1. Computer
experiment
of
Science
and
Engineering
High-‐pass
filter
and
Low-‐pass
filter
University
of
Aizu
s1210199
Masanori
Seino
2. What
is
a
High-‐pass
filter?
A
high-‐pass
filter
(HPF)
is
an
electronic
filter
that
passes
high-‐frequency
signals
but
attenuates
(reduces
the
amplitude
of)
signals
with
frequencies
lower
than
the
cutoff
frequency.
3.
The
product
of
the
resistance
and
capacitance
(R×C)
is
the
time
constant
(τ);
it
is
incersely
proportional
to
the
cutoff
frequency
fc,
that
is,
Fc
=
1
/
2πτ
=
1
/
2πRC
5. What
is
a
Low-‐pass
filter?
A
low-‐pass
filter
is
a
filter
that
passes
low-‐frequency
signals
and
attenuates
(reduces
the
amplitude
of)
signals
with
frequencies
higher
that
the
cutoff
frequency.
6. The
break
frequency,
also
called
the
turnover
frequency
or
cutoff
frequency
(in
hertz),
is
determined
by
the
time
constant:
fc
=
1
/
2πτ
=
1
/
2πRC
7. One
simple
low-‐pass
filter
circuit
consists
of
a
resistor
in
series
with
a
load,
and
a
capacitor
in
parallel
with
the
load.
8. Experiment
1. I
ask
the
f0
of
the
combination
of
CR
that
has
been
selected.
2. I
measure
the
transfer
characteristic.
3. To
draw
a
graph
to
compare
the
two.
9. My
data
(High-‐pass)
f V1
p-‐p V2
p-‐p db Out
of
phase
0.71k 5.16 0.52 -‐19.9 87°
3.58k 5.16 2.36 -‐6.79 63°
7.16k 5.12 3.6 -‐3.05 45°
14.4k 5.12 4.52 -‐1.08 25.4°
71.6k 5.16 5.08 -‐0.13 5.63°
716k 5.16 5.12 -‐0.06 1.24°
10. My
data
(Low-‐pass)
f V1
p-‐p V2
p-‐p dB Out
of
phase
0.71k 4.64 4.56 -‐0.15 -‐18°
3.58k 5.28 4.64 -‐1.12 -‐25.9°
7.16k 5.28 3.68 -‐3.13 -‐45°
14.4k 5.28 2.40 -‐6.84 -‐58.3°
71.6k 5.28 0.72 -‐0.17 -‐60°
716k 5.28 0.32 -‐0.24 88°
13. Result
of
experiments
When
I
wrote
a
graph
based
on
the
my
experimental
data,
graph,
as
defined
could
be.
14. Conclusion
High-‐pass
filter
•High
Frequency
No
attenuation,
asymptotic
to
the
phase
difference
without
•Low
Frequency
Phase
difference
is
asymptotic
to
+90°
15. Low-‐pass
filter
•High
Frequency
No
attenuation,
asymptotic
to
the
phase
difference
without.
•Low
Frequency
Phase
difference
is
asymptotic
to
-‐90°
