# Primary winding and secondary relationship advice

### Current Transformer - Definition, Principle, Equivalent Circuit, Errors, and Types | Owlcation

If the secondary winding has fewer turns than the primary winding, the output voltage A power transformer is used primarily to couple electrical energy from a . An AC transformer's “winding direction” determines whether or not the transformer is “additive” or “subtractive” from a polarity perspective. Generally, this is. The relationship between line current and phase current is multiplying or dividing by root3. 1 Recommendation . Assume there is ratio Two winding transformer with primary star connection and secondary delta connection degree.

If the turns ratio of the transformer is increased to 1: This means the opposition to current is doubled. Thus, voltage is doubled, but current is halved due to the increased opposition to current in the secondary. The important thing to remember is that with the exception of the power consumed within the transformerall power delivered to the primary by the source will be delivered to the load.

The form of the power may change, but the power in the secondary almost equals the power in the primary. Small power transformers used in electrical equipment have an 80 to 90 percent efficiency range, while large, commercial powerline transformers may have efficiencies exceeding 98 percent.

The total power loss in a transformer is a combination of three types of losses. One loss is due to the dc resistance in the primary and secondary windings. Copper loss, eddy-current loss, and hysteresis loss result in undesirable conversion of electrical energy into heat energy. Copper Loss Whenever current flows in a conductor, power is dissipated in the resistance of the conductor in the form of heat. The amount of power dissipated by the conductor is directly proportional to the resistance of the wire, and to the square of the current through it.

The greater the value of either resistance or current, the greater is the power dissipated.

The primary and secondary windings of a transformer are usually made of low-resistance copper wire. The resistance of a given winding is a function of the diameter of the wire and its length. Copper loss can be minimized by using the proper diameter wire.

In this manner, all the power delivered to the primary by the source is also delivered to the load by the secondary minus whatever power is consumed by the transformer in the form of losses. Refer again to the transformer illustrated in figure The turns ratio is If the input to the primary is 0. If the transformer has no losses, 30 watts is delivered to the secondary.

The secondary steps down the voltage to 15 volts and steps up the current to 2 amperes. The reason for this is that when the number of turns in the secondary is decreased, the opposition to the flow of the current is also decreased. Hence, more current will flow in the secondary. If the turns ratio of the transformer is increased to 1: This means the opposition to current is doubled.

### Power Relationship between primary and secondary windings

Thus, voltage is doubled, but current is halved due to the increased opposition to current in the secondary. The important thing to remember is that with the exception of the power consumed within the transformer, all power delivered to the primary by the source will be delivered to the load.

The form of the power may change, but the power in the secondary almost equals the power in the primary. Small power transformers used in electrical equipment have an 80 to 90 percent efficiency range, while large, commercial power line transformers may have efficiencies exceeding 98 percent.

The total power loss in a transformer is a combination of three types of losses. One loss is due to the dc resistance in the primary and secondary windings. Copper loss, eddy-current loss, and Hysteresis loss result in undesirable conversion of electrical energy into heat energy.

Copper Loss Whenever current flows in a conductor, power is dissipated in the resistance of the conductor in the form of heat. The amount of power dissipated by the conductor is directly proportional to the resistance of the wire, and to the square of the current through it. The greater the value of either resistance or current, the greater is the power dissipated.

The primary and secondary windings of a transformer are usually made of low-resistance copper wire. The resistance of a given winding is a function of the diameter of the wire and its length.

Copper loss can be minimized by using the proper diameter wire. Large diameter wire is required for high-current windings, whereas small diameter wire can be used for low-current windings. Eddy-Current Loss The core of a transformer is usually constructed of some type of ferromagnetic material because it is a good conductor of magnetic lines of flux. Whenever the primary of an iron-core transformer is energized by an alternating-current source, a fluctuating magnetic field is produced.

This magnetic field cuts the conducting core material and induces a voltage into it. The induced voltage causes random currents to flow through the core which dissipates power in the form of heat.