DE99919C - - Google Patents

Description

IMPERIAL

PATENT OFFICE.

Dr. JOSEF TUMA in VIENNA. Phase meter.

The subject matter of the present invention relates to phase meters by the D. R. P. No. 95954 protected species, in which appropriately reshaped and by Resistances modified partial currents of the alternating currents to be compared by two Coil systems (an outer fixed and an inner movable coil system) so that, as a result of the circular and uniform rotating field a rotation of the inner movable coil system by one Angle takes place, which is equal to the phase shift angle.

This arrangement has the purpose of simplifying the construction of the apparatus and the same To make determination of the idle current suitable.

The first-mentioned purpose is achieved by the fact that the inner, so far as a coil cross executed coil system in the form of a simple coil, which is carried out by a special arrangement of the outer fixed coil cross is made possible.

The last-mentioned purpose is achieved by the diversion of the movable ones Coil can be returned to the zero position by means of a torsion spring, whereby the idle current can be easily determined.

The circuit takes place according to these purposes in such a way that the one from thick wire of low resistance Coil of the fixed, spherical coil cross through the primary winding (consisting of thick wire) of an iron-free one Transformer over a low resistance with the line of an alternating current (Main current) is connected, while the second coil of the coil cross consists of thin wire of high resistance to the secondary winding (made of thin wire) of said transformer connected. The moving coil is with the line for the second alternating current connected and can be temporarily connected by a switch for the purposes described later be switched into a branch line of the main stream.

For the purpose of correct setting of the instrument, the coil of the spool wound with thin wire is replaced by a second one made of thick wire. Winding, which is connected to a branch line of the main current with the inclusion of a low resistance (Y ₁₀₀ Ω), while in the line to the secondary coil an "adjustable resistor" is connected, so that by changing the latter it can be achieved that the phases of the Fields that are generated by the currents circulating in the two coils, as required, are shifted by exactly 90 ° relative to one another.

The accompanying drawing illustrates an embodiment of the phase meter in FIGS in two longitudinal sections perpendicular to each other.

Fig. 3 is a horizontal section through the instrument along the line xx (Fig. I).

Fig. 4 shows the apparatus seen from below.

Fig. 5 is a diagram explaining the operation of the apparatus.

As can be seen, the apparatus consists of two (fixed) coils forming a coil cross. ¹ and A ² (FIGS. 1, 2 and 5), the windings of which have the shape of spheres in order to achieve a circular rotating field that is as uniform as possible. In the practical implementation, the coils are produced as hemispherical pairs of shells, as shown in FIGS. 1 and 2. The winding of the coil A ¹ attached to the stand B of the apparatus consists of thick wire α 'of low resistance and could therefore also be replaced by a hollow copper ball cut open in a spiral shape.

The coil A ² , the turns of which are perpendicular to those of the coil A ¹ , is enclosed by the coil A ¹ and has many turns of thin wire a ² of high resistance. In addition, this coil receives a second outer auxiliary winding a ³ made of thick wire, the purpose of which will be discussed later.

The ends of the wraps a ¹ respectively. d ² are enclosed in the stand, in the scheme (Fig. 5) made visible lines with the terminals I, I respectively. II, II connected.

Inside the hollow spherical spool A ¹ A ² is a movable coil S rotatable about the vertical spindle 5, the rotating spindle s of which is connected to the axis of the pointer Z, which is enclosed in the box D and which plays on a circular pitch K.

The lower end of the spindle s penetrates outward through the ball coils and has two conductive tips s ^l s ² , which are in conductive connection with the ends of the wire forming the movable coil, because two wires from the coil S to the hollow coil spindle and in it down to the two tips s ^l s ² are performed. These tips either dip into mercury bowls q ¹ q ' ² , which are attached to terminals A " ¹ and Ar ² , or feed lines are attached by means of fine wire spirals. The bowls or the ends of the wire spirals are connected to terminals III, ΠΙ .

On the underside of the stand base plate B ¹ , two double buttons or switches T ¹ and T ² are arranged, which can be moved by means of the handle lever H ¹ (Fig. 3) and H ² (Fig. 2 and 3). The switch T ¹ is always returned to its closed position by a spring t (Fig. 4) and is used to alternately interrupt and close the circuits of the two windings a ² a ^{3 of} the inner fixed coil A ^{2 of the spool.} The changeover switch T ² is used to switch the movable coil S, as described later, into a branch line of the current sent through the external fixed coil A ¹ , in order to check the instrument for correctness.

