Update November 2015:
The MiLight analysis and review below was done in the last few months of 2014. My goal was to find a affordable LED bulb that I could use to retrofit my entire house to LEDs. The MiLight bulb fitted my needs, and they have been in use for over one year. While researching the subject I learned many useful things about LED bulbs, such as the generic Kruithof curve problem. See my page on this topic. I had contacted several Asian manufacturers at the time to find what they were planning to do about this problem, without much success. In the past months, however, I noticed that several companies have created LED bulbs that change color temperature from 'cold' (2700K) to 'warm' (2200K). For example: Philips, Manuman. The bulbs are referred to as "warm dimming" and are based on a control chip (or equivalent) which was released mid-2014 (see Electronics Weekly article). Prices for these bulbs are still above my retrofit target price but these for sure will come down. I will check what options the Asian manufacturers have and will add new info to this web page.
Another note: I found that the Ikea Ledare light bulbs are quite OK if you need a non-dimmable basic bulb. They have decent light output, don't flicker much, and have decent color temperature, especially if you add an ivory balloon (see my balloon page). With a price that varies per country between €2.50 (France) and €3.50 (Netherlands, Belgium) per bulb (a weird pricing approach, by the way) there is no reason to keep your old light bulbs in the house, so I've used these for all the parts of my house that do not need scenic and/or dimmable lights.
I conclude that, even though the EU laws now prohibit the manufacturing of traditional incandescent lightbulbs, a retrofit solution is only available for basic on/off lights. For dimmable lights there are only few LED solutions offering a comparable experience, at too high cost. The longer lifetime and smaller energy consumption of an LED does not validate charging a price (such as by Philips Hue) that is almost 100-fold the price of the traditional lightbulb and is counterproductive to the global need to reduce energy consumption. My suggestion is to only replace the basic on/off lights by LEDs and continue with the inexpensive traditional lightbulbs for another few years until an affordable LED solution with color and dimming experience comparable to the traditional bulbs become available. Key aspects are a quick DIY retrofit of the existing lights by LEDs that should be priced at less than €10. In my house I am now using the MiLight DualWhite bulbs. These do comply with my price and easy retrofit requirements, but I'd prefer to have a better 'warm dimming' solution.
Retrofitting my home with LEDs
In the past few months (late 2014) I've been trying to find a decent replacement for the many incandescent bulbs in my house. Looking at the factory cost of a LED bulb (well under $1 /€ 1), a replacement by a remotely controlled LED should be feasible for under $10 / € 8.
How do I derive at an (smart)LED manufacturing price of well under €1?
The plastic casing of an LED is easier to produce than the glass of a traditional lightbulb (which is sold for far less than €1), let's say 5 cents. Now add 20 Cree LED smd's for about 1 cent each and we're at 25 cents. The type of LED (warm, cold, color, whatever) is irrelevant for the price. Now add a tiny substrate with small UDP receiver and a bit of memory adding another 10 cents. Compare these 'electronics' with the 10-cent cost of a complete wifi transmit/receiver which nowadays is included in every 'internet-of-things' device. Of course this is only true if you produce more than a million but that's the market we're talking about here. Manufacturing costs, testing, quality control, packaging all add up another quarter, so you can imaginge that an 'off-factory' price of about €1 is realistic. Multiply by two to five to include the costs and profits of the retail market, and now understand why Ikea is able to sell their basic Ledare LED for about €2.50.
Remember that you have a market potential of ten billion units and no longer need to differentiate between the 110VAC and 230VAC global markets (they work on anything above 85VAC) and you can consider it may even be less expensive to produce an LED than a glass lightbulb.
A key aspect, actually the most important, of retrofitting a home is NOT having to reinstall new switches and dimmers. The LED should fit the existing fixture and it should be a no-brainer to switch them on/off. Every DIY person should be able to do it without having to rewire live, 'hot', mains connections. For basic LEDs the on/off switch should be good enough. For intelligent LEDs a simple remote control unit and an option to control them via wifi and a smartphone is the only acceptable solution, so that's what I've analysed.
These info pages are a condensed version of my multiple forum discussions and blogs on the (Dutch) tweakers.net technology website.
