projects:blinker:work_logs:8_solar_cells
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projects:blinker:work_logs:8_solar_cells [2022/03/20 01:07] – tjhowse | projects:blinker:work_logs:8_solar_cells [2022/04/17 23:45] (current) – tjhowse | ||
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All of this testing was done on a single 125x125 solar cell. I have another nine of them to experiment with. I would like to see how these cells respond to a CO2 laser. I work with people who built solar racing cars, and so have experience with this kind of thing. We also have a water jet cutter at work, which might be worth a try. | All of this testing was done on a single 125x125 solar cell. I have another nine of them to experiment with. I would like to see how these cells respond to a CO2 laser. I work with people who built solar racing cars, and so have experience with this kind of thing. We also have a water jet cutter at work, which might be worth a try. | ||
- | ===== Video ===== | + | ==== Unearned success |
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+ | I was at Bunnings (a hardware store) for an unrelated reason and I saw some solar-powered garden lights with various configurations of solar cells. They were mostly under AUD$10 so I grabbed an 8-solar-cell LED light on a stake. | ||
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+ | I drilled a small hole in the bezel to make the LED visible from the front. | ||
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+ | I connected the 8 cell panel to a blinker circuit and it generates enough power to overwhelm the voltage limiting zener and the supercap overvolted to 3.1V. I did some experimentation with covering up cells with tape, but quickly realised that dark cells don't pass current. | ||
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+ | I dug through the polymer coating with a hot air gun and knife to expose a connector and soldered on a wire that bypassed two of the cells. This gave me the following results under direct sun when connected to the blinker: | ||
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+ | I was pretty happy with that, however it did sneak pretty close to the voltage limit of the supercap. I decided I would go with a 5-cell array for the final version. | ||
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+ | {{ youtube> | ||
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+ | ==== Success again ==== | ||
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+ | Once I got my [[projects: | ||
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+ | First attempt. Note the cut is approximately parallel to the fine white lines. | ||
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+ | More success. | ||
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+ | Repeatable results. | ||
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+ | Soldered up one five-cell array. | ||
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+ | I used some fine copper wire to join the cells. I used leaded solder, a chisel tip, Chipquik SMD291 flux and 270ºC. I dipped the wire in the flux and laid it across the contact on the panel, wet the iron tip with a good amount of solder then swept across the copper while I held it in place. Once I got my technique sorted it was pretty straightforward. | ||
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+ | Holding this cell in diffuse sunlight gave 2.7V open circuit voltage. | ||
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+ | ===== Videos ===== | ||
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+ | Failure: | ||
{{ youtube> | {{ youtube> | ||
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+ | Success: | ||
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[<6>] | [<6>] | ||
projects/blinker/work_logs/8_solar_cells.1647738425.txt.gz · Last modified: 2022/03/20 01:07 by tjhowse