Liechtenstein Difference between isolated power supply and non isolated power supply(3)

Non isolated LED advertising screen power supply: non isolated LED advertising screen power supply means that input and output are directly connected according to electronic components. There is no transformer difference between isolated LED advertising screen power supply and non isolated LED advertising screen power supply.


Advantages of non isolated LED advertising screen power supply:



1. Conversion efficiency

2. Small volume


3. Very easy to design and low cost

Non isolated LED advertising screen power supply defect:

Regulation of output voltage
For module power products with TRIM or ADJ (adjustable) output pins, the output voltage can be adjusted within a certain range through resistors or potentiometers, and the general adjustment range is ±10%.
For the TRIM output pin, connect the center of the potentiometer to TRIM. In all modules with +S and -S pins, the other two ends are connected to +S and -S respectively. When there is no +S, -S, connect the two ends to the output positive and negative poles of the corresponding main circuit (+S to +Vin, -S to -Vin), and then adjust the potentiometer. The resistance value of the potentiometer is generally more appropriate to use 5 ~ 10kΩ.

Internationally, the inverter power supply series products below 400kVA have come out. In the early 1980s, Toshiba Corporation of Japan was the first to apply AC variable frequency speed regulation technology to air conditioners. By 1997, its share had reached more than 70% of Japan's household air conditioners. Inverter air conditioners have the advantages of comfort and energy saving. In the early 1990s, domestic research on inverter air conditioners began. In 1996, the production line was introduced to produce inverter air conditioners, which gradually formed a hot spot for inverter air conditioner development and production. A climax is expected around 2000. In addition to the variable frequency power supply, the inverter air conditioner also requires a compressor motor suitable for variable frequency speed regulation. Optimizing the control strategy and selecting functional components are the further development direction of the inverter power supply for air conditioners.

1. Low safety factor


2. Poor anti-interference

AC/DC Module power

3. It is difficult to achieve boost conversion and multi-channel output

4. Low input voltage range

Liechtenstein Application site:

rectangular wave of 20 kHz.
Due to the poor working conditions of the welding machine power supply and frequent short-circuit, arcing and open-circuit changes, the working reliability of the high-frequency inverter rectifier welding machine power supply has become the most critical issue and the most concerned issue by users. . The microprocessor is used as the relevant controller of pulse width modulation (PWM), and through the extraction and analysis of multi-parameter and multi-information, the purpose of predicting various working states of the system is achieved, and then the system is adjusted and processed in advance to solve the problem. The reliability of high-power IGBT inverter power supply is improved.
Foreign inverter welding machines can achieve a rated welding current of 300A, a load duration rate of 60%, a full-load voltage of 60~75V, a current adjustment range of 5~300A, and a weight of 29kg.

1. For the LED advertising screen power supply system of IC or part of power circuit in the circuit board, non isolated LED advertising screen power supply shall be adopted from the perspective of property, price and volume;

2. The rechargeable battery LED advertising screen power supply system is selected, with strict requirements on endurance, and non isolated LED advertising screen power supply is used.