SU754495A1 - Dc transformer - Google Patents

Description

The invention relates to the field of electrical engineering and can be used to measure direct current in reversible and non-reversible power sources.

The known DC transformer, which contains an alternating current source, a choke with two on-coils wound on the magnetic circuit, and a peak current limiter connected to the secondary circuit [f].

However, this transformer has a low measurement accuracy due to the measurement of the duty cycle of the secondary current of the transformer, and not the direct current value.

The aim of the invention is to improve the accuracy of measurement of direct current by eliminating the surge current when the remagnetization of the core of the inductor.

This is achieved by the fact that in a DC transformer containing an AC source, a choke with per2

primary and secondary windings wound on the magnetic circuit, measuring circuit and peak current limiter connected in series with the secondary winding of the choke, an additional ⁵ secondary secondary winding, located on the same magnetic core, and a controlled key included in the measuring circuit of the transformer, and the control circuit key connected to an additional secondary winding. Additional secondary winding is designed to control the key during the remagnetization of the core and output connection

_{) 5} DC transformer to the measuring device. The key is a mechanical or semiconductor bidirectional switch.

FIG. 1 shows a diagram of a transformer of a direct current; in fig. 2 diagrams of voltage and currents explaining the operation of a DC transformer.

The DC transformer contains an AC source 1,

754495

two-winding choke with primary 2 and secondary 3 windings wound on magnetic circuit 4, additional secondary winding 5 wound also on magnetic circuit 4 and connected to controllable key 6, resistor 7 and limiter 8 peak currents included in the secondary circuit of a constant current transformer.

The DC transformer operates as follows.

When the flow through the winding 2 of the choke DC, equal to 3,

The magnetic core 4 of the choke is saturated, and the magnetizing force is determined by amperages 3 \ L / £ where V / £ is the number of turns of the winding 2. When an alternating current source is applied to the winding 3 of the half-wave voltage, the demagnetizing magnetic circuit 4 ^ through the winding 3 a current of 3 + 3ts

where \\ / _{g the} number of turns of the winding 3, 0 „-magnichip

Vakatsii throttle current, reduced to the winding 3 (see fig.2a). The choke core is re-magnetized, the voltage induced in the additional winding 5 (see fig.2b) includes a switch 6 and a voltage from the resistor 7 proportional to the value 0 ♦ 3 _n is applied to the output terminals of the DC transformer to which the DC meter is connected. see figv).

At the next half-wave of the voltage source 1, the choke begins to re-magnetize in the direction of the magnetizing force of the ampere turns □ AL / 1. The voltage induced in the winding 3 maintains a current in it equal to 3 E _n , and the voltage induced in the winding 5 turns on the controlled switch 6 and supplies the output voltage on the resistor 7,

go

15

20

25

thirty

35

40

proportional to current 3 ζ (see Fig. 2c). When the magnetic circuit reaches saturation mode, the voltage on the winding 5 decreases to a value close to zero, the switch 6 opens and disconnects the output of the DC transformer from the measuring resistor 7. Thus, at the output of the DC transformer, the average voltage during the on-state of the controlled switch is proportional to current 3 * 7 ₂ .

When you change the direction of the current in the winding 2, the polarity of the output voltage of the DC transformer changes accordingly.

Claims (1)

Claim A DC transformer containing an AC source, a choke with primary and secondary windings wound on a magnetic circuit, a measuring circuit and a peak current limiter connected in series with the secondary winding of a choke, characterized in that, in order to improve the accuracy of current measurement by eliminating current surge at remagnetization of the throttle core, an additional secondary winding, located on the same magnetic core, and a controlled key, included in the measuring circuit of the transfo Matora, the key control circuit connected to the additional secondary winding.