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Basic circuit question — Parallax Forums

Basic circuit question

BobotBobot Posts: 8
edited 2007-10-08 18:22 in General Discussion
I have a basic circuit question.

If I have·four devices at 3 volts each; do I need to supply 3 volts or 12 volts to operate all the devices at the same time?

Thanks.



Post Edited (Bobot) : 10/7/2007 11:52:06 AM GMT

Comments

  • Desy2820Desy2820 Posts: 138
    edited 2007-10-07 11:41
    It depends entirely on wether the devices are connected in serial or parallel.· If in series, then you need 12 volts.· If in parallel, then you need 3 volts.

    Serial connection:· power+ --> device--> device-->device-->device--> power negative.

    Parallel connection:·· power+ --> device-->·power negative;··power+ --> device-->·power negative; repeat two more times.

    I hope this helps!
  • BobotBobot Posts: 8
    edited 2007-10-07 11:49
    Very good.

    Thank you very much. I do appreciate it.


    Post Edited (Bobot) : 10/7/2007 11:58:08 AM GMT
  • LoopyBytelooseLoopyByteloose Posts: 12,537
    edited 2007-10-07 15:45
    Ummm. That assumes that all the devices are resistors or light bulbs.

    It gets more complicated if it is something that is 'non-linear'. And some devices, like capacitors can work regardless of polarity, but other capacitors blow up if you use them backwards.

    I guess I am trying to ask you for more detail, for safety's sake. The devil is in the details.

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  • BobotBobot Posts: 8
    edited 2007-10-07 21:23
    Attached is a very simple diagram. each square represents a 3 volt device. the red lines are positive and the black lines are negative.

    What do think?

    I appreciate any input.

    thanks.
    devices2.jpg
    226 x 498 - 10K
  • LilDiLilDi Posts: 229
    edited 2007-10-07 22:00
    The way you have it in your drawing is exactly right. The black wire is ground and the red wire must be +3.0 volts.
  • Steve JoblinSteve Joblin Posts: 784
    edited 2007-10-07 22:01
    Can you tell us what the devices are? what you are showing is a common power and common ground (a.k.a "parallel circuit"). I don't know what to think without understanding what you are trying to do... you seem very concerned about voltage... what about amps?
  • BobotBobot Posts: 8
    edited 2007-10-08 18:22
    I am concerned about amps also. I am guessing at this point but I think each device will pull about 2 amps.
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