Elenco Electronics EP-130, Руководство пользователя

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Now we’re going to produce a loud sound by
combining the operational amplifier with two
transistors. After you complete the wiring, set the
switch to position A to turn on the power. When you
press the key, you hear a loud sound from the
speaker.
The signal source for this sound is a capacitor-
resistor oscillator. The operational amplifier acts as
an inverting amplifier, and transistors Q2 and Q3
cause the speaker to produce the sound. This circuit
is called a single ended push-pull circuit (SEPP). You
have learned about push-pull circuits. Single ended
means the circuit has only one output. Most
amplifiers have a second output that is connected to
the negative (–) side of the battery.
Notes:
EXPERIMENT #80: POWER AMPLIFIER USING OPERATIONAL AMPLIFIER
-99-
Wiring Sequence:
o
1-29
o
2-30
o
3-90-67-47-44
o
5-94-48-119-124
o
73-81-86-87-32-113-45-131
o
33-63-43
o
35-46-70
o
76-92-36-134
o
91-88-104-40
o
75-100-111-41
o
74-114-42
o
68-80-89
o
69-93
o
79-138
o
82-84
o
83-102-103
o
85-99-101
o
112-137
o
121-135
o
122-132
Schematic