Design Article
Energy harvesting at the press of a button
Frank Schmidt, EnOcean
11/26/2012 8:00 AM EST
Key characteristics
This next-generation energy converter offers a higher number of cycles, greater efficiency of energy conversion and an improved size when compared with the previous generation. Weighing less than 3 ounces and measuring just under 0.28 inches in height, the converter can be integrated into lightweight, slim-line devices. The typical actuating force of 3.5 N is easily produced by manual operation, for example, and can be reduced even further in the overall design if necessary.
The number of switching cycles offered by the converter depends on the precision of the stimulus. With the maximum allowed contact travel of 0.04 inches, more than 300,000 switching cycles are typically completed. With shorter contact travel, the converter switches at the latest after 0.03 inches of spring deviation, significantly more than a million switching cycles are possible. This means a switch can be operated 100 times a day for more than 25 years.
With 120-microwatts of energy, a stabilized voltage of 2V and an according wireless batteryless module, it is possible to transmit three radiotelegrams per operation over a distance of up to 900 feet in open spaces or 90 feet inside buildings. This energy conversion works in both actuating directions. The return movement delivers another energy pulse and so allows start/stop signals to be transmitted, which can be used for functions such as door and blind control or light dimming.
Design considerations for the ECO 200
This next-generation energy converter offers a higher number of cycles, greater efficiency of energy conversion and an improved size when compared with the previous generation. Weighing less than 3 ounces and measuring just under 0.28 inches in height, the converter can be integrated into lightweight, slim-line devices. The typical actuating force of 3.5 N is easily produced by manual operation, for example, and can be reduced even further in the overall design if necessary.
The number of switching cycles offered by the converter depends on the precision of the stimulus. With the maximum allowed contact travel of 0.04 inches, more than 300,000 switching cycles are typically completed. With shorter contact travel, the converter switches at the latest after 0.03 inches of spring deviation, significantly more than a million switching cycles are possible. This means a switch can be operated 100 times a day for more than 25 years.
With 120-microwatts of energy, a stabilized voltage of 2V and an according wireless batteryless module, it is possible to transmit three radiotelegrams per operation over a distance of up to 900 feet in open spaces or 90 feet inside buildings. This energy conversion works in both actuating directions. The return movement delivers another energy pulse and so allows start/stop signals to be transmitted, which can be used for functions such as door and blind control or light dimming.
Key characteristics of the ECO 200 energy converter
Design-in rules
The self-powered wireless module can be connected to the energy converter without soldering thanks to spring contacts and is simply snapped into a suitable plastic housing. This ensures a reliable connection that can be assembled at low cost. The energy converter connects to the board via gold-plated spring contacts that compensate for any assembly tolerances.
ECO 200 snap connects to wireless module
To ensure that the energy converter can consistently meet the specified characteristics, such as a long lifecycle and high energy output, manufacturers should take a number of design rules into account when installing the device in the respective application. The ECO 200 should be firmly connected via the interfaces indicated (free of play) and the minimum actuation stroke of 0.7 inches on the leaf spring should be strictly observed – these are decisive factors for reliable operation. The maximum actuation stroke of 0.13 inches is also important for ensuring that no premature damage occurs to the converter.
The following table gives an overview of the most important design-in rules manufacturers should consider when integrating the energy converter into a case:
Click on image to enlarge
Design-in rules
The self-powered wireless module can be connected to the energy converter without soldering thanks to spring contacts and is simply snapped into a suitable plastic housing. This ensures a reliable connection that can be assembled at low cost. The energy converter connects to the board via gold-plated spring contacts that compensate for any assembly tolerances.
ECO 200 snap connects to wireless module
To ensure that the energy converter can consistently meet the specified characteristics, such as a long lifecycle and high energy output, manufacturers should take a number of design rules into account when installing the device in the respective application. The ECO 200 should be firmly connected via the interfaces indicated (free of play) and the minimum actuation stroke of 0.7 inches on the leaf spring should be strictly observed – these are decisive factors for reliable operation. The maximum actuation stroke of 0.13 inches is also important for ensuring that no premature damage occurs to the converter.
The following table gives an overview of the most important design-in rules manufacturers should consider when integrating the energy converter into a case:
Click on image to enlarge
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