Solar Tracker Circuit Is Giving Me Issues - Appreciate Anyone's Help

[rs14smith]

When both MOSFETs Q3 and Q4 are OFF, then resistors R1 and R2 pull up their drain terminals to 11V (12V). That's how they turn Q1 and Q2 OFF (by setting the Gates of Q1 and Q2 equal to their Source terminals.)

A voltage is different from a current. For a current to flow (e.g. through the motor) the voltages must be different. One end of the motor would be about 12V while the other is about 0V. If both ends of the motor are at about the same voltage, there is no current; the motor receives no power.

The way your meters are hooked up is nice for troubleshooting, but if you really want to understand what the motor sees hook both ends of a meter to both ends of the motor. The motor doesn't know what "ground" is. It's a notation for our convenience as it gives us a reference point. And simulators are homeless without a "0V" to return to.

Ah okay, I think I understand now. I'll have to re-look over left side with the IC's and resistors to fully understand wha'ts going on there. You explained that well, I just need to sit down and really study that side lol.

Time To Build The Hardware:
Do you by chance know of any online/local electrical stores near TN where I can order these components as I'm sure RadioShack doesn't have everything I need, and I usually order from Jameco, but they are located in California? I'm just looking to start building this on the breadboard as soon as possible since I'm on spring break at the moment

 

[mneary]

According to their website, any RadioShack should have LM339. Hopefully you have resistors. The only MOSFET they seem to stock is IRF510 which is OK for the N-channel but apparently no luck from them on the P-channel. Maybe you've already taken care of the MOSFETs.

I feel totally helpless when trying to find local stores; even now I'm discovering 'new' stores within 10 miles of me that have 'always' been here.

 

[rs14smith]

I feel totally helpless when trying to find local stores; even now I'm discovering 'new' stores within 10 miles of me that have 'always' been here.

Haha, same here, I discovered a electric store 5miles from me a month ago that has been there for years. Anyway, the only thing I have to order online then will be the P-channel FETs.

My next goal is to implement the other portion of the tracker which is the vertical axis, which shouldn't be too difficult (more-less a replica of the current circuit), but I want to get this horizontal axis working first, so I'll be posting images/videos on my progress.

Big big thanks again for your help and everyone else's, and I'll let everyone know when I'm ready to implement the vertical axis in this thread as it's a sure thing I'll need help with that lol.

 

[mneary]

If you shop ebay (I know some people don't but I do) one outfit in California dpi4parts has been very good to me. Instant shipping, and USPS should get it to TN pretty quickly. Thing I like best about them is reasonable prices and LOW shipping even on small orders. They accept PayPal which I like.

 

[rs14smith]

If you shop ebay (I know some people don't but I do) one outfit in California dpi4parts has been very good to me. Instant shipping, and USPS should get it to TN pretty quickly. Thing I like best about them is reasonable prices and LOW shipping even on small orders. They accept PayPal which I like.

haha it's funny as I was just about to go to eBay and check there to see if some people closer to my location had the P-Channel FETs. Thanks for the heads up though.

 

[marktinkerman]

haha it's funny as I was just about to go to eBay and check there to see if some people closer to my location had the P-Channel FETs. Thanks for the heads up though.

when u have prices and sellers would appreciate list could be interested in buying completed working unit?

 

[rs14smith]

when u have prices and sellers would appreciate list could be interested in buying completed working unit?

What do you mean, like start up a service where we turn this circuit into a business venture of building this circuit on a printed circuit board and selling it to others?

 

[marktinkerman]

What do you mean, like start up a service where we turn this circuit into a business venture of building this circuit on a printed circuit board and selling it to others?

contact marktinkerman@hotmail.com

 

[mneary]

Mark,

Although this circuit may appear magical to a novice, let me assure you that any competent electronic engineer could easily do an equivalent design. It also needs limit switches, return to East in the morning, and detecting a stalled motor. It also isn't as efficient as it could be.

-Mike

 

[marktinkerman]

Mark,

Although this circuit may appear magical to a novice, let me assure you that any competent electronic engineer could easily do an equivalent design. It also needs limit switches, return to East in the morning, and detecting a stalled motor. It also isn't as efficient as it could be.

