SU652492A1 - Inductive voltage divider - Google Patents

Description

feoe number of turns, and two toroidal cores, one of which has an excitation winding and a separator winding wound on both cores, the excitation winding is made sectioned, and the same intersection taps of both windings are connected to each other.

FIG. 1 The scheme of one cascade of the described divider is shown; in fig. 2 is a diagram of cascade connection in a multi-stage divider; in fig. 3 shows the construction of a single cascade.

As seen in FIG. 1, the excitation winding 1 is wound uniformly on a toroidal core 2 made of a ferromagnetic material with high magnetic permeability and low losses, for example; from permallo. The winding 1 is divided into sections connected in series, and taps 3 are made from the connecting points of the sections. The separating winding 4 covers the winding 1 and the toroidal core 5, which is located coaxially with the core 2 and is made of a material similar to the material of the core 2. The winding 4 is wound uniformly and has the number of turns equal to the number of winding 1 and divided into sections, the number of which is equal to the number of sections of winding 1, and the number of turns in the sections of the same name (for example, counting from the beginning) windings I and 4 are the same. Taps 6 are made from the connection points of the winding sections 4, which are connected to the corresponding branches 3 of the field windings 1. The beginnings and the ends of the windings 1 and 4 are also connected to each other and used as input or to connect to the sections of the previous stage when building multi-stage voltage dividers .

When the alternating voltage source is turned on in the winding 1 of the first cascade, a current arises, the magnetic flux of which passes in the core 2 and induces a self-induction EMF in the winding 1, which, together with the voltage drop on the ohmic resistance and the inductance of the dissipation, balances the applied voltage. The input voltage is also applied to the separating winding 4 and is partially balanced by the EMF induced in it by a note of winding 1, as this flow penetrates the winding 4. A residual voltage that compensates for the voltage drop on the ohmic resistance and inductance resistance of the winding 1 creates in the winding 4 due to the occurrence of a current in it, the magnetic flux of which passes only through the core 5. Since the voltage drop on the ohmic resistance and the inductance of the dissipation of the winding I is much less than the emf with moinduktsii this winding, the winding 4 and the current is also significantly lower than the current in the coil 1. The same ratio of currents is maintained at all connected in parallel sections of both coils.

The distribution of potentials at the ends of the winding 1 is determined by the ratio of the numbers of turns in its sections to the total number of turns of this winding, as well as the degree of proportionality of the residual parameters (ohmic resistance and scattering inductance) to the numbers of turns of the sections. The distribution of potentials on the leads of winding 4 is determined by the ratio of the numbers of turns in its sections to the total number of turns of this winding, the degree of proportionality of the residual parameters to the number of turns of sections, and

also, the identity of the flux linking of the winding 4 with the winding 1. In both windings, the deviation of the potentials at the outputs from the nominal value is a random value, and the connection of the like branches to each other ensures that the potentials are forced to bring to some intermediate value. Since the absolute values of the residual parameters of the winding 1 are less than those of the winding 4, this connection provides an increase in the accuracy of the operation of the cascade in idle mode.

The output impedance of the cascade for this load divider (current, power consumption

external resistance connected to the output of the divider) is determined by the almost common resistance of the parallel connected resistances of the upper and lower arms of the last stage. Resistive:

The upper arm (from the point of connection of the load to the ends of the last sections) is determined in parallel by the connected resistances of the upper sections of windings 1 and 4, and the resistance of the lower arm of the cascade

(from the beginning of the first sections to the load connection point) is determined by the parallelly connected resistances of the lower sections of the windings 1 and 4. Thus, the output resistance of the cascade for the load current is less than the smallest of these resistances. The resistance of sections of winding 1 is less than the resistance of like sections of winding 4, since the diameter of the wire of winding 1 is greater and the length of its turns is smaller. Thus, the output resistance of the divider is less than the output resistance of the known dividers.

When building multi-stage dividers (Fig. 2), the subsequent cascade is

the extreme leads are connected to one of the pairs of sections of the previous (supply) cascade connected in parallel, the voltage acting at the output of the subsequent cascade practically coincides with

phase with the input voltage of the supply stage, and its value is closer to its nominal value, i.e., the sections feeding the next stage in the described device are not transformer windings.

The output resistance of the parallel-connected sections of the windings 1 and 4 of the supply stage is less than the lower resistance of these sections, since energy is transferred from the previous stage to the subsequent one both by electromagnetic and by galvanic coupling of the windings.

Therefore, the mutual influence of cascades is less than in the known device, and the accuracy of operation is higher.

The highest metrological parameters of the proposed divider are provided when, with the same other design and electrical parameters, both windings are made of insulated conductors tightly twisted by a bundle of cables, the number of which is equal to or multiple to the number of sections into which each winding should be divided. . In this case, the highest degree of proportionality of all parameters of the sections of both windings to the numbers of their turns is achieved, which provides an increase in the accuracy of the basic function of the cascade.

The tests of the inductive voltage divider showed that the output resistance of the cascades decreased by a factor of 1, and the division errors decreased by 30-50% compared to a divider with open intersection tapping of the windings, i.e., constructed according to a known scheme.

The use of a divider in various electrical measuring devices will increase their accuracy with the same dimensions and weight of the cascade cores or reduce the weight and dimensions of the divider, if accuracy is not required. In the latter case, the consumption of expensive alloys is reduced and the cost of the divider is reduced.

Claims (3)

1. USSR author's certificate number 249476, cl. G 01R 15/06, 1968. 2. USSR author's certificate number 322723, cl. G 01R 15/06, 1970. 3. The UK patent number 1244212, cl. HIT 1969. -about O-i -about -1-o