iSolar - Charge your gadgets & iDevices

iSolar

Back in Dec. 25 2009 i published this concept on Youtube:
https://www.youtube.com/watch?v=gT6Lsl9aaHc










Back then i was clueless when it comes to 3D printing.. i had no idea that some day i could design it and make it a real thing..

Actually that can be said for many of my other ideas and concepts which you can see on my Youtube channel and on my Accessories for Apple's products section on my shop.


So, the idea is simple - 4 small solar panels (dealextreme.com) each producing 5.5V & 130mA connected to each other in parallel to produce a total of over 500mA - which is basically the amount of current you get from any regular USB on your PC - only this power comes from the Sun - free & saves the environment.

As you can see on the concept video - its compact , swivels to open and close , fits in your pocket easily, you connect your USB cable in the middle and start charging your gadgets & Apple's iDevices immediately
- meaning there is no internal battery that needs to be charged for 10 hours.. before you can use this solar charger
- just point towards the sun and charging begins immediately.

Also no fancy electronics - any one with a bit of soldering experience can do it.


Ok, so i had in mind to publish this DIY project on instructables.com and perhaps drive traffic of Do IT Yourself enthusiasts to shapeways..

But that can wait - the following print came a little bit fused ..

The first swiveling part is OK yet the others were fused to the base though 0.5mm gap was used - so its back to the drawing board to either increase the gaps to 0.7mm or redesign it from scratch so each panel holder is assembled manfully one on top the other - then the last part , the USB "cork", sits on top all and closes the unit.










Back to the drawing board - will update this thread.



Cheers

Great concept!

Some advise - any part of a PV panel that is shaded limits the current... I see that the hinge should open fully (so the hinge area of shading wouldn't be an issue), what I'm getting at is that the unit would need to face the sun directly for no panels to be shaded.

I had a feeling you'd be the first to comment

Each panel holder has a swiveling path (see on the java 3D viewer) which unfortunately because of the fusing only the top one can be swiveled all the way in 90 degrees increments - this puts each panel clear from the one below - no shading none what so ever - and therefore zero current lose.

lol

I already mentioned that I understand the fusing, so the hinge area wouldn't be the issue. I'm saying is that unless the unit is square to the sun, an angle of shadow would go from one frame to shade part of another another panel... partial shading is bad for a PV panel and causes output drop... see how accurately you can get the frame not to cause any shadow 'as-is' and you'll see what I mean. - A RedRok solar tracker might come in useful

"A RedRok solar tracker"... why stop there?.. (no pun intended)
I'll add also a tiny servo and make it like a 007 movie prop


It is after all a pocket solar charger - if the sun inst directly in high noon on top of you , you can easily adjust the angle.
Place it on any surface with the best angle towards the sun.

Btw, It would take 2.5+ hours in direct sun light to charge an iPhone fully. (geographic areas varies)

Go the whole way... panels & tracker mounted on a hat... charge on the move

Still a great concept

lol

Maybe you need to use a bit more force on it to get the parts to move? I had the same thing with a print some time ago.. when I saw it, it looked like it fused but using some more force to make the hinges move, they were just stuck with left over material

I'm not a novice..

Even with a sharp blade i couldn't separate the parts.

They were really fused.
The weird thing is that the first part was loose.

This example make you wonder why Shapeways human reviewers are strict when it comes to abiding to material printing rules but not the other way around such as :
model could fail for "hinges might fuse..", "gap needs to be bigger for this material".. etc..

Just a constructive thought.. Shapeways team.

That would probably extend the human side of it, which is probably more expensive than the printing side. The longer you need a human to review it the more labor you have to pay, and will be added to our material costs

It's quite surprising to hear that the parts have fused even with a 0.5mm gap. Have the 'disks' fused to each other or have they fused to the central 'bolt'? What orientation was the part built at?

strangely enough they were fused to one another as well as to the "bolt"

on another of my concepts the AC key chain charger for iPhone the swiveling part that holds the 2 AC metal rods which also had a 0.5mm gap - this part arrived stuck but i put a little pressure with my finger and it got loose.



The quality print is excellent, no "low resolution" issues as posted recently by others - so i'm confused as to why they were fused.