-Mike

sort of realise this and had thought of limit switches ,return to east but hadn't thought of stalled motors. Ive had 3.5kw of solar panels for about 9 months now and ran two arrays of 4 x 120 watt panels each last year steering them by hand towards max brightness and metering output. Ive realised arrays of 4 are a bit heavy for moving from festie to festie (see **broken link removed** for what we do) so smaller arrays of 2 or3 panels which mean more arrays to steer and therefor more steering units. can't afford to buy this many at professional price and the supposedly competent electronic engineers I've spoken to haven't done anything to help except blind me with tech speak. have found several designs on various forums and am following up a couple that I can sort of understand. Be very happy if you can come up with suggestion that I can follow. mechanics electrics plumbing etc I'm very good with but computers just about work for me and electronics seems like magic ....string beads together and things happen???Know what I want panels to do but not how to get them to do it. Another thing I want to do is have a light sensor (or read panel output) and when voltage drops below 12v approx trigger 3 pole change over relay (or similar) to reconnect panels in array to 24v to cope with dawn/dusk or heavy overcast and because enough charge controllers to run the amperage Ive got cost a fortune I'm planning on using voltage sensor to switch on dump load using a water filter uv steriliser on our hot tub as dump load and possibly a washing machine for towels if I have that much excess power although thats unlikely as we have been asked to power stages and lighting and when we not at festies a loud noise will be enough to tell me its time to get the power tools out (we're offgrid at our workshop)

any suggestions in language a mechanic can follow appreciated. mark

 

[rs14smith]

sort of realise this and had thought of limit switches ,return to east but hadn't thought of stalled motors. Ive had 3.5kw of solar panels for about 9 months now and ran two arrays of 4 x 120 watt panels each last year steering them by hand towards max brightness and metering output. Ive realised arrays of 4 are a bit heavy for moving from festie to festie (see **broken link removed** for what we do) so smaller arrays of 2 or3 panels which mean more arrays to steer and therefor more steering units. can't afford to buy this many at professional price and the supposedly competent electronic engineers I've spoken to haven't done anything to help except blind me with tech speak. have found several designs on various forums and am following up a couple that I can sort of understand. Be very happy if you can come up with suggestion that I can follow. mechanics electrics plumbing etc I'm very good with but computers just about work for me and electronics seems like magic ....string beads together and things happen???Know what I want panels to do but not how to get them to do it. Another thing I want to do is have a light sensor (or read panel output) and when voltage drops below 12v approx trigger 3 pole change over relay (or similar) to reconnect panels in array to 24v to cope with dawn/dusk or heavy overcast and because enough charge controllers to run the amperage Ive got cost a fortune I'm planning on using voltage sensor to switch on dump load using a water filter uv steriliser on our hot tub as dump load and possibly a washing machine for towels if I have that much excess power although thats unlikely as we have been asked to power stages and lighting and when we not at festies a loud noise will be enough to tell me its time to get the power tools out (we're offgrid at our workshop)

any suggestions in language a mechanic can follow appreciated. mark

Well what we have now I would consider the "beta" version, as I'm the type where I like to work from the ground up. So first I'm going to implement this horizontal axis tracker and see how it performs, and then probably work on having it return back to the starting position at night (return to east for the morning). After that is accomplished, I'd like to implement the vertical axis into the horizontal axis which is most popular now days. After achieving that goal, I'll do the same as what I did with my 63 Watt Solar Panel and Solar Power System and create a series of videos/images of how to create the solar tracker. As at the moment, there aren't many tutorial/how-to articles on how to build a solar tracker, and from the looks of it, there aren't many out there available to the consumer at a reasonable price. There is however a guy who owns a company named RedRok I believe, and he sells a nice version of the tracker that you may be interested in, however, considering he does all the soldering, printing the circuit board himself, your order may be put on hold for a while. In other words, he can't meet the solar tracker demand

eBay Listing
His Website (Not the most user friendly site out there )

So hopefully people like Mike (mneary) can help me to meet that goal so I can provide yet another free DIY video/image tutorial for a solar tracker.

