Transformer Applications

Main article: Transformer types

Various specific electrical application designs require a variety of transformer types. Although they all share the basic characteristic transformer principles, they are customized in construction or electrical properties for certain installation requirements or circuit conditions.

In electric power transmission, transformers allow transmission of electric power at high voltages, which reduces the loss due to heating of the wires. This allows generating plants to be located economically at a distance from electrical consumers.[52] All but a tiny fraction of the world's electrical power has passed through a series of transformers by the time it reaches the consumer.

In many electronic devices, a transformer is used to convert voltage from the distribution wiring to convenient values for the circuit requirements, either directly at the power line frequency or through a switch mode power supply.

Signal and audio transformers are used to couple stages of amplifiers and to match devices such as microphones and record players to the input of amplifiers. Audio transformers allowed telephone circuits to carry on a two-way conversation over a single pair of wires. A balun transformer converts a signal that is referenced to ground to a signal that has balanced voltages to ground, such as between external cables and internal circuits. Isolation transformers prevent leakage of current into the secondary circuit and are used in medical equipment and at construction sites. Resonant transformers are used for coupling between stages of radio receivers, or in high-voltage Tesla coils.

Schematic of a large oil-filled power transformer

1. Tank 2. Lid 3. Conservator tank 4. Oil level indicator

5. Buchholz relay for detecting gas bubbles after an internal fault

6. Piping 7. Tap changer 8. Drive motor for tap changer

9. Drive shaft for tap changer 10. High voltage (HV) bushing

11. High voltage bushing current transformers 12. Low voltage (LV) bushing

13. Low voltage current transformers 14. Bushing voltage-transformer for metering

15. Core 16. Yoke of the core 17. Limbs connect the yokes and hold them up

18. Coils 19. Internal wiring between coils and tapchanger

20. Oil release valve 21. Vacuum valve