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Transformers. By Stephen, Victor, Thomas and Tim. What Is a Transformer?. A device designed to transfer energy from one electrical circuit to another. How Does It Work ? Four Main Principles.
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Transformers • By Stephen, Victor, Thomas and Tim
What Is a Transformer? A device designed to transfer energy from one electrical circuit to another.
How Does It Work? Four Main Principles
If Np (number of primary turns) = Ns (number of secondary turns), then no change in voltage or current. • If Np > Ns, voltage is decreased and current is increased. • If Np < Ns, voltage is increased and current is decreased. • If Np = Ns, then energy is simply transferred and no changes take place. • Remember that: Vs/Vp = Ip/Is = Ns/Np • However, it’s not so simple…
Real World Examples – Power Plants • Power plants step up voltage to tens of thousands of volts for efficient transfer (high voltage means low current, which means lower resistance). • Voltage is stepped down using a series of sub-stations, by the time it reaches your house it is at 120v. • Power meters often use an isolation transformer that is 1:1, in order to protect the house from interference from the main line, and visa versa. • Power generators are often three-phased; they have windings places 120 degrees apart. A three-phased transformer consisting of three coils is required to match this. • Advantage is up to 173% more power, because power is available between any two of the three phases
A Demonstration By.. Thomas