I ordered the P-channel FET & BAT54 diode yesterday, so I'm guessing I should get those in no later than the Monday after next.

 

[marktinkerman]

Well what we have now I would consider the "beta" version, as I'm the type where I like to work from the ground up. So first I'm going to implement this horizontal axis tracker and see how it performs, and then probably work on having it return back to the starting position at night (return to east for the morning). After that is accomplished, I'd like to implement the vertical axis into the horizontal axis which is most popular now days. After achieving that goal, I'll do ......

it only single axis I'm interested in as I live and travel with my panels so seasonal adjust irrelevant to me
keep me informed please mark ps. am wading through the links you gave thanks

 

[rs14smith]

Well what we have now I would consider the "beta" version, as I'm the type where I like to work from the ground up. So first I'm going to implement this horizontal axis tracker and see how it performs, and then probably work on having it return back to the starting position at night (return to east for the morning). After that is accomplished, I'd like to implement the vertical axis into the horizontal axis which is most popular now days. After achieving that goal, I'll do ......

it only single axis I'm interested in as I live and travel with my panels so seasonal adjust irrelevant to me
keep me informed please mark ps. am wading through the links you gave thanks

Yeah if you are just looking for a single axis, the eBay Listing link shows one that will be right up your alley:

**broken link removed**

or the cheaper version without the box:

**broken link removed**

 

[marktinkerman]

thanks mark

 

[mneary]

Both,
I'll be glad to help with further development of this as open source.

Mark,
I would encourage you to take some measurements from your array in early morning or late afternoon. Setting the panels in series to get more "voltage" in low light might not give you what you expect. You may find that at those times you can get a higher open circuit voltage but the current isn't useful.

 

[Dragon Tamer]

I'm not sure if this was suggested yet, as I have not been keeping up with this thread, but why don't you try these circuits?

 

[rs14smith]

I'm not sure if this was suggested yet, as I have not been keeping up with this thread, but why don't you try these circuits?

Appears that's a single axis tracker as well, however, I do see it has relays in it which makes me wonder if that circuit returns back to east at nightfall?
I'm not sure yet how we'll have to implement that yet, but we have a working circuit currently, at least by simulation results, so I'm still going to proceed with working with that one since I somewhat understand how it works

Thanks though

 

[Dragon Tamer]

The circuits that I've posted are very similar to your circuit, they just use a different op-amp. If you want a circuit that will reset at night, I can throw a scematic together, but you may have to wait a day or so untill I have some more free time.

 

[rs14smith]

The circuits that I've posted are very similar to your circuit, they just use a different op-amp. If you want a circuit that will reset at night, I can throw a scematic together, but you may have to wait a day or so untill I have some more free time.

Well if you look at this last page here, you can see we are no longer using an OP Amp but a comparator, so that first circult you see on the first page of this thread is no longer what we are building onto

The following is the current "working" circuit that I'm about to build on a breadboard fairly soon. So if you know of a way of implementing a way to get that particular circuit to turn back east, that would be awesome

 

[mneary]

Both of those LM741 circuits are useless. The relays are a good idea, but the implementation is bad.

CdS photocells were once very popular, but I prefer silicon diodes in new designs now that the dangers of cadmium are understood.
The LM741 is a very poor choice for driving a relay through an emitter follower, because the relay will get a lot less than Vcc. (In this circuit the relay may get approximately Vcc-4).
The LM741 performs very poorly below 10V. Vcc is not stated.
The LM741's inputs should be kept between 3 volts and (Vcc-3V). Neither circuit assures this.
The first circuit has the + and - inputs to the two LM741s simply cross connected meaning the motor is always running back and forth. The motor will never stop.
The second circuit does not compare the two photocells. It simply runs when one of them is very dark and the other is not. The motor will stop when it is very dark or it is very light. When the photocells have different amounts of light, the motor won't run until one of them is totally dark.
The limit switches interrupt only the collectors of the transistors, meaning the LM741 is still trying to drive the relay through the transistor b-e junction. The motor might keep running.