1. According to the driving method, it can be divided into two categories

(1) Constant current type

a、 The output current of the constant current drive circuit is stable, while the output DC voltage changes within a certain scale according to the size of the load resistance. If the load resistance is small, the output voltage is low, and the larger the load resistance, the higher the output voltage;

b、 Constant current circuits are not afraid of load short circuits, but it is strictly prohibited for the load to completely open circuit.

c、 A constant current drive circuit is ideal for driving LEDs, but it is relatively expensive.

d、 Attention should be paid to the maximum withstand current and voltage values used, which constrain the number of LED applications;

(2) Voltage stabilizing type

a、 After the various parameters in the voltage regulator circuit are determined, the output voltage is fixed, while the output current changes with the increase or decrease of the load;

b、 The voltage regulator circuit is not afraid of load open circuit, but it is strictly prohibited for the load to be completely short circuited.

c、 Using a voltage stabilizing driving circuit to drive LEDs, appropriate resistors need to be added to each string to ensure uniform brightness of the LEDs;

d、 The brightness will be affected by the voltage changes caused by rectification.

2. Classified by Circuit Structure Method

(1) Resistance and capacitance voltage reduction methods: Through capacitor voltage reduction, during flashing operation, due to the charging and discharging effects, the instantaneous current passing through the LED is extremely high, which can easily damage the chip. Easy to be affected by voltage fluctuations in the power grid, with low power supply and low reliability.

(2) Resistance voltage reduction method: Through resistance voltage reduction, the disturbance caused by changes in the grid voltage is significant. It is not simple to make a stable power supply, and the voltage reduction resistor consumes a large amount of energy. Therefore, this power supply method has low power supply and low system reliability.

(3) Conventional transformer voltage reduction methods: The power supply has a small volume, heavy components, and low power output, generally only 45% to 60%, so it is rarely used and has low reliability.

(4) Electronic transformer voltage reduction method: The power supply has a low power and the voltage scale is not wide, generally 180-240V, with large ripple interference.

(5) RCC voltage reduction method for switching power supply: The voltage regulation scale is relatively wide, the power supply power is relatively high, generally able to reach 70% to 80%, and it is also widely used. Due to the discontinuous oscillation frequency of this control method, the switching frequency is not easy to control, and the load voltage ripple coefficient is also relatively large, resulting in poor adaptability to abnormal loads.

(6) PWM control method for switching power supply: It mainly consists of four parts: input rectification and filtering part, output rectification and filtering part, PWM voltage stabilization control part, and switch energy conversion part. The basic working principle of PWM switching voltage regulation is that, under changes in input voltage, internal parameters, and external load, the control circuit reacts in a closed loop through the difference between the controlled signal and the reference signal, adjusts the pulse width of the main circuit switching devices, and stabilizes the output voltage or current of the switching power supply (i.e. the corresponding regulated power supply or constant current power supply). The power supply is extremely high, generally able to reach 80% to 90%, with stable output voltage and current. Generally, this type of circuit has comprehensive protection measures and belongs to a high reliability power supply.

Article source: Jiangmen LED waterproof power supply manufacturer http://www.gddpdz.com/