Drive mode can be classified
(1) Constant current: a. The current output from the constant current drive circuit is constant, and the output DC voltage varies within a certain range according to the magnitude of the load resistance. The load resistance is small and the output voltage is low. The larger the load resistance is, the higher the output voltage is. b. The constant current circuit is not afraid of load short circuit, but the load is completely open. c, constant current drive circuit to drive LED is more ideal, but relatively high price. d, should pay attention to the maximum withstand current and voltage value used, which limits the number of LEDs used;
(2) Constant Voltage: a. When the parameters in the voltage regulator circuit are determined, the output voltage is fixed, and the output current changes with the increase or decrease of the load; b. The voltage regulator circuit is not afraid of the load open circuit. However, it is strictly forbidden to completely short the load. c. Drive the LED with a voltage-stabilized driving circuit. Each string needs to be added with a suitable resistor to make each string of LEDs display brightness average; d. The brightness will be affected by the rectified voltage change.