Car LED lamps for the house?
 

I just ordered 3 of these 3w LED arrays.. ($9.92USD shipped)

White 8-LED Super Bright Car Light Bulb 3 Watt DC 8-30V - eBay (item 190459203966 end time Nov-20-10 07:52:49 PST)

http://i.suntekstore.com/office_cach...5947_image.jpg

This high quality super bright LED bulb is great to replace your traditional car lamps. It will make your car much more brighter and consume less energy.

* Life expectancy up to 50,000 hours
* The LED base comes with double-side sticker
* Includes a festoon adaptor w/ 30mm long
* Easy to use
* Voltage: DC 8-30V
* Power Consumption: 3 Watt
* 8 Leds
* LED Light Base Dimension: 33mm long & 15mm wide

Package Included:

* 1 x LED bulb
* 1x festoon adapter


Once they come in from China (next month?), I'll check them out to see if they are suitable for under-kitchen-cabinet lighting, and post my findings.

I will use 12v car batteries charged with PV for power..

check this out..I bought from them before.. cheap but slow in shipping 1-2 wks
DealExtreme: $8.00 Car White 42-LED Ceiling Dome Light (DC 12V)

Wow! Deal Extreme has a bunch of car replacement LED lamps..
I buy stuff from them once in a while. Some of it's good, and some
of it has to be modified-on-arrival.. :o

The only problem I see with replacing a burned out tail light with LED, is the long shipping time.
But, once you change out those old incandescent lamps, you won't have to worry about them anymore.
(In theory anyways).

They came today!
 

One of them had a little problem.. Should be repairable..

http://i46.photobucket.com/albums/f1...Solar/z027.jpg

But the specs (on the two good ones) aren't what I expected..

They said..

* Voltage: DC 8-30V
* Power Consumption: 3 Watt


So, I was thinking maybe 1.5 watts at 13 volts.?.

Nope. At 13v, the flow is 66 ma.. 0.066A x 13v = 0.86 watt..

So there shouldn't be a problem if I forget to turn one of these off at night.. :rolleyes:


Maybe if I use a full 30v, the flow would kick up to 3w.. As the lifespan heads down hill..

Even at less than a watt, they feel warm. About 90 deg F in a cool basement..

I used a fuse holder to test them one at a time.
Later, I'll cut off the car lamp adapters and wire them all in parallel
and see how much light they can provide (as a group) in a dark room.

Maybe I can get near 3 watts! (Using all three lamps)! :rolleyes:

I'm not too encouraged, since my cheapo 3AAA LED flashlights make these things look really weak..

Solar+LED=Bliss?
 

Well, I got another LED array (for a total of four) and did a little current test last night.

I wired all 4 in parallel and connected them to 12.54 volts. They used about 2.7 watts total!
Since they were rated for 30volts, I decided to try two batteries is series.
At 25 volts, they got brighter, but the watt meter displayed over 20 watts!!
http://i46.photobucket.com/albums/f1...Solar/z010.jpg

Very warm!! I quickly went back to using 12.54.. I left the array running until midnight,
and checked the battery voltage every hour of so.
The old Toyota battery must have warmed up a little, after sitting on that cold 60f floor,
because in about an hour, the voltage went UP to 12.59v!
It stayed at 12.59v until midnight.

At midnight, I switched to the smaller Honda CRV battery, and let it run until the next morning.

Toyota: 10.8 Wh and Voltage went up for some reason. :confused:
Honda: 18.1 Wh voltage dropped over night. 12.54v to 12.28v

Anyways, I've decided to make these into a small reading lamp for the headboard.
They are good enough for reading and as backlight for watching the little
20" LCDHDTV that's mounted on the wall beside the bed.


Anyways, if my wife and I use this light for a few hours a night, that 2.7w
discharge rate can easily be made up by the 10w PV that's charging the battery.
Under average conditions (unless the sun is absent for weeks on end),
I think for each hour of good sunshine, we should get over 2 hours of good LED lighting.
It's very likely that the SOC will remain high, on average.

