For idealized transformers, although the ratio of voltage to current will change in exact proportion to the square of the winding ratio, the power (measured in watts) remains identical. The ratio of loops in each winding and the efficiency of the coils' magnetic coupling determines the ratio of electrical potential ( voltage) to electrical current and the total power of the output. The collapsing magnetic field then induces an electric field in the secondary winding. When the electrical current through the primary reverses, it causes the established magnetic field to collapse. The electrical signal in the primary coil is converted into a magnetic field in the transformer's core.
The core that they are wound on may either be empty (air core) or, equivalently, a magnetically neutral material like a porcelain support, or it may be a material which is good magnetic conductor like ferrite in modern high-frequency (HF) baluns, or soft iron as in the early days of telegraphy. The primary winding receives the input signal, and the secondary winding puts out the converted signal. This type is sometimes called a voltage balun. The advantage of transformer-type over other types of balun is that the electrically separate windings for input and output allow these baluns to connect circuits whose ground-level voltages are subject to ground loops or are otherwise electrically incompatible for that reason they are often called isolation transformers.
In classical transformers, there are two electrically separate windings of wire coils around the transformer's core.
0 kommentar(er)
