FAQ: 2.1 Questions on the diode assemblies scheme technique.
- 2.1.1 Why on the assemblies for fresh water aquarium aren't the popular manufacturer's diodes (Philips or Cree) used, but only Semileds diodes?Открыть или Закрыть
Yes, Cree and Philips diodes are slightly more effective than the Semileds diodes, but this mostly relates to narrow spectrum diodes. Of the 12 installed diodes for the fresh water aquarium, there are 9 white light diodes that have similar productivity and effectiveness as the Philips and Cree diodes, but they are much cheaper. The narrow spectrum diodes of the assembly serve for corrections of the spectrum errors, as well as for separating some color shades. They seldom are used at 100% capacity. So, in most applications they work at low intensities, and their differences from the best light diodes in this case is negligible. Therefore, if the assemblies were built exclusively with Cree or Philips diodes, we wouldn’t receive significant performance advantages for a fresh water aquarium, and the price would be considerably higher.
- 2.1.2 Why don't you propose assemblies for algae filters with wide spectrum diodes at the wavelengths of 620-630nm?Открыть или Закрыть
For algae growth a spectrum 660-670nm is required. In the illustration, note the curves related to intensiveness of spectral action at photosynthesis (green line) and related intensiveness of chlorophyll absorption (blue line).
It’s not difficult to point out, that photosynthetic activity from 620-630nm light is about 40% of the photosynthetic activity of 660nm light. So the light of 620-630nm is two and a half times less effective than 660nm! Further, you should take into account that LED's of 620-630nm typically have parameters where the light output decreases when the current and/or the crystal temperature increases. We choose diodes with an irradiation of 660nm because they have the lowest of all the diodes light efficiency drop when the current and/or the crystal temperature increases. Also, power conversion into 660nm light is higher than for 620-630nm light. Thus, one watt of 660nm light is approximately three times more effective for photosynthesis than one watt of 620-630nm light.
- 2.1.3 Why do you propose namely 12x assemblies, perhaps 10x or even 6x would be enough?Открыть или Закрыть
In this question there is an undisputed authority – our sun. It represents a full spectrum spotlight. It is necessary to strive to create an analogue of this system for marine aquariums. Namely, the LED assembly should have all light diodes in one point, representing all parts of the spectrum. If in one part of the assembly not all parts of the spectrum are represented, we cannot receive an even distribution of the spectrum for its illuminated area. Even if it is not noticeable to the casual observer, the problem remains nonetheless. One should also bear in mind, that the optimal spectrum for a marine aquarium requires defined proportions of light diodes on an assembly. Thus irradiation from some diodes, for example, the red ones, should be low. Ideally, the assembly should have approximately 24 diodes, so that one red color diode would work at 60% of its capacity. Unfortunately, such multi-lens and compact optics are not manufactured. Besides, accumulation in one point of such a large number of high efficiency diodes would, in fact, represent a searchlight, which is a totally different type of LED assembly. That is why, the 12 LEDs on the assembly is optimal for our tasks.