Tuesday, January 22, 2013

FrånkenLämp Part II

When we last saw this project, everything was disassembled. Now we are going to put FrånkenLämp together.

The metal stalks from TIVED have a slightly larger diameter than the holes in the perforated plate of STRANNE. This required careful drilling of the holes to avoid damaging the densely packed wires. Once the holes were large enough, the three metal stalks were inserted. 
Tie wraps were used to hold the three metal stalks in place. One was snaked around them in the space between the two perforated plates. This was tightened, pulling them together. A second was used just below the bottom perforated plate, holding the ends together and locking them in place. You can see the cut ends of the two tie wraps in the picture above.

Since the ends of the metal stalks extend further, a large hole was drilled in the white plastic cover. This is what it looks like with the modified cover back in place. I didn't quite get the hole centered, luckily it was big enough that everything still fit.

Here you can see what the combined bundle of lights looks like. I was very pleased with how things were coming together.

Now, I just needed to power the thing. Since there were two different types of LED bulbs, each requiring a different voltage, I used both power supplies that came with the two lamps. At this point, I made some modifications that weren't completely necessary. I could have mounted a short power strip inside the lamp or had two separate wires coming out of the base to be plugged in. However, I wanted everything controlled by a single switch, and I didn't want any internal electrical connections that could come loose when the lamp was moved.

So, I opened up each of the power supplies and made soldered connections. This is the first one taken apart.   On the right half of the case are the two contacts that attach to the prongs of the plug hidden beneath. The connector at the bottom center is the DC supply for the LEDs.
 This is what it looked like after I soldered permanent connections to the circuit board. The two tie wraps serve as a strain relief, since they are too large to fit through the hole in the plastic case. This prevents damage to the soldered connections if the wires are pulled.

I did the same thing to the second lamp's power supply, and closed them up with some Gorailla Tape (think Duct Tape, but better) and super glue. I wired the three LED bulbs from the TIVED back together in series and covered everything with more heat-shrink tubing. Below you can see the two power supplies, one for each type of bulb. 

This is the layout of how I mounted things inside the lamp. You can see that there is plenty of room for everything. At the bottom of the picture, you can see the switch built in to the power cord. With the original Ikea design, this would only see low voltage DC power. However, it is clearly marked that it is rated for 120 volts AC and (if I remember correctly) three amps. This is more than sufficient to power both lamps.

A quick test shows everything in working order and a good amount of light.

With everything working, I used some double-sided foam tape to mount the two power supplies inside the lamp.

Then I attached the base... and tried it out for real.
I am extremely happy with the final results. It has the nice soft area lighting from the STRANNE combined with an abundance of usable light from the TIVED. It seems rather perfect, and it is the only one of its kind. 

Tuesday, January 8, 2013

FrånkenLämp Part I

I was recently introduced to the furniture store known as Ikea. It is a Swedish company, and they have fun with their product names. It is an enjoyable store to wander through, even if you are not looking to buy anything. They have a cafe that serves tasty food, including Swedish meatballs. Also, they have reasonably priced, decent furniture.

In one such afternoon of wandering through the lighting section, a rather attractive lamp was discovered. It was named STRANNE and cost about $50.
It consists of 36 flexible stalks, each tipped with an LED bulb. The only drawback is that it doesn't produce very much light, probably not enough light to read by. This was disappointing. 

Further wandering on a different afternoon uncovered another interesting lamp. This one was named TIVED and cost about $70.
It consists of five flexible metal stalks, each with a much brighter LED bulb. It produced plenty of usable light. The only drawback was that it is ugly and boring in comparison. The need for a lamp remained unfilled. 

Sometime later, inspiration struck. The idea was conceived to combine the two lamps, maintaining the best features of each. Now, you might be thinking that $120 is a lot of money to spend on a lamp, especially a lamp that involves dismantling what was just purchased, voiding all warranties. For a normal lamp, you would be right. But, it is a small price to pay in the quest for the perfect lamp. Plus, it became a fun project and an excuse to take things apart. Count me in!

Fair warning:  this subject is going to be divided into two separate posts. This first will detail the disassembling of STRANNE and TIVED. The second will cover the combination into FrånkenLämp. 

Let us start with STRANNE. 
It is shipped in three pieces. The top portion, middle, and base. This allows it to fit in a surprisingly small package. Here is a picture of the top portion. It contains all the electrical parts. 

Removing the four screws allows the white cover to come off and reveals the ends of the bulb stalks mounted in two perforated plates. It also gives access to the wiring that goes to each of the bulbs. Each bulb is wired in parallel. Crimp connectors join all the individual bulb wires together and connect to the positive and negative wires from the power supply. Wired this way, each bulb runs off of 6 volts from the 6 volt power supply. 

Since everything is in parallel, any number of the bulbs can be removed without affecting the others. For my purposes, I removed three of the bulbs to make way for brighter ones from the TIVED. I chose to place them in the center so that they would not take away from the aesthetics of the lamp. The remaining ends of the wires that were cut to remove the bulbs were covered by heat-shrink tubing to insulate them. 

Here is a close-up view of one of the stalks that was removed. There is a flexible plastic tube on the outside with the wiring running down the middle. The two electrical wires going to the LED bulb are cut short. The long wire, with a hook bent at the end is a stiffer wire. This exists so that when you bend the stalk, it stays where you moved it. This allows you to arrange the lamp in a pleasing manner. The plastic plug at the end is what holds the stalk in place in its designated hole. 

That is the extent of the disassembly of STRANNE. Let us move on to TIVED. 

Three screws hold the plastic cover in place over the base of the lamp. Removing them and the cover reveals the following. There are five bulbs and one resistor. They are wired as two parallel sets. One set has three bulbs in series. The other has two bulbs and the resistor in series. Arranged this way, each bulb runs on about four volts from the 12 volt power supply. 
Because of this arrangement, the choices for reusing the bulbs were limited to using 2, 3, or 5. (The set with the resistor, the set with three bulbs, or both sets together.) Using all five seemed like too much, and just two seemed like not enough. The executive decision was made to use three. Three is not as symmetrical as might be desired, but since they would be buried in the middle of the cluster of bulbs, it was deemed to be an acceptable number.

The metal stalks on this lamp are longer than the ones on the STRANNE, as can be seen below.

The ends of the metal stalks are threaded and formed so that they can be attached to the base. A tubing cutter was used to shorten them to the correct length. This also gave a smooth piece that would more easily fit through the holes in the perforated plates of the STRANNE.

Care was taken not to damage the wires running through the center of the stalks. Two layers of heat-shrink tubing were placed on the wires to protect them from the sharp edge left behind by the tubing cutter.

Here you can see the two different bulbs. On the right is one of the stalks remove from the STRANNE. On the left is one of three metal stalks from the TIVED that has been cut to length.

This is where our story pauses for the moment. Tune in next time for the reassembly.