close

Вход

Забыли?

вход по аккаунту

?

код для вставки
' April 11, 1950
J, M, |__ JANssEN
2,503,739
CIRCUIT ARRANGEMENT PRODUCING A PHASE-DISPLACEMENT
HAVING A SUBSTANTIALLY CONSTANT VALUE
'
Filed Jan. 51, 1947
1.30
-
1.80
1.00
-
A I”
+10°
00
110 °
0.5
1.5 ——>- (0113C
3%
AGENT.
Patented Apr. 11, 1950
,
2,503,139
UNITEDFLSTATES PATENT orrice
PHASE DISPLACEMENT HAVING A SUB
STANTIALLY CONSTANT VALUE
‘Johannes Marinus Lodevicus J anssen, Eindhoven,
Netherlands, assignor to Hartford National
Bank and Trust Company, Hartford, Conn,
trustee '
Application January 31, 1947, Serial No. 725,460
'
In the Netherlands February 18, 1946
3' Claims. (01. ‘178-44)
,
2
1,
It is often desirable, inter'alia if use is made of
a so-called reactance tube, to deduce an auxiliary
voltage from an available alternating voltage, the
former exhibiting a certain phase angle e. g. 90°
In the .vector diagram shown in Fig. 2' the
vectors Va and Vc indicating the voltages across
R and‘C of Fig. 1 respectively, extend normally to
one another, so that their point of intersection,‘
with respect to the last-mentioned voltage.
In the drawings:
upon a frequency variation, moves over the‘cir
cumference of a circle of which V2‘ (voltage across
~ Fig. 1 shows a circuit arrangement used in ‘ex
the secondary transformer winding) is the
diameter. Consequently, the value of vector Vu
is always l/gvi, but the phase angle 9) between Va
plaining my invention.
Fig. 2 is a vector diagram related to Fig. 1.
Fig. 3 is a circuit diagram used in explaining
my invention.
'
H)
'
of my invention.
' Fig. 5 shows curves illustrating the operation
of Fig. 4.
'
A circuit arrangement commonly used for this
panying drawing.
of the two output terminals. The series-con
nection of a resistance R and condenser C is con
_
which it is represented as a source of voltage
purpose is represented in Figure 1 of the accom
is branched at the centre A and connected to one
variable.
Vu’ having an internal impedance Zi consisting
of the parallel-connection of R and _C. If
wRC=1, Vu’ is normal to Vi. In this case the
phase angle of the internal impedance Zi amounts
to —45°.
’
The available voltage Vi is supplied to the
primary of transformer T, of which the secondary
and V1
The circuit arrangement shown in Figure 1»
may be replaced by that shown in Figure 3, in
"Fig. 4 shows the wiring diagram of one form
Upon connecting an external impedance Zu be;-v
20
tween points A and B in Fig. 3, which equally has
a phase angle of —45°, the resulting output volt
age appearing between A and B amounts to
nected in parallel with this secondary winding.
Zu
As an alternative the condenser C may be re
placed by an inductance. The junction pointv vB
i.’ e. areal fraction of Vu’ so that it is also normal
to <Vi..
If in this circuit wRC=1 all phase angles except?‘
two terminals has a value corresponding to half
that of Va, which will remain 90°, change if only
the voltage across the secondary, consequently a
?xed ratio relatively to V2‘, and furthermore ex- 30 the phase angles of Vu' and
hibits a phase-displacement covering an angle
Z“,
which. depends upon the relative value of R and
m
C and furthermore upon the frequency. If
between R and C is connected to the other output '
terminal. The output voltage Vu between these
wRC=1(w=21rf) the phase angleamounts to 90°.
change by opposite amounts. Upon calculation
However, this angle di?ers from 90° in regard to 35 it is found that this can be ensured to a close
all frequencies other than J‘.
The invention provides a circuit arrangement
approximation by inserting between A and B the
series-connection of a resistance R1 and a con
which permits an auxiliary voltage to be deduced
denser C1, the impedance of which series-con
from an alternating voltage, the auxiliary voltage
nection is small with respect to Zi, and at the
relatively to the last-mentioned voltage having 40 same time the relation should hold:
not only a constant ratio in value, but also ex-
_
_
hibiting a phase-displacement substantially inwRc_wR1c1_a
dependent of the frequency.
If wRC1=b then
To this end, according to the invention, in a
R (71 b
circuit-arrangement of the aforesaid kind an 45
RI=E=E
auxiliary resistance R in series with an auxiliary
condenser C1 (as the case may be an auxiliary inFigure 4 represents the wiring diagram of one
ductance L) is connected in parallel with the
form of construction of the invention. This dia
output terminals, these circuit elements having
gram corresponds to that shown in Fig. 1 and
such values that R1C1=RQ and R1 is at hast 50 comprises in addition the series connection of a
