Another sensor light: the IKEA Komplement sensor LED strip

Yes, this is yet another write up about sensor lights. I like how sensor-based lights work because of how convenient it is. Having a sensor of sorts allow the pairing of switching on of lights with other actions, such as opening of a wardrobe door. And since I have two sides to my wardrobe, I decided to try out a different sensor light since I was a little disappointed with my Dioder drawer light due to the fact that it only turns on for 15s when the sensor is tripped. I needed something that stays on when my wardrobe door remains open. 15s is way to short for arranging clothes or simply picking out what I want to wear to work.

So, here comes the IKEA Komplement LED strip. I bought the 42cm model for $59.90. This is way longer than the 29cm IKEA Dioder drawer light. Unlike the Dioder drawer light, the Komplement stays on when there is no obstruction in front of the sensor. It uses power from the mains so there is no need to change batteries whatsoever. Hurray! I finally found what I wanted!

But no, it isn't really what I wanted. There are two problems - energy efficiency and ugly cabling. Firstly, the cables are wriggly and it is difficult to line it neatly. This is one problem that is completely mitigated by battery powered devices. It cannot beat the elegance of the Dioder drawer light.

Secondly, and more importantly the energy efficiency - LEDs are meant to be super efficient as they convert a very high percentage of electrical energy into light rather than heat. This is the concept I want to adopt for my room. I want my room to be smart, neat and most of all, energy efficient. Unfortunately, the IKEA Komplement does not really follow through the idea of energy efficiency for the Komplement. This is probably because it is powered by the mains and do not have the same constraints as a battery powered light. I felt disappointed about this partly because I wanted to power this up with a rechargeable battery pack to get rid of the messy looking cables.

Specifically, the things that let this light down are the transformer and the sensor. When the mains are left on and the light deactivated, the transformer still remains (very) slightly warm to the touch and this is bad because considering how little power the sensor takes. This means that the transformer is not very efficient. For the record, I did not measure the power consumption from the mains. It would give a much clearer picture of the intake power to know this and it would be possible to calculate how much it will cost to leave it plugged.

Although I mentioned that the sensor takes in only a little power, the sensor alone (without the light powered on) can drain a pack of 8x AA batteries in about 8days. Compare this to the 6.25months for 6x AAA for the Dioder and it becomes clear how much more parasitic the sensor is. This makes it very impractical for me to use batteries for the Komplement.

Power usage (mW)	Dioder drawer (29cm)	Komplement LED (42cm)
Residual	1.74	120
Activated	783	1440
Sensor/LED %	0.22%	9.09%

I've measured the power usage of both products and I found that for the Komplement, the sensor takes in a whopping 9% of the LEDs power consumption when the light is deactivated, which is why it will drain my battery pack so much quicker than the Dioder drawer. It is quite ironic that LEDs are now so efficient that it makes other components such as transformers and sensor modules look really bad in terms of energy consumption.

Instead of using the sensor to activate and deactivate the light, I am now using it more of a night light. It is easy for me to switch it on and off as the power socket is quite near my bed and it is not too bright to cause discomfort when switching it on at night. Overall, it works the way it should. It will definitely satisfy anyone looking for a quality drawer light. However, I don't like the fact that they did not carry the idea of energy efficiency all the way.

 

My drawer! Now, let there be LED lights!

 Nice warm soothing light from 24 LEDs

 

The sensor is in the middle of the light. It senses frosted glass perfectly well. (Top: Off when it senses nearby object. Bottom: Switches on when doors clear the sensor area)

 Well, yes it has a switch that bypasses the sensor :) But note that the transformer still takes in energy even in OFF.

The small transformer. Judging by the specs and assuming that the max intake (16w) will give the max possible output (6w), the transformer has a conversion efficiency of 37.5% at max load. As far as I know, transformers are generally inefficient at really low loads and becomes better as it reaches middle to max output. Even when the light is on, the load is only 24% of the max permitted load. Chances are, the efficiency never really reaches its peak. Having that said, packaging a higher quality transformer equates to higher price. I'm guessing that they use the same transformer for all their LED lighting range to achieve economy of scale at the cost of higher efficiency.

 Wriggly cabling. Made worse by using sticky tape.

 Komplement's sensor light as seen from a camera. This is a lot brighter than the Dioder's sensor IR light, probably a contributing factor to the sensor's power consumption. On the flip side, the sensor range is a lot further than the Dioder.

 Dim IR sensor light from the Dioder. It may be dim but it works just fine.

It also has a physical switch between the mains and transformer. It makes good sense to have the switch at that position of the circuit because it cuts off all power to the transformer.

Edit: I tried to remove all the wire clutter by powering the Komplement with using a 3x 18650 li-ion battery pack. The 3 batteries total up to around 12v which is a perfect replacement for the included transformer. Sadly, the batteries will drain out by 4-5 days of minimal use due to the fact that it needs a constant stream of electrical current. I know that my batteries are 2000mAh, so at 10mA, the Komplement will drain my batteries within 8 days. This is way too inconvenient. On the other hand, my Dioder with a sensor lasts more than a month without any problems.

 

These cells were salvaged from my gf's old laptop battery pack. The sticky tape on it is to stick on the protection circuit.