Features of LED Driver
(1) High reliability
Especially for the driver of street lights which are mounted on high altitude; the maintenance is inconvenient and maintenance cost is large if the drivers get problems.
(2) High efficiency
LED products are energy-saving products which require high efficiency LED driver. Heat dissipation is very important for driver built-in LED products. With high efficiency driver, the power consumption is lower and heat release smaller, which will reduce the light decay of the products.
(3) High Power Factor
Power factor is load requirements for the electrified wire netting system. There is no mandatory standard for home appliances under 70W. Although it's little impact on the grid for a single low-power electrical device with low power factor, yet, it will produce serious pollution when such lower power device is too concentrated at night when the use of lighting is large. It's said that there will come out some standard requirements to the power factor of 30-40W driver in the future.
Now prevailing in two ways:
1. One constant voltage source leads to multi-channel current sources, and every constant current source supply power to LED in its circuit. In this way, the connecting will be more flexible and the failure of one circuit will not affect other circuits, but the cost will be higher.
2. One constant voltage source only leads to one constant DC current power supply. LEDs work in series or in parallel. The cost is lower but flexibility lower, and you have to solve the problem that one LED failure will not affect operation of other LEDS.
Both driving ways exist at the same time. Multi-channel constant current output power supply maybe the mainstream in the future because it seems better both in cost or performance.
(5) Surge Protection
LED surge capacity is poor for LED products, especially the capability to against the reverse voltage. So, it's important to strengthen the protection of surge. For outdoor LED light like LED street light, they may be damaged by some surge from the grid system which come up on the open of grid system or under thunder weather.
(6) Other protection
Beside normal protection function in driver, we'd better add feedback of LED temperature to avoid LED temperature is too high; also need to meet safety and electromagnetic compatibility requirements.