LED drive power classification

LED drive power can be converted into a specific power supply voltage and current to drive the LED light voltage converter, under normal circumstances: LED drive power input including high frequency alternating current (ie, electricity), low-voltage direct current, high-voltage direct current, low-voltage high frequency AC (eg electronic transformer output).


The LED drive power output is mostly with the LED forward voltage drop may change the voltage value change of the constant current source.

LED Power Core elements include a switch controller, inductor, switching components (MOSfet), the feedback resistor, the input filter components, output filter components, and so on. Depending on the situation, we should also have input overvoltage protection circuit, input undervoltage protection circuit, LED open circuit protection, overcurrent protection circuit.

By driving classification
1.Constant current
Constant current drive circuit output is constant, and the output DC voltage but with the load resistance of different sizes vary within a certain range, the load resistance is small, the output voltage is low, the greater the load resistance, the output voltage higher;
Constant load short circuit is not afraid, but non-load completely open;
LED constant current drive circuit drives are ideal, but relatively higher prices;
It should be noted that the maximum value is used to withstand current and voltage, which limits the number of LED use.

2. Constant voltage
When the voltage regulator circuit to determine the parameters, the output voltage is fixed, and the current output has changed as the load increases or decreases;
Regulator circuit is not afraid of open load, but completely non-load short-circuit;
In the regulator drive circuit drive LED, each string only need to add an appropriate resistor so that each string of LED display brightness average;
Brightness will be affected by changes in the rectified voltage comes.