Download Transistor Amplifier Circuits, 1-1

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When you have completed this exercise, you will be able to locate and identify the functional circuit blocks
on the TRANSISTOR AMPLIFIER CIRCUITS circuit board. You will observe the operation of two basic
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and a source of power to operate.
The active components on the circuit board are the transistors; the power is supplied by the external
power source.
a.
b.
c.
d.
voltage.
current.
power.
All of the above.
The NPN transistor (Q1) within this circuit may be connected in either the common base or the common
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arrangements produce signal gain.
a. 0
b. 1
c. 2
The second circuit block is the COMMON COLLECTOR circuit block.
Potentiometer R4 is the load resistor.
If potentiometer R4 on the COMMON COLLECTOR circuit block were adjusted fully clockwise (CW), the
resistance across R4 would be
a. minimum.
b. maximum.
c. about half the total value.
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The BIAS STABILIZATION circuit block includes a resistor, labeled HEATER, that is physically close to
the case of a transistor.
A separate dc power supply is used to pass a current through this resistor (HEATER).
A positive variable dc power supply is used in the BIAS STABILIZATION circuit block.
This circuit block does not use a sine wave generator.
The heater circuit in the BIAS STABILIZATION circuit block uses
a.
b. a variable dc supply separate from the transistor supply.
c.
d. the same variable dc supply as that used by the transistor.
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The two NPN transistors (Q1 and Q2) can be connected by either RC (resistor-capacitor) or transformer
coupling between the stages.
a. 1
b. 2
c. 3
The DIRECT COUPLING circuit block has components that demonstrate the operation of a two-stage
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Potentiometer R1 is used in the voltage divider circuit.
The second stage contains a PNP transistor (Q2).
All other transistors on the circuit board are NPNs.
The DIRECT COUPLING circuit block uses
a. 2 PNP transistors.
b. 2 NPN transistors.
c. 1 NPN and 1 PNP transistor.
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Examine the TRANSISTOR AMPLIFIER CIRCUITS circuit board. A circuit block that can be
a.
b. COMMON COLLECTOR circuit block.
c. BIAS STABILIZATION circuit block.
d. DIRECT COUPLING circuit block.
฀
Examine the TRANSISTOR AMPLIFIER CIRCUITS circuit board. The circuit blocks that
have a potentiometer are the COMMON
a.
b. COLLECTOR, BIAS STABILIZATION, and DIRECT COUPLING circuit blocks.
c.
d.
circuit blocks.
฀
The circuit block that is powered by a positive variable dc power supply is the
a.
b. COMMON COLLECTOR circuit block.
c. BIAS STABILIZATION circuit block.
d. DIRECT COUPLING circuit block.
฀
Which circuit block has a PNP transistor?
a.
b. COMMON COLLECTOR circuit block
c. BIAS STABILIZATION circuit block
d. DIRECT COUPLING circuit block
฀
Which circuit block does not have a connection for the sine wave generator?
a.
b. COMMON COLLECTOR circuit block
c. BIAS STABILIZATION circuit block
d. DIRECT COUPLING circuit block
฀
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While observing the signal on oscilloscope channel 1, adjust the sine wave generator for a
1 kHz, 50 mVpk-pk input signal (Vi).
฀
Using the oscilloscope channel 2 probe, measure the ac output signal.
Vo =
Vpk-pk (Recall Value 1)
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฀
Is the output signal (Vo) larger than the input signal (Vi)? (This indicates gain.)
a. yes
b. no
Vi = 50 mVpk-pk
Vo =
Vpk-pk (Step 8, Recall Value 1)
฀
฀
While observing the signal on oscilloscope channel 1, adjust the sine wave generator for a 1
kHz, 100 mVpk-pk ac input signal (Vi) at the base of Q1.
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฀
Using the oscilloscope channel 2 probe, measure the ac output signal (Vo).
Vo =
฀
mVpk-pk (Recall Value 2)
Is the output signal (Vo) larger than the input signal (Vi)? (This indicates gain.)
a. yes
b. no
Vo =
mVpk-pk (Step 12, Recall Value 2)
Vi = 100 mVpk-pk
฀
What is the phase relationship between the input and output signals?
a. in phase
b. out of phase
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board.
•
•
The input signal level should be measured at the location shown in the circuit connection diagram.
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1.
a.
b.
c.
d.
base circuit.
emitter circuit.
collector circuit.
All of the above.
a.
b.
c.
d.
RC coupling.
transformer coupling.
direct coupling.
All of the above.
2.
3. When small ac input signals are required,
a.
b.
c.
d.
use channel 1 on the oscilloscope.
use the ATTENUATOR.
adjust the potentiometer carefully.
use the variable dc power supply.
4.
a. COMMON COLLECTOR circuit block.
b. BIAS STABILIZATION circuit block.
c.
d. DIRECT COUPLING circuit block.
5. The potentiometers on some of the circuit blocks
a. change the value of the resistor.
b. adjust the dc voltage supply.
c.
d. adjust the ac input signal.
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