Why ac current is used in a transformer?
AC current or DC current can be used in transformers. A transformer is made of two coils of wire, the input coil induces a current into the output coil. Transformers change the voltage either up (step up transformer) or down (step down transformer). The amount of change in voltage is dependent solely on the number of windings in both coils in the transformer. DC transformers work exactly the same way AC transformers do.
Instrument current transformer is used to adjust the output voltage from power source to be conveniently used by instrument. Measuring current transformer is used to measure AC currents.
A transformer changes the VOLTAGE of AC current (AC to AC). A rectifier changes AC to DC.
AC (alternating current)
DC current cannot be used in a transformer only AC will work. A transformer needs the continual build and collapse of the magnetic field to keep the iron core from reaching saturation. Only alternating current will transfer power through a transformer.
There are no alterations of current (AC) to induce current to flow in the secondary winding of the transformer.
its a simple transformer which converts say 110volt 60hz ac current to 220 volt 60hz ac current. such change in magnitude of ac current from lower value to higher value is know as step up operation. if it vice versa then its called step down
It's a transformer that operates with AC current in and out. It's an ordinary transformer, with the term "static" used to differentiate it from rotating transformers, such as motor-generator sets.
A transformer is used to change an AC (Alternating Current) voltage to a higher (for efficienet transmission) or lower (for general use) voltage.
Yes, the AC current can be amplified by using Step-down transformers, but one problem is the AC voltage will decrease with Step-down transformer.
Probably the most important advantage is in altering voltage - with AC all you need is a transformer.
If DC is applied to the primary of a transformer is there any current in the secondary and if there is then whether ac or DC?
first, understand that a transformer is an AC DEVICE. it wont work on dc...
A current transformer step downs the current in a power circuit to a lower amperage. A voltage transformer steps down the voltage in a power circuit, typically to 110 volts AC for residential and business use.
By using a rectifier. A transformer cannot by itself be used to convert AC to DC, and one cannot use a transformer with DC (say a battery). A transformer requires AC so that it can induce current into the secondary windings, which then steps down (or steps up) the output AC voltage. The output AC can then be rectified into DC using diodes (or a bridge rectifier).
Why the output voltage from a transformer is zero if a direct current flows through the primary coil?
A transformer relies on AC current flowing through the primary to set up changing magnetic fields in the core. The field flows through the core and in to the secondary of the transformer, generating an AC current. The current must be AC, otherwise the magnetic field in the core of the transformer will saturate. In the same way, the armature of a dynamo or alternator must be moving in order to create a changing magnetic… Read More
Yes, the output current of a 40va transformer at 12 volts is 3.33 amps. The replaced unit had an output of 1 amp making it a 12va transformer. By doing this exchange there will be three times the capacity of the new transformer over the old transformer.
Current transformer is a device used to measure the flow of current through a power system and the measured current is inputted to a protective relay system. It is used to detect system malfunction. Current transducer is a device used to measure AC and DC current based on the halt-effect technology.
A transformer is a device to convert high voltage AC to low voltage AC & vice-versa. It works on the principle of induction. Since induction occurs only in an AC supply, a transformer cannot work on DC.. So, it is not possible to convert DC supply to AC using transformer. You would need an inverter to convert DC to AC.
DC current is not used in home wiring. It may be used to power a door bell, alarm system, under counter lights, etc, that uses a transformer powered by AC that converts the power to DC. Other than that homes are wired for AC current only.
No, a transformer changes the ac to a voltage that the user requires. After that a rectifier can be connected to it to provide dc.
No. A transformer has to have AC, alternating current, to work. And since it's alternating, it'll have a frequency.
Transformer is based on the principal of mutual inductance.Induction is produced due to sinusoidal wave form thats why we use Alternating current inspite of Direct current.
welding transformer is a machine supplying of electric current for melting the electrode, where welding recifier is a component of welding machine which converts AC to DC Any transformer by princples works only on Alternating Current. It cannot be used Directly on a DC Supply. Welding can be done using AC or DC depending on the required application. Therefore if any welding Application requires a Direct Current for obtaining optimum weld properties, then along with… Read More
In a DC power supply a transformer is connected. The only time there would be no transformer used would be if the DC voltage wanted was 120 VDC. The transformer in the power supply is connected to 120 VAC on the primary side and the secondary side of the transformer is connected to either a half wave or a full wave diode bridge. The voltage out of the diode bridge will be the same output… Read More
If you apply DC to a transformer, the current in the transformer will rise quickly, depending on inductance, until the available DC current max'es out, the protective device trips, a fire starts, or the transformer blows up, whichever comes first. DO NOT CONNECT DC TO A TRANSFORMER.
transformer will work on ac
Check that the input and output voltages are as required. Check that the transformer is big enough for the current required for the unit you have.
