How does the LCD screen power board achieve high conversion efficiency?
Publish Time: 2024-10-24
LCD screen power board achieves high conversion efficiency mainly through the following ways:
1. Selection of high-quality electronic components:
Switching devices: Select switching devices such as field effect transistors (MOSFET) with low on-resistance and high switching speed. Low on-resistance can reduce the energy loss of the switching device in the on state, and high switching speed can quickly switch the circuit state and reduce the energy loss during the switching process. For example, some advanced CoolMOS devices can significantly reduce the conduction loss while ensuring performance.
Diodes: Use diodes with low forward voltage drop, especially in rectifier circuits. The lower the forward voltage drop, the smaller the energy loss of the diode when it is forward-conducted, thereby improving the overall efficiency of the power board. For example, Schottky diodes have low forward voltage drop and fast recovery time, and are often used in the rectifier circuit of LCD screen power board.
Capacitors: Select high-quality, low equivalent series resistance (ESR) capacitors. Capacitors with low ESR generate less heat and less energy loss during the charging and discharging process, and can better filter and smooth the voltage, thereby improving the stability and efficiency of the power supply.
2. Optimized circuit design:
Topology selection: Use a suitable power supply topology, such as flyback, forward, half-bridge, full-bridge, etc. Each topology has its own characteristics and applicable scenarios. For example, the flyback topology is simple and low-cost, and is suitable for low-power LCD screen power supplies; while the full-bridge topology is suitable for high-power and high-efficiency occasions. By reasonably selecting the topology, the conversion efficiency of the power supply can be improved.
Feedback control circuit: The precise feedback control circuit can monitor the output voltage and current in real time, adjust the working state of the switching device in time according to the change of the load, ensure the stability of the output voltage, and avoid unnecessary energy waste. For example, the use of an optocoupler isolation feedback circuit can effectively feed back the signal at the output end to the control end to achieve precise voltage regulation.
3. Reduce losses in the circuit:
Reduce transformer losses: Optimize the design parameters of the transformer, including the selection of core materials, the number of turns of the winding, and the wire diameter. Selecting high permeability, low-loss core materials and reasonably designing the number of turns and wire diameter of the winding can reduce the hysteresis loss and eddy current loss of the transformer. In addition, the use of special winding processes such as sandwich winding can reduce the leakage inductance of the transformer and improve the energy transmission efficiency.
Reduce line loss: Reasonably plan the layout and wiring of the circuit board, reduce the length of the main current loop, and increase the width of the line to reduce the resistance and inductance of the line. This can reduce the energy loss of the current during transmission and improve the conversion efficiency of the power board.
4. Advanced chip technology:
Use high-performance power management chips, which integrate multiple functions such as high-precision voltage regulation, overcurrent protection, overvoltage protection, etc., and have efficient power conversion capabilities. For example, some power management chips use synchronous rectification technology, which can effectively improve rectification efficiency and reduce energy loss.
