The LED thread.....

[ggiilliiee]

stranger ...id give jerry the shirt off my back ..and i do actually remember my 9th grade eletronics class ..but ...mostly just wondering ....WHY???...hehehe

http://www.improvementscatalog.com/...928396-wireless-wired-led-track-lighting.html

im listening jerry ...just askin questions ...
.as i have a bunch of 2500milicandle led's that ive been pulling out of cheapie butane cigg lighters ...wanted to set up a solar back up lantern like what i have now (batts only)....but hook up the walkway light to it and a diffuser lens ....with larger cells in a new batt pack ....probably put in a potetiometer for an off and dimmer too ...to get around the photo cell ..thanks for the tips ....really .....

 

[ftierson]

I never should have started this........

Not so, Jerry...

Great thread...

Keep plugging away...

Forrest

 

[jerrymrc]

Well since I have drilled the holes in the wrong places I will bend the leads a quarter turn and fold over. This has got to be the worst job I have ever done. Good thing work can't see it.

If you look at the yellow wire and think of it as the + then I branched each leg from there down the side + - + - + - The end lead is the neg.

 

[jerrymrc]

Now all we need to do is mount the resistors and tie both legs to the Neg and our custom assembly will be ready for testing. I have mounted the resistors on the face side and tied them in to complete the circuit.

 

[jerrymrc]

In this case I went with the 15 Ohm resistors so I would have plenty of cushion on the top end of the voltage scale. I chose the LED's I did because one of the supposed features was a 40 degree pattern.

Most LED's have a narrow beam with not much light outside of that. A pic of the finished backside.

 

[jerrymrc]

So I have finished it. Now what? Well testing @13 V showed that it draws .4A and that works out to 5.2W compared to the the 19.1 W (1.47A) that the 1141 bulb drew @ 13V

I may change the resistance to 11 or so and push the bulbs a little further. So how does it look and work?

Installed in the housing We have all the bulbs pointing down.:tongue: The factory lens has a diffuser built in but I may have to add some diamond plate to it.

 

[jerrymrc]

Of course I need to see it work and that's when I realized that I had no batteries in the camper. I was not about to plug it in because the inverter without the batteries as a buffer is a big no-no.

So I grabbed one of the car batteries and hot wired it into the fuse panel. It showed 12.5v so this would be a good test. The lowest my batteries get running off the solar setup is about 12.3v. The LED.

 

[jerrymrc]

The 1141

 

[jerrymrc]

So what does it all mean? The current LED's have come a long way in just a few years. Can you just go and buy what you need? Sometimes. I may pick up a couple of the panels that daimok posted about just to try.

As I posted there are 13 of these in the camper. 5 are single and 4 are doubles like in the picture. One switch for the doubles. One double fixture draws 38.2 W of power. Placing the LED's in there just cut it to 10.4 W.

When your dry camping like I do you count every watt you are using. I am almost at the point that I can dry camp for as long as I want.

My ultimate goal of all this crap that some have seen me doing is to be able to take my one camper and truck and be able to live 2 years without resupply. This is the Survival forum is it not. :wink: :biggrin:

I will work on some other designs just to see how much I can gain and see what the cost is. Since most of the items were scrounged to build the array the cost was under $4 per bulb and my impression of the light output this was a success.

 

[brownknees]

Sweet!
Just one thought.
Could you add a zener diode at the input end to clip any voltage spikes from the battery?
This might be an easy protection measure, especially if you re-charge with a genny.
It'd have to clip at 13.5 volts & be able to handle the total current, but shouldn't be a big item, either financially of physically.
Or use 2 zeners with the correct voltage rating instead of the resistors, that way you'd get double-duty out of one component.

For those not into electronics a zener only allows up to a specified voltage to pass, & dumps any excess as heat.

 

[L Haney]

Hey Jerry, does your camper have a dedicated circuit for the lights? Maybe a breaker or a fuse just for them? If so, I might have something that will let you eliminate all the current limiting resistors on the boards you fabricated. You wouldn't have to remove them, just jumper them out. I might be able to reduce the current consumption another 25~30%.

Lowell

 

[jerrymrc]

Hey Jerry, does your camper have a dedicated circuit for the lights? Maybe a breaker or a fuse just for them? If so, I might have something that will let you eliminate all the current limiting resistors on the boards you fabricated. You wouldn't have to remove them, just jumper them out. I might be able to reduce the current consumption another 25~30%.

Lowell

I never thought of that. Just put the limiter on the fuse block. Now that would work. Do you use the PNP as a shunt with the cathode on the base?

Been 20 years since I taught theory but not all of it goes away.:shades:

If you have a circuit that would handle about 3A that would work since I would never be running more than 7 bulbs at a time. I have to make double certain but I do think that all the lights are on one circuit.

