RossiRay

supplement or charge their plane's flight pack with an on board solar panel?
How would you do it?
Seems to me you could save weight by flying a smaller battery that is charging when you are not flying.

mvigod

this is a great idea and certainly do able. Anybody have any experience or suppliers for such a thing? If not I might look into it for kicks..nothing like a nice gentle solar trickle charge on all day at the sunny field.

mumblety-peg

My Feedback: (3)

I've read of people using Solar cells for Eflight. So this may be a workable idea. Unfortunatly, I dont' recall where I read it. Try a search at the ezone. www.ezonemag.com

Mum

Jazzy

There is a solar cell setup for charging a glow starter... somewhere.

Solar cells would be great for an endurance flyer or a glider. Might just be added weight for a sport plane. The important thing would be to find out the size and output of a set of cells. Figure out how many you would need for a decent voltage and output current and then determine if you have enough available surface area on your aircraft. Areas such as the top center section of the wing and the top of the fuse would be good places to start.
Radio interference?

Rodney

Unfortunately, the weight penalty is much to great to have an efficient onboard solar system unless you have a really BIG bankroll. It is feasable though to keep your 12 volt big battery charged on the ground and then use it to keep toping off your flight packs between flights.

mvigod

I was thinking not just onboard depending on how feasible but also offline when on the ground to hook up an external solar panel to the plane to trickle in some extra juice at the field on a sunny day...

mumblety-peg

My Feedback: (3)

I still think charging a flight pack with solar cells on the wings may work. At least judging from the my very short web search. I see some flexible cells for about $25.00. Weight is measured in grams. Less than 8 grams per panel. Size isn't listed, but a cell would be an ez fit on a 40 size wing. Output is listed as 100ma at 6 volts. I'm a little concerned that no specs are listed on the site though.

Here's the link http://www.allthingssolar.com/index.htm

The idea of not needing to charge my flight pack is appealing. I'd imagine an onboard batt. monitor would be a must.

Mum

TopShelf

My Feedback: (4)

There was a blurb in MAN(I think) some time ago about using solar cells. The particular application was for a glider but the technology is out there. I'll see if I can find the issue.

Rodney

Mumbletypeg, I just checked out your solar cell source and was pleasantly surprised. If the weight is as advertised, it would be very easy to put a 6 volt altralite panel on the top of your wing (perhaps under transparent covering) and hook it directly to your onboard 4.8 volt battery thru a diode (to prevent the battery from discharging thru the solar cell during low light conditions). I believe the cell would be self limiting so would never overcharge your batteries. If you try it, let us know how it works out. Good luck, Rod

Gordon Mc

My Feedback: (11)

There are a couple of guys in our club who do this. One of them browses RCU, so you can ask him. His user id is "tampipes".

Regs,
Gordon

Jazzy

I'm sorry. I just went back and read the thread starter. It says "...while not flying..."
Being that I like to tinker, I just might be adding solar panels to my field box given research above.
Great job folks!

mvigod

Anyone who finds out more or experiments please do post what your results are...this is a pretty cool idea to keep the "tanks" topped off in between flights or possibly all the time if onboard is feasible...I've always been fascinated with solar cells and energy since I was a kid and this would be very interesting.

Jazzy

Aspects of Solar Energy and wind driven generators have reached the public sector. The technology is increasing at an incredible rate for two main reasons: 1.) It's FREE. 2.) It's pollution free.
There are other bonuses associated with using these forms of power generation.

For those of us who can't go anywhere without some form of RC with us, Solar Energy is a fantastic power power source! I am one of those people! A couple years ago I went on a canoeing/camping vacation with some friends. There aren't any 120V receptacles in the mountains! Solar Energy would have been perfect to keep my 12V deep cycle trolling motor battery on constant charge! (It was my source for charging battery packs).

Jeff

lnorris

My Feedback: (1)

I have been thinking about this idea also. My thought was to take a couple of these babies for eflight.

http://www.radioshack.com/product.as...Fid=980%2D1425

They are .45V/1000mA. Basically mount them inside the wing. Cover the wing in clear monocote.
I found a web page (http://www.cnde.iastate.edu/staff/mg...olarplane.html) awhile back that tried this and found that climbing was a pain unless the sun struck the wings just right. I figured then if you also included a low mA/higher voltage battery that would suppliment/charge that might smooth things out.

BTW, I also saw where they are developing spray-on solar cells (http://www.sacbee.com/content/news/s...-2201460c.html). Now THAT would be an interesting looking plane.

mvigod

Is it possible to hook this one up at the field to the rx battery to charge it up between flights? 6.0V at 50ma

http://www.radioshack.com/product.as...Fid=980%2D0879

Jazzy

I don't see why not... I'd use a diode though...
I just might have to get me some of those!

tomgtv6

My Feedback: (1)

RCM and MA magazines had construction articles on this idea in the early to mid 80's. one was for charging the other had built in wing of glider through clear monocote for charging and topping off in flight. Also at autozone there was a panel for charging motorcycle 12v batterys when the bike is sitting a while; add resisters and there you have it.

ilyar

I don't think you need a diode... because a solar cell already is a diode. (don't quote me on this though) However, if you install enough solar cells to run the motor, would you need some sort of charging circuitry to prevent the batteries, radio, etc from getting fried with too much current? I saw this on another post by JimTrainor

> There is a circuit floating around the net:
> http://www.uoguelph.ca/~antoon/gadgets/solar1g.htm

> The data book for the Max639 is more useful, and includes
> some simple examples of 5V regulators using a 5.5-11.5 volt
> source.
> http://pdfserv.maxim-ic.com/arpdf/MAX639-MAX653.pdf


Here is another site that sells flexible solar cells. I was thinking of adding these to my glider to supplement battery power and allow me to put a smaller battery onboard. http://store.sundancesolar.com/powulflexthi.html
I might need a lighter glider (with more wing area) for avg rate of charge to be greater than the rate of discharge. Does anyone know whether a brushless motor would significantly lower power consumption?

