It is to reduce circulating current losses on winding.
The higher-voltage winding has more turns (therefore its conductor will be longer) than the lower-voltage winding and, because it will carry less current, its conductors will have a lower cross-sectional area. Consequently, the higher-voltage winding will have a higher resistance than the lower-voltage winding.
A step-down transformer's primary is high voltage and secondary is low voltage, based on voltage configuration or load we select which winding we do fast.In air-cooled Transformers output voltage is high and load current is low. So in air cooled low voltage winding in side and high voltage winding in out side of the coil . So we can reduce high voltage short problems and we can easily provide coil insulation . reduce short problem. It is cooled in oil.In step-down transformers we can do high voltage inside of the coil and low voltage and high current of the coil is outside. Because we can better coled in outer side . and reduced to temp problems.AnswerThe terms 'primary' and 'secondary' do not relate to a transformer's voltages, but to how its windings are connected. The primary winding is connected to the supply and the secondary winding is connected to the load. So, for a step-up transformer, the secondary winding is the higher-voltage winding while, for a step-down transformer, the secondary winding is the lower-voltage winding. Your question, therefore, should ask whether the higher- or the lower-voltage winding is the 'inside' winding (i.e. the winding closest to the core), and the answer is that it is the lower-voltage windings are innermost and the higher-voltage windings that are outermost.
If you mean how they work then magnetic fields Induction. Voltage applied to one winding induces a voltage in another winding. The voltage induced is dependent upon the turns ratio between the two windings. Current is said to be induced in the other winding as well (since a voltage is induced, current will flow if the circuit is complete). Depending on the transformer type, current may flow directly from the series winding (in autotransformers, for example) to the secondary output (conduction, as opposed to induction).
To test the excitation current of a transformer, you can perform an open-circuit test, where the primary winding is connected to the rated voltage while the secondary winding is left open. Measure the current flowing through the primary winding using an ammeter; this current is the excitation current. It's essential to ensure the transformer is at the specified voltage and frequency during the test for accurate results. Additionally, record the voltage and power factor for further analysis if needed.
Both lap winding and wave winding are found in the use of DC generators. The main difference is as follows: lap winding is high current, low voltage, and wave winding is low current, high voltage.
The terms, 'primary' and 'secondary', describe how a transformer is connected and his nothing to do with which is the lower- and higher-voltage winding.The primary winding is the winding connected to the supply, while the secondary winding is the winding connected to the load. So, for astep-up transformer, the secondary winding is the higher voltage winding, whereas for a step-down transformer, the secondary winding is the lower voltage winding.For a loaded transformer, i.e. a transformer whose secondary is supplying a load, the higher-voltage winding carries the smaller current, while the lower-voltage winding carries the higher current.
because we know that for lap winding P=A. so no of poles=no of parallal paths. so as the no of parallal paths increases ,the current will be also increases.....so total voltage will be decreases....for this we refer lap winding for high current and low voltage.
It is to reduce circulating current losses on winding.
The higher-voltage winding has more turns (therefore its conductor will be longer) than the lower-voltage winding and, because it will carry less current, its conductors will have a lower cross-sectional area. Consequently, the higher-voltage winding will have a higher resistance than the lower-voltage winding.
A step-down transformer's primary is high voltage and secondary is low voltage, based on voltage configuration or load we select which winding we do fast.In air-cooled Transformers output voltage is high and load current is low. So in air cooled low voltage winding in side and high voltage winding in out side of the coil . So we can reduce high voltage short problems and we can easily provide coil insulation . reduce short problem. It is cooled in oil.In step-down transformers we can do high voltage inside of the coil and low voltage and high current of the coil is outside. Because we can better coled in outer side . and reduced to temp problems.AnswerThe terms 'primary' and 'secondary' do not relate to a transformer's voltages, but to how its windings are connected. The primary winding is connected to the supply and the secondary winding is connected to the load. So, for a step-up transformer, the secondary winding is the higher-voltage winding while, for a step-down transformer, the secondary winding is the lower-voltage winding. Your question, therefore, should ask whether the higher- or the lower-voltage winding is the 'inside' winding (i.e. the winding closest to the core), and the answer is that it is the lower-voltage windings are innermost and the higher-voltage windings that are outermost.
Single phase motor will not start automatically unless it has a start and run winding.
If you mean how they work then magnetic fields Induction. Voltage applied to one winding induces a voltage in another winding. The voltage induced is dependent upon the turns ratio between the two windings. Current is said to be induced in the other winding as well (since a voltage is induced, current will flow if the circuit is complete). Depending on the transformer type, current may flow directly from the series winding (in autotransformers, for example) to the secondary output (conduction, as opposed to induction).
A basic, two-winding, transformer consists of two, separate, coils (called windings) wound around a laminated silicon-steel core. The winding connected to the supply (input) is called the primary winding, and the winding supplying the load is called the secondary winding. Alternating current flowing in the primary winding sets up an alternating magnetic field in the core which induces a voltage into the secondary winding. If there are fewer turns in the secondary winding, then the secondary voltage is lower than the primary voltage. If there are more turns in the secondary winding, then the secondary voltage is higher than the primary voltage.
Dc voltage level should not exceed the current carrying capacity of the winding. since winding resistance is very small. We need to be careful in giving the dc voltage to transformer winding.
To test the excitation current of a transformer, you can perform an open-circuit test, where the primary winding is connected to the rated voltage while the secondary winding is left open. Measure the current flowing through the primary winding using an ammeter; this current is the excitation current. It's essential to ensure the transformer is at the specified voltage and frequency during the test for accurate results. Additionally, record the voltage and power factor for further analysis if needed.
apply 3 phase voltage(415V) to the winding whose magnetising current is to be found and open circuit another winding. now measure current using tong tester or connecting an ammeter in series between supply and winding.