Author Topic: solar tracker circuit (Read 85037 times)

snake21 · « **on:** August 02, 2011, 01:02:20 PM »

i was just wandering if such circuit with this function exists for diy solar tracker to save some energy

the circuit should work like this.

it should be connected to the battery and powers on every 30 minutes for about 10seconds to activate a relay which will power on the solar tracker and set it in the correct position.(like a timer)

David HK · « **Reply #1 on:** August 02, 2011, 08:55:08 PM »

The following URL will take you to a circuit I built seven years ago and has worked flawlessly ever since.

The working parameters are pretty much in line with your requirements.

http://www.phoenixnavigation.com/ptbc/home.htm

Regards,

David in Hong Kong where its very HOT at the moment.

David HK · « **Reply #2 on:** August 02, 2011, 09:03:31 PM »

Sorry,

Wrong URL. Try this one and double click on the circuit diagram.

http://www.phoenixnavigation.com/ptbc/articles/ptbc55.htm

David in Hong Kong

oztules · « **Reply #3 on:** August 12, 2011, 08:38:41 AM »

Interesting circuit.

It appears to be one that will not hunt for the sun, but rather, only move when the sun is more westerly than the sensor. It wont move east unless the sun is not present... I think it is a good little circuit, with sound ideas, and should not wear out the servo by useless hunting.... worth a shot I feel.

................oztules

David HK · « **Reply #4 on:** August 14, 2011, 06:37:25 PM »

Oztules,

You are precisely right with your assessment of the circuit.

And of course it has automatic parking in the East at night.

David in Hong Kong

oztules · « **Reply #5 on:** August 14, 2011, 08:21:23 PM »

Thanks for the heads up.... it is good to know I read it right.

The only thing I would change is the relay wiring.

I see that there is an interlock (op amps to driver tranny) to stop both relays from firing at the same time, but there is no reason not to wire the relays in a more traditional motor reversing manner, so that no matter what the relay positions are, the power inputs can never be crossed/shorted....

In the shown wiring, if both relays activate... bang, no relays operate nothing happens, 1 relay operates, something happens.

.................oztules

David HK · « **Reply #6 on:** August 14, 2011, 08:57:36 PM »

Oztules,

Yes, your observation is correct, BUT read this extract from the designers notes:-

So now at the end of the day after the sun has been turned off, the west photocell has one more duty to perform. It sends a voltage to IC1c and when compared with the voltage set by trimpot VR2 its output will go high turning on LED 1 and to transistor Q2 that energizes relay RL2 causing the motor to run in reverse, driving the collector back to the east for the start of the next day.

Also the output of IC1c goes to IC1d, this turns on the output of IC1d that in turn prevents the possibility of transistor Q1 from being turned on. This then keeps relay RL1 from being energized and prevents lots of smoke and fire that would occur if both relays were allowed to be energized at the same time.

Can you PM me me your more exact thoughts about realigning the relay connections.

Glad your interested.

David in Hong Kong

oztules · « **Reply #7 on:** August 15, 2011, 04:50:34 AM »

"Also the output of IC1c goes to IC1d, this turns on the output of IC1d that in turn prevents the possibility of transistor Q1 from being turned on. This then keeps relay RL1 from being energized and prevents lots of smoke and fire that would occur if both relays were allowed to be energized at the same time."

Yep, thats how I figured it to work when I said "I see that there is an interlock (op amps to driver tranny) to stop both relays from firing at the same time,"

Like I said I think he has attacked it the right way, with his tracking , and the return, just don't see why he didn't use normal reversing relay wiring ..... and you only need spst relays (headlight relay etc) .

Will draw out the difference for you and either post it or PM as well.... time in short supply today.

..................oztules

conntaxman · « **Reply #8 on:** September 02, 2011, 01:00:57 PM »

Quote from: oztules on August 12, 2011, 08:38:41 AM

Interesting circuit.

It appears to be one that will not hunt for the sun, but rather, only move when the sun is more westerly than the sensor. It wont move east unless the sun is not present... I think it is a good little circuit, with sound ideas, and should not wear out the servo by useless hunting.... worth a shot I feel.

