As the control component of the solar energy street light (solar garden light), the solar controller plays an irreplaceable role in the solar street light system, like a human brain or a computer processor. Although it is small in size, it plays a central role. It is particularly important to choose a high-quality controller.
(1) Exit protection voltage
Some users have found that when the solar energy street light has been working for a period of time, especially after several consecutive rainy days, the solar street lamp will not turn on for several days or even many days, the voltage of the battery is normal, and the controller and light source are not faulty. This problem has puzzled many maintenance personnel. In fact, this is a problem with the voltage value of "exit under-voltage protection". The higher the value is set, the longer the recovery time after under voltage, which will cause the normal operation for many days.
A high-quality solar energy street light controller should allow each customer to set the voltage value of the exit protection according to the configuration.But it is worth noting that the configuration of the battery panels must be reasonable. If the daily charging capacity of the battery panels cannot meet the discharge capacity of the night, in the long run, the battery is often in deep discharge, and the life span will be greatly shortened. Therefore, the battery panel configuration must enlarge the margin. When the battery panel configuration is larger, the lower the exit protection voltage can be set, so that it will not cause the impact on the battery.
(2) Constant current output
Due to its own characteristics, the LED light source must be constant current or current limited, either in normal use or affecting its life. Common LED solar energy street lights are achieved by adding a driving power supply to achieve constant current to the LED lights, but this driving will consume a lot of power consumption. Therefore, people think of ways to integrate the constant current into the controller, which is not only easy to install, but also less power consumption.
(3) Output period
Ordinary solar street energy light controllers can only be set to turn off after 4 hours or 8 hours after turning on the lights, which cannot meet the needs of many customers. A high-quality controller should be able to freely set the time period, the time of each time period can be set arbitrarily, there are multiple modes of on and off settings, and better yet, it can be set independently.
(4) Power adjustment of LED light output
Among solar energy street lights, LED lights are the most suitable to achieve different power output through pulse width adjustment. While limiting the pulse width or limiting the current, the duty cycle of the entire output of the LED lamp is adjusted. For example, a single 1W LED 6 series and 5 LED lamps totaling 30W can be discharged at night, and the late night and early morning periods can be separately performed Power adjustment, such as adjusting to 15W in the middle of the night and 24W in the early morning, and locking the current, so that it can meet the lighting all night, and save the cost of battery board and battery configuration. Long-term experiments have proved that the LED lamp with pulse width adjustment method generates much less heat, which can prolong the service life of the LED.
(5) Heat dissipation
In order to reduce costs, many controllers do not consider the heat dissipation problem. When the load current or charging current is large, the heat will increase, and the internal resistance of the field tube of the controller will increase, resulting in a substantial decrease in charging efficiency, and the service life of the field tube after overheating. Greatly reduced or even burned. Especially in the summer outdoors, when the ambient temperature is very high, the heating phenomenon is more obvious. Therefore, a good heat dissipation device should be indispensable for the controller. The metal or plastic case cannot meet the heat dissipation requirements in summer. Aluminum is the preferred material for the solar street light controller housing.
(6) MCT charging mode
The charging mode of the conventional solar controller is to copy the three-stage charging method of the mains charger, namely the three stages of constant current, constant voltage, and floating charge. Because the energy of the mains power grid is infinite, if the constant current charging is not carried out, it will directly cause the battery to explode and damage, but the solar energy street lamp system has limited battery power, so it is not necessary to continue to use the constant current charging method of the mains controller. Scientifically, if the current generated by the battery panel is greater than the current limited by the first stage of the controller, it will cause a drop in charging efficiency. The MCT charging method is to track the maximum current of the battery board, without causing waste, by detecting the battery voltage and calculating the temperature compensation value. When the voltage of the battery is close to the peak value, the pulse-type trickle charging method is adopted, which can not only make the battery full but also prevent the battery from overcharging.
(7) Waterproof and moisture-proof performance
Coastal users can best realize that after a non-waterproof controller is used for about half a year, the circuit board may be corroded. In order to facilitate maintenance, most customers put the controller on the base of the light pole. However, the air-tightness of the base of many light pole manufacturers is very poor. When it rains, rainwater will enter, so that the solar street light controller that is not completely waterproof is likely to be corroded by water. When the amount of rainwater entering is large, it will cause a short circuit of the controller circuit in an instant. Another thing to note is that the terminal should be wrapped with waterproof tape, because ordinary insulating tape cannot protect the wiring from water.
(8) Temperature compensation function
The temperature compensation function is a problem that is easily overlooked, but it is very important and is an indispensable function. The unique negative temperature characteristic of the battery, the voltage of the battery becomes higher when the temperature is low, and the voltage of the battery becomes lower when the temperature is high. The controller monitors the voltage of the battery in real time while charging. Generally, a 12V battery detects about 14.5V for protection to prevent overcharge from damaging the battery. If there is no controller with temperature compensation function, and the use environment of high temperature and low temperature, the real-time voltage detected by the solar street light controller of the battery will have a large error, which will directly lead to serious consequences such as dissatisfaction in low temperature environment and overcharge in high temperature environment.