I'm curious if you were able to get the two nonfunctional LEDs to work, and if you did, how?

Electrical wiring and {especially} troubleshooting electrical gremlins has never been my forte. I do have a perfect track record for destroying multimeter's though. :o

LOL! I blasted the little 10A glass fuse in my favorite VOM the other day.
Did some PV current testing and then came back indoors, where I wanted
to plug back into an outlet, to watch my erratic AC line voltage.
Forgot to move the red lead back over the V hole.
It tried to measure 9 Zillion Amps from the wall socket.. But only for 2msec..

~L~E~D
When I looked under the double-sided sticky tape at the PCB, I saw some solder bumps.
Thru-hole stuff. In Ohms mode, I compared the end connections via the + & -
wires with the bumps on a good segment.
One of the end bumps showed open. Hit it with my little soldering iron and presto-fixo.

Trouble Shooting in Stereo. Is when you have one circuit that went bad,
right next to an identical circuit that works. You just put the VOM - on the power supply - and
probe the same connections on both circuits until you see what's different.

Thanks for the part on how you repaired the LED light. I'm sorry to sound continuously ignorant, but does VOM stand for Volt - Ohm- Meter?

That's what they used to call it years ago.. I guess it's a Digital VOM these days.

I guess all mine are DLCDVOMs (Digital Liquid Crystal Display Volt Ohm Meter).. ;)
The Amp measuring capability is a given.?.

There is some 'Safe Use of Electrical Test Equipment: DMMs & VOMs' at this link..
Safety Procedures for Inspecting Residential Electric Panels, how to examine, how to test electric service panels, how to use volt meters and electrical test equipment safely


I like this type of meter for quickie testing..
http://www.matcotools.com/ProductImages/MD921.jpg
It's uses are limited, but the leads are wired in. No way to forget to move them..

These meters,
http://www.matcotools.com/ProductImages/MD3000.jpg

Make life a bit more difficult. You have to change the function selector AND the probe posistion for some jobs.
Most of the meters I use are this style. Most have fuses to protect the amp circuits.

These things get zapped all the time. Mostly because people didn't sit down
and read about the differences between resistance, voltage and current measurements.

I've seen dozens of students try to measure "The Amps" of a power supply
by sticking a meter across the + & - posts.
This normally occurs just after they look at a diagram showing the load..
http://www.bergerweb.net/xb500/ammeter.jpg
Which is the only way to do it..

It's easy to understand the amp meter when it's compared to a water flow meter.
Gallons-per-hour etc is a metaphor for Amps being Electrons-per-hour etc.

Current is likened to the current in a river. It's a flow rate.

Voltage is like pressure. There is 30 PSI in your tires. 3000 psi, in your scuba tank.
48 volts in my battery bank.. It's just like pressure. Or potential..

It's just a static measurement. Those volts (or PSI) have the potential
to do some work.. :)

The key thing is to start off with Ohm's Law and understand it..
Before you start making Amp measurements.. :D

Of course, remembering to change the leads helps save on fuses.. :o

Haha, done that a few times myself. :)

Reminds me of the time many years ago when doing maintenance on a 10Kw HF radio transmitter, some other tech had left an AVO8 multimeter switched to its amps range grounding the HT capacitors rather than the standard earthing stick. When power was reapplied and having forgotten about the meter, its internal fuse didnt help, when 2 amps at 7000 volts was directed through it. We spent several hours picking up small pea sized bits of Bakelite and meter internals from inside the transmitter internals. Sounded good though when it exploded.

Painful memories
 

Lucky no one was holding the meter when it when off!

My teacher was called the Johnson Viking Challenger (HF Ham Transmitter).

