2. Resqueline

    Resqueline

    2,848
    2
    Jul 31, 2009
    I have no idea what a spring powered party popper is, what power/torque is really needed, and what your mechanical setup looks like.
    In your other thread you say you have a 12v 3000mA Ni-MH battery pack, and that the motor draws about 2.5 amps/hour without load. (The /hour term is wrong btw..)
    I also don't know what other spec's the motor has, what kind of electrical setup you ended up with, how the battery pack is built, and surprised it cant deliver the Amp's.
    I'm also surprised the motor is unable to perform its duty. What current does the motor draw under load, and what voltage does it actually receive under load?
    While those big car audio capacitors may carry enough punch to run such a motor for quite a while I think there are other issues that needs clearing up.
     
  3. poor mystic

    poor mystic

    1,072
    33
    Apr 8, 2011
    Last edited: Jul 26, 2011
  4. thorpenny

    thorpenny

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    Jul 21, 2011
    I wish I could give you the information you seek regarding the motor, alas, I lack a multimeter. All I could glean about it online from where I purchased it (ebay) is that "3VDC: 1,400 RPM 850 RPM n/a
    6VDC: 3,150 RPM 2,100 RPM 750 RPM
    12VDC: 6,560 RPM 4,900 RPM 3,400 RPM
    18VDC: 9,800 RPM 7,350 RPM 5,100 RPM
    Starting torque is 2500 gm-cm = 35 oz-in = 2.1 inch-pounds, at 14 amps.
    Operating torque at medium load is 440 gm-cm = 6.1 oz-in at 2.8 amps."

    The first column corresponds to a light load (I couldn't find any hard figures) the second is "medium" and third is "heavy."
    Regarding the setup, I have not built it yet. My nephew took a screwdriver to my batteries that I mentioned in my earlier post, so I wont have any to prototype on for a while.
     
  5. daddles

    daddles

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    3
    Jun 10, 2011
    If you're in the US, you can get them for $5 from Harbor Freight and they are an excellent value for the money. If you can get to a store, sometimes you can find them on sale for $3 or less.
     
  6. thorpenny

    thorpenny

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    Jul 21, 2011
    Buy what exactly? Tuna? Please specify:D
     
  7. poor mystic

    poor mystic

    1,072
    33
    Apr 8, 2011
    How do you know it's the power supply that limits the force applied to the work?

    I've never seen a party popper myself, so I don't know what action sets them off.
     
    Last edited: Jul 27, 2011
  8. thorpenny

    thorpenny

    7
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    Jul 21, 2011
    How do I know? I know because I tested the motor on a series of three 12v gell cell batteries each rated at about 14 amps. Those worked. The batteries that I am trying to use seem to have just below the required amount of energy to perform the amount of work necessary.
     
  9. Resqueline

    Resqueline

    2,848
    2
    Jul 31, 2009
    Those motor spec's left a little to be desired. How can you say the motor can't turn the base of a popper if you don't have a prototype? A burned battery is irrelevant. Many questions go unanswered. Is this the motor?:

    12V DC 5 Pole Johnson Motor, Model Number 9167AK

    Rated to Operate from 6v - 18v. Starts turning at 1v DC

    No Load Stat's @ 12v;
    Speed: 6600 RPM
    Current: 330mA

    Stall Stat's @ 12v;
    Current: 14 amps
    Torque: 2500 gm-cm (35 oz-in or 2.18 in-lb)

    Tested at various loads;

    6VDC:
    Light Load: 3,150 RPM
    Mid Load: 2,100 RPM
    Large Load: 750 RPM

    12VDC:
    Light Load: 6,560 RPM
    Mid Load: 4,900 RPM
    Large Load: 3,400 RPM

    18VDC:
    Light Load: 9,800 RPM
    Mid Load: 7,350 RPM
    Large Load: 5,100 RPM

    With a medium load @ 12v, this provides 6 oz. in. of torque at 2.7A

    Size Dimensions:
    - Can Dimensions (Length x Diameter): 57mm x 36mm
    - Splined (Ribbed) Shaft - 20mm x 3.4mm
     
  10. thorpenny

    thorpenny

    7
    0
    Jul 21, 2011
    Like what? If you are a moderator than you should know better than to post irrelevant data. Instead of sending, "many questions go unanswered" you should first ASK those questions and see then if I can answer them. All this tells me is that yes, you know which motor I bought, and no, you didn't read my original post.
     
  11. Resqueline

    Resqueline

    2,848
    2
    Jul 31, 2009
    So you want people to just guess & help you blindfolded? Did you read my first post or bother to try to resolve much of any issues? You seem to be very secretive about this project (as if it was an invention in the making), knowing it all and wanting something for nothing. Well, go ahead & try to get help, I certainly won't bother you with irrelevant data or questions anymore..
     
    Last edited: Jul 28, 2011
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