Light Emitting Diodes (LEDs) are very particular about the amount of current and voltage that it gets. Operating it at a current higher than the rated current will negatively affect its lifespan and can even lead to its permanent burnout. Also, the output current delivered by most of the MSI circuits is not capable of driving heavy LED loads. This is where a need for constant current LED drivers and LED power supplies come into play. There is a wide variety of led drivers available in the market today. One can choose the ones which serve the purpose best.
LED drivers can be broadly classified into: constant current, constant voltage, and AC LED drivers.
1. Constant current LED drivers- Constant current LED drivers are those LED drivers power which supply a certain constant current over a range of DC voltage. These drivers are used with LEDs which essentially require a constant input current.
2. Constant voltage LED drivers- Constant voltage LED drivers provide a constant output voltage supply with a maximum current rating. Since only the upper limit of the current is fixed, one has to use a constant current LED driver along with a constant voltage LED driver in order to drive a constant current LED.
3. AC LED drivers- These are actually step-down transformers that can provide a lower AC voltage supply for incandescence bulbs. Normal LEDs, however, can’t be used with these drivers because they need a unidirectional constant current (DC). Moreover, the AC led drivers don't have an arrangement for checking for and adjusting to the wattage requirements of the LED loads. So, these drivers must be used with rectifiers and voltage regulating drivers.
Applications:
Dimmable LEDs- Some LED drivers like the iw3989 ICs are used to drive dimmable LEDs and wall lamps. The iw3989 series also have a feedback system that enables it to check for overheating, short-circuits, and open-circuits.
Solid-state lighting- There are some LED drivers like the iw3620 IC which can be used to drive LEDs, supplying power up to 40W. They are very flexible in terms of the input AC voltage which ranges from 85V to 264V. Also, the output frequency can go up to 130 kHz, which ensures optimum efficiency.
There are many other LED drivers with special functions like linear voltage regulation, screen backlight, projector lamp illumination, commercial lighting, and so on. You can buy most of these LED drivers at heisener.com where you stay assured of the quality of components at the best prices.
