Voltage on primary/Primary turns = Voltage on secondary/Secondary turns
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.
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.
The way to identify any transformer is to look at the the transformers nameplate. The primary side will be designated H1 to H4. This is the primary side and the voltage will be stated as to the voltage to connect to. The secondary side will be designated X1 to X4. This is the secondary side and the voltage will be stated as to the voltage it will be transformer to.
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.
The primary current on a loaded transformer depends on the secondary current, which is determined by the load. So, if you know the secondary load current, then you can use the turns ratio of the transformer to determine the primary current:Ip/Is = Ns/Np
Transformer step-up/step-down voltage is turns-ratio, so if a transformer has 20 primary windings and 100 secondary windings (a turns-ratio of 1 to 5) and the secondary voltage is 25, then is the primary voltage is 5.
If a transformer has 20 primary windings and 100 secondary windings, it is a step up transformer. If the secondary voltage is 25v, the primary voltage will be 5v, because the turns ratio is 20 to 100, or 1 to 5.
125 v
It depends on the type of transformer.If it is a step up transformer the number of turns in secondary side is higher than primary.Stepdown means it will have fewer number of windings on the secondary side turns when compared with the primary side.An isolation transformer has the same number of windings on the primary as the secondary.The ratio of the windings is proportional to the increase or decrease in the secondary voltage. For example, twice the windings doubles the voltage and 1/2 the windings halves the secondary voltage. The isolation transformer is denoted as 1:1 and has the same voltage on the secondary as the primary.The ratio of secondary turns to primary turns is the same as the ratio of secondary voltage to primary voltage.e.g. if the secondary to primary turns ratio is 1/10, then the secondary voltage will be one tenth of the primary voltage.
A step-up transformer needs more turns on the secondary windings than on the primary windings to increase the voltage.
The primary and secondary windings of a mutual transformer are electrically isolated, and should have 'infinite' resistance between them when measured appropriately (which depends on voltage ratings of the windings).
The secondary voltage in a transformer is stepped up by having more turns in the secondary coil compared to the primary coil. This creates a higher electromagnetic induction which leads to a higher output voltage. The ratio of the number of turns in the primary coil to the number of turns in the secondary coil determines the degree of voltage stepping up.
A transformer has two windings, termed the 'primary winding' and the 'secondary winding'. The primary winding is the winding connected to the supply, while the secondary winding is connected to the load. The secondary voltage of a 'step up' transformer is higher than the primary voltage; the secondary voltage of a 'step down' transformer is lower than the primary voltage. The simplest way to determine whether a transformer is a step up or step down, is to measure the primary and secondary voltages. If you are simply looking at a transformer, then the transformer's insulated bushings will give you a clue -the higher voltage bushings are much bigger than the lower voltage bushings. If you have access to the inside of the transformer, then the higher voltage windings are thinner and have a greater number of turns than the lower-voltage winding.
The difference between the two transformers is the coil ratios between the primary and secondary windings. A transformer that increases voltage from primary to secondary has more secondary winding turns than primary winding turns and is called a step-up transformer. Conversely, a transformer with fewer secondary windings does just the opposite and is called a step-down transformer.
The ratio of the primary voltage to the secondary voltage is proportional to the ratio of windings. So if the primary voltage is 120 volts and the secondary is 240 volts there are twice as many turns in the secondary.AnswerAs the previous answer says, you can work out the turns ratio of a transformer, but knowing the primary and secondary voltages will not help you determine how many turns are on each winding.
The primary coil is the one with voltage applied, or the 'input'. The secondary coil is the one in which a voltage is induced by electromagnetism, or the 'output'. In a step up transformer, the secondary coil voltage is higher than the primary. In a step down transformer, the secondary coil voltage is lower than the primary. In an isolation transformer, the secondary coil voltage is the same as the primary. Here, the point of the transformer isn't to raise or lower voltage, but to keep a particular circuit electrically disconnected from another circuit, while still allowing the circuits to function together (through electromagnetism).
As far as a transformer is concerned, the secondary voltage Vs value cannot be determined by the primary voltage Vp alone. For the simplest of calculations the transformer primary-secondary turn ratio must be known. For an ideal transformer ( and practicaly ideal transformers don't exist as there will be various losses in the transformer cores and windings), the simple equation relating secondary voltage to primary voltage would be : Vs/Vp=Ns/Np=Ip/Is where Ns is the number of winding turns in the secondary of the transformer, and Np the primary. Ip is the primary current and Is the secondary.