Snmek 1

Educational program: Mechanic electrician

Title of program: Technical training II. class Transistor as an amplifierWorked out: Bc. Chumchal Miroslav

Projekt Anglicky v odbornch pedmtech, CZ.1.07/1.3.09/04.0002je spolufinancovn Evropskm socilnm fondem a sttnm rozpotem esk republiky.

Description of transistorSchematic markingConnection of transistor in circuit, practical exerciseSpecificationDescription of connectionControl question

Transistor as an amplification element

The transistor is active electronic semiconductor element, which has amplification ability. It is created by couple of junctions PN.Bipolar transistor has three outlets marked like B- base, K ( C )- collector and E- emitter.This semiconductor element changing own resistance so that between E and C would not pass through bigger current, than is Beta multiple current, which pass through to the control electrode B.Semiconductor transmitter is occurencing in two types NPN and PNP. Their function is similar, but they are different by opposite polarity. Where at the PNP current pass through by one direction, at the NPN type pass through by opposite direction.Description of transistor

Schematic mark of NPN, PNP transistor

Connection of transistor in circuit

Components Value R1 M1 R2 10K RC 2K7 RE 22K C1 M15 C2 2-10M T Transistor NPN ( BC 549 )Specification

Influence of elements on amplifier workT silicon transistor, amplifying bringing signal.C1 coupling capacitor separate direct- current voltage from alternating element. C2 - coupling capacitor.RC influence of working point of transistor.RE If it is connection, it reduce reachable oscillation of output voltage.R1, R2 setting of working point of transistor. The more current pass through by divider, the more constant voltage is on base of transistor.

Make a connection of given scheme on contact field and compare function of transistor as a circuit breaker and as the amplifier. Explain the different?Practical exercise for students

1.Question Explain function of transistor.2.Question Draw schematic mark PNP and NPN of transistor.3.Question Replace transistor KC 508 by transistor series BC.

Questions for students

Poznvme Elektroniku I.,Vclav Malina, Vydalo nakladatelstv KOPP,esk Budjovice, 1996www.google/Wikipedie - zesilovaeVlastn poznmkov seitLiterature used