I've looked specifically at the Chinese bulb industry. This is where virtually all LED bulbs are made or, at minimum, their components are made for assembly elsewhere. Ordering and shipping bulbs from China is easy. It may take some weeks to arrive but I consider this irrelevant compared to the 50,000 hours they last.
MiLight bulbs are produced by several Chinese manufacturers (e.g. Coxotech, Langma, Top-Atom, Futlight) and are based on a 2.4G RF controlled RGBW (RedGreenBlueWhite) bulb, a remote control, and a wifi box to convert wifi controls from smartphone and tablet apps (Android/iOS) into the 2.4G RF signals.
The RGBW bulb can be ordered with either warm or cool white LEDs and has RGB LEDs for special color effects.
There is also a DualWhite (DW) bulb which uses LED types with 2700K and 6500K temperature allowing for color temperature control between cool and warm using a similar remote controller and apps.
These bulbs are available in 6W and 9 W and with multiple lamp base types from GU11 to E14, E27, E26 and B22.
Several people asked me: "Why not use these quality Dutch Philips Hue smartLEDs?"
Well, because at a price of € 60 each they are a rip-off, knowing that the off-factory price can be around € 1. Although the idea behind Philips Hue is smart, they have a catastrophic design flaw: these bulbs are reset when you use the regular on/off switch. This means they cannot be used as retrofit and if you (or your guests or your kids) happen to make the mistake of using the on/off switch you will need to a) find your smartphone, b) log into the appropriate wifi node that has their controller, c) start up the app and d) restore everything. A nice job to do in the dark, eeh, I mean in a maximum white light room. Smart thinking!
The way they fix this in the marketing is to call this key bug a 'feature'. They now state it has been done purposely for safety reasons (in case you stumble into your home with weird light settings and it takes minutes to open the app on your smartphone). If you conside security a key aspect you may want to take a look at this Youtube video :-).
How easy would it have been for Philips to include a tiny amount of memory on the circuit board (as done by MiLight)? So in order to fix this design flaw they have come up with the Hue Tap. A dumb pushbutton box that you need to stick near the old on/off switch allowing you to.... do the same as the old on/off switch. Obviously this thing will fall off after a few years when the glue no longer sticks, and it is ugly too to have two controls next to each other. To fix this major flaw they now allow you to buy their Hue Tap for the small amount of only € 60. Unbelievable.
The European and Northern US market has about 100 million households looking at retrofitting their homes with LEDs.
What would you do if you want to get rich?
- Sell a billion bulbs @ €5 each and make some €4 billion margin?
- Sell less than 1 million Hue's (max 1% of households) @ €60 each and make some €55 million margin?
Philips Hue aims at the second market and tries to do this via the "Apple" lifestyle approach. Not very smart thinking.
Oh wait! Isn't that what happend to many other Philips ideas such as the compact disc and the cassette tape?
No wonder they are selling the Lighting Division to a Chinese investment consortium. While they focus on the tiny Hue market the Ikea's and other brands in this world are passing them left and right selling reasonable quality "dumb" LEDs for less than € 3 each. By the time that Hue has opened up a tiny bit of the market the 'disruptive' sales of cheap LEDs by the Ikea's of this world have locked in the majority of households for the next 10 to 20 years. A LED lifetime of 20,000 hours means that most of the money is in the initial sale and only little in replacement and market growth, so if you want to make big money from this market you need to do forward pricing.
Actually, I would do both: Have some cool hipster techies and a load of art directors in one business unit marketing the Hue as a hobby project, mainly aimed to position the company as "high-tech", and have a dozen hard-core professional manufacturing experts in another business unit (under a different brand name) to bring home the billions from the other 99% of the market.
Anyway, I guess this makes it clear why I do not consider Philips Hue a proper solution to retrofit my home.
Last but not least: The Philips approach also does not help the "sustainable" society any bit forward. In fact, by charging ridiculous prices they scare the market, resulting in a delay in the introduction of energy-reducing solutions. "Sustainability only for the happy few that can afford it".
For those of you who don't want to be bothered with the details of this research: The control functions of these MiLight bulbs and their prices make them an excellent candidate for retrofitting a house with LED bulbs. The remote control unit and apps are basic but do a proper job. Key advantage of MiLight is that there is no need for other investments such as expensive LED dimmers and/or new wall switches. The existing light fixtures and electricity switches can be maintained. Once set to a preferred color and brightness setting they will keep this setting even after a hard off/on switch.
