1. OCAU Merchandise now available! Check out our 20th Anniversary Mugs, Classic Logo Shirts and much more! Discussion here.
    Dismiss Notice

ADDING Indicator LED's to 240 volts AC - how?

Discussion in 'Electronics & Electrics' started by gregzeng, Feb 2, 2003.

Thread Status:
Not open for further replies.
  1. gregzeng

    gregzeng Member

    Joined:
    Apr 25, 2002
    Messages:
    1,103
    Location:
    ACT
    I guess that resistors and diodes, in series & parallel - might be needed. But where is there a simple circuit diagram?

    Before I switch the mains switch (of any equipment) on, I'd like a LED to show me where the switch is, in the darkroom, or at night time.
     
  2. looktall

    looktall Working Class Doughnut

    Joined:
    Sep 17, 2001
    Messages:
    25,837
    i'm serious when i say this.
    do not fuck around with 240v. pay a sparky to do it.

    if you fuck up with 240v, there's a good chance you'll end up dead. simple as that.
     
  3. dantheman65

    dantheman65 Member

    Joined:
    Aug 18, 2001
    Messages:
    3,840
    Location:
    Melbourne.
    Bolded for emphasis.
     
    Last edited: Feb 2, 2003
  4. Gnuthad

    Gnuthad Member

    Joined:
    Jul 13, 2001
    Messages:
    1,599
    Location:
    Sydney
    Call me dumb, but if the mains switch is off (therefore there is no power), how will you be able to use an indicator across the mains to show you where the switch is?
     
  5. star882

    star882 Member

    Joined:
    Dec 25, 2002
    Messages:
    249
    Connect a NE-2 bulb and a 100k resistor in series, then wire this in parallel with the switch.
     
  6. Fred Nurk

    Fred Nurk Member

    Joined:
    Apr 5, 2002
    Messages:
    2,228
    Location:
    Cairns QLD
    Wouldn't it be easier to just use a nightlight on a double adaptor?

    Its also illegal to play with your 240V household fittings without a licence.
     
  7. The C Man

    The C Man Member

    Joined:
    Dec 24, 2001
    Messages:
    1,611
    Location:
    Dreaming of Electric Sheep
    Dont take the risk, as allready said if you frell up u can die.

    It's really not worth it, if you dont know how to do it, dont. Find someone, a sparky or somethin, who does.
     
  8. BlueSmurf

    BlueSmurf Dream it. Build it.

    Joined:
    Aug 2, 2001
    Messages:
    2,371
    Location:
    Baldivis, WA
    This is the safe and sensible approach.

    Alternately there are powerboards with indicator lights on them, or you can replace your wall socket with one that already has lights built into it.

    Don't jerry rig 240v equipment, leave it to the pros.

    BlueSmurf.
     
  9. Sephir0th

    Sephir0th Member

    Joined:
    Aug 12, 2002
    Messages:
    2,352
    Location:
    Melbourne
    umm ever heard of a torch?
     
  10. Odje

    Odje Member

    Joined:
    Jun 27, 2001
    Messages:
    2,296
    Location:
    Sydney
  11. JaC

    JaC Member

    Joined:
    Jun 27, 2001
    Messages:
    1,041
    Location:
    Brisbane
    another vote for dont DIY
     
  12. Turbokeu

    Turbokeu Member

    Joined:
    Mar 31, 2002
    Messages:
    372
    Location:
    Brussels - Belgium
    Very easy to do but not without danger... (the led is directly connected to mains, so do not touch it under operation, and wait a couple of minutes after powering down the mains before touching the led so that the capacitor C1 can discharge...)

    Use a capacitor (C1) as an AC-resistance and a standard 1W resistor R1 to limit the inrush current of the capacitor. The diode D1 cuts the negative alternance of the AC to the led.

    [​IMG]

    A formula to calculate the capacitor can be found on my webpage

    I used this little schematic on my waterpump relay schematics to indicate the presence of AC power to my pump.

    I already use this schematic for years on my fishtank "baybusses".
    Feel free to ask any questions if you want.

    CD:)
     
    Last edited: Oct 10, 2011
  13. Turbokeu

    Turbokeu Member

    Joined:
    Mar 31, 2002
    Messages:
    372
    Location:
    Brussels - Belgium
    I have to say that the indicated working voltages of capacitor C1 are on the safe side...
    You can easily use an 400VDC capacitor for 220-240V mains (or 250VDC for 110V mains)

    CD:)
     
  14. OP
    OP
    gregzeng

    gregzeng Member

    Joined:
    Apr 25, 2002
    Messages:
    1,103
    Location:
    ACT
    Very easy to do but not without danger...

    THANK YOU !!

    Lots of kiddies & sparkies on OCAU who know nothing about decades of life in isolated parts of the planet, nor about electricity.

    Personally I think it should be compulsory 4 primary school kids to directly experience 240v AC on the tip of one finger. It's like dunking in the swimming pool ... potentially dangerous.

    B4 fiddling with 240v, most should know the safety steps. Mains power off, earth leak detectors, correct fuses/ circuit breakers around, informed bystanders watching, body-earthed properly (not bypassing the fingers on the one hand).

    It's not the raw voltage that's dangerous. Idiots don't know that.
     
  15. [SweN]

    [SweN] Member

    Joined:
    Sep 2, 2002
    Messages:
    2,497
    As opposed to conditioned voltage? :D I might just put this in my sig.

    why not just get a pushbutton light switch installed, by a sparky. pretty sure clipsal have a product available with led indication in the button itself.
     
  16. adamfrederick

    adamfrederick Member

    Joined:
    Mar 15, 2011
    Messages:
    45
    This is a 240v led circuit board used inside Clipsal Saturn Pushbuttons for the indicator led. You can see the smt led mounted on a tiny header board at right angles (bottom left). The board is about a 1cm^2

    It uses a tiny bridge rectifier and smt resistors.

    I assume they avoid caps because they are big, cost more and can fail short.


    Click to view full size!
     
  17. Symon

    Symon Castigat ridendo mores

    Joined:
    Apr 17, 2002
    Messages:
    4,685
    Location:
    Brisbane QLD
    Give me a break, just because we tell you it is dangerous doesn't mean we are stupid city slickers who know nothing about electricity.

    That is the most stupid thing I've ever seen on a forum, and I have seen some stupid things.

    You've just proven you know nothing yourself.

    Thread closed.
     
Thread Status:
Not open for further replies.

Share This Page

Advertisement: