Fourpole

Fourpole (often written as fourpole) is a term used in several contexts in engineering and branding, and its precise meaning depends on the domain. In electrical engineering and machine design, fourpole describes devices or machines that have four magnetic or electrical poles.

In rotating electrical machines, the pole count determines synchronous speed, given by n_s = 120 f / P. With a four-pole configuration at standard 50 Hz supply, the synchronous speed is about 1500 rpm; at 60 Hz it is about 1800 rpm. Four-pole machines are common where moderate speed and torque are desired, offering a balance between footprint and efficiency for generators and motors.

In signal processing and electrical networks, a four-pole (fourth-order) filter contains four reactive energy storage elements. This configuration yields a steeper attenuation slope compared with lower-order filters and is used in audio, communications, and instrumentation applications to achieve sharper frequency selectivity.

In connectors and audio equipment, four-pole connectors refer to interfaces that carry four separate conductors. Such connectors can support stereo audio plus a microphone, or other combinations of signals in a single plug, as seen in certain TRRS-style jacks and similar designs.

Branding and commerce: Fourpole is also used as a brand or product name by various electronics retailers and manufacturers in different regions. Because the term is not unique to a single entity, the specific company or product associated with the name varies by context.

See also: Four-pole motor, Fourth-order filter, TRRS connector.