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jerry adams
(retiredjerry) - MLife

Locale: Oregon and Washington
Re: Re: Of or or? on 10/09/2012 08:09:54 MDT Print View

You should charge more - enough to pay for yours for example - like $60

Wizard of Oz
(wizardofoz)

Locale: New England
Re: Re: Re: Of or or? on 10/09/2012 08:32:54 MDT Print View

I like your thinking Jerry! But I'm just looking to make sure the design gets some use at this point. This is fun for me. If 40 people want these, I can do them up with the the full solar panel and all and actually charge for a final product. But I'm guessing a full up solar panel/board/ and the mini-case that I'm going to do to protect the board will be like $110 when all said and done!

George Geist
(geist) - M

Locale: Smoky Mountains
Re: Who else! on 10/10/2012 12:25:33 MDT Print View

> I can definitely assemble an extra one for you.
> I'll just ask for the cost of PCB and parts, which is about $30.
> I hope to have mine done early next week
> Who else! 1 is spoken for, 4 more available :)

Hi Oz,
I'll take one of the 4 remaining. And I'm happy to pay for
not only the PCB and parts, but your labor for assembling it.
You can contact me at gst (at) ornl (dot) gov

I was wondering if you ever had a chance to test the ThinkGeek
plug to see how it's efficiency compared?

Al

Wizard of Oz
(wizardofoz)

Locale: New England
Re: Re: Who else! on 10/10/2012 14:24:47 MDT Print View

Board 2, SOLD to George :) NP at all. 3 left to claim at this LOW, LOW price...is this how hookers feel??? :)

I didn't end up testing the ThinkGeek cigarette lighter to USB adapter. Basically since I couldn't get even a full 1A out of my solar panel, I didn't see the need to test an even higher capacity circuit. And I'm pretty happy with 90% efficiency I was able to acheive! No need for greener grass other than pure curiosity. Plus when the low light oscillation because an issues, I pretty much knew that a custom solution would be best for the device I'm charging so I'm not strobing it like a little kid standing at a light switch for the halloween party.

I'd still be curious to try it out someday for comparison!

Jack Elliott
(JackElliott) - F

Locale: Bend, Oregon, USA
Wait, wait -- I want one, too! on 10/11/2012 04:57:41 MDT Print View

P-mail sent.

Wizard of Oz
(wizardofoz)

Locale: New England
Re: Wait, wait -- I want one, too! on 10/11/2012 06:24:24 MDT Print View

You got it Jack! Thanks for all your great comments and suggestions during the design too! I got confirmation that the boards are on their way to me and should arrive tonight. I'll let you guys know when they are together and working and get some pics up too!

Wizard of Oz
(wizardofoz)

Locale: New England
Putting it all together...and so pretty... on 10/15/2012 06:10:00 MDT Print View

Bare boards made it in and look shiny and green...until I started to goop them up with flux :) They came out REALLY nice and I'm pretty impressed with the quality of the PCB House! The detail is really clean.

Here's a pre-cut pic:
Bare Board

Didn't get time to do a full assembly yet. I've got two parts that are delayed, but hope to have them early this week, and have the first one fully together on Tuesday. I did get the 'toughest' parts on the first one though, you can see just how SMALL the ICs are. The pains we go through to save weight... Everything soldered on really nicely since the board was so new and tinned.

I didn't clean it yet cause I want to do that all at once, but here's the first partial board!Partially Assembled

Jack Elliott
(JackElliott) - F

Locale: Bend, Oregon, USA
Ain't it nice on 10/15/2012 07:20:03 MDT Print View

Ain't it nice to get your board back from the house, and start putting parts on it? After staring at the board design on the monitor, holding the real thing in your hand is quite rewarding. Even better is powering it up and seeing no smoke!

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

Locale: Silicon Valley
Re: Putting it all together...and so pretty... on 10/15/2012 12:12:48 MDT Print View

Many years ago, it was not so easy to buy complete printed circuit boards like this one. For one thing, everything was through-hole soldered then. Now I see this one is part through-hole and part surface mount. That makes it harder to stuff the board.

I used to make my own single-sided boards from scratch. Those were the good old days. Ahh, yes, the smell of hot ferric chloride solution...

And then, you want to think about weatherproofing this thing. We used to use a full potting compound to make the entire thing into a plastic brick. That is probably unnecessary now, but a clear spray that hardens might be useful as long as it doesn't add much weight.

--B.G.--

Matthew Naylor
(mrnlegato)

Locale: Mid-Atlantic
Re: Re: Putting it all together...and so pretty... on 10/15/2012 12:16:30 MDT Print View

Bob, Are there any specific spray products that you recommend for this kind of thing? And does that lead to any problems with overheating?
Matt

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

Locale: Silicon Valley
Re: Re: Re: Putting it all together...and so pretty... on 10/15/2012 12:29:27 MDT Print View

There probably are some spray products, but I don't know the current ones.

When we were less sophisticated, we would simply paint on clear fingernail polish to any exposed conductors.

If you had components that were radiating a lot of heat, then the coatings can become a problem. However, I'm guessing the high efficiency means that there isn't that much heat radiated, so coatings wouldn't be a big deal. If you do full encapsulation, it can become a big deal. I did that badly once about forty years ago, and I had a smoking hole in the middle of the encapsulation plastic.

If you get too much protectant gooped onto the circuit, then you might have a maintenance problem. You can't easily hook test clips onto it anymore.

I guess it all boils down to the environment that you intend to use it in. Maybe this thing needs to reside in its own cuben fiber bag.

