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SparkFun will be closing early at 3:30 Friday 5/27 and remain closed Monday for Memorial Day (5/30). Orders placed after 2pm MT on Friday (5/27) will process and ship out on Tuesday (5/31).

Member #95790

Member Since: December 9, 2009

Country: United States

  • “The panel is capable of 9 watts in the open sun with a peak power output around 6V at 1500mA.”

    Solar panels are rated for output based upon standard test conditions (STC) of 1000 W/m2 solar irradiance @ 25 degress celsius. Solar irradiance varies dramatically both seasonally and geographically. For a fixed plate solar panel at an angle from horizontal equal to latitude (ideal for mounting a fixed, non-tracking, non-collecting panel), you can look at the NREL website to get average solar irradiance for your area (http://www.nrel.gov/gis/solar.html). If your area, eg Colorado in August, gets about 6 kWh/ms/day, you should get an average of 54 (6 * 9) Wh/day with a 9 W panel. If your area, eg Colorado in January, gets about 3.5 kWh/ms/day, then you should get an average of 31.5 (3.5 * 9) Wh/day with a 9 W panel.

    If you are direct powering, all you need to do is calculate the minimum solar irradiance in you area and pick an appropriately sized solar panel. If you are charging a battery, be sure to factor in power loss due to charging. In this case, Lithium-ion battery would be ideal because of their charging efficiency.

  • Is there a maximum pressure/weight for these? I couldn’t find anything in the documentation. I don’t want to measure weight, just identify if it is present which an FSR seems ideal for. What I want is a pressure sensor that detects if someone is standing on a metal plate.

No public wish lists :(