1. It is a commonly used method to measure the voltage of LED tubes. 2. The LED tube pressure measurement method is to determine the voltage of the LED tube by connecting the LED tube to the circuit and using a voltmeter or multimeter to measure the voltage in the circuit.
The voltage of the LED tube refers to the voltage difference between the two ends of the LED tube under normal working conditions. The principle of this measurement method is that when the LED tube is working forward, there will be a fixed voltage drop, which is related to the material and structure of the LED tube.
By measuring the voltage in the circuit, the voltage of the LED tube can be obtained indirectly. 3. It is worth extending that the voltage of the LED tube is the voltage required for its normal operation, and it is also one of the important parameters for selecting the appropriate power supply and circuit design.
In practical applications, it is necessary to select the appropriate power supply and circuit according to the voltage of the LED tube to ensure that the LED tube can work properly and play its best performance. At the same time, the voltage of the LED tube is also closely related to its characteristics such as brightness and power consumption, so in the design of LED lighting and electronic equipment and other fields, the accurate measurement and control of the voltage of the LED tube is very important.
The tube pressure of LED was measured by domino transverse test.
Because the LED lamp bead voltage is very small, and may even be only a few millivolts, the use of traditional voltmeters for measurement may have a large error.
The Domino transverse test method can calculate the voltage value of the LED lamp bead by accurately measuring the current, so as to obtain more accurate measurement results. At the same time, it should be noted that for different types and brands of LED lamp beads, the voltage value may be different, and it needs to be measured and analyzed according to the specific situation.
1, first determine whether the backlight is CCFL or LED, if it is CCFL, you only need to look at the voltage of the CCFL booster capacitor, and then divide the voltage by 1.414 to get the approximate CCFL voltage.
2, if it is LED, it is necessary to determine whether the LED FPC goldfinger is in parallel or in series, if it is in series, then give a standard 20mA constant current drive, and then gradually increase the voltage from small to large, while observing the position of the LED bright spot several, you can determine the number of LED use. When the voltage of the backlight no longer rises, use this voltage to remove the number of leds to see if it corresponds, if it does not correspond, then there is still a parallel connection within the FPC, and then in accordance with the multiple of 20mA to set, until the obtained voltage and current product is the number of LED power. And then this voltage is the driving voltage of the backlight.
3, if the LED backlight of the FPC goldfinger is in parallel, then only need to separately test the separate line, according to the above method, separate parallel voltage can be obtained.
The ordinary daylight lamp has a small filament at each end, and the two feet of each end of the good lamp tube are connected when measured with a multimeter (only a small cold resistance). The working principle is: when the lamp is manufactured, a small drop of silver (mercury) is filled in the vacuum, and the wall of the tube is coated with fluorescent powder. When the lamp is started, the filament at both ends is heated, the mercury evaporates into a gas, the gas is ionized and conducts electricity into a circuit, and the gas simultaneously emits a large amount of ultraviolet light, which stimulates the fluorescent powder to emit visible light.
In addition, when the lamp is aged, the two ends of the filament evaporation leads to the black at both ends of the lamp, and sometimes the filament of such a lamp is not broken and can not be used (such a lamp is difficult to spark).