It can be used as an amplifier or rotary transformer.

A rotary transformer has none of these limitations.

Rotary transformers are often used instead of slip rings in high speed or low friction environments.

This can be accomplished using slip rings, wireless telemetry, or rotary transformers.

Rotary transformers are most commonly used in videocassette recorders.

These rotary transformers have a cylindrical, rather than a disc-shaped, air gap between windings.

In brushless synchros, typical rotary transformers (in pairs) provide longer life than slip rings.

Supplying signals to a rotating head is also problematic: This is usually accomplished by coupling the signal(s) inductively through a rotary transformer.

Rotary transformers cannot be used in most DC motors instead of commutators, as transformers can only transfer AC current.

So called brushless synchros use rotary transformers (that have no magnetic interaction with the usual rotor and stator) to feed power to the rotor.

After about 20 seconds, however, the RF output would suddenly fall to zero, although the rotary transformer continued to run, and there was plenty of drive to the PA.

HT and bias supplies are obtained from a three commutator rotary transformer which supplies 60mA at 150 volts and 40mA at 40 volts.

Signals must be coupled from the electronics of the VCR to the fast-moving tape heads carried on the rotating head drum; a rotary transformer is ideal for this purpose.

Alternatively, the three-phase alternating current of the power grid can be converted in substations by rotary transformers or static inverters into the voltage and type of current required by the trains.

Rotary transformers are constructed by winding the primary and secondary windings into separate halves of a cup core; these concentric halves face each other, with each half mounted to one of the rotating parts.