Key issue I have with the bulbs is that the Dual White bulb, even at its warmest color, provides too cold light for my 'cold climate' (see info below) and that the RGBW bulb offers only one warm white color (which I find too cold) plus multiple other RGB combinations that are great for 'disco' effects but cannot be mixed to create a warmer color temperature.
The other big issue is that the dimming of an LED does not produce the same pleasant effect as traditional lighbulbs do, as described in my Kruithof/Smartcolor page.
I have contacted several manufacturers to explain the market needs (and revenue potential) of my 'colder climate' market and to stimulate them to create a bulb that fits this market.
In the mean time I am using these bulbs with a simple modification. For details see the MiLight balloon fix page.
I've described the 'ideal' Smart LED with pleasant color representation in the Smart LED color page.
MiLight RGBW bulb
The inside of a MiLight RGBW bulb looks like this:
MiLight RGBW 6 Watt 2700K-3000K bulb
As you see there are:
- 10 smd 5630 type (this is the warmer 2700K-3000K version, there's also a cold 6500K version), which are the yellow smd's near the edge of the bulb;
- 4 smd type 5050 (RGB LEDs), the square white smd's in the inner ring;
- the small circuit board contains the transmitter and control hardware, with the pointy needle towards you being the RF antenna. The AC-DC voltage convertor unit is placed below the pcb, in the foot of the bulb.
In the white mode of the lamp, only the outer smd 5630 LEDs shine. In the RGB mode of the lamp, only the inner smd 5050 LEDs shine.
This was a surprise. In this way the light output in RGB mode is vastly reduced, and there is no way of combining the two smd types to create a warmer white. This appears to me as a missed market opportunity.
The great advantage of the MiLight bulbs (both the RGBW and the Dual White) is their control capability.
They can easily be controlled by a small and inexpensive local remote unit as well as via an android and iOS app connected to the MiLight wifi unit. Although it is 'sexy' to be able to control your lights via an app, there are these moments when you cannot find your tablet or smartphone, when they are connected to another wifi network in the house or when the wifi router is busy with other things. At that point it is great to have a small remote control unit (I use one in each room) allowing you to control the lights.
Another advantage is that the bulb includes a memory function. Once you have set the brightness and color it will remember it the next time you switch it on, even if you use your old mains on/off switch on the wall.
This makes the MiLight bulb an inexpensive way to retrofit your complete house from traditional lights to LEDs. No need for new and expensive phase modulated LED wall dimmers because they are integrated in the bulb, no need to avoid or replace mains on/off switches. If you like fancy remote control options and have a tablet or smartphone you can make use of the apps, and if you prefer a basic setting you'll need one small remote control box per house or per room.
At full power the bulb does not appear to become very warm and I did not observe the flickering that I've noticed with other LED bulbs. There is a slight delay at the on-switch of some few hundred milliseconds. I did not find it annoying. There is no delay when the bulb is switched off.
The prices I paid for the MiLight components in December 2014:
- RGBW or DW bulb: $10 / €8,
- Remote control: $8 / €6,
- MiLight wifi box: $17 / €14)
These prices include shipping to Europe from China. Prices in euro for the bulbs have increased slightly because of the lower euro value.
The RGBW remote control unit (left) has 4 touch on/off switches at the bottom to control 4 zones, with each up to several hundred bulbs (or one bulb if you prefer). The "M" button above is to preset color modes such as red, green or blue color on/off switches and disco lights. It has no presets for warmer light modes (see info below). The "S-" and "S+" buttons are to make the disco modes blink faster or slower. The black ruler above is for dimming the lights. By pressing the color ring the white smd's are switched off and the smd 5050 change colors. The dot in the middle of the ring lights when one of the buttons on the remote control is pressed.
The DW bulb has similar shaped remote control unit (right), without the color dial. The DW control unit cannot be used for RGBW bulbs and vice versa. The MiLight wifi box and smartphone apps support both bulb types.
In addition to these controls, a bulb can be placed in 'night light mode' with very low power consumption.
The apps can be download via the Android/iOS stores for free. They allow the smartphone/tablet to connect to the MiLight wifi box. The wifi box can be set either in standalone mode or as access point connected to an existing wifi switch or router, thereby allowing the smartphones to connect to both the lamps as well as regular internet. Several other apps have been made by third parties allowing for more sophisticated control e.g. via your media player, alarm functions or switch on all the lights if you enter the house.
