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| a scrap or morsel of food left at a meal. |
| a screen or mat covered with a dark material for shielding a camera lens from excess light or glare. |
transformer (trāns-fôr'mər) Pronunciation Key
(click for larger image in new window) A device used to change the voltage of an alternating current in one circuit to a different voltage in a second circuit, or to partially isolate two circuits from each other. Transformers consist of two or more coils of conducting material, such as wire, wrapped around a core (often made of iron). The magnetic field produced by an alternating current in one coil induces a similar current in the other coils. ◇ If there are fewer turns on the coil that carries the source of the power than there are on a second coil, the second coil will provide the same power but at a higher voltage. This is called a step-up transformer. ◇ If there are fewer turns on the second coil than on the source coil, the outgoing power will have a lower voltage. This is called a step-down transformer. Compare converter, rectifier. |
A device used to transfer electrical energy from one circuit to another. With an alternating current, a transformer will either raise or lower the voltage as it makes the transfer.