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Why power remains the same in transformer from primary to secondary?
Wiki User
∙ 12y ago
Because of the law of conservation of energy. Neglecting minor losses from imperfect efficiency, eddy losses, heating, etc., a transformer's output power is always the same as its input power. If the voltage, for instance, is stepped down by a factor of 10, then its current will be stepped up by a factor of 10. Since power is voltage times current, power is preserved.
In reality, looking at the big picture, there are no losses. Whatever is "apparently" lost is made up in heat and electromagnetic radiation. Power In minus Power "Lost" equals Power Out. Always.
Wiki User
∙ 12y ago
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How do you measure the power input and power output for the step-up transformer?
Power input to a transformer = (voltage across the primary winding) x (current through the primary)Power output = (voltage across the secondary winding) x (current through the secondary)It doesn't matter whether the transformer is used in step-up, step-down or simple isolation.
How can you identify the primary secondary of a transformer on a schematic if it is not indicated?
Without knowing the type of transformer (audio/power, step-up, step-down, etc.) it's difficult to offer any advice.
What are the approximation of open circuit and short circuit test of transformer?
A short-circuit test is done to determine the power lost in the resistance of the primary and secondary windings of the transformer. It is done at full load current but with only enough voltage to give the required current with the secondary short circuited. An open-circuit test is done at full load voltage but no current is taken from the secondary, and this enables the power lost in the magnetic core of the transformer to be measured. As well a power, the tests also allow the inductances to be measured as well as the resistances, in order ot characterise the transformer fully.
What is the maximum voltage on the secondary side of the transformer?
Transformers come in very many varieties and voltages. Transformers have ratings regarding the electrical power that they are connected to. The most important ratings are voltage, power and current. In general the insulation level and number of windings in the secondary and primary determine the maximum rated voltage, and the size of the magnetic wire that makes up the windings, and mass of the iron core, determines the rated power and rated current. It is the insulation level therefore, that determines the maximum, safe voltage that can occur on both the secondary side and the primary side. The turns ratio between the primary and secondary coils of the transformer determines the secondary voltage with respect to the primary voltage. If the primary coil has 1000 turns, and the secondary coil has 100 turns, the transformer turns ratio (usually designated by the letter "a") is 100 / 1000 = 0.1. If a = 0.1, then if 1000 volts are applied across the primary coil, ideally, 100 volts will be measured across the secondary. Transformers have been manufactured with secondary voltage ratings in the range of millivolts, to 1,000,000 volts.
What is used to increase or decrease the voltage across a power line?
The device that increases or decreases the voltage impressed across a power line is known as a voltage regulator. A voltage regulator is a type of transformer where the primary and secondary turns ratio are fairly close; one (primary or secondary) often has a tap changing ability to add or remove several windings, allowing more dynamic control of voltage.
Given a Transformer with 110vac at 1 amp applied to the primary with 1000 turns and the secondary of 500 turns what is the voltage current and power of the secondary?
Given a Transformer with 110vac at 1 amp applied to the primary with 1000 turns and the secondary of 500 turns what is the voltage current and power of the secondary?
Can you use a step down transformer as a step up transformer by reversing the primary voltage as a secondary?
Theoretically, yes; practically, no, as you won't have the power ratio to energize the primary with the same power as originally designed without a much larger than usual transformer and much larger than usual secondary power.
How do you calculate current flow transformer when 240 Vrms is supply?
The secondary current of a transformer is determined by the load and the secondary voltage applied to that load, and this, in turn, will determine the primary current by the inverse of the turns ratio. However, if you are asking about a transformer's rated secondary and primary currents, then you need to divide the transformer's apparent power rating (expressed in volt amperes) by the rated secondary and primary voltages respectively.
Why power at the secondary winding is less than the power at the primary winding?
If power were greater at secondary you would have an unlimited source of power. It is less because there are always losses in a transformer.
What are the limitations of power supply?
Power limitation transformer circuit structure of power supply, including: an electromagnetic interference filter unit, a rectifying unit, a power factor correction section, a transformer having a primary input terminal and secondary input terminal, a pulse controlling unit connected with the secondary input terminal of the transformer, a primary power limitation circuit and at least one secondary power limitation circuit, an output current controlling unit and an output voltage controlling unit. The input terminal of the output current controlling unit is connected with the secondary output terminal of the transformer. The primary output terminal and secondary output terminal of the output current controlling unit are respectively serially connected with the primary and secondary power limitation circuits. The input terminal of the output voltage controlling unit is connected with the secondary output terminal of the transformer. The output terminal of the output voltage controlling unit is connected with the secondary power limitation circuit for controlling the magnitude of the voltage and current of the primary and secondary power limitation circuits so as to control the output power.
How do you measure the power input and power output for the step-up transformer?
Power input to a transformer = (voltage across the primary winding) x (current through the primary)Power output = (voltage across the secondary winding) x (current through the secondary)It doesn't matter whether the transformer is used in step-up, step-down or simple isolation.
When the transformer is connected to the power source the secondary current is 0 what is the possible fault in the transformer?
A secondary current of 0 would suggest to me that the secondary circuit is open. A normally operating circuit with zero current flow would be very unusual. No load in secondary circuit. No secondary current can also be attributed to the primary power source open or an open primary winding.
Why is the number of turns in primary coil more than that of the secondary coil?
The number of turns or windings of a transformer can vary. There can be more in the primary, or more in the secondary, or there can be an equal number in a transformer that is simply used for isolation (an isoformer). More turns in the primary than secondary will create a step down transformer. More turns in the secondary are found in a step up transformer. The transformers on power poles have more turns in the primary to step the line voltage down for delivery to residential customers.
How does a transformer work you mean how does it reduce current and increase the voltage you have tried the math this doesnt make any sense?
A transformer has a primary (Where the AC supply voltage is applied); and a secondary where a voltage is induced by a fluctuating magnetic field in the iron core of the transformer. The secondary voltage depends on the ratio of windings between the primary and secondary. Since the transformer can't manufacture power the product of the voltage and current at the primary exceeds that in the secondary. So if the transformer steps up the voltage in the secondary, the maximum current in the secondary must decrease. Similarly if the voltage is stepped down the maximum current increases in the secondary. There are always losses in this process so the power in is always somewhat less than power out.
When secondary coil is open there is no current in the primary coil WHY?
I am assuming the question is about the power / distribution transformer and not the current transformer. The primary current is a function of load connected on secondary. With the open secondary, there is no load, no current, it is open circuit. Hence no primary current. However there is always some small amount of no load current in the primary winding.
Why does transformer draws current when secondary is kept open?
A: If the transformer is connected to a power input of course it will draw current. The primary is a long wire it has own resistance wrap around an iron core. Of course there will be primary current whether there is a load on the secondary or not.
What is the difference between primary electrical distribution and secondary distribution?
Primary electrical distribution carries medium voltage power to distribution transformers near the customers. Secondary electrical distribution transfers the power from the transformer to the households.
