Freddies Comes Thru

My desk lamp quit yesterday. Didn't realize how much I depended on it until then. Set out to track down the problem and finally decided to try a new bulb. Last time I had a Halogen light fail I assumed the bulb had burned out and only after climbing up and down the ladder a couple of times did I discover that there was nothing wrong with the bulb, so I was a little hesitant to blame the bulb this time. I took the bulb out (used my #1 Phillips that I located the other day) and looked at it but there does not appear to be anything wrong: the filament looks intact. I used a VOM (Volt/Ohm Meter) to measure the resistance of across the filament and it showed it was open, but that doesn't mean much. New bulbs act the same way. Measured the voltage coming out of the wall-wart (step down transformer that plugs into the wall) and it was only a volt or two. But this wall-wart weighs practically nothing. Usually these things weigh in around half a pound. This one is only a few ounces. Must be some kind of special electronic gizmo. Probably does not deliver full voltage unless there is a real load, and a meter does not do the job. Tried another 12 Volt wall-wart on the bulb, see if I could get it to light up. That didn't work either. So we have some evidence that the bulb might be bad.

I drive over to Freddies in Cornelius. It takes a while but I eventually find the light bulb display over by the plumbing, and low and behold, they actually have a selection of halogen bulbs. Okay, now which one do I need? Fortunately I checked the output on the transformer: 12VAC & 6 Amps. Volts times amps gives 72 Watts. 60 watts looks like the right choice. 10 and 20 are too small, and the others are too big. Try to read the numbers off my old bulb, but they are tiny and I forgot my glasses. Walk around until I find the reading glasses display. I put on a pair and I am able to convince myself that I have picked the right bulb. I use the U-Scan to pay $6 for the bulb.

Back at the house I try to get the bulb out of the package and into the lamp without touching the glass. (Don't want to get any oil on it. These bulbs get really hot and rumor has it that any oil on the glass will combust and cause the glass to break/shatter/explode.) I fail on both counts. The tips of the leads on the bulb are squared off and require some finesse to get them into their holes. I wipe off the bulb with a cleanish handkerchief and turn on the power and we have light!

Each arm of this lamp is made of two parallel tubes. The rods carry the current. The lamp assembly has a pair of spikes that plug into the ends of the tubes that make up the upper arm. There are no wires, the tubes conduct the electricity.

Note about the picture: I found this image using Google. It appears to be the same as mine, though I bought mine at Costco several years for quite a bit less money. Looking at the picture I see massive jaggies on the arms on my screen, but the original looks very clean, and it is not that much bigger than this one. Curious.

Update December 2016 replaced missing picture.