In the following, the mode of operation of the apparatus will be explained in more detail with reference to FIG described.

L ¹ L ² and Z ¹ Z ² are the two feed lines for the alternating currents, the phase difference of which is to be determined.

The first alternating current (main current) leads through the thick wire primary winding p ^{1 of} an iron-free transformer to the outer primary coil A ^{1 of} the fixed spool. A low resistance W is switched into the line L ^{1 of this main current.}

The secondary winding p ^{2 of} the transformer consisting of thin wire is connected by the line p ³ to the winding a ^{2 of} the secondary coil A ² consisting of thin wire. If J denotes the strength of the first alternating current (main current), then the intensity of the current circulating in the primary coil is 2 = J sin α t, where α is the

Size

2 7Γ

(T = period) and with t

the time is designated.

This current induces in the secondary winding ^{2 of} the transformer and in the secondary winding a ^{2 of} the coil A ² a current of the following dimensions:

Electromotive force: ε = ka J cos a. t, where k means a constant,

• 1 kaJ,

Intensity: i ^l = - cos (at - ψ) ,.

Yw ² Xa ² P

where the root size in the denominator depends on the resistance (w) and the self-induction (I). Since the latter very much

ka J
is small, one can z ' ¹ = cos (at —ψ)

set. The angle et t is reduced by a certain angle ψ.

In order to bring this angle from the formula to the disappearance, the fields produced by the two currents in the Spulenbewickelungen a ¹ a ² of the bobbin cross need to obtain a phase shift, which is exactly 90 ^0th

This is achieved by the following device: A thick-wire winding a ^{3 is} placed over the thin-wire winding a ^{1 of} the secondary coil, which is connected to a branch line a ^{l of} the main current (in L ¹ L ² ) via the low resistance W (V _{100 S?)} and is therefore traversed by a current which has the same phase as the main current circulating in the primary coil and whose strength is in constant proportion with the latter. In addition, an adjustable resistor W _r is connected to the line p ³ leading to the secondary winding a ^{2 of} the coil A ² , by means of which the secondary current can be changed in such a way that the phase of the partial current flowing through the auxiliary winding a _{3 is generated by the secondary current in connection with the auxiliary winding a 3} with the phase of the field generated from the main stream differirt magnetic field by 90 ^0th

S is the moving coil which is connected to the line / ' I ^{2 of} the second alternating current.

T ² is the pop button or switch, by means of which the movable coil S can be switched into a secondary or branch line η of the main current via the low resistance W, so that a current flows through the movable coil which has the same phase as the main current.

If the circuits of the two windings a ² and a ^{3 of} the secondary coil A ^{2 of} the spool are alternately interrupted and closed, the pointer Z of the instrument must not make a twitching movement or be deflected if the instrument is correctly set. To interrupt (and close) the two circuits, the double button or changeover switch T \, which, as can be seen from FIG. 5, is common to both lines leading to α ² <z ^3, is used.

If there is a pointer deflection when this changeover switch T ¹ is closed, the adjustable resistance W _{r can} be changed until the pointer no longer jerks.

With the correct setting of the instrument (assuming no distorted current curves) a rotating field is generated in the fixed coil cross, which causes the movable coil to be twisted and to assume a position which includes the displacement angle with the zero or initial position, which is directly on the circle pitch K can be read.

The mathematical derivation of the above results as follows:

Let the main flow i = J sin α t and the field F ₁ = E ₁ / sin α t generated by it. The current induced in the iron-free transformer is as stated above:

kaJ

= - ^cos ( ^α t - ψ)>

whereby

al

The field created by him
kaJ

cos (at - ψ).

The current sent into the auxiliary winding a ³ is i " = w / sin α t (where w means a constant) and the field F ₃ = έ ₃ w J sin α t.

The two conditions must be met:

ι. F ₂ + F ₃ must give a square shifted by 90 ⁰ _{compared to F 1.}

2. The amplitude of F ₁ must be equal to that of F ₂ 4- F ₃ . If one adds up the above values for F ₂ and F ₃ , where cos (α t - ψ) is expanded, one obtains:

+ F, = ε, k ³

^B "Vw _r ² + a *
aJ

cos α t ■ cos ψ

sin ψ -) - ε ₃ w J] sin α t.

α ^2/2

This equation can also be written more briefly as follows: F ₂ + F ₃ = A cos (at - χ), where the angle χ results from the following

Determine the equation:
E ₉ ka

■ sin ψ + E ₈ w

E ₂ k ά.

