Switch wiring

Discussion in 'Electronics & Electrics' started by Gordonov, Nov 13, 2017 at 3:05 PM.

  1. Gordonov

    Gordonov New Member

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    Hi, I have a project where I'm wanting to wire up the following switch;
    https://www.jaycar.com.au/ip67-blue-illuminated-momentary-switch/p/SP0798

    I've previously wired up the same switch using an 12V source supply, to have the LED ring always illuminated.
    This was easy because the LED required 12V and the object being switched on and off also only needed 12V so I didn't have to 'separate' the power sources.

    However, now my project needs a higher-voltage source (240V), but the LED in the switch will only take 12V. The question is, how can I wire it with these differences in incoming voltages to achieve this without using two separate 'input' sources of power? Is it a question of adding resistors / transformers?

    Imgur gallery linked for some visual help;
    https://imgur.com/a/bBuGl
     
    Last edited: Nov 13, 2017 at 3:18 PM
  2. HSV_Enigma

    HSV_Enigma Member

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    Your images don't work, and if you do not know the answer to this you should not be touching 240v, especially with a metal body switch
     
  3. vladtepes

    vladtepes Member

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    This sounds like a trite put-down BUT it's dead right. Emphasis on the dead.
    Someone might pop in and say "use a relay".
    But just.. don't touch it. Because that could, indeed probably would, still be a disaster.

    Mains power is NOT to be trifled with.
     
  4. RobRoySyd

    RobRoySyd Member

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    As you've noted the switch you want to use is designed for 12V DC operation only thanks in part to the integral LED. Using it to switch more or less voltage is not a grand idea at all, even attempting 24V DC could end in smoke and tears.

    If you're really fixated on using that switch then the solution would be to use it to operate a relay with a 12V coil and 240V 10A AC rated contacts. Mechanical relays aren't expensive, are common and provide excellent isolation between the low voltage on their coil and the switching contacts, The downside to such an approach is you do need a 12V DC supply. It could all get rather messy and if you got the connections to the coil and contacts mixed up potentially lethal.

    If it was my project in the interests of safety and simplicity I'd use a switch designed for the task. There is now LED illuminated 240V PB switches available at a reasonable price. They're not quite as aesthetically appealing, more "overtly industrial".
     
  5. OP
    OP
    Gordonov

    Gordonov New Member

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    True, I was leaning toward a relay type solution originally but over the last day I've given it some thought and will likely swap out the switch for one more fit for purpose. Pity, because these ring switches look quite cool but are a bit of a PITA to work with, not just with this project but from past jobs as well. Thanks for your helpful response.
     
  6. oculi

    oculi Member

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    Did you even read the product description? what do you think

    means? the LED isn't "integral", it is wired separately, hence the 8 terminals on the back of the switch.

    what are you running OP?


    yep pretty much, you could do it with something like this https://www.ebay.com.au/itm/Q4-AC-9...195525&hash=item466fdee980:g:aeAAAOSwlptaB8xS powered from the upstream side of the switch and a few resistors, I don't really know why you would want the light on all the time though. also it is illegal to mess with this stuff (maybe) and yes it is dangerous and don;t do it.

    these switches are dead sexy, I've had a bunch for ages and now I want to make them "breathe" but haven't worked out what to do with them yet.
     
    Last edited: Nov 14, 2017 at 12:56 AM
  7. RobRoySyd

    RobRoySyd Member

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    It means the switch contacts can be used to switch 240V AC but the LED needs 12V DC.
    Yes, one could use a capacitive dropper such as the one you linked to from eBay. Personally I have reservations about these devices. especially where there's a reasonable chance of contact with their output. A safer solution would be a 240V AC to 12V DC power supply. Quite small units from reputable manufacturers are available but they're expensive.
     

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