ĐIỆN tử VIỄN THÔNG DTVT2 nhom7 bai9 khotailieu

Nhóm Nguyễn Bá Duy Dương Văn Hùng Trần Minh Đức Nguyễn Khắc Ngân Đỗ Văn Sang Vũ Văn Chinh Task 1: 1983 – 1984: Sales of singles rose slightly 1986 – 1988: Sales of singles decline gradually 1988 – 1989: Sales of singles remain constant Task 2: Casssettes 1983 – 1986: Sales of cassetes rose steadily Casssettes 1988 – 1989: Sales of cassetes rose slightly LPs 1983 – 1988: : Sales of LPs decline slightly LPs 1988 – 1990: Sales of LPs decline fast CDs 1983 – 1984: Sales of CDs remain constant CDs 1984 – 1985: Sales of CDs rose slightly CDs 1985 – 1986: Sales of CDs rose steadily CDs 1986 – 1990: Sales of CDs rose fast Task 3: CDs and LPs 1986 – 1988: sales of CDs rose steeply, while sales of LPs decease slightly CDs and cassetes 1986 – 1988: sales of CDs rose steeply, sales of cassetes rose gradually Singles and CDs 1983 – 1984: sales of singles rose slightly, while sales of CDs remain constant 4 Cassetes and LPs 1983 – 1986: Sales of casssetes rose steeply, but sales of LPs fell slightly Singles and LPs 1989 – 1990: Sales of singles fell slightly, sales of LPs fell fast Task : Task : Computer record data You can rectify sound on tape or disc A bridge circuit is use to sample alternating current to produce direct current All metals, and some non-metals such as carbon, conduct electricity To prevent radio interference, you must dissipate any source of interference such as car ignition systems Power transistors emit heatsink heat Therefore they must be mounted on a The electron gun in a CRT suppress a stream of electrons When recording a CD, sound is process 44,100 times every second Task : The first quadrant shows the characteristics of the diode when it is forward biased When the voltage is increased, at first the current rise slightly When the voltage reaches about 600mV there is a steeply rise The current continues to rise as fast but eventually a point is reached where the diode would be destroyed by heat The third quadrant show what happens when the diode is reverse biased There is almost no rise The diode is therefore a good rectifier It conducts well in one direction and almost not at all in the other However, there is a slight decrease reverse current This leakage current went down gradually until what is known as breakdown voltage At this point there is a steep decrease in the revense current This sudden increase is called the Zener effect