LED Light Bulb Autopsy

by Ben N on April 27, 2016

It was bound to happen. I finally had an LED light bulb burn out on me.

LED lighting has gone mainstream. For some time now, traditional style light bulbs have been available at affordable prices, and the energy savings can be considerable.

My house has nearly all LED Lighting (Where there aren’t LEDs are specialty applications, like the light in my oven.) I’m using several different brands and styles of bulbs. Bulbs include floodlights, which are great for my “can” lights in my kitchen and living room, round bulbs for lamps, and LED tubes in the 4′ fluorescent fixtures in my garage.

When I got home from work last night, my wife mentioned that the light over our kitchen sink was flashing, and then stopped working.

I got up on the step-stool, removed the bulb, and replaced it with a fresh LED bulb that I had handy. But why had the original stopped working?

One little trick that I do is to WRITE the date of installation on the bulb with a permanent marker. In this case, the bulb had only been in use for about 18 months – FAR shorter than it’s potential lifetime of over 20 years. Of course, the light over the sink is the most-used light in the house. When upgrading from traditional to highly efficient lighting, it’s the very FIRST place a person should look to start saving energy!

When I first examined the bulb, the diffusion cover was already loose. I twisted it counter-clockwise, and the cover popped right off. Below that was the circuit board with 10 surface-mount LEDs. Since it’s a 10-watt bulb, it’s pretty safe to say that each LED is 1 watt. Amazing how much light can come out of these tiny yellow squares!

I removed the screws that held in the circuit board, and flipped the board up out of the way. It was still connected by the wires making the electrical circuit, but I could see below. Inside was a gray, rubbery, potting material, and I spied the corner of a circuit-board and a capacitor sticking out from it.

I snipped the wires to completely remove the circuit board and get better access below. As I did, the reflector fell out. This is a completely separate piece of machined aluminum.

Looking at just the base of the bulb, there really wasn’t anything else to inspect. The potting material is durable stuff. Even if I hit it with a hammer, the blow would simply bounce off. So, it looks like that’s the end of my tear-down.

My best guess is that something in the base of the bulb failed. Likely, one of the components that converts AC to DC. When I pulled the bulb out, the base of it felt pretty warm, even though the light hadn’t been making light for a few hours. Perhaps an internal component failed, due to heat, as the heat couldn’t dissipate well through the potting?

The upside of this particular light bulb design is that I COULD at least take it apart. The plastic diffuser was completely removable, as was the all aluminum reflector. I also looked again and realized the LED circuit board should come right off the piece of aluminum it was on. Sure enough, I pried with a flat screwdriver, and it came right off. Under the LED board was a little dab of heat transfer paste, just like in a computer, between the CPU and a heat sink. In this case, the aluminum plate and the reflector act as the heat sink for the LEDs. About half of this LED bulb could go right in my household recycling bin.

As for the new bulb, I wrote the date on the base with a marker before screwing it in. It makes me wonder when the next time I touch that bulb will be? If it dies as quick as the first one, it might be two years from now. If it lives up to it’s proper life-span, I might not think about it again until after my now five-year-old daughter has graduated from college.

Only time will tell. One thing I can say for sure is that in the mean time, it’s going to be saving me on my electric bill!


PS: The Little Girl and I smashed open the base of the bulb and then cut and picked away at the rubber to see what was inside. I’m not much of an electronics guy, but what I see looks about right for converting AC to DC and DC to a different voltage. Take a look at the photos and leave a comment!

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Star Trek Doors: Progress and Project Overview

by Ben N on December 3, 2015

To be frank, the Star Trek Doors project has been a “back-burner”, a project slowly evolving in the background while my brother-in-law and I are also busy with everything else in our lives.

Just lately, I’ve had a bit of free time, so I got back in to learning Arduino and figuring out how to properly drive the air valves from it.

I was able to spend some time modifying a tutorial on buttons to apply to the project. I wired up an old industrial push-button control to operate the air valves. The buttons send a signal to the Arduino, which then sends an output to a relay on a four-relay board. The relay then applies power to the air valve. The great thing about using an Arduino, instead of hardwiring a button straight to a relay, is that I can use the code to change the properties of the button push.

For example, the buttons are momentary on. They only complete the circuit as long as the button is held down. In this project, that means holding down the button until the door is all the way open or close. Not a big deal, but wouldn’t it be better if you simply pressed the button briefly, and the door then did whatever it had to?

In the “IF..ELSE….” section of code, I simply added a delay after activating the valve. That leaves power to the valve ON for whatever I set the delay to, for example, a second or two – however long I expect it would take for the door to fully open or close.

The other neat thing about a “coded” button is that I can make it do more than one thing at once! I had some 12V LED light tape kicking around and I wired it up to the third relay. Now, the button could not just activate the OPEN valve, but also turn on a light. I think it would be pretty slick to have LED light all the way around the door frame that turns on and off as the door is used. By modifying the code, I can have the button open or close the door AND turn that light on or off.

