A Guide to Low-Frequency Transformers

Low-frequency transformers can be categorized into interstage coupling transformers, input transformers, and output transformers, each of which plays a unique role in audio and power circuits.

Interstage Coupling Transformers: These are placed between two amplifier circuits to transmit output signals and convert impedance for compatibility.

Input Transformers: Widely used in early semiconductor radios, input transformers serve to couple signals between the audio push stage and the power amplifier stage. They can be designed for either single-ended or push-pull circuits, based on the amplifier configuration.

Output Transformers: Output transformers connect the power amplifier’s output to the speaker, ensuring signal transmission and impedance matching. They can be classified into single-ended or push-pull types.