Reply
 
Thread Tools Search this Thread Display Modes
 
Old 10-23-2009, 01:47 PM   #1
2 Rivet Member
 
1995 21' Sovereign
Tracy , California
Join Date: May 2009
Posts: 31
Images: 7
Making and Testing LED Bulbs

I've been spending entirely too much time and money building and testing a variety of LED bulbs for interior lights!

Hopefully my experiments will give some of you a better idea of how some of the different LED's perform.

I should say that a major goal of ours was to make the lights as bright or brighter than the original bulbs.

I intend to post each bulb as a separate message in order to make the project managable.

The first bulb I'll document was constructed by combining 4 "Array LED G4 bulbs"

Array Lighting | Array LED G4

The results are shown in the following pictures. I'm including exposure information for the photographs because it will allow us to compare different bulbs.

The first picture shows the combination of 4 array lights mounted on
perforated circuit board from radio shack. The red wires are only standoffs which hold the bulbs away from the diffuser. The 1156 bulb base can be purchased from:
High Powered LEDs

The second picture was taken at:
exposure 1/1500 sec.
aperture F8
"film speed" ISO 80 on my camera.

To the eye, the light is extremely bright and has a nice warm white color.
The camera settings tone it down considerably to allow direct comparisons between bulbs.

The third picture was taken at:
exposure 1/160 sec.
aperture F8
ISO 80

Here the diffuser from Airstream light fixture has been placed over bulb.

The bulb is running at 12V 0.33A or 4W
It replaces the standard 1156 bulb which uses 21W.

In my next message I'll show pictures for the original bulb.
Attached Thumbnails
Click image for larger version

Name:	Airstream G4 001.jpg
Views:	81
Size:	103.9 KB
ID:	89583   Click image for larger version

Name:	Airstream G4 002.jpg
Views:	87
Size:	38.1 KB
ID:	89584  

Click image for larger version

Name:	Airstream G4 003.jpg
Views:	88
Size:	61.3 KB
ID:	89585  
__________________

__________________
johnobuttons is offline   Reply With Quote
Old 10-23-2009, 02:30 PM   #2
2 Rivet Member
 
1995 21' Sovereign
Tracy , California
Join Date: May 2009
Posts: 31
Images: 7
1156 incandescent light for comparison

Here are pictures of a standard 1156 bulb taken at the same exposure.
The 1156 bulb is at 12.8V, 1.33A or 17W
Attached Thumbnails
Click image for larger version

Name:	Airstream 1156 001.jpg
Views:	73
Size:	23.7 KB
ID:	89586   Click image for larger version

Name:	Airstream 1156 002.jpg
Views:	79
Size:	50.5 KB
ID:	89587  

__________________

__________________
johnobuttons is offline   Reply With Quote
Old 10-23-2009, 03:27 PM   #3
Rivet Master
 
HowieE's Avatar
 
1991 34' Excella
Princeton , New Jersey
Join Date: Aug 2003
Posts: 6,814
Images: 12
Your 4 G4 boards. How are they wired series or parallel to the plug? In other words how many boards could you put on one plug if you wanted more or less light from a given fixture?

What is the cost of the boards
__________________
WBCCI 12156 AIR 3144 WACHUNG TAC NJ6
2004 Excursion 4x4
1991 34 ft. Excella +220,000 miles, new laminated flooring, new upholstery, new 3200 lbs axles

HowieE is offline   Reply With Quote
Old 10-23-2009, 04:54 PM   #4
Rivet Master
 
DaveFL's Avatar
 
2000 31' Land Yacht
Central , Florida
Join Date: Aug 2007
Posts: 1,479
Images: 15
Quote:
Originally Posted by johnobuttons View Post
Here are pictures of a standard 1156 bulb taken at the same exposure.
The 1156 bulb is at 12.8V, 1.33A or 17W
From here it appears to be only one led board needed as it is brighter than the bulb, looks like they need to be pushed back to the reflector to get nice difused light without wire shadows. How do you get the 12v, with prices of led's getting cheap and life so long why not wire direct. Should be able to wire in series with a resistor to get the right voltage.
Thanks,
Dave
__________________
DaveFL is offline   Reply With Quote
Old 10-23-2009, 05:53 PM   #5
Rivet Master
Commercial Member
 
vinstream's Avatar
 
1962 19' Globetrotter
1963 19' Globetrotter
1961 19' Globetrotter
Wheat Ridge , Colorado
Join Date: Dec 2007
Posts: 624
Images: 2
Great Post.... Excited to see what else you come up with!
__________________
www.VINSTREAM.com
Wheat Ridge, Colorado
WBCCI # 1962
Instagram #Vinstream
vinstream is offline   Reply With Quote
Old 10-23-2009, 06:20 PM   #6
2 Rivet Member
 
1995 21' Sovereign
Tracy , California
Join Date: May 2009
Posts: 31
Images: 7
Hi Guys I'll answer some of the questions first.

