06-15-10, 03:09 PM | #21 | |
Lex Parsimoniae
Join Date: Feb 2009
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A little pot?
Quote:
but you may have a better pair of photocells than I got. They are supposed to be a matched pair. Both should have nearly the same response to sunlight. When I first tested mine, it wouldn't work unless the sunshine was directly on the face of the sensor pod. If the light was just slightly dim (window glass or clouds), it wouldn't track.. So, since I wanted it to track on hazy days, I made the mod.. Now, I'm beginning to think the wiper-arm of the pot might be dirty or corroded, making operation intermittently erratic.. A new pot is on my list now.. Have fun making your board. I used an old VCR motor for testing. Cheers, Rich |
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06-15-10, 05:19 PM | #22 |
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Rich...you may want to disconnect the +12v power to your board and rotate the crap out of the pot and you may get lucky and clean it that way....used to work for me years ago....worth a try, eh? Yea, gonna try the board with "stock" parts first then change something later (fingers crossed)....let me know about your pot......Bill
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06-16-10, 02:57 PM | #23 |
Lex Parsimoniae
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I went ahead and pulled out the old pot and installed a new 10k pot..
(The recommended radio shack part). Normally, I adjusted the ref voltage between 1.5 to 1.9 volts (using the old 30k pot). But this one can only get up to 1.25 (or less) volts! Maybe that's the way is should be, since the default voltage is 1.18 volts (w/ fixed 9.1k). I'm going to wait for the next sunny day and see what happens.. (Friday looks promising).. |
06-16-10, 09:24 PM | #24 |
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Got the board put together and was hoping to just see the thing work on the first try.....no luck this time. I was so hot after getting it soldered up, I probably got a cold solder joint in there somewhere......I'll look deeper in the morning when its still somewhat cool in the workshop.....I'll keep ya posted....Bill
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06-17-10, 06:44 AM | #25 |
Lex Parsimoniae
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How did you try to test it?
Since I was indoors, I held the sensor pod up to the window. That didn't work very well at all. The light was too weak.. I needed to open the window (it was cold outside) and hold the sensor pod outside and point it at the sun.. That got the motor spinning! One thing that did work, right off the bat, was the Home-East function. I just had to make sure the the glass was completely covered, using a black cloth. A white cloth let in too much light! |
06-17-10, 08:21 AM | #26 |
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It LIVES!!
Woo-whooooo.....I was right, had a bad cold solder joint on the jumper wire. Fixed that and it fired right up, both East and West, as well as Night reset function. I'm so glad to have this part finished, now to the mounting portion. I'll probably just put some heat shrink on the LDR leads and mount those in a baby food jar up on the mount. Wish me luck, Rich.............Bill
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06-17-10, 08:28 AM | #27 |
Lex Parsimoniae
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That's great!
Baby Food! Hummmm!!
I saw one pic of an inverted test tube.. That's what I should have used! It's so cloudy now, I should get outside and work on my sensor job.. I want to move the west photocell closer to the glass.. |
06-18-10, 11:10 AM | #28 |
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Just finished putting all the LDR stuff inside the Baby Food jar and tested it out......seems to work just fine (picture of test setup). Gotta wait till the weekend for my loaned out ladder to come back home! Pooh!!!! I'll post more when I get it all mounted with some more pictures.......Bill
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06-18-10, 11:13 AM | #29 |
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oops....forgot to include the LDR setup.....works great.....Bill
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06-18-10, 01:11 PM | #30 |
Lex Parsimoniae
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Tracking is good!
Looks good! Too bad about the ladder. I was wobbling all over the place up on
my 6' step ladder, moving that little 10w PV yesterday. My mount is on a slope, so it's not easy to get the legs level.. Moving the photocell seems to have helped the performance of the tracker a lot. It's moving in really small increments and the shadow-post never gets a chance to cast even a small shadow. I'm really pleased with the tracking today. I guess having mostly clear skies helps!! My power output is down a bit, but the boiler is heating up very nicely.. |
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