Author Topic: circut for my lighthouse (Read 4206 times)

Aaron · « **on:** September 27, 2005, 01:53:17 AM »

hello,

i've been working on this lighthouse sculpture for a few months now and i'm almost finished. the idea is that it is a working lighthouse, self sustaining, on a smaller scale of course. this is the first of hopefully many to come.i have been through a lot of experimentation (a years worth) as far as what to use as a power source and in the process converted a induction motor, made one dual axial flux alternator and one single. i ended up using a tape drive motor as that gives me the most volts for my low rpms. i have it hooked up to a timing belt which gives me an 8 to 1 ratio. i know my design isn't ideal for this application but its what i'm using.

on average (a light breeze)i'm getting about 2-3 volts. today, my multimeter was hanging out at around 8vdc. my goal (and it seems very difficult for me to find any help here) is to charge some batteries all day and at night use that power to light as many LEDs as i can. i know that i need a diode to keep the juice from going back to the motor and i think i need a voltage regulator so i don't put to much juice in the batteries all at once. but then......i've seen those battery holders but where are the leads out. i must also need a photo cell on the circut and then a resistor to save the LEDs. could anyone help me draw this up so that i can buy the stuff and install it? i have a good friend who's helping me with the electronics, he only needs some kind of schematic. this is one circut that i want on the lighthouse but there is also another...........it would be nice for it to act as a wind gauge, either lighting different colored LEDs at different voltages or getting brighter as the wind increased.

any help would be greatly appreciated.

thanks,

aaron van de kerckhove

apvsculpture.com

nvmike · « **Reply #1 on:** September 26, 2005, 09:14:10 PM »

I am no help with the wiring but I like the lighthouse. I hope someone can post with help on charging batteries and circut for leds.

DanG · « **Reply #2 on:** September 26, 2005, 09:29:17 PM »

For sheer lumen : watt ratios the LED leaves alot to be desired, compact fluorescent lighting betters in performance. 2 watts can give 150 lumens from CFL - 2w LEDs w/ luxeons maybe half that. That said, the LED will still appear brilliant since its so compact.

Since you are rationing power make sure you research and find a very low forward voltage drop schottky diode to match your power output, can save .3 volts 24/7, well every minute the wind blows. Also, over size your conductor cables - cut 2% loss to 1% etc..

Tom in NH · « **Reply #3 on:** September 26, 2005, 10:04:48 PM »

That is an awesome sculpture. I can just see them lined up along the side of Lake Michigan in Chicago, or on the waterfront in SF or Boston. Didn't your mamma ever teach you not to stand on a ladder like that?! Keep up the good work. --tom

David HK · « **Reply #4 on:** September 27, 2005, 06:37:05 AM »

What a wonderful piece of art. It must be worth several thousand US$ at least. I wish you luck with it and hope some lighting expert can solve your problems.

What is the object to the right of your step ladder?

Dave HK

ghurd · « **Reply #5 on:** September 27, 2005, 07:40:26 AM »

Hey Aaron,

I hope that is not solid steel!

I can sketch out the schematics, but need more information.

Watch your hotmail account.

G-

spinors · « **Reply #6 on:** September 27, 2005, 02:01:00 PM »

For this first lighthouse, I'm trying to charge AA or C batteries that will power a few LEDs at night. I know i'm going to need a voltage regulator, so the batteries don't get damaged (and the whole circuit in general), but i'll also need a photocell that will allow current to pass through at night. My question is how i'm going to get the power from the batteries if they're hooked up to a charger? Will it just be a matter of soldering wires to the nodes? I would imagine there would need to be some kind of switch to stop charging the batteries once they are full, so the batteries are actually being used and not bypassed. These are the major components I would like to install in this first lighthouse. With light winds generating 2-3V, I would think that I can get a decent amount of LEDs to illuminate. Any ideas on what the schematic for this circuit looks like would be helpful. Thanks!

ghurd · « **Reply #7 on:** September 27, 2005, 03:51:56 PM »

Easier to think about it like 2 circuits.

One to charge the batteries.

One to operate the LEDs.

The cut in speed is too high.

Gear it up to maybe 20:1.

It must exceed at least 7.5V open circuit to have this work very well at all.

And 15V open circuit would be a lot easier to make it work reliably.

