Welcome to understanding how transformers work! A transformer is a crucial electrical device that transfers energy between circuits through electromagnetic induction. It consists of two coils of wire wound around an iron core. The primary coil receives input voltage, while the secondary coil provides output voltage. The number of turns in each coil determines whether voltage is stepped up or down.
The key principle behind transformer operation is electromagnetic induction, discovered by Michael Faraday. When alternating current flows through the primary coil, it creates a continuously changing magnetic field. This changing magnetic field passes through the iron core and cuts through the turns of the secondary coil. According to Faraday's Law, this changing magnetic flux induces an electromotive force in the secondary coil.
The voltage transformation in a transformer follows a simple mathematical relationship based on the turns ratio. The ratio of secondary voltage to primary voltage equals the ratio of secondary turns to primary turns. In this step-up transformer example, we have 4 turns in the primary and 8 turns in the secondary. This gives us a turns ratio of 2 to 1, meaning the output voltage will be twice the input voltage. So 120 volts input becomes 240 volts output.
A fundamental principle of transformers is power conservation. In an ideal transformer, the power input equals power output. Since power equals voltage times current, when voltage is stepped up, current must step down proportionally. In our example, the primary has 120 volts and 2 amperes, giving 240 watts. The secondary has 240 volts but only 1 ampere, still giving 240 watts. Real transformers achieve 95 to 99 percent efficiency.
Transformers have countless applications in modern life. In power systems, they step up voltage from power plants to 500 kilovolts for efficient long-distance transmission, then step it down to 120 volts for home use. They're found in phone chargers, welding equipment, audio systems, and medical devices. Their key advantages include high efficiency of 95 to 99 percent, no moving parts for reliability, long lifespan, and electrical isolation for safety. Understanding transformer mechanics helps us appreciate this fundamental technology that powers our modern world.