Elenco Electronics EP-130 - DC-DC Converter

-
124
-
Here’s a D
C
-D
C
converter circuit; it can make 5VD
C
from 3VDC. Assemble the ex
p
eriment, set the switc
h
to
p
osition A, and see how this circuit works.
The schematic shows how it works. IC 1 is a
n
oscillator; its output controls transistor
Q
1.
S
elf
-
induction of the transformer coil
g
enerates a hi
gh
voltage current. Diode D1 rectifies this voltage an
d
passes on a hi
g
h DC volta
g
e current. IC 2 is
a
c
omparator t
h
at exam
i
nes t
h
e vo
l
tage.
Wh
en t
h
e
input volta
g
e to I
C
2 is more than 5V, the LED li
g
hts
.
How does turning the control a
ff
ect the circuit? Th
e
control is used as a fixed resistor of 50k
Ω
k
, so turn
i
n
g
the control has no e
ff
ect.
No
t
es
:
EXPERIMENT #1
0
4 D
C
-D
C
CO
NVERTE
R
Wiring
S
equence:

3
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134

5-
4
7-
130

26
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6
7-7
2
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81

28-69-90-92-9
4

31
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64

33-76-83-86-93-91-70-106-116-48-12
0

46
-7
1
-7
5

89
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88
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63
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131

8
4-
8
7-
65

85
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66
-11
5
-12
9

82-68-105

11
9
-124-1
35

122-1
3
2
S
chemati
c