But an hour or 2 a day would be enough to run quite a few LEDs for quite a few hours.

ruddycrazy · « **Reply #8 on:** September 27, 2005, 05:35:38 PM »

Hiya Aaron,

That's an awesum bit of art their mate, my missus would string me up on top of if I made something like that. Anyway what might be the go for your light is a 3 watt Lambertain style LED they have a forward voltage of 3.6 V and a constant current of 850 mA. www.oatleye.com have the led's and also a driver electronic kit so driving a 3 watt led from the kits will draw 12 volts @ 300mA. The part number for the kit is (K207) and the part number for the 3 watt led is (E3WL). Now also order a colimating lense for them and I would suggest the 25 degree one (ELM25). Now the total cost of these item would come upto $29.10 in Oz dollars plus shipping. This will output a light better than just about anything else for the price and if I can help out in any way just call on me as I'll be glad to help out.

Cheers Ruddy Crazy

ghurd · « **Reply #9 on:** September 27, 2005, 06:12:51 PM »

I do not buy into the high watt LED hype. Not at all.

They are not efficient like their little brothers.

At the 12V numbers...

For that kind of power, I can run 50+ 5mm White LEDs at near max power and make more light. A lot, LOT, LOT more light. With the same power (that needed said twice, lol).

Or 120, maybe 150, 5mm Red LEDs.

For about double that power, you can run a 12V 7W CFL!

I won't even go into the high failure rate of the high watt LEDs...

G-

Aaron · « **Reply #10 on:** September 27, 2005, 09:33:00 PM »

hey,

many thanks to ghurd for the email. here are a couple more shots i took today. the first is looking up from the bottom and the second a closeup of the pulley system (timing pulley), geared 8 to 1. can't do any better that that on this one, don't have the space or the tork. the lights and circut will be mounted on the shaft and turn with it. i really only need to charge some AA batteries (or something) to light a few LEDs at night, and as ghurd suggested have any over charge light additional LEDs. this thing has been putting out 4 volts with some 8-9 volt moments on a daily basis. it does 1.5-3 volts in a light breeze. i think that in a storm it may hit 20 volts so i want to be able to utilize any power it may put out. how might i hook this circut up? thanks,

aaron

ruddycrazy · « **Reply #11 on:** September 28, 2005, 03:40:35 AM »

Eh Ghurd,

One thing about you americans anything you don't know about you just bag it!!!

As far as high wattage LED's failing it's only because your not powering them correctly. They state in the specs 100,000 hours life span and they will attain that if used correctly. As far as 5 mm led's being brighter than a 3 watt luxeon you better get a new pair of glasses. I use 5mm 20,000 mcd led's for basic lighting on some of my machines but comparing the output of them to a 1 watt luxeon is chalk and cheese. I also use 8mm 12 lumen led's that rate at 80mA and even if I hooked 10 of these up they still won't come close to the length of light put out compared to a 3 watt luxeon. Like I say to run a high output led they firstly need a constant current and secondly they need a decent isolated heatsink so without those 2 important things you'll blow 1 after the other then end up calling them crap.

Peppyy · « **Reply #12 on:** September 28, 2005, 05:43:39 AM »

What a great looking machine!

I would concider a couple things before deciding on storage voltage and load. I have had really good luck with small 6 volt sealed lead acid batterys in some yard lighting I have done. I am using various led's and small solar chargers for fountains and spotlights and find that having extra capacity in the batterys is nice when the sun don't shine for a few days.

I am using these http://www.surplusshed.com/pages/item/m3009.html to charge the batterys. I have used 3 types of batterys and they all seem to work well. the most efficient ones seem to be some 6 volt camcorder batterys I found used on e-bay for about $1 each. Duracell DR11 I think. The controlers have a cad cell for automatic dusk to dawn and low voltage shutoff. I have seen just the controllers for about $3 and have a couple if you need one. Since these are desinged for an incandecant lamp they will run a bunch of led's.

Do you want this to be really blindingly bright and seen for miles or just an eye-catcher?

There are hundreds of different types, colors, and viewing angles of led's. I have a nice big collection now and I have to say that for eye-catching, the red-blue flashing led's I have can't be ignored, followed by the full color change led'd. When used with a dimpled reflector they really stand out and since the controlers are built in to each one they change at different rates.

