The first blog in a series on Zhaga. In this part I would like to explain Zhaga organization in some detail. What does Zhaga mean? Actually it does not have a meaning. It is not a short for something. After the name was chosen it was discovered that a waterfall in China is called Zhaga but that is just a coincidence and not intended.
Zhaga is a consortium of over 280 industry players in the lighting industry. What does that mean? Simply said it consists of over 280 companies that have decided that the Zhaga idea is a good idea and needs to be further developed. These companies spent a significant amount of time (money) in making this idea work so they are very interested in the success of Zhaga.
The companies that are working on these standards are coming from the logical industries like luminaire manufactures, LED module manufacturers but also less logical companies like plastic production companies. All companies have an interest and expect that Zhaga can help them and the lighting industry forward.
What does Zhaga do? They develop standards that allow exchangeability of LED Light Engines. So how does that translate? Do they make modules, do they design modules… No they do not. They draw up a specification and modules can be designed to fit that specification, and therefore are Zhaga compatible.
Zhaga is about exchangeability that means that you will find in their specifications only requirements that relate to that. They have defined 4 specific interfaces of a LED module that makes up interchangeability. These interfaces are the thermal, mechanical, electrical and photometric interface. So for every form factor that is being specified in one of their books you will find these interfaces being defined.
The inside of the modules is not being specified. That means that the manufacturer can make it in any way he sees fit as long as he complies with these specifications. This also means that some things are not specified. For example the quality of the light (what is quality of light?) is not defined. So for example the specification does not require a specific CRI. This would be one of the many freedoms for the manufacturer. So a Zhaga specification is not a quality specification. It defines exchangeability.
So what is exchangeability. It means, in the sense of Zhaga developed products, that a module from one manufacturer can be replaced by a module from a different manufacturer without having to change the luminaire. So what factors are important here:
– mechanical
The actual mechanical connection points are at the same place. Module from manufacturer A fits in the same place as the module from manufacturer B. Has the screw holes in the same place etc.
– thermal
The heat transfer will be identical assuring that the heat from the module is transferred effectively to the heat sink of the luminaire.
– electrical
The electrical connections are at a defined place, so the new module can be connected again at the same place. No redesign of the luminaire needed.
– photometric
The light output is defined, that means that for example the Light Emitting Surface is defined (and some more) with the result that you do not have to redesign the optical structure of the luminaire.
The specifications like CRI, life expectancy, energy consumption etc are manufacturer specific. So there will be quality differences between the different manufacturers of modules and with that they will have the possibility to compete with each other.
Compare this with the old industry; in the time of the fluorescent tube (that fore sure has not ended yet!) you did have a specific tube for example 58 W tube. This was available in different colors, different CRI, different life expectancy, etc etc but that all fitted in two G13 lamp caps spaced at a specific distance. The control gear would be operating the different light sources with out problems.
There are maybe still some issues in the exchangeability but I will get back on that in the sequel.
Jacob