Wireless and wire-free are sometimes used interchangeably to describe light switches. In fact, these technologies offer very different outcomes and value.
The conventional wired switch was patented in 1917 by William Newton and Morris Goldberg. Their quick-break on-off toggle switch controlled the flow of current while being hidden beneath a wall plate. Ironically, the invention was slow to catch on because it required wires to be run from the ceiling fixture to the wall switch – an expense homeowners viewed as an exorbitant luxury.
What is a Conventional Wired Light Switch?
A conventional wired light switch is a permanently connected control which opens and closes an electrical circuit, allowing electrical current to flow from a power source to lights and appliances.
These switches are reliable, but they require wire to be run to a switch box inside the wall, which can make installation costly and complex.
What is a Wireless Light Switch?
In the late 1990s, manufacturers advanced the light switch by adding radio – wireless transmitters and receivers. In a wired-wireless system, portable switches transmit on, off, and dim commands to a receiver/switch module installed in the wall. This switch module interrupts the power going to the light fixture.
Wired-wireless switches provide portability, but still require a switch box and wire in the wall for the receiver module.
What is a Wire-Free Light Switch?
Wire-free switches completely separate the switch and electrical contacts. The wireless transmitter switch can be installed on any surface with no wire or boxes inside the wall. The receiver/controller is wired into the circuit and installed in an electrical box.
When the switch is pressed ‘on’, the controller receives the transmitted command and closes its electrical relay to allow power to flow to the load device. When the switch is pressed ‘off’, the controller opens its relay and the device is turned off.
Wire-free switch transmitters can be battery-powered or use piezoelectric power. Piezoelectric switches work when a mechanical force (your finger) presses onto a crystal. They are more expensive and require more force to ‘snap’ the switch and generate the necessary energy for the wireless radio. Battery-powered switches operate silently and are less expensive to manufacture, but the coin-cell battery will have to be replaced after 8-10 years.