If you want it to more closely resemble a lighthouse light it should revolve. The problem with that is you would either need a chase light circut, (Efficient and expensive) or a mechanical unit,(Power hog and unreliable). I would try 4 colorchange led's 90 degrees apart shining on a funnel shaped reflector first and see if it gives you a good effect.

As far as charging goes, I would run a simple voltace regulator that only allowed maximum charge voltage for the battery but I am no expert on charging batterys.

Take this all with a grain of salt and let me know if I can help.

Bruce S · « **Reply #13 on:** September 28, 2005, 09:57:24 AM »

Aaron;

I have a couple ideas for a circuit, but would like to know if you are coing to have the batteries close to the unit or maybe inside of it?

If the batteries and circuit are inside this beauty, then I would go with the NiCd type AAs. These will be able to withstand the freezing cold weather better than Lead-acid and has longer twice the cycle life than NiMHs.

The photo-cell you can get from an old lawn light. These units can be found either new even a wally mart or K-mart pretty cheap. Cheaper if you find them at a Goodwill store.

The solar connection can be used for a backup for when the wind isn't working out. And the charging circuit is already built for you. This circuit will also keep the batteries from discharging through the charging circuit. For extra long lighting times merely parallel the AAs.

If you need AAs let me know I have about 40 1.2vdc @600ma in my office. I get'em near free, and build reading lights using LEDs ( parranh's) and a couple of the AAs fully chargered kept my last one on for days.

I'd only need to the shipping cost back.

For a good self-built regulating charge circuit, I would go with designing one that is more of the buck & boost type. These can take a range of voltages and output a constant so you don't have to worry too much about over charging the batteries.

I'm curcious about the statue on the right side too.

Hope this helps :-))

Cheers

Bruce S

Aaron · « **Reply #14 on:** September 28, 2005, 07:42:46 PM »

thanks to all for the suggestions. bruce s , i'm not sure i have the right situation for charging batteries here as the average volts coming out are around 3 with sudden spikes up to 8 or 9 vdc at random. looks like we are settling on building a led string, so when more volts come through more leds light up. i'm still interested in charging batteries but unclear on the details. as far as the other sculpture in the picture, you can see it even more unpainted here.

http://www.apvsculpture.com/In-Progress

aaron

Aaron · « **Reply #15 on:** September 28, 2005, 07:47:24 PM »

cheers ruddycrazy,

i'm going to check out those lambertain leds for my next piece, this one doesn't put out 12vdc often enough to work out.

aaron

Aaron · « **Reply #16 on:** September 28, 2005, 08:38:19 PM »

bruce s,

the batteries, circut and light will be mounted on the shaft and turn like a lighthouse. it almost sounds like you know of some ready-made solar-battery charging unit that i can use. but what about the irregular voltages?

aaron

spinors · « **Reply #17 on:** September 29, 2005, 02:47:12 AM »

I'm jubal, aaron's friend. We are going to use progressive lighting of the LEDs for this first lighthouse. I've used voltage regulators (VR) like the one shown to regulate small voltages (NTE956 1.2-37V). But i've never powered anything using a dc motor. However, using a VR properly requires an added 3V for the system, in this case then, 6V to power 1 LED. ive' found that even without the regulator, it is taking above 4V to power 1 2.2V LED using a 24 Ohm resistor, which is expected, but not desired. If I wire the LED strings so that they are only protected by resistors, it still takes about the max voltage we generate from the mill to power 4 LEDs approx 12VDC. This may be acceptable, but it will lower the lifetime of the single LED string (Figure 1 without the regulator). How would I spare this poor LED without the regulator? I was thinking of just using a higher wattage resistor, but remembered it won't protect the LED from any increased voltage.

Getting back to the voltage regulator, I was unable to get any light from the circuit in LED 1, I think because I used tantalum capacitors instead of electrolytic (I took a chance, that's all the store had), but I wanted to verify that. But mostly I need to verify the rating on the caps. I'm using C_1=100 microFarads and C_2=10 microFarads (both which should be electrolytic, I think). And secondly I am wondering if there should be a C_3=.1 microFarads of ceramic or polyestor material. If these circuit diagrams checkout, and all I need to verify is the rating and type of component to use, then these strings will be connected in parallel. But it won't help the fact that it will require so much voltage to light the single LED string in Figure 1. Please advise, thank you.

ghurd · « **Reply #18 on:** September 29, 2005, 07:50:04 AM »

I never more than played around with high power LEDs long enough to not care for the efficiency.

