12 volt powered oscillator led light

[totoalas]

Hi nickz, thanks for the reply.
Yes it is a surprising amount of light for 283 milliwatts, I don't know if it's the series/parallel configuration, the type of leds they are or the leds have become conditioned somehow from the pulsing they've been exposed to.
Each led is getting around 3.125 volts.

Hi totoalas, thanks for the reply.
It's a 10 watt, 50 ohm resistor.
Correct, 8 groups all in parallel, each group has 4 leds in series.
Yes, this outperforms my fluorescent setups.
I checked the battery voltage today, I've been lighting the bathroom up for 2 days at night, probably 20 hours total so far and the battery went from 12.37 to 12.34 volts and is not drawing 19 milliamps due to lower battery voltage, though still very good light output.
peace love light
tyson

Sure Winner one resistor and 12v dc source beats all other jt for practicAL home use and easy replication


thanks
totoalas

[NickZ]

SW:
If that is really the case, then you've got something. Please continue to test and let us know the results. I'm sure that time will tell, one way or the other. In any case, that is the direction that I'm going in, also.

[SkyWatcher]

Hi totoalas, yes it does seem practical.
Of course you don't even need the single resistor as the leds are within a very safe voltage zone.
So I removed the resistor and measured 95 milliamps or 1.18 watts for all 32 leds and it was enough light to light up the whole living room with an adequate light level.
When comparing this to the single 20 led string plugged into the wall, the 32 leds are probably double the light output. Wish I had more leds to put in series/parallel.
So something about this configuration is really efficient.
peace love light
tyson

[NickZ]

I notice that when the leds get pulsed that they don't always react the same afterwards with normal voltage from batteries. Sometime they don't want to light at their normal voltage for some reason. Possibly something like that affects them to light with less draw from the source. It would be nice to know what is causing that low draw. 32 leds times 25 mA = 800 mA not 100 mA, if the 32 leds were drawing what they are supposed to draw (25mA), each led. Hard to figure it the way that you've got them.
If the light lasts a good long time, at full brightness, that's whats important.

[SkyWatcher]

Hi nickz, thanks for the reply.
That's interesting that you've observed leds acting differently after being pulsed, It could be a reason for it as i thought it may.
Another theory I have is, since the leds are so close bunched together, could they be feeding one another like solar cells and reducing input, I saw a thread somewhere talking about solar led diodes.
Also, it wouldn't be 800 milliamps, in series the amperage is the same and parallel divides the amperage.
So at 100 milliamps total input no resistor in line, i verified with meter and resistor, we have 12.5 milliamps possible in each parallel branch and each of the 4 leds in series in each parallel branch sees 12.5 milliamps, though the 12 volts is divided among the 4 leds for around 3.125 volts depending on charge state.

The thing is, these leds are at full brightness and a quality of light that exceeds the ones plugged into the wall.
Even if we take into consideration the 20 led string connected to wall outlet is drawing double what it should, due to the use of voltage dropping resistors. I'm running almost twice the amount of leds for even less than half of the string wall connected for an even greater light output in my opinion.
Lets say pulsing the leds did affect them, do you have any idea what could have happened to them to cause this seeming effect?
peace love light
tyson

[NickZ]

No, I don't. An led will light off of a Jt that is outputting 100 or more volts, and will also light on the same device when when it only has 3 volts, I never knew why the led does not get burned out, even on 800 volts, or more.
Using 12 volts direct there is no lack of current to draw from, as with the Jtc.
I would try some new leds, just to compare. But leaving the others intact the way they are.

[SkyWatcher]

Hi folks, I'm testing out a charging setup, just for fun. Two 12 volt sla's in series for 24 volts and charging a 12 volt sla, with the 32 series/parallel leds splitting the positive rail. It's charging fairly well, we'll see how it goes.
Also, just for fun and since many of my led flashlights in my collection have been collecting dust, because I don't feel like buying throw away D and C primary cells and rechargeable C and D size are expensive and i have many AA rechargeables.
I decided to make spacers to hold AA rechargeables to replace mostly C cell flashlights, i used 5/8 plastic nuts i had a bunch of and ground down the sides slightly and bored the holes to fit the AA's. It works quite nicely.
Here are a couple pics if anyone may find this useful.



