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Thread: My $15 12v Automotive 7-port USB hub

  1. #11
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    Do you have a schematic for the DC step down circuit or a website where I can buy one?

  2. #12
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    Cool. So when you turn off your ignition do you go into standby or hibernate on your PC?

  3. #13
    Vendor - Qube colin's Avatar
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    The power converters are on eBay as posted in another thread, no time to look. They're about $8 shipped, maybe less.

    When I shut off my ignition, I hard-off. I don't care about the "possible" problems. If my car goes off, so does the computer. I do have a switch that will hold power but that is risky business. My bootup times are about 10 seconds, so turning on is not a problem for me.

  4. #14
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    Quote Originally Posted by colin View Post
    The power converters are on eBay as posted in another thread, no time to look. They're about $8 shipped, maybe less.

    When I shut off my ignition, I hard-off. I don't care about the "possible" problems. If my car goes off, so does the computer. I do have a switch that will hold power but that is risky business. My bootup times are about 10 seconds, so turning on is not a problem for me.
    I think this was posted before: http://cgi.ebay.com/ws/eBayISAPI.dll...=STRK:MEWAX:IT but it's about $15 shipped. Was this the one or is it a different one?

  5. #15
    Vendor - Qube colin's Avatar
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    That's the one, but it only came to about $8 shipped. To Canada.

  6. #16
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    Guys you're all going overboard on the "step down converter." It's not hard. 5 volt linear regulator, i.e.
    http://www.radioshack.com/product/in...ductId=2062599
    They come up to 5 amp capacity. Simple to hook up, 3 wires (+12 in, +5 out, ground). Add a cap before and after and you're golden. It's all explained in the datasheet:
    http://www.national.com/ds/LM/LM341.pdf

  7. #17
    Variable Bitrate hailrazer's Avatar
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    Quote Originally Posted by theshadow27 View Post
    Guys you're all going overboard on the "step down converter." It's not hard. 5 volt linear regulator, i.e.
    http://www.radioshack.com/product/in...ductId=2062599
    They come up to 5 amp capacity. Simple to hook up, 3 wires (+12 in, +5 out, ground). Add a cap before and after and you're golden. It's all explained in the datasheet:
    http://www.national.com/ds/LM/LM341.pdf
    Yet you link to a 1 amp version. LOL

    Also with a 3A or 5A version you will need a rather large heatsink.

    So it's better to just buy a prebuilt regulator.


  8. #18
    Vendor - Qube colin's Avatar
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    The problem with converting 12v to 5v at 3A is heat.

    Think of it like this, you're dropping 7 volts to get 3 amps. That's gonna be HOT.

  9. #19
    FLAC
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    if you used a little pricier switching type regulator you can eliminate most of that heat, can't you?

  10. #20
    Vendor - Qube colin's Avatar
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    That's exactly what was used...
    theshadow27 proposed a linear regulator instead.

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