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  1. #1
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    can geoman light take 9 volts

    Howdy, bought a batteryspace pack that outputs 12 volts primarily to handle replacement blowtorch duties. However I also have one of those dc/dc converter thingies that your are supposed to plug into your cigarett lighter and run a bunch of different accessories with. The lowest rating is 9 volts. Am I gonna get Magicshine smoke? I know its supposed to be 8.4 peak and then 7.5 continuous.

    TIA

    jv

  2. #2
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    Howdy, bought a batteryspace pack that outputs 12 volts primarily to handle replacement blowtorch duties. However I also have one of those dc/dc converter thingies that your are supposed to plug into your cigarett lighter and run a bunch of different accessories with. The lowest rating is 9 volts. Am I gonna get Magicshine smoke? I know its supposed to be 8.4 peak and then 7.5 continuous.
    JV

    It might be able to handle 12 volts, the driver chip it uses is rated for 36. The only parts that might give you trouble are the input capacitor, the freewheel diode, and the current sense resistors (labeled R100 and R500 in my unit). In my light (from DX not geoman, but they all come from the same factory in China) the input cap was a 10 volt tantalum. I replaced it with a 47 volt one, put in a beefier diode (4 amp instead of 2 amp), and some larger current sense resistors (a couple of 0.16 ohm resistors in 1210 sized packages). The surface mount soldering is a pain but do-able if you take your time. Hint: wear reading glasses even if you don't need them, the magnification helps). Replace the 22 guage power cable with something thicker. I used a tamiya connector that came pre-wired with 14 guage silicone coated wire. With these mods and a lot of heat sinking epoxy (artica alumina works well), you will wind up with a light that should last way longer than the normal 90 warranty period and handle a much wider voltage range.

    Without the above mods, the light will work at 12 volts, for a little while. Eventually the cap will blow or the diode will get too hot (it dissipates more power the higher the input voltage). These lights are built with the cheapest parts the factory can find, so if you overstress them even just a bit, don't expect them to last. 9 volts would be pushing it, but would be better than 12. Your cig lighter adapter will need to be rated for at least 2 amps of output.

    Mark
    Nimium est melior!

  3. #3
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    Quote Originally Posted by jvossman
    Howdy, bought a batteryspace pack that outputs 12 volts primarily to handle replacement blowtorch duties. However I also have one of those dc/dc converter thingies that your are supposed to plug into your cigarett lighter and run a bunch of different accessories with. The lowest rating is 9 volts. Am I gonna get Magicshine smoke? I know its supposed to be 8.4 peak and then 7.5 continuous.

    TIA

    jv
    What's the output current rating on that converter? I think there's a good chance it's not high enough. It needs to be at least 1.5 amps. Those types of converts also tend to be inefficient. It doesn't matter so much when running from a car since almost unlimited power is available. For a battery powered light, it'll really shorten the runtime.

    I think the light will be fine on 9V, but I wouldn't go above 10 volts due to the input capacitor rating. Capacitor voltage ratings are not ones you want to push, the capacitors really do tend to blow if you go over them by much.

    It would be much better to run the light on 12Vs, but that would take some of the modifications suggested above.

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