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Description
12 Segments Bargraph LED Digital Display Tube Digital LED Light Bar 12 Grid Light Indicator Bar 58*7 LED Column Light
Product Description
Dot matrix modules, digital tubes, flat tubes, etc. are all regularly arranged LED (light emitting diode) products, and the commonly used colors are red, yellow-green, emerald green, orange, blue, white and so on. The normal working current of the LED is generally 1mA-20mA. The higher the current, the higher the brightness. Depending on the brightness, the current should be within this range. The forward voltage drop of different colors (commonly represented by Ve) is different, about 1.8V for red, yellow-green, and orange, about 3.1V for emerald green, blue, and white, and the parallel driving voltage of LEDs remains unchanged. For large-sized nixie tubes, the LEDs are connected in series, and the total voltage drop must be multiplied by the number N of LEDs in series, that is, Vp#N, and the driving voltage must be greater than the total voltage drop of the LEDs to light up. A current limiting resistor should be added to drive the LED to prevent the device from burning out. The value R of the current limiting resistor is determined by the following formula: R= (VCC-Vf*N)/I, where VCC is the power supply voltage, Vf is the LED voltage drop, N is the number of LEDs connected in series, and I is the set working voltage Current (unit A, 1A=1000mA), such as VCC -5V, Vf=1.8V, N=1, I=10mA, the resistance value can be calculated to be 320Ω, and the standard resistance can be 330Ω, if it is blue light, Vf= 3. 1V, substitute R=190Ω. The actual parameters should be based on the working voltage and required The current is calculated according to the above formula. The power consumption of the LED is Pled=Vf*N*I, and the power consumption of the current limiting resistor is Pr=I*I*R, corresponding to the above example Pled=1. 8*1*10mA-18mW, Pr=10mA*10mA*330Ω=33mW The above calculation is based on a single LED. If N LEDs are lit at the same time, please multiply by N The following is an example of a common LED drive circuit (absolutely prohibit the test without current limiting resistance!!)