Howie wants to know the price of the G4 array boards. They are about $10 apiece.
They are wired in parallel and direct to the socket, so each board sees 12.8 volts or so. These boards seem to have some active regulation (not just resistors). As the voltage goes up, the current rises to a certain point and then remains constant.
__________________
johnobuttons is offline   Reply With Quote
Old 10-23-2009, 06:41 PM   #7
2 Rivet Member
 
1995 21' Sovereign
Tracy , California
Join Date: May 2009
Posts: 31
Images: 7
Next Bulb - 76 5mm white leds in series/parallel

This next bulb is probably the most cost effective.
It consists of 76 white leds. The leds come from China and cost about 10 cents each. They emit light over a narrow angle of about 15 degrees.
DealExtreme: $10.51 14000mcd 100Packs White 5Mm Led

The leds are wired with 19 parallel strings of 4 LEDS. In order to play it safe and avoid any possible burning out LEDs I included a simple voltage regulator on the board. I will describe the voltage regulator on next post.

The first picture shows the board.
The second picture shows the board using 1/1500 sec, f8, ISO 80. Because the board is not aimed precisely at the camera the LEC's appear dim.
The third picture is identical to the second picture except the board is aimed more at the camera and more of the LED's appear bright. (remember these LEDs have a narrow 15 degree beams).
The fourth picture shows the board with a diffuser over it. 1/160 sec, f8,
ISO 80.

This makes a really nice reading light over our couch. The only drawback is the cool white color.
Attached Thumbnails
Click image for larger version

Name:	Airstream Deal Extreme 5mm 001.jpg
Views:	83
Size:	93.3 KB
ID:	89589   Click image for larger version

Name:	Airstream Deal Extreme 5mm 002.jpg
Views:	77
Size:	73.4 KB
ID:	89590  

Click image for larger version

Name:	Airstream Deal Extreme 5mm 003.jpg
Views:	77
Size:	104.6 KB
ID:	89591   Click image for larger version

Name:	Airstream Deal Extreme 5mm 004.jpg
Views:	80
Size:	72.4 KB
ID:	89592  

__________________
johnobuttons is offline   Reply With Quote
Old 10-23-2009, 07:13 PM   #8
Rivet Master
 
HowieE's Avatar
 
1991 34' Excella
Princeton , New Jersey
Join Date: Aug 2003
Posts: 6,814
Images: 12
Any chance you will post the diagram?
__________________
WBCCI 12156 AIR 3144 WACHUNG TAC NJ6
2004 Excursion 4x4
1991 34 ft. Excella +220,000 miles, new laminated flooring, new upholstery, new 3200 lbs axles

HowieE is offline   Reply With Quote
Old 10-23-2009, 07:18 PM   #9
2 Rivet Member
 
1995 21' Sovereign
Tracy , California
Join Date: May 2009
Posts: 31
Images: 7
Voltage Regulator for LED's

One of the challenges of using LED's in an RV is the range of voltages which range from 12V for a nearly discharged battery, to well over 13V for a battery being charged. Overvoltage is a real enemy of LED's because current increases very rapidly with voltage and with heating. The puppies run away with the current going up, making them hot, and so forth.

For some of these LED bulbs I added a voltage or current regulator.
The simplest is a voltage regulator. For efficiency, the LM2941T is the best IC. Here's a link to the datasheet.

http://www.national.com/ds/LM/LM2941.pdf

Initially, I used R1 = 1000 ohms
R2 = 8200 ohms

This works out to an output of 11.5 Volts

Later, I increased R2 to 9200 ohms giving a nominal output of 12.9 Volts.
This voltage is not seen under most conditions, but it does insure that LEDs will never be exposed to more than 12 .9 Volts.
Attached Files
File Type: pdf VoltageRegulator.pdf (20.9 KB, 71 views)
__________________
johnobuttons is offline   Reply With Quote
Old 10-23-2009, 07:27 PM   #10
2 Rivet Member
 
1995 21' Sovereign
Tracy , California
Join Date: May 2009
Posts: 31
Images: 7
Picture of Incandescent 1156 is too dim!!!!

It's been bothering me that the picture of the 1156 bulb is SO dim.
There's a reason why my picture isn't quite fair.
In an RV, the 1156 is placed with a white reflector above it.

