LED lights

Over time I have been replacing most of my CFL bulbs with LED bulbs. Even though I produce more electricity than I use and I believe in using the power it takes do what I want, I still don’t want to waste energy that could have been put to a better use somewhere else.

I hate CFL’s for all of the usual reasons:

  • They are slow to turn on, which usually gets worse as they get older. 
  • They hate cold weather, which makes them take even longer turn on. 
  • They have a poor CRI value. (So I really have to google numerous consumer group reports when at the supermarket to figure out if they are any good)
  • It seems you almost need a hazmat suit to clean up a broken CFL bulb.
  • They are often oversold so it is rarely equal of a 60w incandescent as the package says but often more 50w, and that gets worse as they get older. (Yes, I know, get used to Lumens already)

Too big to fit even when I removed the reflector.


Poor design on this one too, at least it was cheap.

LED bulbs also often suffers from a poor CRI value, but they turn on fast, they like cold weather, they are not a danger to your health and they don’t seem to be oversold in the lumens department. So when you compare LED to a CFL in the supermarket, look at the lumens and don’t believe the Watt comparison written on the CFL bulb. If you need a CFL bulb to match a 60w incandescent, you often need to buy a “75 Watt” instead.

G4 Halogen

I have finally taken the time to find a replacement for the 6 10w G4 Halogen under my cupboards in the kitchen. I had to replace the power supplies because the new LED bulbs does not draw enough power for them to work, and I want them to supply DC to the lights to make sure they don’t flickr.

I have bought different G4 LED replacements to test and most of them were useless. The first I got, had a huge plastic cover on the back to prevent it from shorting out when touching the reflector. But that also meant that it would never fit. See the upper right picture.

The second one I tried recently had a huge capacitor on the back so that you can use it with AC current without flickr. So that also would never fit and they decided to place it at the edge, making it even worse. Further more, I don’t think it will survive long with the heat that the LEDs produce.

Then I finally found some useful substitute.


2 Watt


1,6 Watt

Serious cooling


It actually fits

They have the right dimensions, they claim to have a CRI > 90,  a neat heat sink on their back and they seem to work with AC current also(but I am still going for DC).

I made a few temperature measurements. The ambient temperature was around 24c-25c. I made each measurement after having kept the bulbs running for 7 hours.

Halogen bulbs runs HOT and I measured on the wood shelf inside the cupboard, a temperature hot spot of about 45c from a 10w bulb. That dropped to 28c-29c with the 1,6w LED installed.

As any other electronics, LEDs likes it cool so I tried to remove the reflector to leave more room for cooling the LED. It might have had some effect but not something I could measure. The temperature inside the cupboard may have gone up to 30c but I could not measure any difference on the LED’s.

In my final test I ran them with the glass cover on and removed. With the glass cover removed, I saw temperatures on the LED around 75c. With the glass cover on, it went all the way up to 105c, ouch. According to wikipedia, the optimal operating temperature to ensure a long lifespan of the LED’s, their temperature should be kept below 120c, and the SMD mounted capacitor should be able to take it as well(if they have used the right type), so it should be good but not a lot of headroom, but I wonder what would happen if I installed a 2 watt, that might get to close for comfort. 

Time will tell if they are any good in the long run, but so far I am happy.

10w Halogen to the left and 1,6W LED to the right(there’s socket for a bulb in the middle). This picture is not as accurate as I had hoped. The LED is 50% more bright and the Halogen looks more yellow(but perhaps that is just because of the less light emitted).

These 2 pictures below shows better the difference between the two as I perceive them.


1,6 Watt LED


10 Watt halogen

I have begun testing the 2W bulbs and will update this with more information later on.

© rud.dk 2019