Transformer

A component that transfers AC energy between two coils at a different voltage via mutual induction.

How it works

A transformer transfers electrical energy between two or more separate coils of wire through electromagnetic induction. When an alternating current (AC) flows through the primary coil, it creates a fluctuating magnetic field that induces a corresponding voltage in the secondary coil.

Transformers are used to step-up (increase) or step-down (decrease) AC voltages. The ratio of the input voltage to the output voltage is determined entirely by the ratio of the number of turns of wire in each coil. Note: Transformers only work with AC or fluctuating signals; they block steady DC voltages entirely.

Key Formulas

Turns Ratio / Voltage RatioV_primary / V_secondary = N_primary / N_secondary
Ideal Power TransferP_primary = P_secondary (or V_p × I_p = V_s × I_s)

Common Mistakes

Applying a steady DC voltage to the primary coil. A steady DC current creates a static magnetic field, which induces zero voltage in the secondary. Worse, without the inductive reactance of AC, the primary coil acts like a short wire and will draw massive DC current, causing it to burn up.

Common Variants

Variants for this component will be listed here soon.