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Why does a transformer need continuous rise and fall of current to induce a current into the secondary windings?
Wiki User
∙ 11y ago
That is how inductance works. The rise is needed to charge the primary. When the field collapses, that is when the current is induced in the secondary winding(s).
Wiki User
∙ 11y ago
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What is transformer open circuit test?
An open-circuit test measures a transformer's iron losses. With no current flowing in the secondary windings, and only a tiny 'magnetising' current flowing in the primary windings, there is no significant energy lost due to the resistance of the winding conductors. So a wattmeter attached to the primary of the transformer will not read any 'copper losses', only the 'iron losses' that occur in the core.
What is the difference between ideal transformer and practical transformer?
There are basically 4 major differences :- 1. The windings (both primary and secondary) of an ideal transformer are considered to have zero resistance, hence the transformer is lossless. 2. There is no leakage flux in an ideal transformer. 3. The permiability of the core material in ideal transformer is considered to be tending to infinity and hence the current needed to set up the flux in the transformer is negligible. 4. There is zero hysterisis and eddy current losses in an ideal transformer.
What is the function of the primary current when the secondary winding of the transformer is open?
When the secondary of a transformer is opened, there is no longer any load on the transformer. There will be some current flowing in the primary winding, which is needed to induce the voltage in the secondary. This primary current is referred to as the "no load" current, and is indicative of the core losses in the transformer.
What is magneto safety gap?
- connected in series to secondary windings by two electrodes - bypasses secondary windings if path is interrupted - helps protect the secondary windings in the coil to provide an alternate path for current if there is an open in the secondary circuit
What is the secondary amps of 315kva transformer?
The secondary current is determined by the load, not by the transformer. But the load current mustn't continuously exceed the rated current of the secondary winding. To determine the secondary rated current, you need to know the rated secondary voltage of the transformer, and divide 315 kV.A by this figure.Incidentally, the correct symbol for 'kilovolt ampere' is 'kV.A', not 'kva'.
When working on a current transformer the secondary windings must be?
When working on a current transformer the secondary windings must be shorted. <<>> Properly loaded
Why a transformer only work with alternating currents?
The iron core of a transformer holds a magnetic field when energized by the primary windings that conduct current. It is the building up and collapse of the magnetic field that induces current in the secondary windings. Direct current has no build up or decay of magnetic field (except when turned on and shut off) so no current is induced in the secondary windings.
What is the secondary rating of a 50KVA transformer?
The secondary current is determined by the load, not by the transformer. For example, if the secondary voltage is 50 V and the load is 100 ohms, then the secondary current will be 0.5 A. If the load is 25 ohms, then the secondary current will be 2 A. It is important that a continuous secondary current doesn't exceed the rated secondary current of the transformer.
What is transformer open circuit test?
An open-circuit test measures a transformer's iron losses. With no current flowing in the secondary windings, and only a tiny 'magnetising' current flowing in the primary windings, there is no significant energy lost due to the resistance of the winding conductors. So a wattmeter attached to the primary of the transformer will not read any 'copper losses', only the 'iron losses' that occur in the core.
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.
What is principle of Current transformer?
why does have to short-circuit secondary wire of current transformer ?
What is the difference between ideal transformer and practical transformer?
There are basically 4 major differences :- 1. The windings (both primary and secondary) of an ideal transformer are considered to have zero resistance, hence the transformer is lossless. 2. There is no leakage flux in an ideal transformer. 3. The permiability of the core material in ideal transformer is considered to be tending to infinity and hence the current needed to set up the flux in the transformer is negligible. 4. There is zero hysterisis and eddy current losses in an ideal transformer.
What are the connections on a transformer?
The connections on a transformer are circuit ties for the primary and secondary windings, and any taps. This is a very general question, and only a very general answer can be given. The basic transformer (outside the autoformer) has four connections, and two of them are for the ends of the primary windings, and two of them are for the ends of the scondary windings. Certainly there are many variations on the theme for taps in the primary and/or secondary, additional primary or secondary windings, different windings for different phases (as in power distribution applications), etc. More information on transformers can be had by using the link to the Wikipedia article on these electrical and electronic devices that are used to step up voltages, step down voltages, or isolate electrical circuits (as well as a number of other things).
Can a transformer be used to transform direct voltage and direct current?
For all intents and purposes, none. Transformers pass alternating current. Now, if you want to split hairs, when a direct current is initially connected to a transformer, magnetic field starts to build in the primary windings, and as this field builds, the lines of force cut through the secondary windings, MOMENTARILY producing an output voltage in the secondary windings. However, once the magnetic field is stable (within a millisecond or so) the output of the secondary windings fall back to zero. When you remove the direct current from the primary winding, the same thing happens again. As the magnetic field collapses, the magnetic lines of flux cut through the secondary, momentarily producing an output voltage. After the magnetic field collapes completely, the secondary output is zero. That is basically what you are doing with alternating current...inputting a positive voltage, then going to zero, then negative, then back to zero, building and collapsing magnetic fields so that it induces current to flow in the secondary windings.
What is magneto gap?
- connected in series to secondary windings by two electrodes - bypasses secondary windings if path is interrupted - helps protect the secondary windings in the coil to provide an alternate path for current if there is an open in the secondary circuit
Does a basic transfomer in its normal operation use step up voltage step down voltage step up current or all?
A transformer has a primary and a secondary side. There is a ratio of windings from one side to the other that dictates whether it is a step up or step down transformer. The transformer is usually marked as to the input and output specifications. The current is directly proportional to voltage. If you had a transformer that was a step up from primary to secondary, it would be step down from secondary to primary.
What is the function of the primary current when the secondary winding of the transformer is open?
When the secondary of a transformer is opened, there is no longer any load on the transformer. There will be some current flowing in the primary winding, which is needed to induce the voltage in the secondary. This primary current is referred to as the "no load" current, and is indicative of the core losses in the transformer.