The failure rate I was considering is in commercially produced devices. Maybe nobody is doing it right. I didn't design any of those.

The 100,000 hour rating is good for colored, standard type, LEDs. Not white LEDs. The phosphor in white LEDs degrades the life to more like 20,000 to 35,000 hours at best. Some manufactures have revised the life expectancy of white LEDs to 5,000 to 10,000 hours. I saw one manufacturer list 2500 hours. I expect the high power LEDs, even the little spyder LEDs to be even less. Heat decreases the life of all LEDs, and high power LEDs are hot.

I didn't mean a single 5mm LED is brighter than a 3W. I meant an array of 50 or 100 5mm, using the same total power as the 3W, would be brighter.

The high power LEDs have reverted to old, less efficient, technology, to help get the heat out of them. That's pretty much how they can take so much power.

As far as efficiency.

A regular old bulb makes 12~15 lumens/W.

The best sorted and ranked LEDs, commercially available, are about 30 to 35 l/W. Nichia has one ready to come out at 37.5 l/W.

The stuff from the 'surplus' catalogs is not going to be anywhere near 30 l/W, maybe more like 3 to 10 l/W.

CFLs make at least 50 l/W, usually considerably more.

The cream of the crop, sorted, high power LEDs make about 25 l/W. Less than half a standard CFL.

I expect the standard type supplied to a hobbiest to be maybe 18 or 20 l/W. An increase of 50% and it will catch up with LEDs I can get right now.

For a lot of efficient light, CFLs win hands down. And they are cheap too.

The only high power LEDs I burned out was done on purpose. I need to know what they can, and what they can't take.

So no, I won't buy into the hype quite yet. This American will leave those in the bag for a couple more years.

laskey · « **Reply #19 on:** September 29, 2005, 07:58:54 PM »

I would put them in parallel, and you want to increase that resistor to about 100 ohms. Check the working rating for your LEDs. But I'm pretty sure they won't need more than 20 mA each.

I'm positive you don't need C2 or C3. The problem you are likely having is that this is an adjustable VR, and not just a VR. I looked it up on google, and it's data sheet says that when you ground your adjustment terminal it locks the output to 1.2 volts, which will just barely light those 2.2 volt LEDs.

Pick that adjustment terminal up from ground and place a variable resistor between it and the output terminal(with the third leg to ground...so you have a variable voltage divider). and you should be able to program your output voltage from there.

also remember that if you exceed more than 20 Watts of disappation this VR will start to shut the current down until it cools off to 20 Watts... which I don't think will be a problem here.

Hope that helps,

Chris

laskey · « **Reply #20 on:** September 29, 2005, 08:31:54 PM »

Here this part of a PDF might help. Your VR is alot like the LM117.

Hope that helps,

Chris

steak2k1 · « **Reply #21 on:** September 29, 2005, 08:54:43 PM »

Awesomne looking stuff guys. I definitely like the looks.

Just a bit of light advice though and don't take offense...

please resize your photos before ya upload em..LOL they are huge.!!

Best rgds,

stk

Peppyy · « **Reply #22 on:** September 30, 2005, 06:47:11 AM »

"the batteries, circut and light will be mounted on the shaft and turn like a lighthouse."

Perhaps I don't quite understand. You are planning to use a slip rings and brushes to connect the charging circuit to the batterys?

ghurd · « **Reply #23 on:** September 30, 2005, 08:55:29 AM »

I think he should go with a 7805, a 7806, a 7809 and a 7812.

They could light progressively!

The LEDs only need 5 or 10ma to light up quite well in the dark. They never should have over 20ma for long life.

Aaron · « **Reply #24 on:** October 04, 2005, 09:45:55 PM »

pep,

if you look at the last photo i included of the inside, you can see that the TDM is mounted to the shaft, so the wires, circut and light spins with the shaft. i did it that way to avoid brushes. the 16" pulley is stationary, make sense? saw 15 volts dc yesterday in high winds!

aaron

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Author Topic: circut for my lighthouse (Read 4206 times)