Some improvements of this app, which was crudely translated from Chinese, may be useful. Up to now no one seems to have bothered to fix its name "Moinitor" to Monitor but the bulb control functions do a proper job.
How do these apps behave in practice? They do the necessary thing and allow people who want to turn their home-lighting into a fun project add items like sound control.
After about one week I quit using the wifi solution. It was too much of a hassle to use a smartphone or tablet for something as basic as home lighting. A waste of time. Once you have set the proper color and illumination levels you do not need to go back to these unless you want to change them (or show-off the capabilities to your guests). An additional issue is the fact that I have several wifi networks in my house so my smartphone and tablets connect to the one with the best connection, not to the one which happens to have the wifi light controller.
Rather than the wifi control, the inexpensive hand controller (compare it's €6 price to the €60 Hue Tap) is the easier way to do this. Given the low price of these units you can have one of these per room (next to all your other remote controllers or use the small wall slot unit if you want to know where you left it). The other 99% of the time you make use of your good old wall switch.
To get an adequate presentation of the colors of this MiLight RGBW I placed it in the center of a white (printer) paper funnel. While a camera will have difficulty capturing the colors of a bright LED by looking at it directly, the white paper funnel provided the lower brightness background to properly capture these colors. Before taking the images I made sure that the light in my viewfinder properly represented the emitted light from the bulb. It will not be 100% accurate but quite close.
Below is the lamp with (left) maximum dimmed white and (right) brightest white. I had to reduce camera exposure with factor of 32 to create similar image in the second (brightest) shot.
White mode: Left is max dimmed, Right is max brightness
Notice that the 10 smd placed in a circle create a more diffuse source of light than the heated filament of an incandescent lamp.
In RGB mode, the white LEDs are switched off and light is only provided by the 4 smd 5050 RGB LEDs.
This is the reason why these MiLight bulbs cannot provide the color ranges between each of these primary colors and white. It is not possible to create warmer variations of white, nor more reddish, greenish or blueish versions of white. As stated above, this is a missed opportunity to capture the regular household market that demands for lamp colors more or less similar to incandescent bulbs.
Left: Yellow; Middle: Reddish yellow; Right: Greenish yellow
The yellow on left side is the best one can get as 'warm white' color. Pressing the color dial on the controller towards the red one gets the more warmer yellow (middle image) and pressing the dial towards green one obtains a greenish yellow that I do not consider as very pleasant.
Moving the color dial on the controller results in many other colors and their mixtures but nothing that gets closer to warm white. It is a pity that the RGB smd 5050 LEDs cannot work in combination with the white smd 5630 LEDs to allow for a wider white range.
The 'pure' red, magenta, blue and green mode
Between these colors are combinations that are mixes of adjacent colors, e.g. blueish green and greenish blue. From green, the color circle goes clockwise back to yellow via above depicted greenish yellow to pure yellow.
MiLight DW bulb
This bulb contains 20 smd's type 5630 in a mix of 2700K and 6500K white, a temperature control option between these two colors, and brightness between 100% and 1%. There are 6W and 9W versions. The remote controller is different from the RGBW bulbs and offers a light color setting and brightness setting. The bulb can also be controlled via wifi using MiLight wifi box and apps, selecting the DW controller in place of the RGBW controller.
Making accurate images of the color temperature controlled Dual White bulb is more complex than for the RGBW bulb. Using same white paper funnel as used above and a carefully set manual white balance on the camera I took a set of images that is as close as I could get to the actual colors.
DW 6 Watt, left is coolest setting (6500K), right is warmest setting (2700K)
The cool setting is bluish and less than useful in my view. The warm setting is a brownish type of yellow that may be acceptable for hallways and bathrooms but not for the living room. The color temperature is somewhat similar to the Ikea Ledare products and significantly better than other discount LEDs such as Majestic/Calex. The warm setting is more or less identical to the color of the 2700K warm version of the RGBW bulb shown above.
The capability to control the color of these bulbs makes it more useful than the 'disco' RGBW bulb if it weren't for the fact that the colors are not what I like.
