[Test 5 continued from previous page)
What is lc?
a:
lc = _ __
_
GO TO BLOCK 4
b.
19
0.4Bma ~ I a ~ 1. 92ma
TM 11ng1 In o wu tourtd to M ' O. Sire S o
lrom ltsson one .
~
O. PP. Form11l• 3
Did you get the same result ? If not, do not go on,
but check your celculatlon.
20
YOU ARE CORRECT!
Collector to ground
GO TO BLOCK 12
21 YOU
ARE INCORRECT!
The output from an emitter-follower is
from
Refer to the text and return to BLOCK 2.
a.
[End of programmed test for Lesson
Fi ve)
Emi tter to ground
GO TO BLOCK 2
BREADBOARD PROJECT FOR LESSON 5:
Emitter Follower Design
"Wire up" the circuit in figure
1 on the breadboard. Before
applying power, set P to the full
CCW position .
1.
2.
and the transistor is operating at
point C in figure S-2, on the curve
Vin = V (where V equals -6V) . The
output voltage is now almost -6V
Apply power, -6V only.
-6V
-6V
3. The lamp should not light.
The circuit is operating at A in
figure 5-2. The base is zero biased
and, therefore, IE = 0. The only
current flowing is leo which is too
small to cause a voltage drop
across RE worth accountin for. A
voltmeter (if one is available)
would verify this fact.
The output is also at OV since the
voltage across the lamp is OV.
4. Adjust the potentiometer
slowly to about halfway to the CW
position .
Note that the lamp begins to glow.
The circuit is now operating at
point B in figure S-2, on the curve
Vin3. The voltage from base to
ground is, of course, about 3V.
The voltage across the lamp is
about 2.8 volts . (When the
transistor is operating in the
"active region," VBE = 0.2V for
germanium transistors.)
5. Set P to the full CW position .
The lamp is now glowing "full"
p
and the voltage drop across the
transistor is about VBE.
By performing this experiment,
the student should have observed
the fact that the emitter "follows"
the base as the base voltage is ad -
justed up and down . Hence, the
term "emitter follower." Second-
ly, he should have noticed that the
input and output voltages are in
phase .
6.
Disconnect the power.
7.
"Wire-up" the circuit in figure
on the breadboard . Before
applying , set S to the low (L)
position .
2
Figure 1
8.
-6V
r
I
I
-
Apply power, -6V only.
-6V
-~
I
s,
I
~ l--J
Figure 2
9. The lamp should not light.
The circuit is operating at point A
in figure S-2, on the curve Vin = 0.
The output is at a low level.
10. Set S1 to the high (H)
position . The lamp should glow.
The circuit is now operating at
point C in figure S-2, on the curve
Vin = V (where Vin = -6V ). The
circuit has made a rapid transition
through point B.
The output is now at a high level
and in phase with the input.
Sega had lower earnings in Japan in '80
LOS ANGELES- Sega Enterprises,
Inc. reported net earnings of $3.2
million, or 45¢ per share, for the
second quarter of its fiscal 1981 ,
ending December 31, 1980. This
compared with $4 million, or 55¢ per
share, for the prior year's second
quarter.
Net earnings for the second
quarter included gains from trans-
lation of foreign currency denomina·
ted assets and liabilities into U.S.
dollars and foreign currency transac-
tions of $396,000, or 6¢ per share,
versus $551,000, or 8¢ per share, in
14
the fiscal 1980 second quarter.
Net earnings were $5.4 million, or
76¢ per share, for th six months
ended December 31, as against $10.2
million, or $1.42 per share in the
previous year's first half.
Revenues for the current six
months fell to $74.4 million
compared with $83.3 million for the
same period last ~ear .
The company's consolidated net
earnings for the quarter were down
as a result of a decline in net earnings
from its Japanese business interests,
the company an~ounced. However,
the company's U.S. business had
record second quarter revenues and
net earnings from the sale of its coin-
operated electyronic video amuse-
ment games, said David Rosen,
chairman of the board and president
of Sega.
The company experienced lower
revenues from games operated in
Japan, as well as higher costs of
games sold and operated in that
country.
Sega is an 85-percent owned
subsidiary of Gulf +We s tern
Industries, Inc.
PLAY METER, May 1, 1981