................oztules

David, I have tried to make this cir and everytime I will not work, and I know/talked with on line they had the same problem. What changes did you make to the cir? and could you post them. The wiring of the relay's don't seem to be correct, it looks like he is only useing one set of contacts.
Could you post your corrections to the cir . for us.
tks
John

David HK · « **Reply #9 on:** September 02, 2011, 06:31:54 PM »

John,

For quick reference please note the following:-

The circuit as shown does work but the designer did publish a second revised circuit layout which is not shown on the web site.

The following changes were made:- Resistor R11 was changed from 10K to 4.7 K to slow down the tracking. This is a good move as it removes the irritation of the actuator winding every minute or so.

The next improvement was to install a manual switch to directly drive the actuator East or West - rather handy when setting up the system.

After I got this far I found my actuator would not work. After much head scratching I discovered that the limit switches in the actuator were the wrong type ( as I type I cannot remember which they were - but either NC or NO with just two connector tabs). As a result i installed an improved type of limit switch which had three connector tabs and could thus be wired for NC or NO.

The other important thing I did was to use PCB Express to design, build and purchase a circuit board to accommodate the majority of the electronics.

As for the relay wiring I have followed the original design exactly without a problem.

I have enclosed a photograph which shows my controller circuit and the relays.

Please contact me by PM or forum reply if you need more help. I should be able to scan and send you the updated schematic if you need it.

Whatever you do - don't give up.

Regards,

David in Hong Kong

oztules · « **Reply #10 on:** September 02, 2011, 09:05:46 PM »

Relays need to be NO. When they close, they short the base of Q1 or Q2 to ground..... making that (whichever one is at limit) tracker relay unable to activate.

...........oztules

fabricator · « **Reply #11 on:** September 03, 2011, 05:38:52 PM »

I wish one of you Gurus would come up with a kit for this controller that could be soldered together by those of us who are illiterate as far as the parts go.
I'm good with a soldering iron but the rest is Greek to me, it looks like an excellent idea.

David HK · « **Reply #12 on:** September 03, 2011, 06:50:31 PM »

Fabricator and all,

The idea of making up these circuits for sale at cost plus postage (no profit) did cross my mind some years ago and that is as far as it got.

If there is a demand from forumites I can resurrect it.

The design would be be a two board system - electronics on one and electrical hardware on the other - inside a weatherproof box plus the sensor arrangement in weatherproof boxes.

I may also consider changing the electronics to surface mount components.

In other words it would be built and ready to go - just connect the sensor, an actuator and the power supply and that's it.

Minimum life expectancy with a caring owner say more than twenty years.

Any views or comments from anyone?

David in HK

bj · « **Reply #13 on:** September 03, 2011, 06:54:07 PM »

Most generous David, I am like Fab, and would welcome the opportunity to buy.

fabricator · « **Reply #14 on:** September 03, 2011, 08:29:58 PM »

I'm definitely in for at least one, I intend to have two tracking arrays in the near future, hopefully Oztules modifications would be considered, and I for one am not against a guy making a fair profit.
And BTW it is hot as hell here right now too.

wilfor03 · « **Reply #15 on:** September 03, 2011, 08:40:15 PM »

Quote from: David HK on September 03, 2011, 06:50:31 PM

Fabricator and all,

The idea of making up these circuits for sale at cost plus postage (no profit) did cross my mind some years ago and that is as far as it got.

If there is a demand from forumites I can resurrect it.

David in HK

David.....would you have any idea of the cost, IF you decided to do this sort of thing? I think you would have a lot of interest in this, from a lot of the forum members! Can't get RedRok to do much, especially answering any emails...LOL

Bill

fabricator · « **Reply #16 on:** September 03, 2011, 08:46:28 PM »

From my study of the red rock, the way this unit uses the sensors seems to me to be a better approach. FWIW.

David HK · « **Reply #17 on:** September 03, 2011, 09:02:13 PM »

The few replies I have read so far are encouraging.

