In what kind of environment is the LED plant light most suitable for plant growth? How many hours does it need to fill up the light a day?
The wavelength of the LED plant light is very suitable for the growth, flowering and fruiting of plants. Generally, indoor plants and flowers will grow worse and worse with time. The main reason is the lack of light irradiation, which is irradiated by LED plant lights that are suitable for the required spectrum of plants. , Not only can promote its growth, but also prolong the flowering period and improve the quality of flowers. The application of this high-efficiency light source system to agricultural production such as greenhouses, greenhouses and other facilities on the one hand can solve the shortcomings of the lack of sunlight leading to the decrease in the taste of tomatoes, cucumbers and other greenhouse vegetables, and on the other hand, it can also advance the winter solanum vegetables It will be listed around the Spring Festival, so as to achieve the purpose of off-season cultivation.
There are two reasons for low light intensity:
1. The luminous intensity of the LED plant light itself is low, and the solution needs to be replaced or increased.
2. The LED plant light has high luminous intensity, but the distance between the light and the plant is too high, so that the light intensity reaches the surface of the leaf and is lower than the light compensation point of the plant. The solution is to reduce the height of the luminaire.
The strength of photosynthesis of any kind of crop is closely related to the intensity of light. The trend of photosynthetic intensity changing with the intensity of light is similar. When light is enhanced, photosynthesis will increase, and when light is weakened, photosynthesis will decrease. But when the light is increased to a certain extent, the photosynthetic intensity will no longer increase, and the light intensity at this time is the light saturation point of photosynthesis. When the light is weakened to a certain limit, the photosynthetic intensity cannot be measured (the photosynthetic intensity and the respiratory intensity are exactly equal, the ratio is 1), and the light intensity at this time is called the photosynthetic light compensation point.
Plant supplement light can be used during the day when the sun is shining, and it can be used in the day when there is no sunlight, or during the day when it is rainy or rainy, or it can be used at night. Add light. If it is a sun-fast plant, you can give it more. In fact, if there is no need for viewing, it is better to supplement the plant light at night according to the light time of the plant's native place. Combining seasonality, you can adjust the light. For example, the native land has sufficient light, 12 hours a day. You can set it up when there is natural light during the day, and then supplement the plant lights at the same time.
This way you don't need very large power. The photometric value can be measured with a photometer. It is enough to meet the light conditions for growth. If the natural light in your local area is only 8 hours, the daytime natural light will shine for 8 hours together, which is not enough. If you want to illuminate the plant light alone at night, you must increase the light power for another 4 hours.
Since the junction temperature can be determined by the average power consumption, even a large ripple current has little effect on power consumption. For example, in a buck converter, a peak-to-peak ripple current equal to the DC output current (Ipk-pk=Iout) will increase the total power loss by no more than 10%. If the above loss level is far exceeded, then the AC ripple current from the power supply needs to be reduced in order to keep the junction temperature and operating life constant. A very useful rule of thumb is that for every 10 degrees Celsius decrease in junction temperature, semiconductor lifetime will increase twice. In fact, due to the inhibitory effect of inductors, most designs tend to have lower ripple currents. In addition, the peak current in the LED plant light should not exceed the maximum safe working current rating specified by the manufacturer.
When it is lower than the turn-on threshold of the LED plant light (the turn-on voltage threshold of the white light LED is about 3.5V), the current passing through the LED is very small. Above this threshold, the current will increase exponentially in the form of a forward voltage. This allows the LED plant light to be shaped as a voltage source with a series resistor, with a warning note: this model is only valid under a single working DC current. If the DC current in the LED plant light changes, then the resistance of the model should also change immediately to reflect the new operating current. Under a large forward current, the power dissipation in the LED plant light will cause the device to heat up, which will change the forward voltage drop and dynamic impedance. It is very important to fully consider the heat dissipation environment when determining the impedance of the LED plant light.
Adjustable brightness requires a constant current to drive the LED plant light, and the current must be kept constant regardless of the input voltage. This is more challenging than simply connecting an incandescent bulb to a battery to power it.
The use of LED plant lights is coordinated with the light saturation point and light compensation point of different plants. The light saturation point and light compensation point of plants vary with crop types and cultivation conditions. If plants are growing due to lack of sunlight in the environment, such as basements and balconies, they are planted. Artificial light (plant light) needs to be used to replace sunlight to provide the energy required for photosynthesis for plant growth. The light intensity of the required light source must reach the light compensation point required by the plant to grow normally.
Below the light compensation point, the plants grow excessively or grow slowly; above the light saturation point, the photosynthetic rate will no longer increase, and light inhibition will occur, resulting in waste of light energy. The light intensity is between the light saturation point and the light compensation point. The use of LED plant lights to grow fruits and vegetables can promote plant photosynthesis, shorten the growth cycle, increase production and income by 20-80%, promote flowers and fruits, increase fruit setting rate, and repel insects It is resistant to diseases, reduces deformed fruits, and improves the taste, sweetness, quality and appearance of the fruits. This is why the use of plant growth lights has no effect. If the temperature, humidity, water, fertilizer, and carbon dioxide concentration are normal, the biggest reason is that the light intensity of the LED plant lights is lower than the light compensation point of the plants.
