Earthing an upcycled lamp with touch switch

[Upcycled123]

Hi all,

I am upcycling a lamp which I've done before but this time I want to try and add a touch switch dimmer.
The lamp has Earth live and neutral and I've taken it apart to swap the base over for an old fuel can.
The lamps original metal base was earthed with the earth wire.
My question is if I swap the base for a metal fuel can, should I earth the can itself and apply the touch switch wire to the can? Would this work? I want it so you touch the can to turn it on and off but I want it earthed too obviously.
Any help appreciated thanks

 

[telectrix]

think you're on the right track.

 

[Upcycled123]

Thanks. Can you help a bit further and advise if I can connect the earth and the switch sensor wire to the same point? Thanks

 

[telectrix]

i would thing so. but not sure how these things work. some trial and error might be required.

 

[Upcycled123]

Hmmm so I drilled a whole and put a bolt through the base of the fuel can.
Then on the other side of the bolt I have a larger washer that fits snug then I've wrapped the earth wire around the bolt then added a smaller washer and then the touch panel connector/sensor (and bolt at the end of course). So both the earth and the sensor is on the same bolt.

This produced a lamp on all the time and none of the on off dimmer features work when I touch the can.

I suspected the box or bulb may be an issue at this point but I've removed the sensor now wired it all back minus the sensor and plugged it back in this time I can touch the sensor on/off but it won't seem to connect through the semi rusted can.
So not sure what to do now.... :/ ?
Can anyone offer any suggestions?

 

[Lucien Nunes]

Single-contact touch switches usually work by capacitance. When something large and at least slightly conductive touches the sensor wire (e.g. a person), the minute current that flows to the outside world by its stray capacitance triggers the dimmer functions. The touch plate must not be too large otherwise it will have too much stray capacitance itself, and would equate to a person holding their finger on the plate permanently. It must also not be earthed, as this bypasses the capacitance effect completely. So your earthed can is not going to work, first on account of being earthed but possibly also on account of its size.

You say 'obviously' you want the can earthed. It's not obvious to me - it might be possible to make it class II if you meet the necessary construction standards. But you would have to be certain that the dimmer will work reliably with that size of touch plate and with any surface leakage that might occcur due to condensation etc.

 

[Upcycled123]

Nice reply buddy. It's basically what I read across 15 different websites condensed into one statement so I appreciate your response. It makes complete sense though that was my concern in the first place. I like to Earth it as the lamps Ive done in the past contained the earth so I stick to what I know. I'm going to make a small design change to sort the issue
Many thanks

 

[UKMeterman]

Or get a nice proper switch from RS!