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from 5V to 12 V — Parallax Forums

from 5V to 12 V

CamaneyCamaney Posts: 16
edited 2009-09-27 19:15 in BASIC Stamp
I am running my circuit with 5V and if·a conditiion is met I want to·turn a lamp on, the lamp requires 12V.
Can someone help how can I do that? go from 5V to 12V?
Thanks.

Comments

  • FranklinFranklin Posts: 4,747
    edited 2009-09-25 03:23
    Depending on the load you could use a transistor or a MOSFET both are well covered and you should find what you need with a Google search.

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    - Stephen
  • dev/nulldev/null Posts: 381
    edited 2009-09-25 09:12
    I think what you need is a step-up converter. There are specialized IC's that can do this (dont have any in mind), or you can use a 555 timer. The problem with stepping up voltage is that you loose a lot of current capacity. If you're only driving a lamp, you might do with a 555 circuit. Try googling "555 step up".

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    Don't worry. Be happy
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2009-09-25 15:57
    Camaney,

    It's not clear from your post (which the two very different answers you've gotten illustrate) whether you have a source of 12V that you want to switch on and off to control the lamp, or whether you need to create a source of 12V from the 5V available.

    -Phil
  • CamaneyCamaney Posts: 16
    edited 2009-09-25 16:28
    I am running with a source of 5V to power up my circuit.

    I have two external·lamps RED and GREEN, either one·could be ON based on an IF condition, but I don't know how to power up the lamp with 12V.

    Preferably I am looking for something I can add to my circuit, or separate but not too bulky.

    Thanks for your help.
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2009-09-25 17:09
    What kind of current do the lamps require when fed with 12V? Where does your 5V supply come from?

    -Phil
  • ercoerco Posts: 20,257
    edited 2009-09-25 18:10
    You've got some work to do. Suggestions:

    1) Wiki "Charge Pump"
    2) Use the Stamp to switch an external 12V supply to your bulbs using transistors or relays
    3) Change your 12V lamps to Ultrabright LED clusters in series/parallel strings that run off 5V

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    ·"If you build it, they will come."
  • dev/nulldev/null Posts: 381
    edited 2009-09-25 18:11
    Here is a simple circuit, but with this you need a separate 12V supply. To turn the light on you code "HIGH 0", and to turn off "LOW 0".

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    Don't worry. Be happy
    tmptmp.jpg
    250 x 251 - 7K
  • YoshtiYoshti Posts: 108
    edited 2009-09-27 02:54
    Hi,
    Great dev/null I just love it when it sparkling clear like this! Easy schematics!
    Don't get me wrong, I do read all the info, done the book whats a microcontroller twice,read the nuts and volts, but for me, reading gets me nowhere! I learn only with examples... guess getting too old ! I've done the RTFM so many times, I get lost ! wink.gif

    Really appreciate great schematics! Seems so easy for you guys.. just incredible! LOL I have not got my head around the law of ohm yet. It does not make sense!
    I've read many 101 books about this... still no can do! even the water pressure thingy is still weird.

    Sould I start a thread on basic stuff, so you guys can direct a new noob at this?

    Cheers
    Yosh..
  • dev/nulldev/null Posts: 381
    edited 2009-09-27 09:09
    Thx Yohsti. I'm the master of Microsoft Visio!!! smile.gif (and I love to draw neat stuff)

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    Don't worry. Be happy

    Post Edited (dev/null) : 9/27/2009 7:17:33 PM GMT
  • hover1hover1 Posts: 1,929
    edited 2009-09-27 12:15
    Should the transistor be a 2N3904?
    dev/null said...
    Here is a simple circuit, but with this you need a separate 12V supply. To turn the light on you code "HIGH 0", and to turn off "LOW 0".

  • dev/nulldev/null Posts: 381
    edited 2009-09-27 19:15
    Yes, sorry about that. Any general purpose NPN transistor will do. For example 2N3904, PN2222, BC547, 2N4400.

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    Don't worry. Be happy
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