Hot batteries

Discussion in 'General Electronics Chat' started by Cougar22, Apr 1, 2013.

  1. Cougar22

    Thread Starter New Member

    Apr 1, 2013
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    I am NEW at Electronics and Circuits and I am trying to make a Spaceship Prototype.

    Here is the Problem: I have a 2 AAA Battery holder that is getting excessively HOT when the Switch is OFF. When the Switch is ON, all the LED's go on and the batteries do NOT overheat. The problem is when the switch is OFF.

    Here is the Circuit;

    2 AAA Battery Holder (3V) is connect to the 3A 250VAC Switch.

    From the Switch I am completing the Circuit to Six (6) .28ma LED's.

    Can someone HELP me with this Problem???
     
  2. GopherT

    AAC Fanatic!

    Nov 23, 2012
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    Your switch is connected in parallel. It should be in series. As of now, you are connecting the battery negative to battery positive with just copper wire in between when you turn the switch on - don't do that because the battery gets hot and can pop open and hurt someone.


    You cannot just connect black to black and red to red on a switch.
     
  3. GopherT

    AAC Fanatic!

    Nov 23, 2012
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  4. Markd77

    Senior Member

    Sep 7, 2009
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    I imagine the switch has three terminals, correct me if I'm wrong.
    Connect (+) of the battery to the centre terminal
    Connect one of the other terminals to one end of the LEDs and resistors (I hope there are resistors)
    Connect the other end of the LEDs to the (-) of the battery
    Don't make any other connections.
     
  5. Cougar22

    Thread Starter New Member

    Apr 1, 2013
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    So from the Switch I must connect Black to Red and Red to Black???
     
  6. WBahn

    Moderator

    Mar 31, 2012
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    Could you PLEASE post some kind of a sketch of what you have and how you are making your connections. Saying something like the battery holder is connected to the switch isn't helpful because the battery holder has TWO wires and the switch has at least two terminals. So sketch something. It doesn't have to be fancy -- something in Paint will do. Or hand draw it and scan it. Or take a picture and post that.
     
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  7. DerStrom8

    Well-Known Member

    Feb 20, 2011
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    No, you can't go by color codes! Just read the above posts! It tells you EXACTLY how to wire it, step by step!
     
  8. GopherT

    AAC Fanatic!

    Nov 23, 2012
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    Switches on small DC circuits do not have polarity (ignore color).

    Red battery wire to one switch lead
    Other switch lead to all six resistors (100 ohms each)
    Connect each resistor to the anode (+) of an LED
    Connect the cathode (-) of all six LEDs to the negative battery lead (black)
     
  9. Cougar22

    Thread Starter New Member

    Apr 1, 2013
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    So I need RESISTORS in between each LED????

    Right NOW I do not have any resistors on the project.

    What do Resistors Do???
     
  10. DerStrom8

    Well-Known Member

    Feb 20, 2011
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    Forgive my rudeness, but you're expecting to build a spaceship prototype without the slightest idea of what any of the components are or what they do? How do you think that'll work?

    Sorry if this sounds mean, I'm not intending it that way. I just can't really wrap my mind around it :rolleyes:
     
  11. Cougar22

    Thread Starter New Member

    Apr 1, 2013
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    Its OK I am from New Jersey and don't mind your Rudeness.

    This is a FUN project so I am learning as I go and ask questions as problems arise.

    I have learned alot already at Radio Shack, so I am almost there.

    I just have to get this HOT BATTERY Corrected.
     
  12. WBahn

    Moderator

    Mar 31, 2012
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    What LEDs do you have? Do you have a part number? You've said they are each 0.28mA (seems awfully low current, but then LEDs have come a long way since I last tinkered with them), but what is the forward voltage?

    What kind of switch do you have? Does it have just two terminals or three (I'm guessing three because you managed to short the battery pack when it was off).

    Could you PLEASE post some kind of drawing!
     
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  13. WBahn

    Moderator

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    Let's use this as a reference.
     
  14. DerStrom8

    Well-Known Member

    Feb 20, 2011
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    No LEDs run on 0.28mA. 28mA is much more reasonable.
     
  15. Cougar22

    Thread Starter New Member

    Apr 1, 2013
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    2 AAA Batteries at 1.5V x 2 = 3V

    Switch = SPST 3A 250VAC (2 terminals)

    LED Forward Voltage = 3.0 - 3.2

    LED Current = 24ma

    LED = 13,000 MCD


    I am trying to put together a DIAGRAM.
     
  16. WBahn

    Moderator

    Mar 31, 2012
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    24ma is very, very different form the .28ma you mentioned in your first post!

    If you try to run six 24ma LEDs from 2 AAA batteries, your batteries aren't going to last long.

    How much current you are actually getting is a huge unknown. You are right on the edge of not having enough voltage to get any current to flow at all, even with fresh batteries, and it only takes a small difference to result in a significant current flowing. I would expect your LEDs would not see enough voltage to light up within a half hour or so (if you are using Alkaline batteries).
     
  17. WBahn

    Moderator

    Mar 31, 2012
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    I just did a quick check and it appears that 2mA is about the lowest. The OP may want to consider those over the 24mA ones he is talking about now.

    He may also want to investigate the Joule Thief circuit, but that is probably a bit advanced for him right now -- however it is a pretty simple circuit and he should be able to progress to it fairly quickly.
     
  18. Cougar22

    Thread Starter New Member

    Apr 1, 2013
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    OK----I was thinking about that also----NOT enough VOLATAGE.

    Should I jump up to the 9V Battery?????
     
  19. WBahn

    Moderator

    Mar 31, 2012
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    Depends on what you are doing.

    You're saying that all six LEDs come on bright enough right now?

    Have you operated them long enough to see how long the batteries can power them?

    Do you have access to a multimeter (also known as a VOM or volt-ohm-millammeter)?

    How long do you need them to run in your spaceship prototype?
     
  20. Cougar22

    Thread Starter New Member

    Apr 1, 2013
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    I took pictures and tried to attach them, however I could NOT.

    This is a COST SENSITIVE project so I am looking for CHEAP PRODUCTION avenues with High Quality Output.
     
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