PCB hacking
 

Today I decided to work on my board. It starting loosing tracking a few days
after I installed some fancy glass enclosed LDRs.

So, I removed the power jumper and connected the +13.6 into the board at the relays.
Built a little adjustable regulator for the logic circuity and relays.



http://i46.photobucket.com/albums/f1...Solar/l030.jpg

I also pulled up the 1K pull-up for the East LDR and replaced it with a pot.
Using the pot, I should be able to balance the LDRs, so the voltage is the same on both, when both have full sun on them.
Using the reference pot (on left side), I might be able to tune the board
to work with most any LDR. Matched or not.


http://i46.photobucket.com/albums/f1...Solar/l031.jpg


Edit:
Yesterday, it wouldn't track east. Last night, the tracker didn't go home.
Today, I checked the board using a jumper (& open) across the LDR inputs.
It tracks west, but not east. The east replay is pulling in, 'Clicks', but is not
outputting power to the motor. A motor control contact must be 'open'.
Checked the board with full +12v (bypassing the regulator).

I wonder if radio shack carries this relay? ;)

bug's ear
 

Well, I looked up the relays, they appear to be rated for 3A max.. Non-inductive..

And, then I went back to the Red Rock site.. Took my time, and looked around for a while..

It arrears that this tracker comes with a 5.1v regulated power supply..
http://www.redrok.com/images/led3xc1.gif

And, I kinda like the idea of not hearing the clicking of tiny relays,
and quite MOSFETs, able to run 8 or 9 amps.. :D

And the Red Rock board, is as cute as a bug's ear.. :)

http://www.redrok.com/images/led3xc1rf.jpg

Sorta the same
 

Hey Rich......sorta been having the same problems with mine except mine will track back to the east (at night) (sometimes) and NOT track to west. I think my problem is with the relays. I got ahold of Michael at MTM and he's sent me two new relays and another LM339 comparator. I put them in and the board worked great for a day and a half, then the same problems all over again. I may try and use several automobile relays (12v) that can handle alot more amps and see if that cures the problem on my end.
It looks like you've really been burning the oil on your board, too! I'm also going to try and play around with some LED's for the sensors and try to get away from the LDR's. Finally got the time in life to play again. Isn't old age grand???
I'll keep ya posted with what I do/find out with my quests here. Good luck with your side and hopefully, the sun will keep on shining for us???/ Bill :cool::(

Heavy rain yesterday and maybe some today. Partly cloudy now.
My tracker is locked in the middle posistion for now.
The hardware is on the bench, awaiting an autopsy..:confused:


I don't know what's going on with the LDRs, but it seems like the second
pair that I installed started changing after a few days.
Not sure, but I think the west LDR went higher in resistance.
So, I tried out some different LDRs that I had.
These don't seem to be changing, but now I've got this replay problem.
If I'm right about the relay rating of 3A, I don't think all that rapid-fire clicking was too good for them.
It seems a waste to replace them with new ones that will also have a short life span..
I would consider using them to drive other relays, but solid state has more appeal, right now.

I had been thinking it would be fun to tweak up the tracker and make little mods to it.
But, that was before I spent so much time in the July sunshine. It's been HOT here.
And it seems like I'm not as young as I used to be..

I ordered a Red Rock board last night. :) Got it pre-built.. (Extra $15)..
I guess being retired makes you extra lazy.?.

Yup....know what ya mean bout tweaking out in the hot sun. We haven't been lucky to have any rain for over two weeks now. Some days, clouds, but NO rain.
How did you get a hold of Duane (RedRok), email or phone? I've sent him probably six emails and no response back from him!! Just got tired of waiting for him. I just wanted to get the tracker going good before I ordered more panels to finish my system. Let me know how it works out for you and the RedRok tracker, okay??? Meanwhile, I gonna still play with this thing and tweak till my fingers get tired........regards.........Bill :rolleyes:

Sure, I'll post a review. That's part of the deal. Experiments don't mean much, if people can't read the results.
Right now, the final results aren't in yet on the MTM board. But, it's not looking so good.

I've seen a lot of trackers using Red Rock boards, so there is a good chance, that
I'm going to get a trouble free tracker going..

I didn't actually contact Duane, I just put a message in with the PayPal payment.
If he's going to build it, I want the LEDs pointing upwards, instead off the end of the PCB.
I told him if it's pre-built, no problemo, I can move the LEDs around myself.

I want to stick the whole board inside my little water-resistant tracker module..
And, I think it will fit best if it's mounted flat. PCB Parallel to the glass.
I'll cover about 86% of the glass with mirror tape, to keep it cool.. :cool:

In theory, it should work. If Murphy don't come around... :(


Cheers,
Rich

PS:
I picked up a DC amps probe today. Should be good for checking the amps my actuator motor is drawing.

Hi, guys!

I'm from Brazil. My friend and I will make a sun tracker for the Final Project of the Control and Automation Engineering Course.
Our plan is to use cheap elements to make it. We thought this:

- 2 LDR in North/South Axis and 2 LDR in East/West Axis.
- An Operational Amplifier Circuit to compare the results of the 2 axis.
- A L297/L298 to drive the stepper motors.
- 2 Stepper Motors, to guide the structure to follow the sun.
- A simple and slight structure, to avoid work to the motors.

Do you think that is a good idea?! Do you have any suggestions?!
Thanks for your attetion.
Regards,
Edio Pereira

Hello Edio,

Welcome to DIY paradise. :D

- 2 LDR in North/South Axis and 2 LDR in East/West Axis.

Most solar trackers do not use N/S axis, since this can be done manually every 2 or 3 months.
Saving about 50% on hardware and complexity. This is a quick and simple adjustment on a polar mount.
YouTube - Satellite Polar Mount

The tilted 'hinge' of a polar mount is simple to setup and can be very accurate in tracking the sun, from horizon to horizon.

- An Operational Amplifier Circuit to compare the results of the 2 axis.

It might be better to use a Comparator chip that has a TTL or other output that are compatible with your motor drive circuit.
And, most Comparator chips use a single power supply vs. many OpAmps using dual PS + & - 15v etc.



- A L297/L298 to drive the stepper motors.
- 2 Stepper Motors, to guide the structure to follow the sun.
- A simple and slight structure, to avoid work to the motors.

These drivers and motors seem like low powered devices.
You might want to start off with the goal of a Self-Powered tracker.
Meaning you want to track the sun with a PV panel that has
enough power output, to run the motors and controller circuits.

Also With enough rechargeable battery power to re-turn the tracker to the
east (Home posistion) at the end of the day. (So it's ready for sunrise).
This takes some careful design work. Don't want it going 'Home',
if the sky gets a bit dark in the middle of the day.


Your design should start off with the size & weight factors of the PV panel.
Once the PV is selected, the size and power of the other components can be selected,
Based on their capability to handle the PV panel.

Sounds like a fun project..

Good Luck,
Rich

I've been looking at this:
http://www.redrok.com/images/led3xc1.gif
and I'm wondering how the Return East at night mode works.?.
Is it R-1, the 1megohm?

And, what's the current flow out (or polarity) of an LED that's being used like a PV cell??
Is it in the opposite direction as when it makes light?
Light coming in, makes voltage (and current) in the reverse direction?
(That seems logical).

Noticed less water heat on sunny days..
 

http://i46.photobucket.com/albums/f1...Solar/l070.jpg

Well, the J-B weld epoxy didn't work.. It's coming apart, making the hot-plate over-heat..

It seems I need some real thermal conductive epoxy.. Otherwise, my wires are going to really melt..