Battery-free Wireless Pushbuttons and Limit Switches

The energy required for signal transmission in wireless pushbuttons and limit switches is generated by the switching operation itself and, thus, the modules are self-powered and low-maintenance. The wireless transmitter modules (ref. DFA16 / DFA22) are suitable for all actuators of the Schlegel product range with a 6 mm travel, as well as for the limit switches of the EK-FA series.
The tactile feedback makes the switching process clearly perceptible. The radio signal is transmitted with a power of 10mW in Europa and other countries and involves license-free operation using SRD bands (Short Range Devices) at 868 MHz. Modules have been developed for the use in the USA and Asia, which broadcast in the usual local frequency range of 315 MHz. Within 25 ms, three very short telegrams are sent, each containing an individual 32 bit transmitter ID, the polarity of the supply voltage, as well as the actual payload data (one to four input signals). This multiple transmission ensures maximum transmission reliability. The transmission range of the signals is up to 200m in the open field, however, strongly depends on the surrounding materials and the position to other energy generators or metal surfaces. This should be considered when planning. The modules have a size of 24.3 x 24.3 x 51.0mm (ref. DFA16) or 24.3 x 24.3 x 49.5mm (ref. DFA22) and are now suitable for a temperature range of -25°C up to + 65°C. They are in compliance with the R & TTE-EU Directive for wireless equipments.