Anyway, would love to hear some insight from anyone that has done this successfully.

nollie

From the Graupner website:

Graupner Order-No. 4274 "Solar-Uhu"

http://www.graupner.de/prod_en_elektroflug/4274.asp

WP SOLAR-UHU 4274

R/C sailplane model for electric drive. 6 channels. Solar E/F model for a 6-cell storage battery. Quickie with R/C installation accessories.

Product information

SOLAR-UHU is a simple, compact solar-powered E/F model plane. The solar cells mounted atop the wing charge the 6-cell storage battery at a quickcharging current of approx. 1 Amp under the action of light in the time prior to take-off and during flight. As a result of the selected NiCad/Solar cell ratio of 1:3.333, overcharging the storage battery is not possible. In addition to the advantage provided by using solar energy for charging purpose while on the go, the model sports some technical peculiarities form which SOLAR-UHU benefits fully, even when flown as a pure E/F sailplane model without solar cells. Good rate of climb with a powerful direct drive system. Wide speed range with very good low-speed flight characteristics. Good-mannered stall behaviour. Stable flight characteristics in circling flight due to 60° canted winglets. Simple, robust wing in rib construction. 2-piece wing with carbon-fiber reinforced plastic joiner. Removable tailplane. Ready-formed fuselage with detachable canopy. Prefabbed balsa empennage.

Contents of the Quickie kit
Quick-build plan including R/C installation, illustrated building instructions, with detailed description of the practical application of solar cells, in Dutch, English, French, German and Italien. Ready-formed PERFEKT fuselage, die-cut and printed balsa and plywood sheet, pine mouldings, contour-milled balsa leading edges, extruded canopy, wing joiner of carbon-fiber reinforced plastic, trim sheet, miscellaneous parts and R/C installation accessries.

R/C functions Rudder
Elevator Speed control

Specification
Wing span 1880 mm
Length, o. a. 820 mm
Wing area 30 dmē
Aspect ration 11
Tailplane area 4.5 dmē
Total surface area 34.5 dmē
Weight, ready to fly 1250 g
Total surface area loading 36 g/dmē

ChuckAuger

My Feedback: (12)

I had a buddy that did uplink installs on remote sites, he gave me a "surplus" solar panel, it's like 20v and a couple hundred milliamps..I'll look at the brand and rating when I get home. My intention was to make a trickle chargler with taps for about 11v for TX and 6v for RX, but I'm using more 5 cell stuff now so maybe 7.2 or what ever. I have a field charger, a 12V battery in the flight box, and power from the topper shell to run the charger/electric starter..but I'm like Marc..I just like the appeal of a solar charger. Might be nice at a larger fly-in where I couldn't run a cord from the truck...make a 13.8V out for flight box trickle. The field charger sure puts a hurt on the motorcycle battery on my flight box.

But it seems like I recall this panel was a couple hundred bucks new, not sure that even if I worked something out if it would be something that anybody else would want to copy

theox

Solar field battery charger:

http://www.rcgroups.com/forums/showt...hreadid=116909

ChuckAuger

My Feedback: (12)

Thanks for the link, theox.

My panel is not very big, a Solarex MSX-10, 10 watt.

17.1V at load, .58A at load.

This is half the size of the guy in the link, but for $37 I think I will just see how much it will do.

r1morris

My Feedback: (1)

In the early 90's while attending the QSAA event in Las Vegas I purchased a small solar power ni-starter battery charger. It was manufactured by a small California company called Airborn Solar Technologies. As I recall they also made an in-flight battery charger setup for the radio packs.
I have owned the little charger for over 12 years. It will charge up a Ni-starter that will kick the glow plug off in about 20 min.
To date I have never had to plug in any Ni-Starter with a wall type charger. As far as I can see other then breaking the thing somehow it should last for many more years. Makes me wonder why such products never seam to catch on.

elevator_up

I've been thinking of doing this last couple of years just for fun but never got around to it. I was going to place 2-3 of the 5-6V/70ma panels in parallel on the turtle deck as a flight power supplement. Aside for the fun of it, maybe at 200ma it could be just enough to help you stumble in on a sunny day if your pack has a problem (I'm sure some purist will find a problem with idea, but it's for fun!). I looked at the radio shack panels but found them too bulky compared to others on the market. There are lots sites but one that I like is solarbotics, ie www.solarbotics.com. They make fun things and small solar powered robot toys, plus other more serious items. There was even a forum connected to the site last time I was there. I'll bet one of the members there has played with this idea. I look forward to hearing what others have done or tried.

mvigod

I would love to have an article on this for the RC Universe magazine if anybody is game.