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Thread: what resistor for 445 diodes in parallel?

  1. #21
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    They're 2.2MΩ
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  2. #22
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    mega ohms?

    so im guessing the chap in maplin gave me the wrong ones?
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  3. #23
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    Quote Originally Posted by andy_con View Post
    so im guessing the chap in maplin gave me the wrong ones?
    Standard...

    - There is no such word as "can't" -
    - 60% of the time it works every time -

  4. #24
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    ill use ebay, you can go wrong with ebay
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  5. #25
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    Don't forget the power involved @ 1Amp they will be dropping 2.2v.

    2.2v x 1Amp = 2.2W dissipated.

    http://cgi.ebay.co.uk/2-x-2-2-Ohm-3W...item19c0e41eba
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  6. #26
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    ok cheers .
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  7. #27
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    If I am understanding all this correctly, 4x 445nm diodes wired in series would need 4x 2.2 ohm 3 watt resistors. The first resistor in the + side wire going to the the first diode. The next 3 resistors inbetween each of the remaining 3 diodes, correct?

    For a single 445nm diode use the same resistor?

  8. #28
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    Quote Originally Posted by Phredy1 View Post
    If I am understanding all this correctly, 4x 445nm diodes wired in series would need 4x 2.2 ohm 3 watt resistors. The first resistor in the + side wire going to the the first diode. The next 3 resistors inbetween each of the remaining 3 diodes, correct?

    For a single 445nm diode use the same resistor?
    Diodes in series don't need a resistor. The current will be the same through a series circuit. A single diode doesn't need a resistor because it is not "fighting" for current with any other diodes.

    hope this helps.

  9. #29
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    Quote Originally Posted by logsquared View Post
    Diodes in series don't need a resistor. The current will be the same through a series circuit. A single diode doesn't need a resistor because it is not "fighting" for current with any other diodes.

    hope this helps.
    It might be one of those rare high-binned diodes that chooses the right to fight with itself.
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  10. #30
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    Wait a minute....what?

    Only multiple diodes wired in parallel do we need to put resistors in? Wired in series no resistors needed?

    I'm going to borrow Andy's word. WTFook?

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