Why the outdoor LED display chooses the new technology of Common Cathode Energy Saving?

Publish Time : Apr 30 2021

As the main method of media communication, display screens have developed rapidly in recent years, especially LED advertising display screens. Many outdoor large screens are now using LED displays. The main reason is that, compared with LCD displays, LED displays can save more energy, have a longer service life, and can achieve the seamless splicing. Because of this, LED displays have gradually replaced LCD displays and become the mainstream of the screen market.
However, for large LED display screens, reducing power consumption has always been a relatively difficult problem to overcome. Although it has saved a lot of energy compared with LCD displays, it is still not enough to meet the market demand. Therefore, after years of hard work, LEDFUL Technology has successfully developed an LED display with Common Cathode Technology, which is what we call LED Energy-saving Screen.
Common Cathode, is an Energy-saving Technology for LED display. It separates the red, green, and blue lamp beads of the display, and then accurately powers it. Its current passes through the lamp beads and then to the negative pole of driving IC, which is opposite of the conventional common anode power supply. So it is called the Common Cathode Power Supply.

Since the current of the common cathode power supply first passes through the lamp beads and then to the driver IC, it avoids the voltage drop of the common anode power supply so that reduces the current loss. In addition, the precise and separate power supply for the red, green, and blue lamp beads can ensure that each lamp bead can work at an excellent voltage. Because different lamp beads require different voltages. Powering it alone can avoid more power loss and improve power utilization. In addition, the reduction in power consumption will also let the display module to generate less heat, ensuring its components have a longer service life.

In addition to the technical parameters that make the Common Cathode LED display different from the conventional display, the most direct and significant advantage that the Common Cathode LED display brings to the operator is to reduce the power consumption of the LED display and reduce the operating cost; Moreover, working characteristics such as low temperature rise can eliminate heat dissipation equipment such as air conditioners and then reduce input costs. Under the condition of ensuring high brightness and high contrast, Common Cathode saves energy to the greatest extent, and at the same time has the advantages of low temperature rise, low heat, low power consumption, long life, and good display effect.

And by adopting the LED display of Common Cathode Technology, its power consumption can be reduced by up to 75%, while the high brightness and high contrast are not damaged. Compared with traditional LED displays, Common Cathode Energy-saving LED displays can reduce more power consumption, generate less heat and in the meantime, have a longer service life and greatly improve power utilization. Especially for outdoor large-size LED displays , It can save a lot of electricity expenses every year. In the long run, the Common Cathode Energy-saving LED screen has a higher rate of return on investment, and is superior to traditional LED screens in terms of display effect, product maintenance, service life, and power utilization.

Below is LEDFUL common cathode LED display test report

Testing Environment	Brightness	Ambient Temp		Air Temp		Wind-Force
Testing Environment	1500CD	24℃		16℃-26℃		Gentle Breeze
Testing Requirements	Facing the sun and the white balance of the display is 255 gray scales；The brightness is continuously tested under 6500CD.
Test Items	1.The temperature rise test refers to the process in which the temperature of the display screen gradually rises over time. 2. Screen color fading test refers to the change of color gamut parameters such as display brightness, white balance coordinates, color temperature, etc. with temperature changes. 3. The power test refers to the test of the power consumption of the LEDFUL LED display screen.
Temperature Rise Test
Common Cathode Temp Rise Parameter				Common Anode Temp Rise Parameter
Initial Temp	36℃
Time	Common cathode lamp surface temp/℃	Common cathode PCB temp/℃	Common cathode temp/℃	Time	Common anode lamp surface temp/℃	Common anode PCB temp/℃	Common anode temp/℃
3min	41.4	36.5	36.1	3min	59	55.4	56
6min	45.2	37.2	38.5	6min	64.5	54.5	63.3
9min	46.5	37.4	39.6	9min	76.3	64.2	68.5
12min	48.1	37.6	40.8	12min	83.1	63.5	70.4
15min	48.1	37.8	40.8	15min	79.1	64.7	68.5
18min	49.5	37.4	40.9	18min	79.8	68.2	69.3
21min	52.3	38.5	41.3	21min	79.1	68.2	68.1
24min	49.1	38.6	41.5	24min	80.3	68.5	68.7
27min	50.5	38.6	41.6	27min	82.4	70.4	69.4
30min	51	38.7	41.9	30min	81.1	68.5	69
Result analysis: The common cathode solution is about 20 degrees Celsius lower in temperature than the conventional common anode solution.

Screen Color Fading Test
	Common cathode chroma parameter				Common anode chroma parameter
TIME	Common cathode brightness	Common cathode X	Common cathode Y	Common cathode color temp	Common anode brightness	Common anode X	Common anode Y	Common anode color temp
3min	6568	0.2975	0.3222	7474	6561	0.2957	0.3211	7523
6min	6442	0.2969	0.3239	7490	6168	0.2881	0.3263	8023
9min	6209	0.2963	0.3254	7487	6048	0.2864	0.3281	8057
12min	6247	0.2965	0.3256	7479	6041	0.2852	0.3271	8102
15min	6247	0.2969	0.3262	7449	6008	0.2851	0.3261	8122
18min	6321	0.2978	0.3265	7391	6081	0.2847	0.3275	8212
21min	6257	0.2963	0.3274	7462	5981	0.2872	0.3277	8044
24min	6248	0.2967	0.3284	7425	5930	0.2863	0.33275	8079
27min	6210	0.2935	0.3274	7489	5924	0.2852	0.3272	8184
30min	6246	0.2964	0.3276	7460	5906	0.2864	0.3278	8208
Result analysis: The common cathode directly improves the common anode during the continuous rise of temperature. The common anode has obvious fluctuations in color fading (brightness, color gamut, color temperature). And it still maintains color consistency under extreme temperatures.

Power Consumption Test
	Supply voltage	Single board current	Power factor	Power/㎡ (W)	Average consumption/㎡ (W)
Common cathode	2.8V+3.8V	2.85A+3.56A	0.72	700	152
Common anode	5V	7.02A	0.67	1030	253
Result analysis: The common cathode improves the power factor to achieve the purpose of increasing the active power, and uses a low voltage (2.8V+3.8V) power supply in the lamp bead power supply to reduce the reactive power of the LED display in use. So as to achieve energy saving of 20%-30%.