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Thread: How do i make -8V from 12V power?

  1. #1
    Low Bitrate
    Join Date
    Feb 2001

    Post How do i make -8V from 12V power?

    How do i make -8V from 12V power?

    Do i just need to use

    -8V regulator(7908) and connect like this?
    |    7908       |
    |      |        |
    |      |        |
    12V    Ground   X
    then will I get -8 from X?

    is that all i have to do it? or do i need other stuff too?

    let me know about this and if you have good web site about this or schematic..

    PS: i am trying to Sharp 6" work so i need 12V(from car) 5V( and -8V...

    LQ6RA01 from bought from jay) i think.. and have only bare LCD part
    <A HREF="" TARGET=_blank></A>

  2. #2
    Retired Admin Aaron Cake's Avatar
    Join Date
    Jan 2000
    London, Ontario, Canada


    That won't work. The 79xx series regulators require a negative voltage input. Check out under Voltage Inverter and Voltage Inverter II for some circuits...
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  3. #3
    Low Bitrate
    Join Date
    Feb 2001
    Kuutinkylä, FINLAND


    I was jus designing almost free DC-DC ps for myself and I found this:
    This will make -12V@ ~500mA from 5V

    It will easily do -8V if you use 7908 after that circuit and 7805 before.
    You need only few parts besides that and they all are easy to get!
    Project almost ready


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