Window Physics Project

Discussion in 'The Projects Forum' started by Damian3395, Jan 22, 2013.

  1. Damian3395

    Thread Starter New Member

    Jan 22, 2013
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    I just learned how to work with DC circuits in physics class and I am having a little trouble. I created a box with a window that can be lift upwards with 2 gears and a motor. When the motor is connected directly to my AC-DC converter at 4.5V, it works perfectly.

    I have a secondary power source, which is a 9V battery case, but when I connect it to my two-way toggle switch [OFF], the batteries still overheat without doing any work and when I turn the switch on it works fine.

    My AC-DC converter has its own toggle switch as well. Both power sources were initially turned to [OFF]. The two toggle switch output wires were combined together into one wire to be connected to the three-way toggle switch input source, which was in neutral. Then the output was connected to the motor.

    When I wire everything together, the motor will not move in either of the three-way toggle directions, when either power supplies are turned on. Please help.

    Also, when the battery switch was turned on and the AC-DC was turned off, not connected to the outlet too, the batteries powered the AC-DC adapter instead of moving the motor.

    http://i1093.photobucket.com/albums/i427/Damian3395/DSCN1207_zpsc7f1554b.jpg
    http://i1093.photobucket.com/albums/i427/Damian3395/DSCN1206_zpse61395c1.jpg
    http://i1093.photobucket.com/albums/i427/Damian3395/DSCN1205_zpsf3c1c34d.jpg
     
  2. kubeek

    AAC Fanatic!

    Sep 20, 2005
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    Can you draw it for example on a piece of paper? The connections in the box are really hard to comprehend. Also I don´t see where is the AC/DC adaptor connected..
     
  3. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
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    You need to diode or' the 2 supplies maybe? Can't tell if thats the problem without a schematic. but sounds like it may be.
     
  4. Damian3395

    Thread Starter New Member

    Jan 22, 2013
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    Thanks for the reply.
     
  5. kubeek

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    Sep 20, 2005
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    That´s what I suspected, the diagram is completely wrong.
    How can a three-way toggle switch have only two contacts?
    Also, don´t you see you are shorting both the supplies, right from + to -?
    Look at this drawing.
     
  6. Damian3395

    Thread Starter New Member

    Jan 22, 2013
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    I understand that I would shorten the voltage by applying both the batteries and the outlet, but instead I would like to use a single source of power at a time, by using a 2 terminal switch. Both sources of power would have its own switch. Once a single switch is turned on, then the power would be directed to a neutral 6 terminal switch, which would allow the motor to go in both directions. Thanks for the diagram and help guys.

    The part that worries me the most, is that the batteries were becoming very hot, even if the first single switch was off.
     
    Last edited: Jan 22, 2013
  7. kubeek

    AAC Fanatic!

    Sep 20, 2005
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    No wonder, when you short anything it usually either gets hot or right away bursts into flames, so please next time don´t do it.
    And I don´t mean having both sourcees on at the same time, I mean that wire that you drew right from + terminal of the battery to the - terminal. This creates a low resistance loop so high current flows through that wire and drains your battery very quickly. Connecting the switch like you did to this shorting wire really makes no sense.

    It seems you have trouble with the basic concepts of how electricity works, maybe you should read through our e-book here http://www.allaboutcircuits.com/vol_1/index.html.


    Instead of Switch5 you could use two single-pole switches, similar to your diagram, but you need to make sure that you don´t turn both on at the same time, that´s why the double pole I drew there is a safer and better solution.
     
  8. Damian3395

    Thread Starter New Member

    Jan 22, 2013
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    Thanks for the link, my physic class does not cover that many detail on circuits, we only have one section of a chapter in our book. I think i know what I am doing wrong now. I need to connect the negative wire directly from the battery to the motor and the positive from the battery to the 2 terminal switch to terminal C, but then how do I get a negative wire to terminal D, if I connect the negative wire from the battery to terminal C, then from the motor again, won't that short circuit the batteries?
     
  9. Damian3395

    Thread Starter New Member

    Jan 22, 2013
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    I think grounding wire should work since it is a negative wire not being used.
     
  10. kubeek

    AAC Fanatic!

    Sep 20, 2005
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    Look at that diagram I posted, The left switch - Switch5 - deals with choosing which supply is active, and this can be one single pole-double throw switch like in the diagram, or two single pole-single throw switches like in the diagram you posted.
    The double pole-double throw switch on the right switches each end of the motor to either positive or negative supply.
    The way it is now the motor gets positive voltage on the upper terminal and negative on the lower terminal. If you toggle Switch3 and Switch 4, the motor get positive voltage on the lower terminal and negative in the upper terminal.
     
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