The key improvement I suggest is to replace the 6500K smd's with 2700K smd's and use smd's with color temperature range between 2000K and 2300K in place of the warm smd's. This will allow for a smooth color change when dimming the light, more or less in line with the Kruithof curve that I discuss here.
Warm or Cold light?
The perception of 'warm' light differs around the world:
- Colder climates such as northern sections of Europe, the USA, and Canada (as well as southern sections of South America) prefer warm lights, ideally the range from 2000K to 2700K (from candle-light to warm sunlight).
This is probably because people come from the cold weather into their homes and prefer to experience a warm environment.
- People in warm climates, closer to the equator, prefer a cool light when they enter their home from the heat. This suggests that the inside temperature is cool.
Typically, Asian people prefer cooler white lights than Europeans or Americans. With the LED manufacturing being dominated by Asian companies this results in cooler bulbs.
The key problem is that the perception of "warm" and "cold" light varies with the illuminance (in lux): Although a bright LED may have a pleasant color temperature it will become more bluish and too cool when you dim the light. This is represented in a curve called the Kruithof curve. See the explanation on this Wiki page and on my SmartLED color page.
The MiLight RGBW and DW bulbs would be perfect for retrofitting a house with LEDs in a very cost-effective way if it weren't for its limitations in color changing. The present RGBW bulbs appear to be more aimed at the 'disco' market rather than the household lamp replacement market (which probably is 50 times larger). My 5-year old son loves these colorful lights and shows them to all his friends, but that's about all these RGB bulbs are useful for. The DW bulb offers the basic color temperature control that one would like for normal household conditions except that its color range is a little too cold for me.
Keep in mind that the vast majority of competitive LED bulbs offer a too cool color temperature, often are more expensive than these MiLight bulbs and offer no control capabilities whatsoever, so require you to add pricy external dimmers. In that respect these MiLight bulbs are great value for money, if only they would be a little warmer in color...
Control options via remote unit and apps are great and, even more important, one can continue to use the standard on-off switch. This way, controls are not restricted to whoever has a smartphone but can be done by everyone including guests and small children. It may be an improvement to include an open protocol for the RF control of the bulbs such as Zigbee (this is currently being worked). This will enable software developers to make creative apps for the MiLight products. From a functional, every-day-use perspective the present control functionalty of these bulbs is sufficient.
A MiLight-type bulb that allows the user to combine the colors from the ten white LEDs with the four RGB LEDs may be a significant improvement. Alternative is to create a bulb that has a mixture of white LEDs, yellow LEDs and few red, green and blue LEDs. These bulb versions could be the perfect solution to capture the global LED retrofit market which I estimate to be in the 10+ billion dollar/euro range. If I were a manufacturer I'd have my R&D team do something quickly to fix the color temperature and capture market share (see Smart LED colors page). I have suggested this (as free advice) to several Chinese manufacturers. It might take some time but I expect this will result in some adaptations sooner or later.
The controlling option of these smart LEDs will allow software engineers to create an app that combines a color change towards red when the light is dimmed. Such control option would make the color temperature stay within the boundaries of the Kruithof curve.
Given the massive price difference between e.g. the Philips Hue 'lifestyle' bulbs and the MiLight bulbs my recommendation is to wait a few years until a warmer color temperature solution becomes available (or until the Hue bulbs are priced at less than 10 euro/dollar and Philips has fixed their disastrous mistake of not including a memory setting in the bulb). The extra electricity costs for incandescent lamps in this interim period will outweigh the price difference.
For those who don't want to wait I've experimented with these products and found an inexpensive workaround.
At present I have about two dozen of these smart bulbs in my house and am pleased with them, especially because I paid only about € 200 for this retrofit.
Cheers and good luck with your retrofit!
If you have any comments, suggestions, questions, feel free to send me e-mail.
Please note that I have moved on to other fun projects so be patient in expecting a response.
Useful links for comparison & background:
- CNET comparison (Philips Hue vs Tabu Lumen LED Color; both expensive)
- Olino Testinfo comparable AppLamp dual white (in Dutch, and only the cool version was tested)
- LED forum on Tweakers.net (in Dutch)
- OSRAM presentation (2011, pdf, English) on warm high CRI LED
- Kruithof curve and preferred color temperature - illuminance settings
©January 2015, Gert Nieveld, Amsterdam