First of all, let’s talk about what is the LED driver power supply? It can convert the power supply to a specific voltage current to drive the LED voltage converter, normally: LED drive power supply input, including high voltage ac power frequency (mains), low-voltage dc, high-voltage direct current, low voltage high frequency ac (such as the output of electronic transformer). And the output of the LED driver power supply are mostly can change with LED positive pressure drop values and change the voltage of the constant current source.

LED core components including power switch controller, the inductor, switch components (MOSfet), the feedback resistance, input filter, output filter parts, etc. In accordance with the requirements of different occasions, also have input over-voltage protection circuit, input under-voltage protection circuit, LED open circuit protection, over current protection circuit, etc.

According to the drive mode classification

(1) the constant flow

Constant current drive circuit of the output current is constant, and the output dc voltage is different as the size of the load resistance within a certain range, load resistance is small, the output voltage is low, the greater the load resistance, the higher the output voltage.

Constant current circuit is not afraid of load short circuit, but it is forbidden to load completely open;

LED constant current drive circuit drive is ideal, but relatively high prices;

Should be paid attention to by using maximum current and voltage, it limits the number of using leds.

(2) voltage type

When the voltage regulation circuit, to determine the various parameters of the output voltage is fixed, and the output current is as the load increase and decrease and change;

Regulating circuit is not afraid of open load, but it is forbidden to load completely short circuit;

With voltage driving circuit to drive the LED, each string need to add the appropriate resistance can make average a string of LED display brightness;

Affected by the rectifier voltage variation of brightness.