range, etc.
The swip-generator’s frequency meter in the frequency change mode works
according to next algorithm.
Firstly, control unit became to form a saw-tension voltage after the arrival of the
U
МC
pulses from the microcontroller MC (fig. 3.2, a). The frequency of the output
voltage of the swip-generator SG (ƒ
SG
) connected to the first input of the stroboscopic
mixer SM changes during the direct current of the voltage from the control unit in an
approximation to the linear law (fig. 3.2, b).
At the second input of the stroboscopic mixer through the adder (ADD), provides
a voltage in the form of short pulses from the first (RG1), or from the first and the
second RG at the same time. The generators have close frequencies ƒ1, ƒ2. Harmonics
of the output voltage of the reference generators, are evenly distributed in the operating
frequency range of the swip-generator with the ƒ1, ƒ2 step, respectively.
During the first period of the deployment of the generator’s frequency a first
reference generator with a frequency ƒ1 connects to the stroboscopic mixer and the
second reference generator doesn’t work.
At this time, the microcontroller transmits the controlled filter (CF) to a low pass
filter mode with a bandwidth –
21
()
MAX
n
f
f
−
, where
MAX
n
is the maximum harmonic
number of the first reference generator. Herewith, in the output of controlled filter
releases a low-frequency voltage, according to which marks maker (MM) creates
mark’s pulses with the step ƒ
1
(fig. 3.2, c) in the input of microcontroller. Time position
of these marks writes in the microcontroller’s memory. According to this algorithm
coordinate marks can be formed.
Stroboscopic mixer connects to the second reference generator with a frequency
of ƒ2, during the second period of the deployment swip-generator’s frequency.
The microcontroller turn the controlled filter into a mode with band
21
()
MAX
n
f
f
−
…
1
21
()
2
MAX
f
n
f
f
−−
. After the appearance of the first coordinate mark (fig. 3.2, d), in
the output of marks maker (MM) appears a pulse of the permission (fig. 3.2, c) for the
microcontroller to determine a frequency of oscillation
21
()
F
nf
f
=−
in the output of
the low pass filter (LPF), where n is the harmonic number of the first reference
generator. The low pass filter’s bandwidth –
21
()
MAX
n
f
f
−
. There is a subjected to a
square by a quadrator (QD) voltage from the controlled filter in the input.
Using the next formula
1
1
21
М
fF
f
ff
=
−
, (3.1)
frequency of the first mark can be calculated. The microcontroller, according to
the known frequency of the first coordinate mark
1
М
f
, determines the frequencies of all
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