What are the differences between LED switching power supplies and conventional switching power supplies?
The high-frequency development of LED switching power supplies is the direction of their development. High frequency technology enables the miniaturization of switching power supplies and enables them to enter a wider range of application fields, especially in high-tech fields, promoting the miniaturization and lightweight of high-tech products. In addition, the development and application of switch mode power supplies are of great significance in energy conservation, resource conservation, and environmental protection. The electronic components used in LED switching power supplies mainly include LED diodes, IGBTs, and MOSFETs. SCR has limited applications in input rectification circuits and soft start circuits of switching power supplies. GTR is difficult to drive and has low switching frequencies, gradually being replaced by IGBT and MOSFET.
The difference between LED switching power supply and ordinary switching power supply
The biggest difference is that LED power supply is a constant current source, while general switching power supply is a constant voltage source.
The design difficulties of LED switch power supply are volume and price.
LED switch power supply: 1. Constant current is required. 2. Low temperature, low heat, and long lifespan. 3. Small volume. 4. Waterproof, anti-corrosion, and anti-static. 5. High frequency pollution. Ordinary switching power supplies suffer from severe high-frequency pollution, and even with the addition of inductors and large capacitors for filtering, the waveform of the output DC is very complex. Poor power supply, the power supply itself may not be damaged, but the lifespan and light decay of the LED are greatly reduced.
The LED switch power supply circuit is actually composed of a switch power supply circuit and a feedback circuit. The feedback circuit samples from the load and adjusts the pulse duty cycle or frequency of the switch circuit to achieve the purpose of controlling the output of the switch circuit.
Three conditions for LED switch power supply
1. Switch: Power electronic devices operate in a switch state rather than a linear state
2. High frequency: Power electronic devices operate at high frequencies rather than low frequencies close to the power frequency
3. DC: Switching power supplies output DC instead of AC
