Post by rickj on Jan 20, 2017 22:20:08 GMT
Bought a solar ventilation package a few years ago to ventilate my house when I'm not there for longer periods. Idea is that the fan is powered only when the sun shines, so the air is dry, so the house is kept dry. This works fine! Specs: "blue" cells panel 12V/5W , fan 12-17 V 0.8W
As that package costs a lot more than its parts, and is no longer available, I decided to assemble my own, using an amorphous gray panel, 12V/4W (actually: 230 mA @ 17.5V) and a Panasonic 24 V fan (90mA @ 24V, allowed is 10 .. 27 V). This does not work well. It does make the fan turn, but it has no power. And, it starts later and stops far earlier than the blue panel, with the same sun exposure.
Measured the voltage across the terminals with the fan connected: 7.5 V instead of the promised 17 V. That same fan connected to the other "blue" panel runs absolutely fine: the voltage is 17 V, with the fan running fine.
Do you know of a reason why that gray 4W (230 mA @ 17.5 V) panel cannot power a 90 mA @ 10-27 V fan, and the voltage across collapses?
Many thanks for ideas!
rick
As that package costs a lot more than its parts, and is no longer available, I decided to assemble my own, using an amorphous gray panel, 12V/4W (actually: 230 mA @ 17.5V) and a Panasonic 24 V fan (90mA @ 24V, allowed is 10 .. 27 V). This does not work well. It does make the fan turn, but it has no power. And, it starts later and stops far earlier than the blue panel, with the same sun exposure.
Measured the voltage across the terminals with the fan connected: 7.5 V instead of the promised 17 V. That same fan connected to the other "blue" panel runs absolutely fine: the voltage is 17 V, with the fan running fine.
Do you know of a reason why that gray 4W (230 mA @ 17.5 V) panel cannot power a 90 mA @ 10-27 V fan, and the voltage across collapses?
Many thanks for ideas!
rick
