home made dual axis solar tracker


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Tinker

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Joined: 07/11/2007
Location: Australia
Posts: 1904
Posted: 01:28pm 22 Sep 2009      

  davef said   A couple of photos showing the detail of the 2nd axis would be helpful. It looks like you raise and lower the back end of the panel assembly.

Like the idea of advancing the panel every 15 minutes rather than trying to track the sun. What is the drive motor?

Nice job!

Dave


Thanks Dave. The tracker advances the panel every hour, not 15 mins. Hourly intervals are really good enough IMO, besides there is a limit of timing intervals on the digital timers.
Regarding timers, yes, the mechanical 240V timers have 15min intervals around the clock but I found these types rather poor time keepers. Also, the tracking motors only run for seconds so applying power to the circuit for 15 min is not desired. The circuit is self resetting, the timer supplies 12V for 1 minute to the motor control, that's all, no other control wires are used.

The azimuth drive uses a windscreen wiper motor (55:1 worm gear), driving another 50:1 worm gearbox which has the solar panel shaft on its output.
The declination drive uses a little 12V geared (50:1) motor from Jaycar, which drives a home made 82:1 wormgear, turning the spindle made up from lengths of allthread.

Declination drive pics:







The 'calibration stick' in the last picture lets me adjust for the day of the year, the drive motor has a quick connect link to stop it to adjust for leap years and other adjustments.

Klaus