Besides doing more than one thing at once, I can also use code to create a series of actions. I set up the STOP button so that it would open the door, pause long enough for a person to go through, then close the door. It would also activate the light at the beginning of the actions and turn it off at the end. (Of course, this will still need a safety added. You do NOT want the door to close with a person standing in it…)

For those of you experienced in programming Arduinos, this probably seems pretty simple to you. In my case, it’s pretty new and I’m just learning, but loving the fact that I can change machine behavior with just a few clicks.

I mounted the valves, the Arduino and breadboard, the relay board, and a 12V fuse board, all down to a piece of plywood. It’s still not that pretty, but at least I have a functional “control panel” that’s all together. For the moment, everything is running from a single 12V power supply, except the Arduino. Since I was programming it, I had that running on a USB cable anyways. I’ll still want to wire that up with a DC barrel connector to run it from the 12V as well.

In the mean time, Fred has still been working on the physical doors themselves. The garage side of the doors are finished, other than paint. On the inside, he started building the interior false wall, which will hide the doors when they are retracted. This includes a geometric upper bump-out for the connecting bracket to pass through.

He also built the decorative door frame for the garage side. It’s flat wood, but with pieces cut in a geometric pattern and contrasting colors. The middle horizontal pieces were laminated together by cutting wood to two different lengths, then alternating them and gluing them together. The planned finish for the wood frame is to stain it with contrasting light and dark wood stain. The finished effect should be somewhat steam-punk sci-fi.

This whole “panel” that I’ve been working on will still need some cleaning up. I’m using a very large power supply for the moment. I’d like to trim that down to a more typical “wall-wort”. I think we also want to have power for the project all running through a switched outlet. That way, if something is ever not working right, we can just flip a switch to turn it off, and open and close the doors manually. I’m using a physically very large fuse board, which supports multiple circuits. I really only need something small and simple. A single 12V fuse should probably be fine. I also need to find a good way to attach the tiny jumper wires from the Arduino to the physically larger wires (18 ga lamp cord) that I’m using to go to the buttons. Maybe there’s some sort of small screw-down terminal strips I can use, or a custom circuit board with everything wired to it? I do NOT intend to use alligator clips between the two in any sort of permanent fashion!

So, that’s your update for now. Look for more soon!


PS: To see everything on this project, visit the project home page: http://ecoprojecteer.net/star-trek-doors/


LED Bulbs Revisited

December 1, 2015

About a year ago, I shot a video showing off my favorite and most affordable LED light bulb at the time – a TCP 60-watt equivalent – which was available for $6 each while on sale and purchased in 6-packs. (See video above.)
Today, I had to do some shopping, and I looked around to see [...]

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POP Bottle Exploding Target

November 7, 2015

Two weeks ago, I was at the MOTHER EARTH NEWS FAIR in Kansas. I looked through the vendors for anything unusual and found a “prepper” booth that sold a target system which used compressed air and a soda bottle. It looked like fun, so I bought one.
Of course, I also wondered how hard it would [...]

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Bowling Ball vs Solar Panels

May 11, 2015

A while back, I posted a video of a bowling ball smashing into a “Bullet-Proof Coffee Table” that I had built. The idea was that I wanted to test whether or not it really was bullet-proof, only WITHOUT firing guns in my residential neighborhood. I DID have a bowling ball and a ladder, so I [...]

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PIRs and Scratch-n-Dent Doors

February 27, 2015

Progress continues on the STAR TREK DOORS!
Last night, I got a chance to stop on over at Fred’s to work on the doors. I purchased a bag of PIRs (Passive Infrared sensors) from Amazon, and started playing with them, hooking one up to my Arduino Uno. By playing around with a bit of sample code, [...]

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The Girl’s First Robot

February 17, 2015

Recently, I started learning about Arduino – a popular hobbyist microprocessor board. I’d like to use it for home automation and several other projects. In a nut-shell, an Arduino lets you have sensors in, process data, and output signals back to the real world. It’s great for all sorts of things, including robots.
My four-year-old daughter, [...]

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Air Cylinder Position Sensors

February 13, 2015

The latest excitement on the Star Trek Doors project is that I just got two Bimba 18″ air cylinders in the mail from an eBay purchase. The cylinders have a built-in position sensor with a 3-pin M8 connector right on the end.
I was able to look up some information on the cylinders to find out [...]

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Michael Jackson Light-Up Eyes

February 2, 2015

This weekend, I had a chance to start playing with some tutorials and an Arduino Uno, so that I could finally learn about micro controllers, and eventually use those skills for some DIY home automation and LED lighting controls. On a completely different note, my four-year-old girl is now completely obsessed with Michael Jackson, especially [...]

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FLIR One Thermal Camera – First Impressions

January 7, 2015

Today, my FLIR One camera arrived in the mail.
I excitedly tore open the package, but then I slowed down to make sure to take some photos so you all could get my first impressions of this thermal camera designed to work with an Apple iPhone 5 camera.
In the box is the FLIR One camera, the [...]

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