Researcher has developed, at a cost of less than one dollar, a wireless light switch that runs without batteries, can be installed anywhere on a wall and could reduce the cost of wiring a house by …::A U of A engineering researcher has developed a wireless light switch that could reduce the cost of wiring a house by as much as 50 per cent.
I have a Philips Hue wireless switch that has no batteries. The click action when you press the button is enough to drive the transmitter. The button moves in about 4-5mm when pressed and that is all that’s needed to drive the transmitter.
What’s really mind-blowing is that such trivial amounts of energy runs a transmitter that sends a specially coded pulse (not even just an on off pulse of RF) thirty feet to the receiver.