I can’t quite understand why you need a negative wire to run an on/off switch if you don’t need one to run a dimmer. But then I was always a little baffled by electrickery.
It’s because the switch needs to be powered.
Dimmer switches take their power inline from the lighting circuit. They are never actually “off” but, effectively, are dimmed to such a low level that the bulb doesn’t visibly turn on. A trickle current runs though the lighting circuit, including the bulb, and this powers the switch.
A true on/off switch cannot work this way: the the circuit is completely turned off there is no circuit for a current to flow. The switch has no way to get power from the lighting circuit unless a neutral wire is present (which it almost never is on light switch wiring).
The only possible way an on/off switch could be made to work for most people would be to have an embedded battery, which has challenges and issues of it’s own.
I actually think (and have thought before) that a ceiling rose solution like skiv suggest would be an interesting product. Alternatively an inline module that could be installed behind a ceiling rose would be good (and more flexible) product.
I personally think the whole industry should be considered if the way we wire lighting for homes makes sense any more. I actually think it makes increasing sense to wire homes with 12/24V DC for lighting. This would support modern lighting fixtures like LED and halogen to be used without needing expensive and bulky onboard transformers or electrical circuits to make them compatible with mains-voltage AC circuits, dimming, etc.
It would also make battery backup lighting during power outages every easy to achieve.
Of course, this is going to require a concerted industry-wide effort to achieve, so the chances are slim to none.
You must be logged in to reply to this topic.