How do electrical transformers work?

Answer 1

To do its magic on the high voltage and change it to low voltage the electrical transformer uses two rather intriguing and important phenomena. Firstly whenever an electric current flows, there is magnetism around it. Secondly whenever a magnetic field changes (by moving or by changing strength) a voltage is made. If there's a wire close by when this happens then a current will flow in the wire as the magnetism changes.

The electrical transformer takes in high voltage electricity and lets it run through lots of coils wound around an iron core. Because the current is alternating the magnetism in the core is also alternating. Also round the core is an output wire with less coils. The changing magnetism generates a current in the wire and less coils means less voltage. So the voltage is 'stepped-down'.

Answer#1...Wire produces a magnetic field when current is passed through it. If you wrap the wire around something (a core) to make a coil, it concentrates that field. The core isn't actually necessary but it helps concentrate the field and make the transformer more efficient.

#2...If you pass a magnetic field through a wire, it produces electron flow.

If you make a coil with 100 wraps and pass current through it, it will produce the magnetic field. If you have another coil close enough to be IN that magnetic field, and it has 10 turns, you will get about 1/10 the voltage from the second coil that you put into the first one.

It gets a lot more complicated than that with formulas and all kinds of mathematics, but that is the basics of a "step down" transformer.

AnswerWhen an electron travels through a conductor it generates "ripples" in a fluid like medium (EMF) those ripples induce the electrons in conductors in close proximity to move(=current). In a transformer electrons in the input or primary side travel around the core perpendicularly causing the electrons in the core to spin(the core resembles a doughnut like shape) the secondary coil gets induced by the motion of electrons in the core. The a out put voltage is determine by the turns ration of the primary to secondary coils. In the mechanical world an electrical transformer is like a car transmission, converting torque (current) into speed(voltage) or vies versa. Total input power= Total output power.

Answer 2

When signal current goes through the primary winding, it generates a magnetic field which induces a voltage across the secondary winding. Connecting a load to the secondary causes an AC current to flow in the load.It is generally necessary to control terminating impedances of RF signal paths, especially in wide-band applications where path lengths are not negligible relative to wavelength. Wideband RF Transformers are wound using twisted wires which behave as transmission lines, and the required coupling occurs along the length of these lines as well as magnetically via the core. Optimum performance is achieved when primary and secondary windings are connected to resistive terminating impedances for which the transformer is designed. Transformers having a turns ratio of 1:1, for example, are typically designed for use in a 50- or 75-ohm system.In this application note, reference is continually made to terminating impedances which the user should provide for transformers, both for performance testing and in actual use. For the sake of consistency in the discussion, transformers with turns ratio greater than 1:1 will be described as step-up; that is, the secondary impedance is greater that the primary impedance. In actual use, however, connection can be step-up or step-down as needed.