As cool as it is to have the whole thing printed as a whole, you'll get much better fit and no danger of fusing if you print the parts separately and plug them together afterwards. I'd still go for 0.1-0.2mm clearance, as 3D printing is not always that precise and it might be difficult to move if it's too tight.

check out this thingy I made recently:
https://www.shapeways.com/model/207257/3_axis_camera_gimbal_f or_gopro__back_cage%3C/u%3E.html?gid=ug5911

The little twisty knob is in the same 3D file, but needs to be plugged in after printing. It's a nice, tight fit, and as it has little triangular clips at one end it snaps into place and won't fall out. I think your design could e.g. have the central bolt in two parts - one which provides the shaft for the panels, and a small one that snaps into it from the other side to hold in in place.

Yes, that's what i wrote on my first post - i will probably have to do that.

Customer support contacted me about the fusing saying it should not have happened and issued a coupon + filed a compliant with the production guys

I really thought it was my bad using only 0.4-0.5mm clearance which according to CS is way more then the minimum of 0.2 required... (?)



Still, having the whole unit as one part is what i aimed for - each "wing" has a cut off path on the shaft so each wing stops at 90 degrees increments - meaning with a slight push of a finger each wing is revolved to its designated place - creating a "sun flower" solar charger.

... oh, indeed you did say that... need to read more carefully

I don't know where you saw 0.2 mm clearance - I remember seeing 0.5, or better 0.7mm. I think though that e.g. a narrow ring will be less likely to fuse than a higher cylinder, and that it might help to reduce the "contact" area and provide gaps for the dust to get out. If you want a smooth outer look, maybe it works better to have a number of radial fins protruding from the outer ring inwards, to form the bearing surface with the inner cylinder? I haven't really tried this, but it might make it easier to wiggle it loose if it is slightly stuck. I had the impression with previous models that sometimes it's not really fused, but the compressed nylon dust is so dense that it's quite stuck. Once it's loose, the dust comes out and isn't actually solid. No guarantee that this helps, but might be worth a try...

..I also wrote about that ..
They were really fused not stuck.. i even tried a thin sharp "Japanese knife" .. but no success.


My biggest problem right now is to master the energy to go back to this project :laughing:

it is a cool idea and looks really cool to though the electronics would need to be a little more then you think. At minimum a diode in series with each cell to prevent the bright cell from breaking the darker ones. to do it properly though you really should have a buck/boost converter on each cell to make sure each cell outputs the same voltage. Also most cell phones adhere at least in part to the USB spec that requires they ask permission to get high current out before they draw it. This means you also need a micro-controller on board to except and acknowledge this request. However many cell phones also have a cheat circuit they use which detects a specific resistance on the data cables so they can tell if it is there charger without spending more money on building there chargers. I forget exactly what values are needed to get a blackberry to work. The USB spec is pretty easy to do with the parallax propeller and can probably be done with other cheaper processors also.

I would also consider dropping your design down to 3 blades or making the blades stand out farther from the body to reduce how easily the blades will shadow the cells.

PS you need 0.7mm for WSF not to fuse.

Correct about the diodes and 0.7mm for WSF .

You dont need a boost circuitry for a solar panel - it already outputs 5.5V and up to 500ma when 4 of them are connected in parallel.

The cheat circuitry to notify the iPhone's charging IC it can draw 500ma is very simple and made with 4 simple resistors and one cap to smooth the current.

You can read more about it here -

It's a bit more technical than that dizingof... as soon as the current is being drawn from the PV panels, the voltage will drop. Also reading from the page you linked too, the suitable circuit for 500mA charging is the one at the bottom of the page feeding 2.0v to the data lines. I haven't got an iPhone to experiment with, but I'd imagine if Apple have gone to the lengths of being as specific as having 2.8v & 2.0v vs 2x 2.0v for 1000mA & 500mA respectively, they may also detect for power supply current ability via voltage detection.

not bad. pretty cheap looking over my inventory i calculate.

resisters: $0.002*4=$0.008
diodes: $0.03885*4=$0.1554

i don't have any usb jacks in stock at moment but a quick search of digikey shows that USB 3 jacks are only $1.9425

A custom PCB would cost about $1. so total part cost is: $3.1059

To break even need to charge at least 4 times that so $12.42

not bad when competitors are about $100. How much is printed parts and solar cells?

edit: stop4stuff is right need to put a boost converter after all. Not to expensive say $30 minimum retail.