At present, there are non-isolated design and isolated drive power supply in the LED lighting market.
The non-isolated design is limited to double-insulated products, such as the replacements light of the bulb, which the LED and the entire product are integrated and sealed in a non-conductive plastic, so there is no risk of electric shock to the end-user.
As shown in the picture
where the user has access to touch the LED and the output wiring, isolated drive power supply is required.
An isolated transformer or electrically isolated LED drive power supply means the LED can be touched directly by hand without being electrocuted. Although the LED drive power without isolation transformer can still achieve partial mechanical insulation with the help of the protective shell, the LED at this time can not be directly contacted when working. Insulated lights will become mainstream in the future.
As shown in the figure
Non-isolated type and isolated type LED drive power supply to have their own advantages and disadvantages, mainly from the following four points:
In terms of safety: the isolation power supply has more advantages, because the isolation type power supply with wide voltage, performance is better and stable, also will not cause any harm to the human body, and the isolation technology more and more mature. Non-isolated type the voltage range is slightly worse than the isolation, the voltage range is between 110V-300V, and the isolation power supply can do 60-300V, high and low current is very uniform.
In terms of efficiency: isolation type drive safety but low efficiency, non-isolation type drive efficiency is higher.
In terms of the circuit structure: the current isolation scheme is mostly AC/DC flyback circuit scheme, so the relative circuit is more complex, high cost. Non-isolation type is basically use DC/DC boost or buck circuit, the relative circuit is simple, so the cost is relatively low.
In terms of constant current accuracy: the isolation type can be within ±5%. Non-isolation type is difficult achieve.
Application:
1, the IC or part of the circuit board power supply, from the price and volume, the selection of non-isolated power supply.
2, the use of battery power supply, on the battery life requirements, the selection of non-isolated power supply.
Post time: Jan-20-2021
