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Project: 4oz 1A USB Charger
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Richard Cullip
(RichardCullip) - M

Locale: San Diego County
Re: Re: My PowerFilm lightening steps on 11/27/2012 17:49:27 MST Print View

Thanks Al. My apologies for calling you George in previous posts and PM's


P.S. I'm going to show my ignorance here and ask, is there a proper way to connect Jay's USB charging circuit board to the PowerFilm solar panel? In other words, is there a possibility of connecting the solar panel to the circuit board backwards - wrong solar panel wires to the 12V input (red wire) and the GND (black wire) on the circuit board? I didn't pay attention when I originally clipped the solar panel wires.

George Geist
(geist) - M

Locale: Smoky Mountains
Re: My PowerFilm lightening steps on 11/28/2012 19:29:18 MST Print View

Richard,
Yes the board can be hooked up wrong. You need to get your volt meter take the panel out into the sun and hook the wires to the meter to determine positive and negative

let us know how well the panel charges your phone

Richard Cullip
(RichardCullip) - M

Locale: San Diego County
Re: My PowerFilm lightening steps on 11/29/2012 15:07:32 MST Print View

Making slow progress. I found my wiring error (had it wired up backwards) and now can get the green light to come on and signify success. Verified that the output is 5V. However, due to a cloudy day down here in San Diego this afternoon, I haven't been able to run it long enough to get any battery charge into my iPhone5. For the brief moment that the sun peeks thru the clouds, I get the green light and the phone signifies that it's charging but this only lasts a short moment before the sun hides again and the unit fails to generate enough power. I'll have to wait for a sunny afternoon to complete the charging test. This has been fun and I'm relearning lots about electricity and circuits. It's been an enlightening experience.

Wizard of Oz
(wizardofoz)

Locale: New England
Re: Re: My PowerFilm lightening steps on 12/03/2012 08:27:07 MST Print View

Rich,

Glad to hear you're making progress! Yea, as was said, it can, but shouldn't, be hooked up backward. I honestly don't know if it can cause any damage to the board, as I've never tried it. It's fairly low power from the Powerfilms, so hopefully it's ok.

I will throw out there, that a standard incandescent lightbulb (not a flourescent) can generate a small voltage on the panel to allow you to check the polarity in the house. I think I got between 1.6 and 3.5V on my panel indoors, which wont run the board obviously, but is enough to measure the leads with a DMM and label them. I just marked the negative wire with a black sharpie since they are orginally red (or at least mine were). That way if/when I change panels, I'll know how it was and not have to measure each time.

The winter sun is DEFINITELY way less powerful here in New England (I'm in MA). I think that for winter use a heavier 10W panel may be helpful, if not necessary.

Jay

Richard Cullip
(RichardCullip) - M

Locale: San Diego County
Re: My PowerFilm lightening steps on 12/04/2012 11:58:45 MST Print View

The good news - The sun finally came out in San Diego and I got to run the first test charge into my iPhone5. Without the phone plugged in, I get a nice steady green light and the USB connector is putting out a nice steady 5V. No flucuations, just a nice steady green light. Both the solar panel and the circuit board are working as designed. Things are looking good.

The bad news - as soon as I plug in my iPhone5 the circuit board and iPhone5 go thru the same 1 sec on, 9-10 sec off cycle that George's (or is it Al's) Motorola Razr Maxx Phone experienced. The circuit board is set to the 0.5A option. In spite of a good strong sun and clear no cloud day, the system won't charge my iPhone5. Bummer. I might need the larger 10W panel to handle the charging needs of an iPhone5.

Any thoughts?