According to the first condition, tg χ = O, i.e.:

E ₂ ka

■ sin ψ 4- s ₃ w =

Furthermore one finds

/ 12 / SL 2

A -J Ie ₂ ..

• ft-

YW _r ² + a ² I ²

sin ψ 4 "ε?

Y ² I

which expression is found in fulfilling the first Condition reduced to:

λ ε ₂ k α ^N ,

A = J COS ψ.

^ 2 * 4, _α 2/2.

In order to meet the second condition, one must

ka

■ cos ψ

2.

be. 'From i.

sin ψ

substituted in 2. results

and since

so you get

tglj / =

al

~ W

, w W ₁ .

In order for the phase shift to be constant 90 ⁰ , as can be seen from 1., W ₁ - pro

. W ₁ .
change proportionally to α, thus be constant.

If one divides the numerator in equation 1 and denominator of the first term by α, we get:

- sin ψ + ε ₃ w = O.

Since now onser

W _r

all other values

are only given quantities, then W _r must change proportionally to α, therefore as indicated

W ₁ .
give be constant.

If one makes the amplitude of F ₁ equal to that of F ₂ + F ₃ for any α, then this also applies to other values of a, if according to 3.

Wr

also ■

is constant. The required

The change in W _r is carried out in the manner mentioned above and the apparatus can also be set up in such a way that the number of periods per second can be read off immediately from the resistor.

From this it follows that the two conditions are fulfilled at the same time by the same resistance and thus a circular rotating field is always achieved by setting W _r.

Let us now consider the moving coil in this circular rotating field, through which a current i. sin (at + φ) flow.

The components of the rotating field are:

H ₁ = sin α t and H ₂ = H ■ cos α t
and it encloses the movable coil with the fixed one which the former component H ₁ produces, the angle ρ.

It is then the torque exerted

= k H ₁ sin ρ ■ i sin (α t + φ) -
k H ₂ cos ρ ■ i sin (α t + φ),

D = k H i sin (α t + φ) [sin ρ sin at -
cos ρ cos at],

D = - k Hi sin (α t + φ) cos (α ί + ρ).
It is then the mean torque

D = - ki J sin (φ - ρ),

since H is proportional to J.

So that D becomes equal to zero, the coil must adjust itself in such a way that zi. P = zl Φ and one can read off £ _ ρ directly from the circle division.

If the instrument is switched in such a way that an alternating current forms the main current that passes through the primary winding of the transformer and the solid one with thick turns Ball coil flows while the moving coil has a constant series resistance is switched into a Vpltmeterüberbrückung of the same alternating current, so is for p = 0

D = - ki / sin φ.

If the instrument is designed as a torsion instrument, so that the movable coil is returned to the zero position by means of a spiral spring and a pointer connected to this spring indicates its voltage, then it measures the idle current J sin φ if the voltage and thus i is kept constant as is the case, for example, in Centralen.

Claims (1)

Patent Claims: ι. A modification of the phase measuring apparatus for alternating currents protected by DRP No. 95954, characterized by a fixed spool (A ¹ A ² J and an inner movable coil (S), the latter, as well as the windings (a ¹ a?) The spool with the lines (L ¹ L ² ■ I ¹ Γ ² ) are connected for the alternating currents in such a way that a circular rotating field that is as homogeneous as possible is produced in the fixed spool and the movable coil therefore rotates until its zero or off initial position includes the displacement angle, which can be read off directly can. An embodiment of the under i. specified phase measuring apparatus for alternating currents, characterized in that the stationary coil cross is composed of two pairs of hemispherical coils (A ¹ A ² ) , of which the outer coil (A ¹ J ) wound with thick wire (a ¹ ) has a low resistance (W ) and p across the primary winding ⁽¹⁾ of an iron-free transformer in the line (L ¹⁾ of an alternating current (main current) is turned on, while the inner thin wire (a wound package ²⁾ (a τρ in the Secundärbewickelung ^{(2) 1} ) of the transformer is switched on and is also provided with an outer winding (a?) made of thick wire, which is switched on via the resistor W in a branch line (a ^) of the main power line L ¹ and in conjunction with one in the secondary line a ^{2 of} the coil A ² switched on adjustable resistor (W _r ) enables the correct adjustment of the instrument.
An embodiment of the under i. specified phase measuring apparatus, characterized in that the movable coil of the above instrument is returned to the zero position by means of a torsion spring, so that the pointer connected to the torsion spring indicates the idle current. For this purpose ι sheet of drawings.