Lively touch light switch too cold?

[tellyaddict]

I have a touch light switch, and noticed that in the coldest months of January (UK here) that sometimes it wouldn't work. I though that this may be down to my hands being too cold but even after washing them under warm water the switch wouldn't work, not for fifteen minutes or so, perhaps the switch was cold itself and the sensors didn't work as expected?


It's February now and I don't have that problem. Granted, it was fitted in January and *could* have been teething issues, but don't believe so, was it down to the cold?

 

[Marvo]

There's a few ways a touch switch can work, some of them are completely non-contact because they sense the capacitance of a nearby body. Some require physical contact with the switch by something that's partially conductive such as a finger which basically completes an extremely low current circuit which causes the switch to operate. Some actually use a quartz substance that generates a small current when it is pressed or touched lightly which in turn operates the switch, this type often take a bit of pressure to operate not just proximity or very light contact. There used to be a fourth type that used a small amount of electrical leakage through a person touching it to operate the switch but I haven't seen this type around for several years so they seem to have gone out of fashion.

My best guess is that if it wasn't working in colder weather it's probably the second type I mentioned which would require a little moisture on the finger that touched it. In cold weather people don't sweat so the chances are your finger was too dry to operate the electronics that do the sensing.

 

[tellyaddict]

Hi, thanks for your reply. It happened again yesterday and I wet my digit with both saliva and water from a tap, but to no avail.

I don't know why it takes time to work? This time only about 10mins though.

I have another of the same light switches installed in the same room but it's remote activated (the other is not) and will always function when a physical button on the remote is pressed no problems.

What do you think it is?

 

[Marvo]

It's possibly a faulty switch in that case.

 

[tellyaddict]

I don't think so.

I don't have a problem now, I think it was when it was colder, it's far warmer now in March and everything seems to be fine.

 

[Deleted member 26818]

I installed some touch light switches in a flat in Gibralter last year.
Apparently some of them have been playing up.
I think it's touch and go whether these type of switches will work.

 

[Marvo]

They were all the rage a few years ago and there were small touch-operated dimmer modules as well that could be installed in place of a standard switch module, then they all but disappeared, I think the problem was with consistency and reliability.