The driver is the core component of LED lighting. As the LED chip technology become more and more mature, its quality has already been very stable.Since LED is complied to every field of electronics, its changes in luminous intensity, light color and on-off control are almost Unpredictable, so it has become almost one-to-one servo devices. In order to fit the usage of different equipment and LED lights on the market, more and more types of LED drivers spring up, so understand the classification of drivers is a necessary step to choose the right LED driver. The following is a classification of LED drivers on the market:
●Classified by output performance Constant current, constant voltage, both constant current and constant voltage.
●Classified by shape and structure PCBA open frame and with shell.
●Classified by safety structure
Isolation and non-isolation.
●Classified by circuit structure
Capacitor buck, transformer buck, resistance buck, RCC buck, PWM control ●Classified by power factor
With power factor correction and no power factor
●Classified by waterproof performance: waterproof and non-waterproof.
●Classification by incentive method: auto-excitation type and other-excitation type.
●Classified by circuit topology:
RCC、Flyback、Forward、Half-Bridge、Full-Bridge、Push-PLL 、LLC etc
●Classified by conversion method
AC-DC、DC-DC and AC-DC-DC.
It seems that there are many types of LED drivers and are difficult to distinguish them, but the main classification of LED drivers is constant current and constant voltage. This is the main content to be introduced today and can be used as a start to understand LED drivers.
A: Constant voltage led driver
When the various parameters in the voltage stabilizing circuit are determined, the output voltage is fixed, but the output current changes with the increase or decrease of the load; the constant voltage circuit is allowed open load, but it is strictly forbidden the load short-circuit ; The circuit drives the LED, and each string needs to add a suitable resistance to make each string of LED display brightness average; the brightness will be affected by the voltage change from the rectification. This driving method can sample the output voltage at the load side. The linear regulated power supply feedback loop is the most typical constant voltage control application. Take our hot-selling constant voltage power supply model HZD100AYI as an example. This product is suitable for constant voltage fields. The isolated high-efficiency non-flicker bipolar power supply, as shown in Figure 2, when other parameters are determined, the output voltage is a fixed value.
B: Constant current led driver
The output current of the constant current driver is constant, but the output DC voltage varies within a certain range with the size of the load resistance. The smaller the load resistance, the lower the output voltage. The larger the load resistance, the higher the output voltage is; the constant current circuit is allowed short-circuiting the load, but it is strictly forbidden the load completely opened. Constant current driving circuit is ideal for driving LEDs, but the price is relatively high; attention should be paid to the maximum current and voltage values used, which limits the number of LEDs used. Constant current drive is usually used in the design of lighting equipment or backlight in the current power supply research and development and design fields. The main reason for the need for constant current drive in these aspects is that the constant current method can avoid the drive current from exceeding The rated value can effectively improve its reliability. At the same time, the constant current driving method can also ensure that the LED meets the expected brightness requirements, and ensure that the brightness and chromaticity of each LED are consistent, and effectively extend its service life. This is constant voltage unattainable by the driving method. Also take our hot-selling product HZD048CXI-B as an example. This is a stable external ceiling lamp downlight panel light constant current power supply. When the output current of this product is a fixed value, the output voltage is within a range changes.
Fig. 3 HZD048CXI-B hot sale constant current led driver
Our company has constant current, constant voltage, and constant current and constant voltage products. We continue to develop and innovate to meet customer needs. At the same time, we optimize products to improve product quality and adjust parameters to improve work efficiency, so that LED can play its role. Excellent characteristics, you can click on the link www.hzleddriver.com to learn more about related products.
