Step down transformer is used to play radio of 12 V. It is because, input supply at house hold is 220 V so that the step down transformer in the adopter changes it into 12 V.
If there are MORE windings on the SECONDARY than on the primary, figure 82, the transformer is a STEP UP. If the windings are reversed, with MORE on the PRIMARY, the transformer is a STEP DOWN. The amount of step up or step down is directly proPortional to the TURNS RATIO between primary and secondary.A resonant transformer is a transformer in which one or both windings has a capacitor across it and functions as a tuned circuit. Used at radio frequencies, resonant transformers can function as high Q factor bandpass filters.
A transformer designed to reduce the voltage from primary to secondary is called a step-down transformer. The transformation ratio of a transformer will be equal to the square root of its primary to secondary inductance (L) ratio.Audio Transformers are designed for use in audio amplifier applications for coupling and impedance matching of amplifiers and speakers. As well as stepping up (increase) or stepping down (decrease) a signal voltage, transformers also have one very other useful property, isolation.
A Step down Transformer is a type of transformer, which converts a high voltage at the primary side to a low voltage at the secondary side. If we speak in terms of the coil windings, the primary winding of a Step down Transformer has more turns than the secondary winding.
Transformers generally have one of two types of cores: Core Type and Shell Type. These two types are distinguished from each other by the manner in which the primary and secondary coils are place around the steel core.The concept of a step down transformer is actually quite simple. The transfer has more turns of wire on the primary coil as compared to the turns on the secondary coil. This reduces the induced voltage running through the secondary coil, which ultimately reduces the output voltage.