Non-isolated Drive Power Will Be the Best for LED Lighting

The design of LED lighting power supply consists of non isolated power supply and isolated power supply. LED drive power with isolation transformer or electrical isolation means that the LED can be directly touched by hand without electric shock. The driving power supply of LED without isolation transformer can still achieve partial mechanical insulation by means of protective shell, but the LED can not be directly contacted at work.

The design determines whether the driver is isolated or non isolated. Safety rules usually require two separate isolation layers. Designers can choose between two physical isolation layers, a plastic astigmatic mask and a glass shield, and use a non-isolated power supply. If physical isolation costs are too high, mechanical difficulties exist, or too much light is absorbed, electrical isolation must be solved in the power supply. The isolated power supply is usually larger than the non isolated power of the same power level. Lighting designers have to do a lot of cost and design optimization for each product they design.

In addition to isolation and non isolation design, the expert also mentioned a design mode of constant voltage and current limiting. "Isolation is the circuit isolation design through the transformer output, non-isolation is mainly the power supply requirements, relatively speaking, this mode of use to ensure the safety of the site. Constant voltage and current limiting is a newly emerging mode, which is likely to be a future direction, if the technology matures can be maintainable, or no drive (in fact, there is still drive), but it also has a drawback is that the output current is too small.

The development of drive power starts from constant voltage constant current isolation mode and constant voltage mode, and develops faster. Now the larger proportion is the resistance-capacitance step-down mode, its cost is relatively low, but the current is not very stable, mainly small wattage, for the use of a relatively low life requirements or very high cost-effective LED lamp proportion is higher. Isolated power supply from the former three-winding, Four-winding to the present two-winding development, convenient for large-scale production. Non-isolation is also slowly developing, such as the current panel lamp, ceiling lamp, etc. when security is guaranteed slowly to use this, because its cost is relatively low. In terms of price, the resistor-capacitor buck mode power supply price is the lowest, but the large wattage is still relatively deficient, the most suitable range is less than 5 watt, although there are more than 10 watt on the market now, but the risk is relatively large. The non-isolation price is higher than the resistance-capacitance step-down, and the range of application is generally 3-20 watts and 25-36 watts, but the circuit structure may be short-circuit or electric shock and other risks. The isolation mode has the highest cost, but its quality is the best. After all, its development time is relatively long and the technology is mature.