Current transformer is measured a positive current flow. we used in neutral ct for measure the unbalance load
DC current will not pass through a transformer, in the sense that a DC current on the primary will not produce a DC output from the secondary. A constant DC current will not produce any output from the secondary but there may be transient effects as the DC current is connected or disconnected (in which case, it's really an AC current, isn't it?) More about this below because I don't think that's really the question… Read More
in welding machine, the transformer used is basically a current transforrmer. so by changing the tap of secondary side of transformer, we can increase or decrease the current in the transformer.
A transformer is used to raise or lower one voltage level to another or isolate one circuit from another. A rectified changes an AC (alternating current) voltage potential to a DC (direct current) voltage potential.
A transformer steps the voltage of an electrical power supply up or down. The transformer must be correctly designed for the voltage and current levels that it is intended for. Only ac can be used with a transformer, which is designed to work at a particular frequency.
Transformer is the only device which is capable to stepup or stepdown an ac signal. That's why its used widely in ac supply.
Transformer are passive devices thattransform AC to AC by magnetics and coupling. DC IS UNIDIRECTIONAL it does not change POLARITY. While it is possible to saturate a transformer primary it output cannot reflect the change since it has reached steady state
Transformers do not work in DC circuits. They only work in AC circuits.
There is no 'standard' output current from a transformer. The secondary (output) current depends on the load, and should not exceed the rated secondary current. To find the rated secondary current, you divide the transformer's rated volt amperes by the rated secondary voltage. The above cited answer need more descriptive ; a) V/Z = I, b) V/Z = I + Magnetizing current of the transformer taken from Primary side of the transformer.
If the transformer was designed for the specific frequency in use, it will step up or down voltage and current as it was designed to do. Transformers transform how power "looks" by increasing and decreasing voltage and current, while keeping power output equivalent to input (if you ignore the transformer losses).
step-down transformer Transformer in which the output AC voltage is less than the input AC voltage. step-up transformer Transformer in which the output AC voltage is greater than the input AC voltage.
I believe you meant transformer. If so it is a transformer used in high voltage circuits to reduce the current to a safer measurable value. It can be used as a direct input to a metering or protective relay to covert high currents to a lower value. It is used in AC circuits and typically encircles the conductor(s) it is monitoring, then works by using the expanding/ collapsing field which is the theory of induction… Read More
Current transformer are used for measuring current in a bus bar without disconnecting it by means of ammeter.There are three types 1.bar type current transformer 2.toroidal current transformer 3.wound type current transformer
AC is used for transmission because AC can be stepped up in voltage with a transformer, and then stepped back down at the destination. Since power is voltage times current, a higher voltage requires a smaller current to achieve the same power. Since the current carrying capacity of wires is based on wire size, a smaller wire size can be used to transmit the lower current.
connect 3 - phase supply to transformer primary winding.....keep transformer secondary winding open..... apply 3-phase voltage i.e.400v ac, and measure the amount of current flowing in each phase of the transformer primary winding...this current is the transformer magnetising current..... we can keep multimeters in series with the source....so we can measure directly the current readings.....(keep multimeters in current mode, and generally magnetising current will come in terms of milli amps for 400 v )
Think of a transformer as a foot pump. Putting pressure on it will cause it to pump air but you need to release the pressure to do it again. The transformer does the same for electricity, if DC is applied to it it will create one pulse of current from the output but that is all. You need the continues rise and fall of AC to work the pump.
a transformer require AC to function as desired it transform the AC to different levels. DC on a transformer can only see the actual primary or secondary resistance if the source is not limited in current it will burn the transformer by excessive heating since it will see only wire resistance. Answer 2 the application of an AC voltage, V on one winding of the transformer produces alternating flux that links the entire core of… Read More
As happens with voltage and current, flux is steady for dc but keeps altering for ac. A transformer works through the ac flux in the magnetic core.
Nope. A rectifier is used instead. A transformer can only reduce the voltage of the AC but does not change it into DC.
Yes, a transformer could be termed a voltage converter. Converting or transforming one AC voltage into a higher or lower AC voltage is the main purpose of a transformer.
Nikola Tesla invented AC, probably a transformer as well but don't quote that.
A bridge rectifier may be called as ac to dc transformer
how to calibrate current transformer ?
When a transformer is initially connected to a source of AC voltage, there may be a substantial surge of current through the primary winding called inrush current. Inrush current can be up to ten times higher than the continuously needed current because there is low initial resistance.