Elenco Fiber Optics Voice and Data Kit - Manual (Page 20)

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INSERT THE CABLE
TESTING PROCEDURE
Answ ers: (1) pow er supply , phototransistor , audio op-amp , speak er (2) light, electrical (3) intensity
(4) 20 (5) C4 (6) electrical, sound (7) On-Off (8) noise (9) v olume (10) audio
Slide the cable through the lug
and butt the cable up against the
phototransistor.
1. Plug a fresh 9 volt battery into the battery holder.
2. Turn S1 on (toward the pot), observe that LED
D1 is on.
3. If you have a voltmeter, measure the DC voltage
at pin 5, it should be about 4V.
4. Connect one end of the fiber to the source
connector to the transmitter, and the other end to
the detector connector of the receiver. Make sure
switch S2 of the transmitter is in the off position
(toward the battery). Now, speak into the
microphone. You should hear your voice from the
speaker of the receiver. Now, place C4 into the
circuit by sliding switch S2 toward the infrared
LED. You should hear a shrill noise from the
speaker.
1. The receiver consists of 4 main components.
They are _________, _________, _________
and ________.
2. The phototransistor Q1 converts a __________
signal into an __________ signal.
3. The flow of the current through Q1 is directly
proportional to the ________ of light that strikes
its base.
4. The gain of the audio amplifier (LM386) is
internally set to _________.
5. The amplifier signal is coupled to the speaker
through __________.
6. The speaker converts an _________ signal into
a _________ signal.
7. The LED D1 acts as an _________ indicator.
8. C2 filters out any __________ at the power
supply.
9. The pot R1 is a __________ control device.
10. The LM386 chip is an __________ amplifier.
QUIZ 3