Practica 8

ABSTRACT

The respective analysis of the start windings processors gives us a complex sample of the whole potential locked up in these instruments of generation. The use of these give us multiple activities in the industry and their fields of application hence the strong interest in able to manipulate and understand everything that concerns with regard to coils coupled (transformers). Then weShow the analysis of the winding both input and output of a transformer TR 509 N laps.

INTRODUCTION

The transformer is an electrical device designed based on the concept of magnetic coupling. It uses magnetic coils coupled to transfer energy from one circuit to another.Transformers are key elements of circuits used in power systems to increase or decrease AC voltages or currents or radio andtelevision receivers for purposes such as impedance matching, isolation of part of another circuit.In addition to testing vacuum and counter circuit used to determine the regulation and performance of transformers daily business other trials are usually done to put a transformer in service.This report based on the concept of mutual inductance and the dot convention. We will determine thephaseand voltage polarities inductively coupled components.

OBJECTIVES

* Learn the behavior that a transformer.

* Analyze the determination of the points of the transformer winding.

* Determine the polarity of the coils of a single-phase transformer.

* Understanding the relationship between primary and secondary coil mutual inductance.

RESULTS

Observation of the transformerInput

Output

V Primary | [V] | V sec. practico | V sec.theoretical | % error |
| | | | |
125 [V] | Vab | 3,68 | 4 | 8 |
| Vbc | 7,35 | 8 | 8,125 |
| Vcd | 7,35 | 8 | 8,125 |
| Vde | 3,68 | 4 | 8 |

The reasons for the error in a previous voltage is partly due to the applied voltage thatis 125 [V] instead of the 120 for which they were takenfrom the theoretical voltage.The other part of the coils may have one or two laps from those stated in the specifications or the insulation may be damaged.

Ratio of the number of turns
VabVAB=NabNAB=3.68 V125 V=0,02944

Take with reference NAB=1 Nab=0,02944

NAB | 1 |
Nab | 0,02944 |
Nbc | 0,0588 |
Ncd | 0,0588 |
Nde | 0,02944 |

At the time of the turns ratio of the impedance in the primary winding isseen to bemuch larger than the secondary, which confirms us that it is a transformer-type gear, you can also compare by voltages in the secondary are smaller than the primary.

Bridge polarity
To determine the points or polarities of the coils of the transformer uses the polarity of the bridge, which is a short between line a and the end of the coil, while q is sampledby output.Voltagebetween the missing terminals without connecting to the other coil, taking into account this configuration were determined following results:

Van tension is much lower than the voltage VNB so the polarity is additive.

While in a configuration being greaterthan VNB Van becomes known that the polarity of the coils is a subtractive polarity.With the meter impedance determine the value of the inductanceof primary windingand secondary winding. With these values ​​we can calculate the value of a mutual inductance M. Keep in mind that the transformer practice has several configurations depending on the allocation of central tap.

M=Lb3-Lab-L232=67.8 mH

Graphical representation of a series additive.

Graphical representation of a series subtractive.

As we have hoped in keeping with thetheory studied and the source of continued supplied to the coil coupled magnetically, as observed in the images obtained from the oscilloscope was placed in the two signals the entry that was the entrance to the coil ( source ) and exit, being the voltage at the terminals of the coil.

For when the series gave us additive was clear highlight it because the input signal and output signal...