Step-up transformer

Definition

A step-up transformer increases the voltage from the primary coil to the secondary coil while decreasing the current proportionally. This is achieved using a higher number of turns in the secondary coil compared to the primary coil.

5 Must Know Facts For Your Next Test

1. Step-up transformers are used to increase voltage levels, which makes them essential for efficient long-distance power transmission.
2. The voltage increase is directly proportional to the ratio of turns between the secondary and primary coils: $V_s / V_p = N_s / N_p$.
3. The power in an ideal transformer remains constant, so if voltage increases, current decreases: $P = IV$.
4. Core losses (hysteresis and eddy currents) are factors that affect real-world transformer efficiency.
5. Applications include electrical substations, x-ray machines, and various electronic devices requiring high voltages.

Review Questions

• What is the purpose of a step-up transformer in electrical systems?
• How does the number of turns in the coils affect the voltage transformation in a step-up transformer?
• Why does current decrease when voltage increases in an ideal step-up transformer?

Related terms

Primary Coil:

The coil connected to the input voltage source in a transformer.

Secondary Coil:

The coil connected to the output load where increased or decreased voltage is delivered.

Turns Ratio: $N_s / N_p$, where $N_s$ is the number of turns in the secondary coil and $N_p$ is the number of turns in the primary coil; determines how much voltage is stepped up or down.