Wizard of Oz
(wizardofoz)

Locale: New England
Re: Re: My PowerFilm lightening steps on 12/04/2012 13:50:38 MST Print View

Aren't you supposed to be in 'sunny' california :)

Fake Suggestion: Downgrade to an iPhone 3G...I think they take less power

Real Suggestions:
1. So I wonder if you have a bad panel in your 6 panel powerfilm, cause I would think at your latitude, that if I can charge in AZ with the same panel, you should be fine. You've probably already done this, but to check it. Clip a voltmeter onto the panel leads that go to the board (you can leave it connected to the board, just don't plug you're phone in. So you should get the green light. Measure the voltage to the board, it should be just under 20V! Then take a strategically cut piece of plane white paper, and cover just one of the 6 power film panels. You should see the voltage drop to the board, record that change for that panel. Remove the paper, see that the voltage goes back up, put the paper on the next panel, see that it goes back down about the same amount, and repeat. You might find that your total voltage out of the unloaded panels is low, and/or that covering one of your panels does not change the output voltage to the board by as much as other ones indicating a poorly performing panel or panels.
*****Most solar panels will drain energy from the system if they are damaged, so it's very important to know! With the same 5W powerfilm, my setup would NOT charge my iPhone 4S at .5A when any single one of the panels were covered! A bad or covered panel not only doesn't produce power, but sucks power, so it's a double hit.


2. The angle of the panel to the sun is VERY important. I'm sure you tried many placements, but I found in the canyon that 10AM to noon sun was the best even though I had to have the panel at a steep angle to catch the low sun.
*****The easiest way to gauge if your angle is right is to make sure that SHADOW it makes on the ground is a perfect rectangle or is is a trapezoid! I always held it up to see the shadow and get the angel in my head, I made sure the phone would charge at that ideal positioning, then I looked for a place to leave it in the same orientation for a while.


3. I haven't tried it, but I've heard of some guys using mylar or tinfoil wrapped cardboard to make a lightweight reflector to direct additional sun to the panel! If you try this, let us know how it works! It's probably not a permanent solution for you, but might give you some insight if the above stuff doesn't help.

Keep us posted!
Jay

Richard Cullip
(RichardCullip) - M

Locale: San Diego County
Re: Re: Re: My PowerFilm lightening steps on 12/04/2012 15:50:38 MST Print View

Thanks for the troubleshooting tips, Jay.

I did manage to measure the total voltage on my PowerFilm unit, before the clouds rolled in this afternoon, and it came in ranging btwn 18.0V and 18.8V, depending on the angle with the sun. Didn't have the opportunity to test individual panels but I should be able to, weather permitting, take that step tomorrow. Currently it looks like my panel is not only a bit heavier (by an ounce) than yours but it may also be under powered. (Frownie Face icon goes here)

George Geist
(geist) - M

Locale: Smoky Mountains
Re: My PowerFilm lightening steps on 12/04/2012 22:46:30 MST Print View

Hi Richard,

Given that your and my 5W PowerFilms have the same behavior, I'm inclined to say that ours are not underpowered. Our's are probably normal and Jay's PowerFilm is a bit more powerful. In strong noontime sun my panel produces a little over 19V, but it won't charge my RAZR MAXX smart phone. I plug it in and I just get oscillation and battery discharge.

I'm going out with the scouts this weekend and I'm going to take my StrongVolt Solar 6 panel with me and see if I can keep my RAZR MAXX charged.

Richard Cullip
(RichardCullip) - M

Locale: San Diego County
Re: My PowerFilm lightening steps on 12/06/2012 23:01:33 MST Print View

I have not yet been successful charging my iPhone 5 with my 5W PowerFilm Solar Panel and Jay's nifty little circuit board. This has led me to wandering around cyberspace reading lots of info on charging an iPhone 5. I have not yet reached the end of the Internet but I think I'm close. As best I can tell, Apple changed something in the iPhone 5 (or maybe in the new 9-pin lightning connector the iPhone 5 uses). The change renders useless some chargers that would charge an iPhone 4. I wish I could find the details on the change but reliable info has been hard to find. There's some speculation that the iPhone 5 requires 1A to charge. Other speculation is centered on the idea that an iPhone 5 talks to a charger differently than an iPhone 4 and is more stringent about accepting chargers than the iPhone 4 was. Wish I had an iPhone 4 to plug into my PowerFilm/Jay's charging circuit board to see if my setup will charge an iPhone 4.

Edited by RichardCullip on 12/07/2012 10:09:39 MST.

