led数码管知识简介（Knowledge of LED digital tube）.docVIP

led数码管知识简介（Knowledge of LED digital tube） Knowledge of LED digital tube LED digital tube is a simple device that commonly used electronic components, the following will introduce its performance characteristics, simple detection method and application notes etc.. 1. performance features The following main features of LED digital tube: (1) to drive the light in the low voltage and low current conditions, can be compatible with CMOS and ITL circuit. (2) emitting short response time (0.1 s), high frequency characteristics, good monochromaticity, high brightness. (3) small volume, light weight, good anti impact performance. (4) long service life, service life of 100 thousand hours or more, even up to 1 million hours. Low cost. Therefore, it is widely used as digital devices, digital instruments and computer numerical control device. Simple detection performance 2. LED digital tube appearance of uniform color, no local color and no bubble, in the spare dry battery conditions available for further examination. The 3 volt battery anode lead wire fixed contact in public negative extreme LED digital tube, cathode lead in moving contact stroke is extreme. The lead wires exposed to extreme is a stroke, the stroke should be displayed. In this simple way to check out whether there is a digital tube (a broken pen strokes do not display), cursive (some strokes together), and can be relatively out of the strength of the different strokes light if can check common anode digital tube, only the battery to adjust the outlet,. LED digital tube per stroke ILED working current is about 5 10mA, if the current excessive damage to the digital tube, so it must be preceded by a current limiting resistor, the resistance can be calculated as follows: R = (U - ULED) / ILED Where U is added to the voltage across LED, ULED for LED digital tube of each painting drop (approximately 2 volts). The use of digital multimeter hFE socket can easily check the LED digital tube light. Select the NPN block, C