A transformer does not operate on direct current (DC) because its operation relies on the principle of electromagnetic induction, which requires a changing magnetic field. In a transformer, an alternating current (AC) in the primary coil generates a varying magnetic field in the core. This variable field induces a voltage in the secondary coil.
Direct current provides a constant magnetic field, which does not induce voltage in the secondary coil, making the transformer ineffective for direct current.
Transformers operate only on alternating current (AC), because alternating current creates a constantly changing magnetic field in the transformer core. This changing magnetic field is necessary to induce a voltage in the secondary coil through electromagnetic induction.
The ability of alternating current to alternate its direction and intensity allows the transformer to efficiently transfer electrical energy between circuits.
The operating principle of a transformer is based on electromagnetic induction. When an alternating voltage is applied to the primary coil, it creates a varying magnetic field in the transformer core. This variable field induces a voltage in the secondary coil according to Faraday’s law of induction.
The ratio of voltages in the primary and secondary coils is proportional to the ratio of the number of turns in each coil, allowing voltage transformation.
Alternating current (AC) is transformed into direct current (DC) using a rectifier. A rectifier is an electronic component or circuit that converts alternating current to direct current by allowing the current to flow in only one direction. This process involves the use of diodes, which are semiconductor devices that conduct current only when forward biased.
AC voltage passes through these diodes, which block reverse current and only allow positive half-cycles to pass, effectively smoothing the AC waveform into a DC signal.
Direct current (DC) is less commonly used for long-distance power transmission due to its high losses and difficulty in voltage transformation compared to alternating current (AC). Alternating current is preferred because it can be easily transformed to higher or lower voltages using transformers, reducing power losses over long distances.
Additionally, AC generators and motors are generally simpler and more cost-effective to design and maintain than their DC counterparts.