 

[L Haney]

Well, close. These are power MOSFET's that have a free running oscillator that sets the duty cycle. You trim with an external resistor that sets from about 5 to 95% on time. The other control input sets the frequency. Mot sure about the range on that one without looking. But 60 to 120 hz ought to be about right for this application. Best part is the on resistance of that FET is about .05 ohms. Set up right, it should run the lights with no decrease in brightness (to the eye) and trim a good bit off the power consumption. Taking non-flash photographs under those lights would be sort of hit or miss though. :biggrin:

 

[jerrymrc]

Well, close. These are power MOSFET's that have a free running oscillator that sets the duty cycle. You trim with an external resistor that sets from about 5 to 95% on time. The other control input sets the frequency. Mot sure about the range on that one without looking. But 60 to 120 hz ought to be about right for this application. Best part is the on resistance of that FET is about .05 ohms. Set up right, it should run the lights with no decrease in brightness (to the eye) and trim a good bit off the power consumption. Taking non-flash photographs under those lights would be sort of hit or miss though. :biggrin:

PM sent.

 

[mosbysmen]

great thread , someone who is out there doing stuff ..
i will stick this on top in a few more days ,so if you dont see it look at the
top of the page .. you will see the other 2 thread jerry has up there

 

[jerrymrc]

Thanks. We are not done with this. Lot's of ideas just got to get the time to do them.:whiskey:

 

[jerrymrc]

Well I added a little clear diamond to defuse the pattern and it worked like a champ. Nice even light with no hot spot whatsoever.

Was cooking up something with L Haney but even though the circuit says "Ceiling" only 1/2 the lights are on it.

I am now working on the reading lights that will be 3 leds each. The housing is small but it will work. I have potted 3 LED's with epoxy and will work them into a bulb.:whiskey:

 

[jerrymrc]

I have now finished 5 of my lights. 4 6 LED's and one 3 LED. Now in all fairness I did order a few of the ones that daimok posted about.

I do not know as yet how they will work but at the very least I will use them in the bathroom. I will measure the current draw when they get here.

I will say that with the diffuser my 11 watt housings with the LED's are much better than the 38 watt 1141's. It is brighter, it is whiter and I have dropped my power consumption by over 2/3. I can light up the main room for 22 watts vs the 76 it used to take.

I guess that means more TV time when I dry camp. My TV SAT set up takes 56 Watts to run.:whiskey:

 

[jerrymrc]

As an update and for those interested I did receive the 3 lights that daimok had posted about. For those wanting to buy without the hassle of making your own these are an alternative.

The good and the bad...... IMO.

Good.

Plug and play.
Bright
Draw 3.7 watts

Bad.

The white is almost annoying.
Very small pattern
in my case for 3 of these I can build 7 of the others.

The verdict.

I chose the LED's I did because of the output and the pattern. Not as focused as a normal LED. The end result was a bulb that gives good light and dispersion. The store bought LED's have a very narrow beam even with a diffuser. The output within a 4' circle is about the same as mine but there is a very sharp cutoff after that.

My home built ones work more like regular bulbs as to dispersion. they will light up the area that the bought ones will not.

They do draw only 3.7 VS 5.2W for mine. The incandescent's were very yellow. The LED's made it more like a fluorescent bulb but the store bought ones have that color temperature that is almost annoying.

I will be using them for the stove lighting because it has a 168 mount.

Just some thoughts.

 

[dirtyrice]

This is great stuff jerry. First time I noticed this thread.

 

[gunsmoke]

This is a really GREAT idea and project. Very very worthwhile and useful information that almost everyone can use if they choose to.

Please keep thinking, tinkering, achieving and teaching!

:whiskey: :whiskey: :whiskey:

 

[jerrymrc]

BTW. For those attending Falfest they can see a couple of these in action.
I will have the 6 double, 6 single, 3 single and the store bought ones in action.

 

[jerrymrc]

Some updates. While the LED'S are great I found out that the inverters used in campers are not kind to them.

The quick story is that while it only shows 13.5V the ripple from the inverter will kill the LED's. I am sure that it only uses a half wave rectifier.

I was getting set up on Wednesday and had the light over the sink on. I looked up and it was out and the familiar smell hit me.

I pulled all the other LED's out and put the bulbs back in. I did leave the two commercial ones in the bathroom. By Friday half of the bulbs in them were burnt out as well.

The bottom line IMO is that if you are going to be using the inverter use bulbs or modify it. Dry camping or just using battery power as in a SHTF situation the LED's are great and use much less power.

I will still build the rest of them but put them in the camper as replacements in case I ever need them.

I now have another project to deal with (the inverter) :beer: If I have to I will convert it to full wave and with some caps hope to smooth it out.

 

[saltshaker]

Any news on the inverter work yet?...Great thread......I can use this info on my boat.........My BOB.....Bug out boat...........salt:fal:

 

[Nevarwinter]

Just to add to this thread:

http://ledcalc.com/

I know there's a link above for a similar thing, but I used this recently for a home project and it draws it out for you.

Become an expert! Impress your friends! Fun at parties! Hover over the question marks if you're unsure.

I got 6 5mm LED's running on 1 9v battery for just about 40 hours.