Uploaded with ImageShack.us


Uploaded with ImageShack.us

peace love light
tyson

[Tectalabyss]

Last year

Sure Winner one resistor and 12v dc source beats all other jt for practicAL home use and easy replication


thanks
totoalas

Hello All
I've not been on sense last year..But This is what I tried to tell everyone on the Big JT thread....I've ran 20 10mm bright white leds since then with out losing one no burnout's that is for you Watson has you said Leds from Hong Kong were junk...Only one 1/2 watt resistor to keep the current from burning the Leds up...and these Battery's are car battery.s to boot....You can find picture's on the Big JT thread....Thanks Tec

[SkyWatcher]

Hi Tectalabyss, thanks for letting me know that, I was not aware you posted test results of that kind of setup.
Yes, i agree, the way they power christmas led strings and the kind that mount under cabinets is not needed, with all those resistors.
The leds will never last without some kind of heavy protection from voltage fluctuations, like a buffer battery or something.
I've been running this 32 led series/paralle setup for many days now and they all run solid at even light output and color levels.
I'll check that thread out, thanks.
peace love light
tyson

[SkyWatcher]

Hi again tectalabyss, i saw your posts from the big joule thief thread and i noticed my posts as well, lol, almost forgot i posted my results of the very same thing i posted here about the series /parallel direct to 12 volts.
Though I noticed you initially had the leds in parallel with much heat loss in your resistor, then you placed them in series.
The way I have mine wired, i don't need a resistor at all. Though maybe you already tried that setup for the 12 volt car battery.
Yes im convinced, the only way to properly power these leds and get good color and even light is to use dc current and if using wall power, needs to be completely voltage spike proof for the leds to last as long as they are rated for.
peace love light
tyson

[FRC]

I have done the series /parallel Xmas light leds before a few years ago running off 12v in my camper van. I did not get that good of results. Of course, I was
using the 12v battery for other purposes as well, and not just dedicated to the leds. So, had I just used the 12v for the leds, maybe the results would have been better.

By following this thread, it made me think of trying a full 25 led Xmas string running off of a Fuji circuit. I had tried 3.5 watt led bulbs before and they worked well - better than a CFL. The full Xmas string works very well also.
I had these mounted on a mirror and positioned a 1.8 watt solar panel to
catch the light. It read that it was giving 1.5 volts, so I hooked up the output back to the rechargeable 1.2 battery running the Fuji circuit. This concept was discussed on another thread before. I will try adding another string and another solar panel to see if OU or close to it can be achieved.

FRC

[NickZ]

FRC:
Even if OU is not obtained it may still be worth the effort.
I often wondered if recycled energy from small solar cells that are placed around a light source (bulb), which is picked-up by the solar cells and is send back to charge the source battery. If not, the power can always be used to light other leds instead of recharging the battery.
This idea is especially useful at night when there is no sunlight to work with, but there are lights on.
What happens if the recycled energy from the solar cells is sent to a Jtc and is then pulsed back to the source battery, or another battery.
I know this has been tried, but I don't recall the results.

[dR-Green]

I often wondered if recycled energy from small solar cells that are placed around a light source (bulb), which is picked-up by the solar cells and is send back to charge the source battery.

I also often wondered when I was a kid, why can't you, once you set the circuit into motion, recycle the energy of a light back into a solar panel to power itself. It seemed to my young mind only to be a simple matter of delaying or storing a charge temporarily, so there's a buffer if you will that allows it to work in a loop. Now that I'm older I'm aware of losses in circuits, but I still think the principle of choking the energy could be used for something along these lines.

Anyway, I haven't really been following this thread, but over the last few weeks I've bought two sets of LED string lights, I think both sets consist of 50 LEDs with a solar panel to charge the battery. I proceeded to take one apart to start experimenting with, but then I realised that all 50 LEDs are already being powered off that 1 AA battery So I closed the thing back up and went to work on something else.

No doubt there's a more efficient way to do it than that existing circuit, but still, that took all the fun out of what I was planning to do. They must already be using some of these principles in the products on the shelf.

[NickZ]

Yes, they have incorporating the Jt technology into the Christmas Lights. There are some strings that have 150 leds running off of one rechargeable AA battery, and they are running for 8 hours.
82FT 150 RED LED 2-IN-1 SOLAR STRING FAIRY LIGHT-XMAS | eBay

[SkyWatcher]

Hi folks, thanks for the replies.
I decided to again, make use of things that have been sitting around collecting dust, like a few of my 28 and up led flashlights that use AAA's which I have none of.
So I decided to desolder the leds (5mm white/bluish) off of these flashlights and convert them for using 12 volts direct as home lighting.
Now I had to give some thought as to how I was going to pull this off, considering the led leads were so short due to being on a circuit board, I could barely solder connections between them.
So I decided to use clear packing tape to bundle a group of 4 together in series, as this is compatible with my 12 volt batteries.
Also the clear packing tape provides a really nice diffuser for spreading the light around.
Then i stripped the insulation off what i think is 22 gauge connect wire and used that for solder interconnecting the leds in series, then used 18 gauge insulated connect wire as the terminal wires, then I hot glued the bottom off the leds and bottom of wires so as to keep it all safe and snug.
These little group of 4 in series modules can then be connected in parallel on a breadboard or other and hooked directly to a 12 volt battery and provide nice diffused lighting.
Here are a couple pics of two of the modules with no resistor, it is drawing 45 milliamps at 12.63 volts



Uploaded with ImageShack.us


Uploaded with ImageShack.us

peace love light
tyson