Wizard of Oz
(wizardofoz)

Locale: New England
Iphone 5 charging and New Board Case on 12/11/2012 06:55:00 MST Print View

I'm trying to catch a friend of mine with an Iphone 5 to run that test to see if the switch works with the new Iphone and cable or not, to adjust from .5 to 1A modes. I'll let you know!

Some folks wanted the case that I made for the Canyon, and taking some lessons that I learned, I've updated the orignal case design to slim it down a little and give better access for the buttons and switches. I think it looks sweet! I'll post real pics when it comes in!

Updated case

Jay

Richard Cullip
(RichardCullip) - M

Locale: San Diego County
Re: Iphone 5 charging and New Board Case on 12/11/2012 08:40:52 MST Print View

Jay, I'm trying to run down an iPhone 4 to borrow for a sunny hour or so to test my panels/circuit board setup. I'm still wondering if the new iPhone 5 Lightning connection is doing something your circuit board doesn't like (e.g. draw enough current at handshake that your board drops below the 7-8 volts and shuts off) or if there's something funny about my solar panel. I'm getting ready to sacrifice a short USB extension cable to allow me to measure the current being drwan by my iPhone 5 as it get plugged in. However, I'm not sure my simple (cheap) multimeter and electrical skills are up to that task.

BTW - nice looking design on that case.

Ryan Lusso
(Loosenuts)

Locale: Pacific Northwest
Wiz - are still making these? on 12/26/2012 23:57:04 MST Print View

Wiz,

Awesome project you took on. I'm not too good at the electronics. Would this work for a Samsung Galaxy note 1? Wondering if you are interested in selling one that works on a Galaxy note and iPhone? I have some ultra light stuff for trade and/or cash - titanium MYOG caldera cone keg and stuff like that. If you are still tinkering with this and interested please drop me a note.

Thanks

Wizard of Oz
(wizardofoz)

Locale: New England
Re: Wiz - are still making these? on 12/30/2012 16:11:12 MST Print View

Yea Definitely! It looks like the Galaxy Note 1 charges off of a micro-USB, so as long as you have the cable that plugs into your computer's USB to charge it, than it'll work! The key is to take a look at your phone, car, and wall charger and get an idea of how much current it draws. This board can control a max of 1.3A which is good for most phones, and some tablets like the iPad, BUT YOUR SOLAR PANEL HAS TO MEET THE PHONE'S CURRENT REQUIREMENT. For an iPhone, it can be set by the board for a .5A mode, but folks still find that a 10W panel is good idea if you're not in max bright sun (which can be hard to find!)

I'm working on getting a website together, but it's slow working out all the details! hopefully it'll be up the next week or so. But we can talk over PM and figure it out. I've got a couple board ready to go!

Bob Gross
(--B.G.--) - F

Locale: Silicon Valley
Re: Re: Iphone 5 charging and New Board Case on 12/30/2012 16:19:07 MST Print View

"I'm not sure my simple (cheap) multimeter"

As a general rule, the really cheap multimeters are operated by those with poor multimeter skills, and those can get toasted in a hurry. As you move up to a slightly better multimeter, it will likely have some better scales for amperage (current). That is pretty handy once you start experimenting with solar panels.

You can troubleshoot a lot with just a voltmeter, but the current scales are much more useful for measuring just how perfectly the panel is working.

--B.G.--

Wizard of Oz
(wizardofoz)

Locale: New England
New Case Design is in! on 12/30/2012 16:31:07 MST Print View

Got two colors of the new case in. It's just a bit slimmer, much nicer finish than the original case, and allows for easier access to the switches without having them stick out and get caught on gear. The lettering is no longer extruded so it's easier to get in and out of the pack too. It doesn't snap shut, so I expect to use a small bit of silicon to seal it up and am contemplating looking for some really flexible clear silicon to really make it water resistant!

I've got 6 colors available to me but got two colors to start. Here's the red, this is a laser sintered material and is strong but still a bit flexible. It's got a nice matte finish.

Red Case

same in white but this is a very smooth, shiny material. The detail is really nice, but it's more expensive and heavier.

white

This gives you a feel for the 2 parts of the case, and the size relative to the board.

