determine a step of marks.
(
)
1
1
cos2
u
U
nft
=
, (3.4)
(
)
2
2
cos2
u
U
nft
=
, (3.5)
Difference of frequencies
1
f,
2
f selects from term
1(2)
12
2
MAX
f
ff
n
−
. (3.6)
Maximum number of harmonic
МАКС
n
coordinates with the highest work
frequency of swip-generator.
1
SGH
MAX
f
n
f
=. (3.7)
Voltage in the output of the stroboscopic mixer:
(
)
(
)
(
)
1
2
1
2
2
0
cos2
cos2
1
cos2
,
2
SG
ADD
SM
SG
ADD
SM
ADD
SG
U
K
K
u
uu
K
KU
U
nft
nft
ft
t
=
+
=
+
+
(3.8)
where
ADD
K
– transfer factor of the adder;
SM
K
– conversion factor of stroboscopic
mixer.
After the transformation:
(
)
(
)
(
)
(
)
2
1
0
1
2
2
2
0
2
0
2
0
1
cos2
2
cos2
2
2
cos2
2
cos2
2
.
SM
ADD
SM
ADD
SG
ADD
SM
U
K
KU
UK
K
nft
ft
t
nft
ft
t
nft
ft
t
nft
ft
t
=
−
−
+
+
+
+
−
−
+
+
+
(3.9)
In order to neutralize the negative influence on the result of measurements of
harmonics
1
n−,
1
n+, at the output of the stroboscopic mixer was added a low pass
filter (LPF1) with bandwith:
1(2)
12
42
f
ff
+
. (3.10)
Voltage that provides by such filter
12
4
ff
+
and with transmission factor
1
Ф
K
:
2
1
1
1
0
2
20
1
1
cos2
2
2
2
1
cos2
2
.
2
F
ADD
SM
F
ADD
SG
U
K
K
KU
U
nft
ft
t
nft
ft
t
=
−
+
+
+
−
+
(3.11)
Voltage at the output of qudrator (QD):
2
1
QD
QD
F
u
K
u
=
. (3.12)
After the transformation:
- 477 -