Generally, the most common LED lamp beads work power is set below 30 to 60 milliwatts of power. Commercial grade LEDs that can be used continuously at 1 watt power input were introduced in 1999. These LEDs use extra-large semiconductor chips to deal with high power input, and the semiconductor chips are fixed on metal iron sheets to help dissipate heat. In 2002, 5-watt LEDs began to appear on the market, and their efficiency was about 18 to 22 lumens per watt. down to 35% lighting efficiency. They also produced a commercial white LED at 65 lumens per watt, the brightest white LED on the market at the time. In 2005 they demonstrated a white LED prototype with a record efficiency of 70 lumens per watt operating at 350 mA. Today, the working efficiency of OLED is much lower than that of ordinary LED, and the highest is only about 10%. But OLEDs are much cheaper to produce, for example, a simple printing method can be used to place oversized arrays of OLEDs on a screen to make color displays.

      Dimming control of LED lamp beads:

     People often say true color (True Color) PWM dimming is to use a PWM signal to adjust the brightness of the LED, there are three common ways to adjust the brightness of the LED:

    1. Using PWM technology, using PWM control signal to adjust the luminous brightness of ALED by controlling the duty cycle of the forward working current of the LED.

    2. Use SET resistors, connect different conversion resistors in parallel across the LED drive control IC pin RSET, and use a DC voltage to set the power of the LED drive control IC pin RSET.

flow, thereby changing the forward working current of the LED, and achieving the purpose of adjusting the brightness of the ALED.

    3. Linear adjustment, the easiest way is to use an external SET resistor in the LED drive control C to realize the dimming control of the LED. While this method of dimming control works, it lacks the flexibility to allow the user to change the light intensity. Linear scaling reduces efficiency and causes a color shift of white LEDs toward the yellow spectrum. May be a slight offset, but detectable in sensitive applications. The digital or PWM LED dimming control method is used to realize the LED dimming control with a switching frequency greater than 100HZ, and the pulse duty cycle of the LED driving current is changed by a pulse width modulation method. The frequency is mainly to prevent the human eye from feeling the dimming flickering phenomenon. Under the PWM dimming control of the LED, the luminous brightness of the LED is proportional to the pulse duty cycle of the PWM. Under this dimming control method, the light can be dimmed at high The luminous color of the LED is kept unchanged within the ratio range, and the dimming ratio range of the PWM LED dimming control can reach 3000:1. The linear LED dimming control method adopts the analog dimming control method. Under the analog dimming control, the LED dimming control is realized by adjusting the forward working current of the LED, and the dimming control range can reach 10:1. If the forward working current of the LED is to be further reduced, there will be problems that the color of the light emitted by the LED changes and the forward working current of the LED cannot be accurately adjusted and controlled.