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240v LED ?

Discussion in 'Electronics & Electrics' started by aussie-revhead, Sep 2, 2006.

  1. aussie-revhead

    aussie-revhead Member

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    Hi guys , I am wiring a relay in my water cooled case to allow my psu to turn on the 240v water pump automatically , but I want some kind of confirmation that the pump is activated . What can I mount in the front of my case , like a blue LED , that will illuminate when my pump is operating ? I went to DSE and they said they have never seen a 240v LED , and couldnt tell me what resistor to use to step 240 down to allow use of a 12v LED .

    Can one of you modding guys help me with this ? What do I need to do to set this up ?

    Any help would be great .

    :thumbup:

    PS I dont want it to light up half the room like a blue spotlight either , just a gentle light .

    ;)
     
    Last edited: Sep 2, 2006
  2. -KoMoD0-

    -KoMoD0- Member

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    no, you cant get a 240v AC led.


    You need a DC source and most led's are roughly 3v
     
  3. OP
    OP
    aussie-revhead

    aussie-revhead Member

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    OK , then what do you suggest I use ? OK so LED wont work with AC , what about a normal globe in a bezel ? Have you seen anything like this ?

    :thumbup:
     
  4. dakiller

    dakiller (Oscillating & Impeding)

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    Something like this would run a LED off 240vAC

    [​IMG]
     
  5. Goth

    Goth Grumpy Member

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    Just use a neon indicator lamp which is designed for 240VAC use.

    For example, Jaycar SL2633
     
    Last edited: Sep 2, 2006
  6. Odje

    Odje Member

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    If you use dakiller's circuit make sure the capacitor is rated for 240V AC. The resister will be need to be rated to handle the power dissipated too.
     
  7. OP
    OP
    aussie-revhead

    aussie-revhead Member

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    Goths idea is good , thanks man .

    :thumbup:
     
  8. Odje

    Odje Member

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    Too tired to do the maths to work out values, so after a few minutes of googling I found some pages of use.

    General info and theory for LED of mains with capacitor:
    http://www.marcspages.co.uk/tech/6103.htm

    And I found a little application that will do the calculations for all different types of configurations, including AC with resistor, capacitor and dioide or bridge.
    http://www.miscel.dk/MiscEl/miscelLeds.html

    EDIT: that app mentioned above looks very handy, just downloaded it. It does alot more than just calculate LED circuit, does all sorts of things.
     
    Last edited: Sep 2, 2006
  9. mAJORD

    mAJORD Member

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    love the mspaint schematic dak :D

    neon is probably the simplest and best Idea

    remeber you still need a resistor if you don't buy it in a premade 'lamp' , (i.e you just buy the neon globe with flying leads).
     
  10. GOATMAN!!!

    GOATMAN!!! Member

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    Be carefull with this dude.

    Anyway, we use plenty of extension leads at work with LEDs in them to tell you if they have power. They just have a resistor in line with the led across the active and neutral. Not sure on the value of the resistor. I could check at work tomorrow if you want.
     
  11. OP
    OP
    aussie-revhead

    aussie-revhead Member

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    Im not really keen on touching the 240 at all , hence the questions , but I am waiting for a certain electrician to turn up at work and I will quiz him about it all .

    :thumbup:
     
  12. dirtyd

    dirtyd Member

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    Bit of a thread revival, thanks to Odje's links I was able to replace the little incandescent globe in a 4 socket power board, just had to get a high voltage cap from Jaycar for $2. Winner :thumbup:
     
  13. Odje

    Odje Member

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    Power boards have incandescent globes?

    Make sure you include a bleeding resistor across the capaictor to discharge the capacitor. Otherwise you might get a bit of a zap if you happened to unplug it and touch the pins on the mains plug.
     
  14. dirtyd

    dirtyd Member

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    This one had a tiny little one, the board is a bit of a relic that was found in the depths of a relatives house. I intended to include a bleeding resistor and then forgot all about it when I was soldering everything together :Paranoid: Hopefully won't be touching it for a long time anyway.
     

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