In my pictures I didn't use a reflector, so the picture of the 1156 is too dim.
__________________
johnobuttons is offline   Reply With Quote
Old 10-23-2009, 08:12 PM   #11
4 Rivet Member
 
bibbs's Avatar
 
1977 Argosy Minuet 6.0 Metre
1973 21' Globetrotter
1975 26' Argosy 26
Vista , California
Join Date: Sep 2006
Posts: 265
I am realy glad you are posting this LED info.
I have wanted to make some of thoes.This will help A lot. Reflectors will help spread the light a little more
__________________
bibbs is offline   Reply With Quote
Old 10-23-2009, 08:18 PM   #12
2 Rivet Member
 
1995 21' Sovereign
Tracy , California
Join Date: May 2009
Posts: 31
Images: 7
LED light constructed from LED "tape"

This light was constructed from a LED "tape" purchased from Deal Extreme in China. A single 2 inch piece of tape contains 3LED's and a resistor.

DealExtreme: $18.55 12V Flexible Cuttable LED Tape (1M 60-LED White)

The tape was cut into 4 inch pieces containing 6 LED's.
These pieces of tape were attached to a piece of flexible plastic about 4" x 4".

The pieces were wired in parallel.
The whole thing takes 4A at 12.8V.

The pictures are as before:
First, finished light "bulb"
Second operating "bulb" 1/1500 sec. F8 ISO 80
Third diffuser 1/160 sec. F8 ISO 80
Attached Thumbnails
Click image for larger version

Name:	Airstream Deal Extreme Tape 001.jpg
Views:	86
Size:	101.1 KB
ID:	89599   Click image for larger version

Name:	Airstream Deal Extreme Tape 002.jpg
Views:	82
Size:	50.8 KB
ID:	89600  

Click image for larger version

Name:	Airstream Deal Extreme Tape 003.jpg
Views:	77
Size:	68.9 KB
ID:	89601  
__________________
johnobuttons is offline   Reply With Quote
Old 10-23-2009, 10:36 PM   #13
2 Rivet Member
 
1995 21' Sovereign
Tracy , California
Join Date: May 2009
Posts: 31
Images: 7
The "Endor Star"

Here's one of the newest HIGH power LED's.
It's called an Endor Star and it's a heavy hitter.

EndorStar - Luxeon Rebel - LED Supply.com

I used the 300 lumen neutral white star (Price about $17)

These things get HOT and need a heat sink and a current regulator.
I'll put the details for the regulator in the next post.
It controls the current limiting it to 400mA in this case.

Here are the pictures:
The first shows the endor star mounted on a 2"x2"x0.5" heatsink.
The second shows the endor star running at 400mA. 1/1500 sec, F8, ISO 80.
The third shows the endor star with diffuser. 1/160 sec, F8, ISO 80.

These things can actually operate up to 1A = 1000mA. However a bigger heat sink would almost certainly be required.
Attached Thumbnails
Click image for larger version

Name:	Airstream Endor Star 003.jpg
Views:	77
Size:	87.0 KB
ID:	89616   Click image for larger version

Name:	Airstream Endor Star 001.jpg
Views:	74
Size:	35.3 KB
ID:	89617  

Click image for larger version

Name:	Airstream Endor Star 002.jpg
Views:	88
Size:	63.9 KB
ID:	89618  
__________________
johnobuttons is offline   Reply With Quote
Old 10-24-2009, 01:09 AM   #14
2 Rivet Member
 
1995 21' Sovereign
Tracy , California
Join Date: May 2009
Posts: 31
Images: 7
Current Regulator for Endor LED

Current regulators are the holy grail for LED's. No matter what happens to the temperature or voltage, the current stays the same. There are lots of ways to make a current regulator.

One way is to use the LM2941 chip again.
The circuit is shown in the attachment.
I used a value of 3.3 ohms for R1.

The current produced will be 1275/R1 (milliamps).
So for this resister choice the current is 386 milliamps.

All of the current flowing through the LEDs will flow through R1.
So the power dissipated by R1 is the square of the current x R1 or
about half a watt. I used a 1 watt resistor for R1.

If this is too technical I'll be happy to do the calculation for a different current should you want to soup it up. Remember if you increase the currrent you will probably need a bigger heat sink. This was about the biggest heat sink I could fit in my smaller light fixtures.
Attached Files
File Type: pdf Current Regulatort.pdf (5.2 KB, 126 views)
__________________

__________________
johnobuttons is offline   Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
interior lites/LED bulbs joqin Electrical - Systems, Generators, Batteries & Solar 2 01-23-2007 08:47 PM
taillight bulbs davidz71 Lights - Interior & Exterior 4 02-14-2003 09:59 AM


Virginia Campgrounds

Reviews provided by




Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 11:50 AM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.

Airstream is a registered trademark of Airstream Inc. All rights reserved. Airstream trademark used under license to Social Knowledge LLC.