Indoor LED lighting power supply introduction

Any indoor LED lighting fixture needs to be driven. Because the basic condition of LED LED operation is DC power supply, it needs a stable DC voltage VF working environment. More importantly, it needs constant DC current IF to drive it strong. Light without flicker. LED light-emitting diodes are a low-voltage device that cannot directly use alternating current (AC) high voltage power.

Even the so-called AC direct-emitting LEDs are diode self-rectifying and long afterglow technologies that utilize LEDs. The working principle of the AC LED light source is to divide a stack of small LED chips into five strings in a staggered matrix arrangement process.

The AC LED die is composed of a rectifier bridge. The two ends of the rectifier bridge are connected to the AC source, and the other ends are connected to a string of LED chips. The positive half of the AC flows along the blue path, and the three strings of LEDs emit light. Flowing along the green path, three strings of LED illuminates, and the LED dies on the four bridge arms illuminate, and the LED dies on the bridge arm emit light at the same time. The middle string of LED dies are always illuminated due to sharing. In 60 Hz AC, it will be lit at a frequency of 60 times per second.

The DC obtained by the rectifier bridge is pulsating DC, the LED's illumination is also flashing, and the LED has the characteristics of power-off afterglow, and the afterglow can be kept for tens of microseconds, because the human eye is inert to the flow point memory, so people The eye's interpretation of the working mode of the LED + light source + afterglow is continuous illumination.

AC LED has been born for five or six years. Due to its large dispersion, the electrical parameters of LED particles are difficult to match and costly in practical applications. The application circuit sets the current limiting resistor to be very fine, and the production cost is high. The promotion progress is slow.

The LED light-emitting diode is powered by the simplest and cheapest resistor-resistance (resistance + capacitor) step-down scheme. It is because there is no suitable power supply in the early stage, and there is no constant current driving power chip for LED light-emitting diodes. Resistor-capacitor buck is a power-supply method that consumes a lot of power and is not energy-efficient and extremely unsafe.

In 2013, in response to the ERP directive, it is difficult to meet the minimum energy efficiency requirements and power factor (PF) requirements of the EU market, and even the underdeveloped countries have begun to resist the use of unsafe RC LED lamps. Therefore, the method of resisting and reducing the voltage will face a complete elimination.

The LED driver power chip and the LED light source bead surface are mounted on the same side of the aluminum substrate , thus creating a new generation of products "integrated photovoltaic module" in which the usual drive power board or power module is not visible. . It is not the so-called "de-energization", the drive power is still there, but the innovation of the drive power is not a separate manifestation of the power module.

The driving power supply commonly used in indoor LED lighting fixtures is: the primary side controlled switching constant current power supply, also known as the PSR isolation switch constant current power supply and the non-isolated switch constant current power supply. Last year, high-voltage linear constant current technology matured, and high-voltage linear constant current power supply will become one of the mainstream.