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Thread: another voltage reduction question

  1. #1
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    Default another voltage reduction question

    Hi Guys

    I know this has been asked before but I need some more info.
    I have a 13.8vdc power source 'bike' and am going run my UHF at 6vdc & <300mAh at full transmit. <50mAh on standby. As a cheap solution I was going to use a 7806 reg with a small sink. Do I need any capacitors or diodes with this reg and if so why? I know caps are used when coming from an AC to DC converter to filter ac ripple but what value in an all DC circuit?

    Help aprreciated
    cheers snoop



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    Default

    It's recommended to place some bypass capacitors on both input and output pins of the regulator to prevent it "taking off" or oscillating.

    You can find some 0.1MF capacitors rated at 25V or so which will be small enough to solder right on the pins of the regulator up close to the base of the regulator pins. This way you can solder your input and output wires to the far end of the pins and negate the need for any circuit board or tagstrip etc.

    I have done this successfully many times for similar regulator situations. I have used a small aluminium box or even just a scrap of aluminium sheet for the regulator with holes drilled for the regulator (nut and bolt), and holes for cable ties to hold the wires so they can't pull off the solder connections.

    It will work !

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    Default

    Too right mate.
    We used to fix a certain model VCR that didnt have those caps and thats what happened.Dont know how they got thru the warranty period without it happening.Used to look like dirty heads but it was all this RF on the rail.

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