Give me some time to update my Express PCB drawings for pin-through-the-hole and SMD boards for the electronics - this is the first step.

Having built and used one circuit for many years I can see ways to improve the layout on the boards. Also i want to upgrade the PCB line track thickness to 50 thousandths of an inch (PCB Express is American).

I know exactly what materials I need to copy my own set up so estimating costs will not be difficult. Stainless steel brackets will be prefabricated which includes drilled and tapped holes for mounting arrangements.

For renewable energy equipment I never use ferrous metals so any metal parts will be in stainless steel.

Some of you may suggest a one piece PCB for all electrical items. I have thought about this. What are the pros and cons?

I am not in the game for shoddy products and I expect what I build to be in use long after I am in the ground. Its a waste of time building RE products that are doomed to fail or have a short life - barring lightning damage, building fires etc.

I will endeavour to make up a full working system, photograph it thoroughly and put costs on the forum. People will have to accept postage costs for whatever they are but the items will be shipped in a sturdy box by airmail. The declared value of the product will have to be low so as not to attract Customs interest. I can actually nail the costs down to individual items via an Excel spreadsheet,

As you can see, there is much preparation work.

Electrical cable between the control box and the actuator, sensor and power supply will not be included unless someone requires it as an extra.

David in Hong Kong

fabricator · « **Reply #18 on:** September 03, 2011, 09:14:48 PM »

I like the way you think, I've been a steel fabricator all my life, if you are going to take the time to build something you might as well do it right. In the end it really doesn't cost that much more to do it right.

oztules · « **Reply #19 on:** September 03, 2011, 10:26:49 PM »

Apologies
"Relays need to be NO. When they close, they short the base of Q1 or Q2 to ground..... making that (whichever one is at limit) tracker relay unable to activate."
Should read
LIMIT SWITCHES (not relays good grief) need to be NO. When they close, they short the base of Q1 or Q2 to ground..... making that (whichever one is at limit) tracker relay unable to activate.

not thinking when writing......

...............oztules

SparWeb · « **Reply #20 on:** September 06, 2011, 04:28:21 PM »

David you can count me in, if you're printing a board.
I would just be interested in a printed board. The parts list I can procure easily.

I would build it myself, but I'm sure you will be done before I got a round tuit.

David HK · « **Reply #21 on:** September 06, 2011, 07:02:23 PM »

Sparweb,

Thank you for the note. Rest assured i will never produce a 100% SMD board. There are good reasons not to do this because taking chips off an SMD board can easily wreck it.

I do have a mixed pin-through-the-hole and SMD board designed and only resistors and a few capacitors are SMD. I am making good progress and below is a photograph of a board made seven years ago that is languishing on my home office shelf. I shall soon in corpate this into a full blown system and offer it to the forum - I should be able to do this before Christamas this year.

By the way, the first circuit is for a 12 VDC system. I want to be able to create a 24 volt option but I need to seek advice from the forum about various technical aspects.

Regards,

David in Hong Kong

fabricator · « **Reply #22 on:** September 06, 2011, 07:57:07 PM »

!2 volt works for me, looking good so far, just for informational purposes what does SMD stand for?

Tinbendr · « **Reply #23 on:** September 06, 2011, 08:31:10 PM »

Quote from: fabricator on September 06, 2011, 07:57:07 PM

...what does SMD stand for?

Surface Mount Doohickie

fabricator · « **Reply #24 on:** September 06, 2011, 08:42:13 PM »

LOL, you gotta be kidding.

TomW · « **Reply #25 on:** September 06, 2011, 08:47:30 PM »

SMD is essentially impossibly tiny electrical components that mount on the surface of boards as opposed to through hole parts. Takes special gear and or skill to do. Usually done with hot air and good eyesight. Kind of the same evil that took cell phones from the size of cinder blocks to the size of a deck of cards

Just how I think of them.

