1.
Part of Made in India,
Design Innovation
Workshop,2015
A
Fresh
New
Experience
in
Project-­‐Making
&
Learning!

2.
PHYSICSINVESTIGATORY
PROJECTON
H-BRIDGE
USINGTRANSISTORS

3.
The
H-­‐Bridge
circuit
also
known
as
a
motor
driving
circuit
is
used
in
robo9cs
to
drive
motors
forwards
and
backwards.
You
can
make
an
H-­‐Bridge
circuit
and
control
the
direc9on
of
motor
rota9on
by
controlling
the
polarity
of
applied
voltage
across
its
terminals.
In
this
project,
you
will
need
a
breadboard,
four
transistors
(PNP1,
PNP2,
NPN1,
NPN2),
a
DC
motor,
four
diodes,
four
resistors
and
a
few
connec9ng
wires.
The
connec9ons
are
made
such
that
the
collectors
of
all
the
transistors
are
connected
to
the
motor
and
the
circuit
has
an
H-­‐like
configura9on
with
a
load
(motor)
at
the
center.
The
circuit
was
tested
by
giving
different
polari9es
to
different
base
resistors
(R1,
R2,
R3
and
R4)
and
the
behavior
of
the
motor
was
observed
at
each
condi9on
and
the
results
were
compared
to
the
following
output
table:

4.
R1 R2 R3 R4 Direc+on
of
current
Effect
on
the
four
transistors
Effect
on
motor
Ground No
Supply No
Supply Vcc LeC
to
right PNP1
and
NPN2
turns
ON Motor
spins
clockwise
No
Supply Vcc Ground No
Supply Right
to
leC PNP2
and
NPN1
turns
ON Motor
spins
anHclockwise
Ground No
Supply Ground No
Supply -­‐ PNP1
and
PNP2
turns
ON Motor
breaks
No
Supply No
Supply No
Supply No
Supply -­‐ No
Supply Free
rotaHon
AQer
verifying
the
experimental
outputs
in
four
different
cases
of
the
inputs,
we
do
the
‘path
of
current’
analysis
and
reason
out
the
motor
behavior
by
iden9fying
which
transistors
turn
ON
in
each
case
.
All
the
transistors
used
above
are
in
the
satura9on
region.

5.
Have
a
look
at
what
we
provide
in
our
Project
Kit!
CoolJunk
is
India's
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DIY
(do-­‐it-­‐yourself)
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focused
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Having
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India,
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innovaHon
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CoolJunk
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including
Wallstreet,
Yourstory,
Hindu
Business
Line,
NextBigWhat
and
was
tagged
as
the
coolest
Indian
start-­‐up
in
IAN
Bootcamp-­‐2011.
For
more
projects
visit
our
website:
CoolJunk
All
tools
and
components
in
one
box.
Step
by
step
visual
instrucHons
Detailed
experiment
theory
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on:
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