“Low-voltage LED products are generally designed with a voltage of 12V-36V, and the number of LEDs in each loop is 3-6 in series, and the resistance is used to reduce the current and limit the current. The current of each loop is less than 20mA. An LED product is composed of multiple LEDs. The advantages are low voltage, simple structure, and easy design; the disadvantage is that the current is large when the product is large, and a low-voltage switching power supply is required.
1. Features of LED Controller
The characteristics of the LED controller mainly include two points: high reliability and high efficiency.
Feature 1: High reliability
It is not like an LED street light controller, which needs to be installed at a high place, so it is very inconvenient to repair it during use, and it will increase the maintenance cost. Using this device can save such troubles.
Feature 2: High efficiency
Since LEDs are energy-saving products, the efficiency of the controller must be improved. Of course, the heat dissipation structure of the equipment installed in the luminaire is also very important. The equipment not only has high efficiency, but also has low power consumption and low heat generation, which can increase the service life of LED lamps.
Two, two different types of LED controllers
(1) Low-voltage LED products high-power controller
Low-voltage LED products are generally designed with a voltage of 12V-36V, and the number of LEDs in each loop is 3-6 in series, and the resistance is used to reduce the current and limit the current. The current of each loop is less than 20mA. An LED product is composed of multiple LEDs. The advantages are low voltage, simple structure, and easy design; the disadvantage is that the current is large when the product is large, and a low-voltage switching power supply is required. Due to the shortcomings of the product, long-distance low-voltage power transmission is not possible, and it is limited to small products, such as logo letters, small patterns, etc. According to this feature, the controller design specification: 12V uses 75A/30V MOS power tube control, output current 8A/channel; 24-36V uses 60A/50V MOS power tube control, output current 5A/channel. The user can choose the number of controllers according to the above specifications, and the jumper can choose NE20 low voltage series, and gradient type NE10 low voltage series. Note that the LED must have a common anode (+) pole connection, the controller controls the negative (-) pole, and the controller does not include a low-voltage power supply.
(2) High-voltage LED product controller
The design voltage of high-voltage LED products is AC/DC 220V, the number of LED strings in each loop is 36-48, and the current in each loop is below 20mA. There are two current limiting methods: one is resistance current limiting. It consumes a lot of energy. It is recommended to connect a 1/4W metal mold resistor in series for every 4 LEDs to distribute the heat evenly. This kind of connection is currently stable and reliable; the other is the series current limiting of resistors and capacitors, which is large in quantity. Part of the voltage drop is on the capacitor, and the resistor has low power consumption and can only be used in a stable and long-bright state. If the flash capacitor stores energy, the voltage will double and the LED will easily be damaged. All LEDs using the controller must use the resistance current limiting method. Generally, each LED circuit is one meter, the power is 5W, and the tri-color power is 15W per meter. Commonly used gradient controller NE112K controls DC 1200W, NE103D AC load 4500W DC load 1500W, if there are more flash units, use NE112K, if you only need to use the whole flash, use NE103D. If using the gradual change method, pay attention to load matching. The light distribution characteristics of neon lights and LEDs are different, and different types of loads cannot be mixed in the same circuit.
3. Precautions for designing waterproof led controller
Let’s take a look, if we ourselves are designing a waterproof LED controller, what we need to pay attention to.
First of all, the use of waterproof LED controllers is great, and its existence can overcome the use of equipment in harsh environments. When selecting and designing this type of controller, we must pay attention to its reliability, especially LED street lights. Due to the high installation location of the controller and inconvenient maintenance, the reliability of the waterproof performance must be strong.
Secondly, the worst thing about the waterproof LED controller is the anti-surge capability, and the anti-reverse voltage effect is not ideal. Therefore, we must pay attention to this protection in the design process, because the grid load is enabled. Induction and lightning strikes can cause various surges in the grid system. However, these surges can cause very serious damage to the equipment. Therefore, it is necessary to make a corresponding solution to this problem when designing.
To ensure the high power factor of the equipment. This factor is the basic requirement of the power grid on the load. Under normal circumstances, there are no mandatory indicators, but similar loads should not be too concentrated, otherwise it will pollute the grid and affect the use of equipment; this equipment is an energy-saving product, so the efficiency will be very high. When designing, the equipment should be installed in the structure of the luminaire.