The development of LED is attributed to the fact that in 1993 Japan Nichia Corporation realized the mass production of Blu-ray chips. The emergence of blue LEDs has opened up new areas of human lighting. With the development of LED technology, LED plant lights used in agricultural planting applications are also Initiated the era of innovation, the quality of LED plant lights and LED lamp beads have a close relationship, then how to choose a good LED lamp beads has become a top priority, the following articles will be analyzed in various aspects to help everyone clearer and deeper Understand the LED, and choose the LED plant lamp lamp beads suitable for the company’s products.
The application rules described below require long-term testing and design experience, and the difficulty of mastering is relatively large. To this end, we have innovatively proposed a plant lamp test sharing laboratory, so that companies without plant lamp spectrum technology can make professional grades. The product.
LED lamp beads application rules
The driving current of the LED lamp bead should not exceed the specification current. The current chip current specification is close to the upper limit of the chip, although the driving current can be increased by improving the heat dissipation to obtain a higher PPF value, and at the same time, the lamp bead The power is also increased, and the increase in PPF and power is non-linear, with the result that the QE value is reduced.
The mechanism of this phenomenon is that the recombination rate of electron holes decreases after the current is increased, the lattice defects of the chip begin to protrude, and the heat generation of the chip increases, resulting in a decrease in the radiation efficiency of the chip, and the increase in power consumption is higher than that of the PPF. The QE value of the plant lamp decreased.
A good design is to find the highest priority between the heat dissipation index and the radiation efficiency of the lamp, instead of using expensive radiators to increase the power of the light source. The result is often to reduce the QE indicator after increasing the power.
It is a phenomenon I often see to make a good lamp bead. Some plant lights make the QE1.3 of the lamp bead QE0.8 of the plant lamp. If the QE of the plant lamp is below 0.7, I suggest to change it. With inexpensive lighting, these problems arise because companies have not built the idea of spectral parameterization.
Tip: By reducing the drive current of the lamp bead is an effective way to get a higher QE value.
The LED lamp bead is a current device. Try to choose a lower junction voltage (Vf), which can increase the QE value accordingly. The lower Vf can also reduce the heat generated by the lamp bead. The high-power plant lamp is especially important for the selection of Vf.
The radiation efficiency of the lamp bead determines the amount of heat generated by the plant lamp.
The heating power of the lamp bead = (1 – radiation efficiency ratio) * electric power.
The actual thermal power of the lamp bead can be calculated by testing to check whether the radiation efficiency value is correct.
Under the premise of spectral design capability, the non-continuous spectrum with the monochromatic lamp bead ratio will be guaranteed in the light decay index. When using continuous spectrum lamp beads, both the light fade indicator and the blue shift indicator are the first considerations, but the cost of the continuous spectrum lamp is advantageous.
Continuous spectroscopy needs to pay attention to the R:B and R:FR indicators. At the same time, the amount of green light radiation is too large to cause QE distortion.
The measurement parameters of the lamp bead are limited by the limit parameters. Any test data close to the limit parameter needs to be evaluated by a professional evaluation agency and cannot be easily believed.
The abnormality of the LED lamp bead measurement parameters is mainly to observe the radiation efficiency and QE value, and the QE value is relatively intuitive. The abnormalities of these two indicators need to be re-measured.
I am most concerned about the measurement error and virtual standard of LED chips. I have always stressed that plant lights are parametric products. Plant lamps sell spectral parameters, spectral parameters are distorted, and planting effects are impossible to talk about.
For the measurement error and the virtual standard parameters, my spectral design theory sets a detection link, that is, the XD factor. By measuring the XD factor, we can convert the illuminance value into PPFD using the XD factor, and the PPFD can be used to test Whether the QE is accurate or not is the innovation of our plant lamp spectroscopy technology. This closed-loop design theory is more reliable to ensure the accuracy of the spectral parameters of the plant lamp.
LED lamp bead price judgment
For the purchase of lamp beads, the most concerned about the cost performance of the lamp beads, usually people compare the price of the same package, we provide a lamp cost-performance calculation formula, you can easily compare the price of the product.
The cost performance of the lamp bead = QE / price, which means the QE value bought at the unit price.
High cost performance, indicating that the QE value obtained per unit price is large
For SMD packages, the price is recommended.
For COB packaging, the price is recommended to use yuan.
Mastering the above knowledge points, the parametric concept of plant lights will be more clear. I believe that the procurement and evaluation of plant lamp beads will greatly help, thus improving the market competitiveness of plant lamps.
Plant lamps are parametric technology products. Professional spectral parameters should be used to describe products and marketing, so that fake and shoddy products can not flood the market and jointly maintain the healthy development of the plant lamp industry.