Connect with us

Voltage help?

Discussion in 'General Electronics Discussion' started by Major Tom, Feb 7, 2013.

Scroll to continue with content
  1. Major Tom

    Major Tom

    6
    0
    Feb 7, 2013
    Hey guys, I'm a beginner with electronics, but I'm wiring up a nightvision rig with a b/w camera and a retrofitted viewfinder off an old camcorder. Trouble is, these components are power hungry, enough to exhaust a single 9v in <5 minutes. Awhile back I tried wiring two 9v to the setup, and it fried my camera. So new camera, both components are rated for 12v with the viewfinder running at ~<1/3 amp (does that sound right?) and the camera @ 1.56W.
    How would i go about powering these with only 9v? And if that is not at all efficient or reasonable, what should I power it with?
    Sorry if I sound like an idiot, I'm pretty new to this stuff.
    Any help is appreciated!
     
  2. davenn

    davenn Moderator

    13,838
    1,952
    Sep 5, 2009
    hi there
    welcome to the forums :)

    Are you referring to the small rectangular 9V PP3 battery ?

    if so, Im not suprised, those batteries have a very low current supply capacity
    You would probably need a 12V 7.2A/H Gel Cel, sealed lead acid etc type
    to get the sort of supply capabilities you require

    Dave
     
    Last edited: Feb 7, 2013
  3. (*steve*)

    (*steve*) ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd Moderator

    25,497
    2,838
    Jan 21, 2010
    I'm almost amazed you got 5 minutes out of a 9V battery.

    Get a 7AH 12V lead acid battery and you can probably run the camera all day.

    Two 9V batteries (you place them in parallel NOT series) would let you run the camera for ten minutes.
     
  4. Major Tom

    Major Tom

    6
    0
    Feb 7, 2013
    Thanks! Yeah, I like the rectangular 9vs because they are common, and I have a bunch of connectors for them that are hooked into the circuit. So if possible I would like to use these, but it sounds like the gel cells are a good way to go. These wouldnt fry the setup would they?
    Edit: I looked at the 7ah batteries online, they are extremely expensive and look huge. :eek: Any smaller options?
     
    Last edited: Feb 7, 2013
  5. davenn

    davenn Moderator

    13,838
    1,952
    Sep 5, 2009
    if your gear requires 9V, then you would need a voltage regulator to drop the 12V to 9V thats no big deal :)

    But you wont get anywhere with the small 9V batteries, they are designed for very low current drain devices

    Dave
     
  6. Major Tom

    Major Tom

    6
    0
    Feb 7, 2013
    Alright thanks, I'll look into some alternative batteries.
     
  7. (*steve*)

    (*steve*) ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd Moderator

    25,497
    2,838
    Jan 21, 2010
    But you did say:

    edit: you may be able to get away with an 3 cell lithium battery. You have to be careful not to discharge them too far, and you MUST use the correct charger. They are much lighter than lead acid.
     
    Last edited: Feb 8, 2013
  8. Major Tom

    Major Tom

    6
    0
    Feb 7, 2013
  9. (*steve*)

    (*steve*) ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd Moderator

    25,497
    2,838
    Jan 21, 2010
    According to what you say, you will get about an hour per 300mAh of capacity.

    Aside from that, yes. Be careful because these batteries can be dangerous if overcharged.
     
  10. Major Tom

    Major Tom

    6
    0
    Feb 7, 2013
    So these won't fry my system from the current? I'm not well educated on the workings of mAh.
     
  11. davenn

    davenn Moderator

    13,838
    1,952
    Sep 5, 2009
    Thats OK :) its all live and learn

    Its a common misunderstanding that if a power supply of hi current capability is connected to a piece of gear that requires a lower current, that it will fry the gear

    This doesnt happen

    the current flowing in the piece of gear is set by the the load resistance of that gear and the voltage of the supply

    have a look in this thread for some Ohm's Law explanations I did for some one else regarding voltage resistance and current --- posts # 7 and 8

    cheers
    Dave
     
  12. Major Tom

    Major Tom

    6
    0
    Feb 7, 2013
    Awesome! Thanks man, I appreciate your patience :p
    Ive had that deal before when I went on a big forum and asked a stupid question, and had like 80 people ask me why the hell I was doing x,y,z :p but this forum is really nice. I'll definitely be using this for more electronics questions in the future!
    Thanks :)
     
  13. davenn

    davenn Moderator

    13,838
    1,952
    Sep 5, 2009
    You're welcome :)

    Dave
     
Ask a Question
Want to reply to this thread or ask your own question?
You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.
Electronics Point Logo
Continue to site
Quote of the day

-