Constant Current LED Drivers
Safely Powering High Power LEDs
High power LEDs have become very popular due to their high-efficiency of generating light as costs continue to drop. Driving high power LEDs safely will ensure their long life. To achieve maximum efficiency and life, LEDs require a constant current source.
Most of the time, we are use to proving a constant voltage to circuits and let them pull the current they require. LEDs prefer current applied to them that does not change (constant current), regardless of the voltage being applied.
Constant Current Drivers
The constant current driver is an inexpensive active circuit that goes in the circuit between the power source and the LED and limits the current on the output, without regard to the incoming voltages. The constant current driver is available in sizes 0.5, 1, 3 and 5 watts.
Several of the drivers also include a feature which allows for a pulse width modulation (PWM) input. A PWM input allows for the adjustment in the intensity (dimming) of the connected LEDs. PWM can be as simple as an input from a microcontroller.
Connecting to LEDs
To connect in a circuit, the driver goes in series with the LED and power supply. There are several options available in drivers, some with very basic features, others which have more advanced features like PWM. Below are examples of connecting the drivers with LEDs.