| English | Step-up transformer |
|---|---|
| Bahasa Melayu | Transformer injak naik |
| 中文 | 升压变压器 |
Definition
A transformer with more turns on the secondary coil than the primary, which increases the alternating voltage.
In exam terms
A step-up transformer has more turns on the secondary coil than on the primary coil (N_s > N_p), which increases the alternating voltage from primary to secondary. Voltage is measured in volts (V).
Because the turns ratio equals the voltage ratio, V_s / V_p = N_s / N_p, and in an ideal transformer power is conserved (V_p I_p = V_s I_s), a higher output voltage comes with a smaller output current. Example of correct use: A step-up transformer with 100 primary turns and 500 secondary turns raises 240 V to 1200 V. Step-up transformers are used at power stations to raise voltage for efficient transmission through the National Grid.
Do not confuse it with…
Do not confuse a step-up transformer with a step-down transformer. A step-up transformer has more secondary turns and raises the voltage; a step-down transformer has fewer secondary turns and lowers it.
The only structural difference is which coil has more turns.
In Paper 2 this is asked as state or calculate: state whether a transformer steps up or down from its turns, or calculate the output voltage. When answering, compare N_s with N_p first, then use the turns ratio to find the new voltage.
Source: DSKP KSSM Physics Form 4 and 5 (Versi English) (Bahagian Pembangunan Kurikulum (BPK), KPM)