You can see the little ma meter (mili-Amp meter) on the right top.
http://www.radioing.com/museum/challenger.jpg


In this picture from the rear with cover off, the meter is on the left.. With Orange Disc Bypass caps on each side.
http://t3.gstatic.com/images?q=tbn:A...oTy4RHEDnP7MXz

Anyways, the year was 1968 or 69, when I was about 22 years old.
Just received Novice ham ticket and figured I could adjust the little
trimmer cap underneath the deck, just below the ma meter.

Never thinking that those meter posts were sitting at 850vdc with about 400 ma available..
I carefully tweaked the trimmer left-handed, with a long skinny little green Xcelite screwdriver.
I was it transmit mode, watching the ma meter.
Carelessly, my upper right right arm touched the backside of my large D104 microphone.
(it was at ground potential).
At that exact instant, my left forefinger slipped down and came in contact with the 850 B+.
I think the point of contact was the solder lugs holding the bypass caps..

I saw the light. I don't remember much, but it appears I did a back-flip out
of my chair and slammed into the door about 8 feet behind me.
I slid down the door to the floor before waking.
When I awoke, I was unable to lift either arm.
It's not easy to get up off the floor, without the use of your arms.
So, I sat there.. For maybe an hour..
But a short while later, the numbness began to leave, replaced by pain.
It took a long time for feeling to return to my right arm.
And it when it did, it was excruciating!

So, I learned my lesson. I don't really recall being shocked since then.
The next day, I went out and got some long nylon tuning tools.
Much better than steel screwdrivers.. :o


haha! I can't remember what I had for lunch today, but I sure can recall that
afternoon over 40 years ago..

Modernized Antique reading lamp
 

Modernized our reading lamp with the LEDs.

http://i46.photobucket.com/albums/f1...Solar/z101.jpg
That old lamp was running at 40 watts and could burn your fingers,
when you reached back to adjust it, or turn it off.
http://i46.photobucket.com/albums/f1...Solar/z105.jpg

I ran about 12' of old speaker wire down to the battery area in the Ham shack.
Put a 2A fuse in the line. Used one of those insulated inline 3AG types.


This lamp is used 2 to 3 hours almost every night. It was starting to get really old. (over 30).
When I removed the old socket, I found the diode, that I had installed
many years ago (to get half power) had burned in half, but the molten
halfs were still touching under the insulation. No wonder it seemed so bight.
Not a safe lamp IMHO.. :o

Anyways, this will be our first DIY Solar powered lamp. I think it will be pretty useful too.

At 2.7 watts, it should be perfect for those really long power-failures.. :p

Note:
The installed picture seems to show some pearls floating up out of the little
heat vents on the socket end of the lamp housing.
They aren't phantom pearls, it's an aberration caused by shaking hands.. I think..
Humm, maybe the ghost of ancient technology?

It's overcast and snowing!!!
 

I wonder how long a car battery would last using about 3watts .?.

Assuming 30Ah, and the LEDs were drawing about 0.25 Amp?

30Ah/ 0.25A = 120 hours of use.
About a month at 4 hours a night. Or 5 days at 24/7.

The new LED lamp got a few hours of use last night. My wife likes it.

Strangely, the little 10w PV seems to be charging the Toyota battery up this cloudy morning.
Even with the small amount of light we had early this morning, the battery
I expected to be around 12.5V, is up to 13V already.. :D

Haha, sounds like its working great. :)

Hey, we got sun!!

The reading lamp battery had been charging slowly this AM in the dim overcast sunlight..
But then after lunch it came out in full force to show us those long winter solstice shadows.

I took a quick look and saw green LEDs on both chargers. They are full-o-electrons..

I love when a plan works out.. :D

It's been working every night for about a month now and we are very happy with
the performance of the light and the solar rig that runs it.

The only bug seen so far, is the toggle switch. It's a little worn and sometimes causes the LEDs to flicker,
until the switch is jiggled.
I plan to replace the switch with a small (modern) toggle, after my next trip to Radio Shack..
(I still need a meter fuse)! ;)