Tom

fabricator · « **Reply #26 on:** September 06, 2011, 08:51:03 PM »

That sounds more technical than the doohickey thing.

rossw · « **Reply #27 on:** September 06, 2011, 09:17:40 PM »

Quote from: TomW on September 06, 2011, 08:47:30 PM

SMD is essentially impossibly tiny electrical components that mount on the surface of boards as opposed to through hole parts. Takes special gear and or skill to do. Usually done with hot air and good eyesight. Kind of the same evil that took cell phones from the size of cinder blocks to the size of a deck of cards

Yup. "Surface Mount Devices".

Here are some resistors - not even particularly small ones - on the end of my finger....

David HK · « **Reply #28 on:** September 06, 2011, 09:23:26 PM »

SMD - surface mount devices.

Its not that difficult if one sticks with simple devices like resistors, capacitors, LED's and three leg transistors. I would certainly never tackle any IC's with a large number of pins/legs. The thing to remember with RE products that some folks live way out in the wilderness and may have the wherewithal to tackle a part replacement - an LM7809 for example with one salvaged from other redundant equipment. A 7809 in SMD form would be a nightmare to replace because of the difficulty of getting it off the board and, even worse, finding a like for like replacement. This is not the way to go. A hybrid mixing both is not likely to be a disaster.

For the interest of all I have made a SMD version of Ghurd's dump load circuit and I am pleased to say I have been using one without any problem at all for about two consecutive years now, The first parts that may 'wear out' are the LED's which exceed their lifespan.

I can see by the trend of replies that there is a preference for pin-through-the-hole components so my next job for today or tomorrow is to update that circuit - same as in the photograph above.

David in Hong Kong

fabricator · « **Reply #29 on:** September 06, 2011, 09:28:05 PM »

Quote from: rossw on September 06, 2011, 09:17:40 PM

Quote from: TomW on September 06, 2011, 08:47:30 PM
SMD is essentially impossibly tiny electrical components that mount on the surface of boards as opposed to through hole parts. Takes special gear and or skill to do. Usually done with hot air and good eyesight. Kind of the same evil that took cell phones from the size of cinder blocks to the size of a deck of cards

Yup. "Surface Mount Devices".

Here are some resistors - not even particularly small ones - on the end of my finger....

Holy crap.

fabricator · « **Reply #30 on:** September 06, 2011, 09:29:38 PM »

Quote from: David HK on September 06, 2011, 09:23:26 PM

SMD - surface mount devices.

Its not that difficult if one sticks with simple devices like resistors, capacitors, LED's and three leg transistors. I would certainly never tackle any IC's with a large number of pins/legs. The thing to remember with RE products that some folks live way out in the wilderness and may have the wherewithal to tackle a part replacement - an LM7809 for example with one salvaged from other redundant equipment. A 7809 in SMD form would be a nightmare to replace because of the difficulty of getting it off the board and, even worse, finding a like for like replacement. This is not the way to go. A hybrid mixing both is not likely to be a disaster.

For the interest of all I have made a SMD version of Ghurd's dump load circuit and I am pleased to say I have been using one without any problem at all for about two consecutive years now, The first parts that may 'wear out' are the LED's which exceed their lifespan.

I can see by the trend of replies that there is a preference for pin-through-the-hole components so my next job for today or tomorrow is to update that circuit - same as in the photograph above.

David in Hong Kong

Yeah I like that idea.

SparWeb · « **Reply #31 on:** September 07, 2011, 04:13:37 PM »

David,

It's very kind of you to volunteer like this. My system runs at 24 volts right now, and I do not have plans to change in the future.
The next "big" job I want to do is add an array of solar panels, and it wouldn't be fun if it didn't track!

So count me in if you do have a chance.
No rush... I won't be cementing in new footings until next summer!

PS: for SMD stuff you can look up Youtube videos of how to solder the stuff, including multi-legged chips... but it takes a sharp eye and a steady hand regardless.

defed · « **Reply #32 on:** September 07, 2011, 06:00:51 PM »

i have to re-read this thread as i lost track of what tracker we are talking about, but i plan to track and would be interested in a kit of some sort.

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Author Topic: solar tracker circuit (Read 85037 times)