Wesley's Tool-Box

After successfully deploying LED lamps across the FPL lamp fixtures, I thought that the lamps installed in the traditional screw-in sockets should be replaced as well. Ever since these lamps started to go mainstream about 5 years ago, the price kept dropping and the choices kept on growing. This meant that it was a good time to make the move.

Comparing the various offerings on the market, I ultimately settled on the BEAM series of lightbulbs from Sigma LED (formerly Sunsea). They were among the brightest for the rated power, yet priced competitively. Both the 8W and 10W versions cost me about US$3.75 (KRW 4,500) per bulb.


They were set to replace the 20W compact fluorescent (CFL) bulbs made by Hankuk Lighting and installed throughout the house by default. Here is how they compare.


The LED bulbs are shaped closer to the traditional incandescent bulbs, making them thicker and shorter than the CFL ones. Because of the larger diameter, some of the fixtures that were designed only with the CFL in mind may have trouble taking in the 10W ones. This is why I got 8W ones as a fallback.

Meanwhile, the spec comparison reveals a similar trend seen with the longer cousins. The LED bulbs meant to replace the CFL comes in at about half the power consumption and slightly lower total amount of light. I'll be checking if the reality reflects these numbers, of course.

Having a smart meter giving real-time power consumption data provided a lot of insights for my home. The baseline load when everything is idle is about 80W, and the refrigerator running at full power adds 90W to that. So when I noticed that more than 300W were being used during the evening hours even with the TV turned off, I had to track down what the culprit was.

It turned out that the sole reason for this uptick was the lighting. Fluorescent lights in the living room and the study room were turned on for several hours every day and contributing much to the total consumption. Knowing that LED lights were more efficient and that the price has come down a lot recently, I decided to make some major investment.


As with a lot of apartments in Korea, the typical type of lighting installed was PL compact fluorescent lights, or FPL for short. It uses 4-pin 2G11 socket and has external ballast. Lots of replacement methods exist - lamp-only, ballast + lamp (socket is kept), or total replacement. As the lamp-only method is simplest by far and not much more expensive than replacing everything, the choice was obvious for me. I ordered the relevant LED lamps manufactured and sold by TopLux of Korea which were on sale - 23W version cost about KRW 21,000 (US$17.50) and 15W one, KRW 14,000 (US$11.70). Here is how they stack up with the existing FPL lamps.


According to the specifications, the LED lamp consumes about half the power while putting out about 85% of total light, or luminous flux, compared to the similarly sized FPL counterpart. This is indeed quite an increase in efficiency if it delivers. Visually, one side of the lamp is taken up by a long heat sink and uses the same four-pin layout. The pins themselves are simply round, not dimpled in the middle like the FPL it's replacing, so I suppose it won't "hook in" quite as well.

Using a Schmidt-Cassegrain telescope (SCT) like my Celestron NexStar 6SE requires the secondary mirror to be collimated properly to get a crisp image. I've done the collimation after fixing the screws, but I wanted to fine-tune further. The adjustment I will be making won't be the definitive for all the cases because the gravity affects the secondary mirror subtly with differing angles. But because the diameter (and consequently, weight) of the mirror is relatively small the deviation after the fine adjustment was hoped to be small.


Unfortunately, the real stars often look too shaky, so I decided to try the artificial star method for this tuning instead. An artificial star is basically a bright light source coming from a tiny hole. For the light source, I do indeed have one - an LED flashlight that I bought many years ago. It's actually an external battery for charging phones with a bright LED as a bonus feature, but it's so old that the charging port is a Korean 24-pin standard that was popular about a decade prior. Now it was time for this little gadget to be useful again.


I initially tried it out as is, but the LED part was too big. It was time for a little modification. After trying out different materials, I found that a sheet of back cover for making presentation handouts was effective at blocking light, yet did not require complicated tools to work with. A pair of scissors let me cut one up to make a cover over the flashlight. Next, I punched a tiny hole where the LED was supposed to be at.

Celine and I had some fun making light trails at home during the night. The whole thing was spontaneous, but the results were pretty good. There weren't so much to prepare. All I needed to do was to have my iPhone 5S shoot at 1/2 second shutter speed, while Celine swung this LED-equipped electric fan all over the place.