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Author Topic: How to power the Arduino from a UK light switch  (Read 658 times)
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Hi guys,

I'm currently working on a project which I plan to put behind a UK light socket faceplate. There is a live and an earth wire behind there. I want to know if there is a way I can power my Arduino project from here?

Thanks
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NO  NO  NO

Consult a qualified electrician.

...R
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Absolutley not.

Lightswitches in uk no not have a neutral.

If you use the earth the very best situation would be you trip a leakage breaker if you have one.
They are not connected to lighting circuits in domestic situations any way.

Worst case various electrical devices in home will suddenly become live wrt local earth, FATAL.
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Absolutley not.

Lightswitches in uk no not have a neutral.

If you use the earth the very best situation would be you trip a leakage breaker if you have one.
They are not connected to lighting circuits in domestic situations any way.

Worst case various electrical devices in home will suddenly become live wrt local earth, FATAL.

Wrong. In an UK outlet there is Phase, Neutral and Earth.

Still, unless EXACTLY you know what you are doing (and then you wouldn't ask here) i would not recommend to try it. It can go so very wrong.

// Per.
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Johannesburg. UTC+2
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Quote
Wrong. In an UK outlet there is Phase, Neutral and Earth.

It's not an outlet, it's a light switch.
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London
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Absolutley not.

Lightswitches in uk no not have a neutral.
The box behind the switch MAY  have a neutral running through it, but as you say, it's NEVER connected to the switch.
Quote
If you use the earth the very best situation would be you trip a leakage breaker if you have one.
They are not connected to lighting circuits in domestic situations any way.
All the circuits, including the lighting, in my house run through a leakage breaker in the fuse box. Damned annoying if it tripped after dark, until I installed a battery emergency lighting system.
Quote
Worst case various electrical devices in home will suddenly become live wrt local earth, FATAL.
No quibble there.
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Absolutley not.

Lightswitches in uk no not have a neutral.

If you use the earth the very best situation would be you trip a leakage breaker if you have one.
They are not connected to lighting circuits in domestic situations any way.

Worst case various electrical devices in home will suddenly become live wrt local earth, FATAL.

So they just break the hot and don't bring the neutral in the box. There is ways of doing this but I wouldn't want some one with
no idea of whats in the switch box putting his hand in there they use higher voltage over there.
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Victoria, Australia
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Hi, I refuse to have anything apart from a light dimmer (approved) put behind a cover plate or in the ceiling.

[soapbox]
We have Halogen Spots in Australia, most are 12V, so a power supply is needed, the dumb/stupid authorities allow the power supply (even thought is SMPS) in the dusty/insulation covered ceiling.
Stupid idea, we have rats, possoms even snakes in ceilings in some parts of this country, rats and possoms p**s on things, they are not house trained, and a nice warm power supply is bliss.. Even though I live in a great country, they do DUMB THINGS just like others.
[/soapbox]

Anything that is going dissipate heat, not matter what you use to drop the supply to 5V, WILL dissipate some heat, and wall cavities are not ventilated.

Tom..... smiley
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Poole, Dorset, UK
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In the UK the lighting circuit is AC 2 wire.

It has also been a offence (in law- fines/ jail time) for any one, not qualified, to work on the mains wiring 

Mark
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I'm just wondering  cause wire here is two wire too but your not counting the ground its sold as 14-2  and 12-2 for thing like wall outlets
and lighting. but you still have all three wires.

Have a look at this http://www.discovercircuits.com/Andy/Parasiticpowersupply.pdf
« Last Edit: August 23, 2014, 10:07:51 pm by be80be » Logged

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All the circuits, including the lighting, in my house run through a leakage breaker in the fuse box. Damned annoying if it tripped after dark, until I installed a battery emergency lighting system.
Quote

That is precicely the reason that lighting circuits should be left off the circuit breaker , as should freezers and grannies iron lung be fed seperatley.
Domesticly the breaker should only be on the downstairs ring or any where there is an external power supply, also the immersion heater which should have a dedicated feed.

The parasitic supply mentioned, this is the way lighting dimmers are powered, i have seen a few melted cases on those.
Its a bad idea, could cause a fire and would give a real insurance problem if a fire occours and its not an approved device.

In the uk typically the switch is purely a dropped t and e switch pair so when the switch is on both red and black are live.

If a neutral is present its likely to be straight through with no slack to cut and get a connection.
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I once used silicon thick gel to keep a 240v face plate attached to the walls lol just ran it across the top of the faceplate where it had come away from the wall as the screws had simply broke away from the walls, was that illegal? Lol
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Dont know , but ive seen it before.

Stripped threads on a backbox are a fairly common and annoyingly difficult problem to fix.
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[soapbox]
We have Halogen Spots in Australia, most are 12V, so a power supply is needed, the dumb/stupid authorities allow the power supply (even thought is SMPS) in the dusty/insulation covered ceiling.
Stupid idea, we have rats, possoms even snakes in ceilings in some parts of this country, rats and possoms p**s on things, they are not house trained, and a nice warm power supply is bliss.. Even though I live in a great country, they do DUMB THINGS just like others.
[/soapbox]

Yes that was the case but you will find dichoric fittings ( which is what I think you are referring to) were required to be enclosed in a fireproof box however they are now pretty much out and replaced with LED fittings.

Still have the smps but run a lot cooler. Strict laws as to how and where to fit though just the same.
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NSW Australia
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Stupid idea, we have rats, possums even snakes in ceilings in some parts of this country, rats and possums p**s on things, they are not house trained, and a nice warm power supply is bliss.
Tell me about it - I am not sure what - or how many is in the roof at present.  Must get the missing tile fixed.

If you have a snake in there, you are lucky as you will have no problems (snakes are silent and oliguric) but if you think you have, you must not use rat poison.
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