Transcript AVOP-ELEKTRO-CHUM-007

Educational program: Mechanic - electrician
Title of program: Technical training
II. class
The powerful amplifiers
Worked out: Bc. Chumchal Miroslav
Projekt Anglicky v odborných předmětech, CZ.1.07/1.3.09/04.0002
je spolufinancován Evropským sociálním fondem a státním rozpočtem České republiky.
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Description of the powerful amplifier
Terminal stage with complementary couple of the powerful
transistors.
Scheme K.S. (t.s.) with complementary couple of the powerful
transistor.
Measuring of frequency characteristic.
Internal connection of the integrated circuit of the amplifier.
Work with catalogue
Students activities
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Job of the powerful amplifier is deliver the required performance to the load of
the amplifier ( loudspeaker ).
The performance of the amplifier is product of voltage and current P=U.I,
P=U2/Rz ( W, V, Ω ).
Basic parameters:
- frequency attenuation characteristic ( 20 Hz – 20 KHz )
- output performance
- nonlinear shape distortion
- distance
- brum
If we bring on the corporate base sin. signal, each of the transistor choose the
own half-wave.
The current passing alternating by one and than by second transistor.
In emitters connection point T1, T2 arising an alternating voltage. From this
point is taking an alternating voltage, performance.
It is necessary to split off speaker by galvanic way through the C1 so that it
would not cause the short- circuit of T1.
If we connect voltage power supply, the both T is passing the standstill current
which is very small. It is increasing with bringing input signal.
By the both of T is passing the same current, the voltage of the source is
distributing on both transistors by the same amount.
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Start measuring on frequency 1kHz, set up the level of signal 0 dB on output.
Select the amount of the input signal U1 so that it is equal to the half power
of the amplifier.
Volume controller on max level, pith and depth controller set up on medium
value of potentiometers.
Measuring on fixed frequency of acoustics band.
To the prepared table write down the resultant values.
Resultants graphically display.
Chip – miniature desk of semiconductor ( Si ), on which there is the whole
connection.
Necessary number of active elements, transistors, the next parts are
subsidiarities circuits. It is as a protection against thermal or power overload, it
automatically setting the work point.
Types of the cases
Size of the cases, maintenance
Simplicity connection of I.O. outlet
Cooling of integrated circuits
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Explain the function of the powerful amplifiers.
Work with catalogue, explanation of concepts in the catalogue.
Explain internal connection of integrated circuit.
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Interconnect pattern practice desks of voltage, correction and final stage of
the amplifier.
Measure current passing through by the powerful amplifier
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Poznáváme Elektroniku I.,Václav Malina, Vydalo nakladatelství KOPP,České
Budějovice, 1996
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