What a dimmable constant current LED driver does, essentially, is allow for a constant flow of electricity in the range of an LED’s functionality that can be dimmed. Think of it like a floodgate or a portcullis; but in this case the water is electricity. The primary advantages come in energy conservation and the retention of intended function, which over time will end up saving money.
A dimmable constant current LED driver will help you to avoid any violation of the AMCR (Absolute Maximum Current Rating), which will very likely make your LED unreliable over time. Such constant current drivers also help you to attain levels of luminosity which can be predicted and matched. Especially in situations where LEDs are used as a lighting scheme for a stage or theatre, it is penultimate that luminosity levels be constant and equal across the board.
Constant current in an LED driver is exactly what it sounds like: electricity whose flow is constant. The thing about these drivers is that they’re not always included with the LED that’s been purchased. You can certainly dim an LED without using a constant current driver; but you won’t be able to ensure its luminosity when compared to other LEDs plugged into the same power source remains constant. Furthermore, depending on where you’ve plugged that thing in, there’s a very possible likelihood that it may be receiving an excess of power. While for a portion of time, LEDs will be able to sustain such excess energy, over time they will become worn down. That’s why AMCR limitations are specified in the first place.
There’s an important distinction to remember when you’re on the market for a dimmable constant current LED driver. Constant current, and constant voltage, are not the same thing. While there are definitely LED applications that would benefit–or at the very least, not be harmed–by a constant voltage driver, in most cases this is going to make the luminosity of the LED variable. It will fluctuate higher and lower over time. It all depends on what your energy needs are, and what the needs of the LED are. Certainly there are applications where constant current or constant voltage in an LED driver don’t really matter. But in scenarios where the maximum energy retention is sought, this issue is going to come up. LEDs cost more initially, but save money over time through their conservative energy consumption.