simples, no battery, no mains

[bernardgreen]

Using self-generation technology, it includes two parts, the transmitter (switch) and the receiver.
Inside the switch there is a magnetic coil and when the switch rocker is pressed it will convert the mechanical energy into electrical energy to send out a radio signal to the receiver. The signal ID is unique and it is activated only the intended receiver.

It can single control (one switch controls one lights), or multiple control (one switch controls multiple lights, no limit) ,double control (two switches control one light, at most 24 switches controled one light)

As LEDs get more efficient there will come the day when the radio signal will have enough energy harvested from the click of the switch to power the lamp for many hours.

 

[nflowers]

Current LEDS are about 25% (very ballpark) efficient at converting electricity into light - assuming they do evolve to be 100% efficient (and of course they can never be more than this), you'll still need a few watts to light a room. Cherry energy harvesting switches are quoted as generating 0.33mWs per click so one click would generate enough power for 2 watts of light for 0.000165 seconds. Blink and you'll miss the flash!

I suppose the energy generators could become more efficient, but we are way, way off anything other than signalling. Alternatively the energy generator switch could be a big handle that you turn like on a wind-up torch

See http://cherryswitches.com/product/energy-harvesting-generators/

 

[ericmark]

Nikola Tesla claimed to have sent power through the air but since his labs burnt down there is more rummer that fact about what really was done. Remember at this time spark transmitters were still permitted and EMC had not even been considered. If one considers the type of switch shown in Jurassic Park where you tension a spring then fire in the contacts some switches need a massive amount of energy to close.

We had this problem taking vehicles for MOT there were no figures for how much effort one should put on the brake peddle so it could fail with one person in drivers seat and pass with another. What is more of a problem is the storing of energy to use as required. Capacitor can accept and deliver quite quickly but batteries tend to need far more time.

But the idea of a speed hump producing the energy to light or open gates is possible.

 

[Jackrae]

Sounds a bit like a chocolate fire guard - lots of technology to drive a tx module. you'd be greener using a potato and 2 wires