--B.G.--

David Thomas
(DavidinKenai) - MLife

Locale: North Woods. Far North.
Waterproofing on 10/15/2012 16:13:17 MDT Print View

How about the spray version of Plasti Dip?

http://www.plastidip.com/

The can I have says, "flexible, won't crack" "insulates electrical shock, vibration" "provides non-slip grip" and "resists weather, chemicals, impact and abrasion".

That's been my experience with it. I've used multiple coatins to provide more cushioning on tool handles, but you can make it even thinner by adding xylene or toluene.

I concur with Bob's thoughts on overheating. Definitely a consideration, but with a high-efficiency circuit, there's not much power to disapate.

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

Locale: Silicon Valley
Re: Waterproofing on 10/15/2012 17:17:32 MDT Print View

What David said about flexibility could be important.

If you had the wrong stuff, when it dries it might "force up" a surface mount component. With flexible stuff, it wouldn't have such force.

Think about it the other way around. If you got the circuit cold enough (high in the mountains), it might have unpredictable problems with the cold. But, with an extra layer of waterproof insulation on it, the cold problem can't last long.

--B.G.--

Jack Elliott
(JackElliott) - F

Locale: Bend, Oregon, USA
RC guys face the same issues on 10/15/2012 23:06:14 MDT Print View

This might give some ideas for weatherproofing.

http://www.rccrawler.com/forum/electronics/26785-water-proofing-electronics-14.html

Steve G
(sgrobben) - M

Locale: Ohio
Re: Waterproofing on 10/16/2012 06:51:18 MDT Print View

I have successfully used "hot glue" but am not sure how it compares in weight to other solutions.

Wizard of Oz
(wizardofoz)

Locale: New England
Success!!! for 'green' solar! on 10/16/2012 12:31:08 MDT Print View

I'll definitely check that site out Jack. I think I agree that Plasti-dip is probably a good spray on candidate. It wouldn't affect the components and can be easily removed if necessary. Heating up of the whole assembly isn't a concern, but localized component overheating can cause degradation and short life (inductor), so I don't think I'll go that route personally. I think a bit of silicone based dielectric grease (like you use on spark plugs and bulbs) is all I'll use to keep corrosion down. That way I'll always have access to the components and allow heat to 'get out'.

I remember etching boards from scratch :) and then adding jumpers when your mask didn't quite hold and you got a questionable trace! This board came out better than I expected, and most of the credit is due to the quality pads and soldermask. This was really fun and useful project for me. I learned tons and have something I can take with me on all my long excursions, so thanks for all the inputs and help.

Here's the first board! Lovingly called my E-Lite Gear (pronouced EE light). Works like a charm on both .5A and 1A mode.
Done Board

I had a little issue with the momentary 'test switch' being a intermittent just after I cleaned the board, but it's must have just had a little cleaner or oxidation on the contacts, cause it's working great now. Actually I had a short-lived gulp when I plugged it in because I forgot that the same circuit that protects it from oscillation in low light, also delays the turn on for about 12 seconds as the cap charges up. Green is good, and this is no exception to the rule! Lighted

I'm going to do some more testing this week to make sure everything as expected and then I'll start putting the rest of the board together. I'll get in touch with those who've asked for one in the order they made the request as I get them done!

Next step, (forget all this talk of sprays and sealants) I'll design a snap together case for it, and have it 3D printed! A friend of mine just has something done in stereolithography and it's SWEET! so I figure all this effort should culminate in an awesome little case with the extra .2 oz I have :) Not sure I can get it done before my Nov trip, but I can try...

Jack Elliott
(JackElliott) - F

Locale: Bend, Oregon, USA
Looking good on 10/16/2012 16:48:28 MDT Print View

The project seems to be coming along swimmingly, and looks like you'll have something to take on your GC trip. Once I get my copy of the board I'll set it with the rest of the backpacking gear for next season (gonna start snowing here and Jack don't backpack in the snow, preferring someplace warm and comfortable, like a pub, under such conditions), and in the meantime start looking for a solar panel array for something less than the $120 (or so) that the one you're using lists for.

Wizard of Oz
(wizardofoz)

Locale: New England
Powerfilm Solar Panel on 10/18/2012 07:15:26 MDT Print View

Jack,

I'm using the 5W Powerfilm, P/N F15-300N. It's $76 bucks on Amazon shipped with a couple buy options. If memory serves (it was in an early post), it's 3.2oz stripped down. Please let me know if you find something cheaper, or more watts per oz! I used these guys in the past, so they were easy for this project. But I looked for other options and didn't come up with much that could beat it! I'm hoping someone will breakthrough with an even higher efficiently/weight panel soon and I can keep my project improving by just swapping out panels!

Jay

Wizard of Oz
(wizardofoz)

Locale: New England
the case for a Case on 10/19/2012 09:19:01 MDT Print View

So I've got two weeks before the trip that started this project! and now that i have my board done and working. I need to finish the thought and protect it, right. You guys have thrown out lots of great ideas, but I'm old fashioned and don't like slop all over my creation, so I'm going clamshell style.

Case

This way I can, if needed, still get inside it. And although it won't be waterproof, I wasn't planning on taking it swimming.

I'm hoping to get this 3D printed quickly (times a ticking), so let me know your thoughts or suggestions! I'm looking at i.materialise.com to do the job, but I'm waiting on a quote now. And in between all this, I'm trying to get some extra boards made for all those folks who've asked for them!

Richard Cullip
(RichardCullip) - M

Locale: San Diego County
Re: the case for a Case on 10/19/2012 09:42:08 MDT Print View

That's a cool looking case. Should do the job for you. What material do you plan to make it out of?