several times smaller than R.
resistance R1 and a condenser Cl between points
This will be explained more fully with refAandB.
erence to the diagrams shown in Figs. 2, 3 and 5,
Figure 5 represents several curves indicating
Figure 4 representing a wiring diagram accordthe variation of the output voltage and of the
ing to the invention.
55 phase displacement respectively as a function of
:
the frequency and more particularly for several
having values at which the output voltage estab-l
values of the ratio b/a.
lished at said output terminals has a predeter
From these curves it
mined phase displacement substantially inde
appears’ that even if
pendent of frequency within the frequency range
of the input voltage.
B: 5
a
.
, 2. Apparatus for deriving a phase-displaced
the phase displacement, upon a frequency varia
tion of 50% will not change more than 10°, which
will often be su?icient. The variation of the out
' output voltage from an alternating input voltage
whose frequency is variable within a predeter
mined range, said apparatus comprising a trans
put voltage as a function of the frequency is sub- ‘ former having a primary and a centertapped sec
stantially independent of the ratio b/a. An in
ondary, a resistance R, a condenser C connected
crease of this ratio i. e. the-insertion of a smaller
in series with resistance R. across said second
impedance Zu between A and B, and consequently
ary, “output terminals connected between the
centertap of said secondary and the junction of
series connected resistance R and condenser C,
varesistance R1, and'a condenser 01 connected in
series with resistance R1 across said output ter
minals. said resistances and condensers having
a decrease of the available output voltage is use- '
ful only when it is of importance to make the
phase displacement highly independent of the
frequency.
‘
Also for values of the phase displacement other _
than 90° the invention permits a satisfactory fre
values satisfying the expression:
quency-independency over a large __frequency
range to be obtained by making the ratio ZuIZi_
sufficiently small.
'
1,
\/RCR1C1 2”“
>
" For any desired phase angle q: ‘the equation
where fa is the average frequency of said range
and the R:R1 exceeds unity by an amount
at which the phase displacement of the output
voltage established across the output terminals is
substantially independent of frequency within the
frequency range of the input voltage.
so that the phase angle q? will be most inde
pendent of the frequency if
,
3. Apparatus for deriving a phase-displaced
30 output voltage from an alternating input voltage
whose frequency is variable within a predeter
mined range, said apparatus comprising a trans
former having a primary and a centertapped sec
°’ #1301210,
ondary, a resistance R, an inductance L connect
'Consequently,_when it is desired tov obtain a 09 ;vi ed in series with resistance R across said'sec
1
phase displacement practically independent of the‘
ondary, output terminals connected between the
frequency over a more or less Wide frequency
range it is necessary to satisfy the aforesaid equa;
tion, in which w=21r times the average frequency
over this range.
What I claim is:
1. Apparatus for deriving a phase-displaced
output voltage from an alternating input voltage
whose frequency ' is variable Within a prede
' termined range, said apparatus comprising a
transformer having a primary and a center
tapped secondary, a ?rst resistance, a ?rst-re-:
actance connected in series with said ?rst resist
ance across said secondary, output terminals"
44
centertap of said secondary and the junction of
the series connected resistance R, and inductance
L, said resistances and inductances having values
satisfying the expression:
.
l
521
>
211' f a _
LL‘
where fa. is the average frequency of said range»
and the ratio R :R1 exceeds unity by an an amount
at which the phase displacement of the, output‘
voltage established across the output terminals
is substantially independent of frequency within ,
connected between the centertap of said second-‘ 50 the frequency range of the input voltage.~
ary and the junction of said series connected
J OHANNES MARINUS
?rst resistance and ?rst reactance, a second re
LODEVICUS JANSSEN.
sistance, and a second reactance connected in
series with said second resistance across said out
put terminals, said resistances and reactances
No references cited.
Документ
Категория
Без категории
Просмотров
0
Размер файла
272 Кб
Теги
1/--страниц
Пожаловаться на содержимое документа