The wireless and battery-free switch technology from ZF provides various possible application fields to increase connectivity, flexibility, and convenience. Bus stop buttons are a smart application integrating the inductive RF generator module. The aim is to evade cabling (up to 100m) and costly maintenance work created by cable breaks in buses. The energy harvesting switch ensures design freedom and decreases maintenance work to a minimum as it has a lifetime of over 1,000,000 switching cycles.
The switch can be combined directly into the plastic housing of the stop request buttons in buses. The compact design (20.1mm x 7.3mm x 14.3mm) makes it simple to integrate. Also, the company’s radio switch produces a voltage pulse by mechanical actuation as it relies on the inductive principle. Consequently, RF commands can be reliably transmitted by commercially available radio protocols such as EnOcean3.0 at a frequency band of 868MHz. In this case, there is no risk of RF interference with Bluetooth devices that function at a 2.4GHz frequency range. Collectively, the radio switch is free of batteries or cabling, enables a reliable RF transmission and provides a high degree of flexibility in mounting in buses.
Each RF switch has a unique ID and maybe programmed individually. This indicates that each stop request button can be assigned to a particular command group, such as opening doors at the front, back or initiating measures for wheelchair users. The buttons are paired to the central receiver unit, which is also connected to the electrical bus system. Depending on the received command, the receiver triggers a visible or acoustic signal to provide the bus driver relevant instructions.