What is the name of a voltage selector consisting of an iron core transformer with taps at various points?

The name of a voltage selector that consists of an iron core transformer with taps at various points is an autotransformer. An autotransformer functions by providing a variable voltage output through the use of its taps, which are connected to different points on a single winding. This design allows for more efficient voltage regulation by utilizing the same winding for both the primary and secondary circuits, as opposed to traditional transformers that use separate windings.

The ability to tap different voltage levels at various points makes the autotransformer ideal for applications requiring precise voltage adjustments while minimizing losses associated with energy transfer. Its construction typically features one winding that is shared between the input and the output, thus simplifying the design and reducing the amount of copper needed compared to a double-wound transformer.

In contrast, step-down transformers typically convert a high input voltage to a lower output voltage but do not allow for the same versatility in voltage selection as an autotransformer. Rectifiers are used to convert alternating current (AC) to direct current (DC), while voltage regulators maintain a constant output voltage despite variations in input voltage or load conditions.