硅實驗室能量收集參考設計的實踐回顧

　　低功耗無線傳感器在工業和醫療應用中越來越普遍，遠程測量橋梁和建筑物的壓力，甚至人類的心臟壓力。傳感器節點需要超低功耗，因為更換電池可能代價高昂，不切實際，甚至不可能。在這些應用中，環境能源的獲取成為一個高度優先事項，甚至是必要的。如果你考慮這樣的設計，硅實驗室制造一個便宜的能量收集板，它既是概念的證明，也是設計你自己應用程序的跳板。

　　硅實驗室的能量收集參考設計（見圖1）由一個無線傳感器節點和一個USB無線適配器組成。無線傳感器節點是由太陽能電池供電，雖然有一個輔助輸入，將允許電源來自其他能源采集的替代品，如熱，壓電或射頻。傳感器節點采用了Silicon Labs si1012a無線單片機測量溫度，光照水平和收費水平，無線傳輸數據到EZRadioPRO?USB適配器，從而使用一個單獨的Silicon Labs C8051F342單片機和4431無線電。這次審查將使董事會通過它的步伐，建議在無線傳感器節點的能量收集源有意義。

　　The sensor node is powered entirely by a solar cell， with energy stored in an Infinite Power Solutions’ THINERGY? thin-film battery with power management handled by Linear Technology’s LTC4071 regulator chip （see Figure 2）。 The system is designed for ultra-low power operation， with the Si1012 consuming only 50 nA when it is not transmitting data. The leakage current of the energy harvesting supply is approximately 3 μA， which can be overcome by as little as 50 lux shining on the solar cell. When the battery is fully charged， the system can operate for approximately seven days in total darkness or indefinitely when exposed to light. The system can operate using either indoor lighting （200 lux） or sunlight （10，000 lux）。 Silicon Labs puts the life expectancy of the sensor board at 15 years， over which time it can deliver 7000 mA-H.