2 parts and board

Edited by wizardofoz on 12/30/2012 16:34:31 MST.

Stuart R
(Scunnered) - F

Locale: Scotland
Re: Project: 4oz 1A USB Charger on 12/31/2012 05:23:16 MST Print View

As I mentioned on page 2 of this thread, the big problem with a standard voltage converter is that there is no limit to the amount of current it will try to draw from the solar panel. If the combination of panel area and incident sunlight is insufficient to provide the power demanded by the load, the voltage converter will short circuit the solar panel and almost no power will be delivered.
Large commercial instalations avoid this problem by incorporating an electronic circuit (usually a microcontroller) which performs Maximum Power Point Tracking - so the panel output is always maintained at the voltage/current that provides maxumum power from the available light.

MPPT diagram

I have designed a simple modification to a standard LM2596 regulator circuit that will perform a simple form of Maximum Power Point Tracking. Parts are on order and I'll start a new thread when I have something to show.

Edited by Scunnered on 12/31/2012 05:31:27 MST.

Wizard of Oz
(wizardofoz)

Locale: New England
MPPT Idea on 12/31/2012 06:23:19 MST Print View

Definitely post the thread link here, I've very curious to see what you come up with. MPPTs are usually used in very large arrays and require a secondary conditioning step because they inherently vary the output voltage, and we obviously need a fixed 5V output for USB devices.

"If the combination of panel area and incident sunlight is insufficient to provide the power demanded by the load, the voltage converter will short circuit the solar panel and almost no power will be delivered" So if the panel and sunlight is insufficient for the load, how will the MPPT find the missing power? The problem in this case is lack of panel surface, right?

I've looked at this option (such as the SPV1040), but found greater efficiency with a step-down converter.

Keep us posted on your progress!!

Stuart R
(Scunnered) - F

Locale: Scotland
Re: MPPT Idea on 12/31/2012 07:23:11 MST Print View

"So if the panel and sunlight is insufficient for the load, how will the MPPT find the missing power? The problem in this case is lack of panel surface, right?"

Yes, MPPT can't find power that isn't there, it can only deliver the maximum power that is available. It does this by controlling the output voltage/current, so in the case of a USB output, the voltage will drop below 5V. From wikpedia: "A USB charging port supplies up to 500 mA at 5 V, up to the rated current at 3.6 V or more, and drop its output voltage if the portable device attempts to draw more than the rated current." so dropping the output voltage is permissable. Whether an i-phone will accept that is another matter. However, I was thinking more in terms of charging AA NiMh directly and MPPT would simply have the effect of varying the charge current.

Bob Gross
(--B.G.--) - F

Locale: Silicon Valley
Re: Re: MPPT Idea on 12/31/2012 13:56:27 MST Print View

"charging AA NiMh directly"

That also gets a little complicated since different NiMH cells require or tolerate different charging voltages, currents, and time. You want to consult the manufacturer's specifications for cells of this type, but in general you want to get a charging current that is approximately 5% to 10% of the cell's maximum output current. In other words, you charge the cell at 10 times or 20 times slower than you can use up the charge. Some people try to charge the cell much faster than that, and they toast the cell chemistry. Not recommended.

--B.G.--

Richard Cullip
(RichardCullip) - M

Locale: San Diego County
Re: iPhone5 success at last on 01/08/2013 13:46:03 MST Print View

As best I can tell, my first PowerFilm panel was underpowered and wouldn't charge my iPhone5. I was curious enough to find out why, so I bought another PowerFilm panel and this one works. Wired up to Jay's neat little circuit board, this new panel has enough power to charge my iPhone5. Today, in the noontime bright winter sun in San Diego, my iPhone5 went from 89% charge to 99% charge in 30 minutes with no problems. It never went thru the low voltage shut-down cycle that plagued my first setup.

The big difference in the two panels is that the first (bad) panel has 17.65 volts with no load. The second (good) panel has 20.5 volts with no load.

During testing, the good PowerFilm panel and Jay's circuit board had 4.95 volts and .471 amps thru a 10ohm resistor and 4.95 volts and .097 amps thru a 50ohm resistor.