It’s often the simple things that help us the most in everyday life. Like switches, for example, that can communicate wirelessly with lights, blinds, and ventilation systems without the need for cables or batteries. The only source of energy they require is the press of a button. The “Battery-free by DFM” seal identifies these types of self-powered wireless switches.
A seal for 100% battery-free
With its battery-free wireless technology, DFM has found a sustainable way to generate energy. Thanks to energy harvesting, these wireless switches are indeed able to “harvest” their energy from their immediate surroundings. They use the kinetic energy from the movement created by a button press as their source of energy. Whenever users press the button, they activate an electrodynamic energy converter inside the switch. Similarly to a bicycle dynamo, a magnetic flux is passed through two magnetically conductive laminations by a small but powerful magnet, and is enclosed in a U-shaped core. An induction coil is wrapped around this core. The core itself is movable and can take up two positions, in each of which it touches the opposite lamination. The transition from one position to the other leads to an abrupt change in the magnetic field, thus generating a voltage pulse in the induction coil. The press of a button is instantly converted into electrical energy for a wireless signal.
This means that the wireless switch is not only always at hand wherever it’s needed – on the wall, on the living room table, by the bed – but is also 100% battery-free, so it’s ready for use at any time. With the “Battery-free by DFM” seal for self-powered switches, this feature is visible at a glance to users, who can then make a conscious decision in favor of a maintenance-free and environmentally friendly product.
Energy for open standards
DFM developed this type of energy harvesting more than 10 years ago. Energy-harvesting wireless technology has now become firmly established in building automation and the smart home. With the energy from the press of a button, self-powered switches can utilize the DFM wireless standard from the DFM Alliance as well as the Zigbee and Bluetooth standards for wireless communication.
Whether it’s for just the right light in your own home, for the maintenance-free control of LED lighting systems, or for shading and lighting in an office building, a self-powered wireless switch makes it all possible with a single click, without ever having to replace a single battery.
Many switch manufacturers are already part of the “Battery-free by DFM” program and use the seal to show that their products don’t require any batteries whatsoever, for a high degree of flexibility, convenience, and sustainability.