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--- projects:blinker:work_logs:9_resin_casting [2022/04/17 23:28] – tjhowse
+++ projects:blinker:work_logs:9_resin_casting [2022/04/18 00:00] – tjhowse
@@ Line 33: / Line 33: @@
   * Solder.
-In direct sunlight this panel generates 3.1V open circuit voltage, 190mA closed circuit current.
+In direct sunlight this panel generates 3.1V open circuit voltage, 190mA closed circuit current. That was about double the current I was anticipating. This caused me mild concern as the voltage limiting zener might not be able to keep the voltage down. I could add more in parallel to pass more overvoltage current, but that would increase the passive energy loss in the system [[projects:blinker:work_logs:6_power_consumption_testing#conclusions|considerably.]]
-I soldered it to a blinker circuit
+I soldered it to a blinker circuit and put it in the sun:
+{{:projects:blinker:work_logs:pasted:20220417-234821.png}}
+Awesome!
+I was puzzling over why the voltage dropped off so quickly. I wanted to check whether it was panel degradation related to the discolouration or due to the panel heating up inside a pretty good thermal insulator. I put the whole shebang in the freezer for a while to see if that had any effect.
+{{:projects:blinker:work_logs:pasted:20220417-235051.png}}
+This seemed to indicate that the voltage limit was related to the temperature of the panel. Part of the way through this test the panel fell into shade, probably at the inflection point at 2710 seconds.
 ==== Failure ====