How do Resistors Work?

When an electronic circuit is created often times precise amounts of resistance are needed. This is often achieved by adding components called resistors. These resistors have two connections which are used to hook into a circuit to create the resistance required.

Inside the resistor is a coil of copper wire with a ceramic rod running through the middle. The number of turns the copper wire has dictates how much resistance the resistor offers. Copper resistors are generally more precise and stable than their carbon-film counterparts.

A common type of resistor used is the high voltage resistor, these are used in many common appliances and equipment. Uses such as printers, copiers and air conditioning units. As well as this high voltage resistors are used in machinery such as wind turbines and various medical equipment.

Variable resistors are another common type of resistor available today. These, as the name suggests, are adjustable based on the level of resistance needed. The potentiometer is the most common type of variable resistor available to buy today. A popular use of a variable resistor is for volume control on an amplifier and the tuning of circuits.

Digital resistors are a type of variable resistor where the resistance is performed by digital signals rather than mechanical movement. A protocol called I2C is usually used to change the resistance in small steps, simple up/down signals can also be used.

These are just some of the resistors available on the market today. More specialist resistors can be purchased for specific requirements such as the high voltage resistors mentioned above as well as high temperature and military grade resistors.

Resistors

Eddy Current Separator Systems

Eddy Current Separator Systems

The Eddy Current Separator is an advanced metal sorting unit that is capable of separating non-ferrous metals such as aluminium and copper from dry recyclables. Non-ferrous separators are very common in the fast growing market of beverage can sorting, where they can provide an accurate separation of aluminium cans from waste streams.

The Eddy Current Separator is applied to a conveyor belt carrying a thin layer of mixed waste. At the end of the conveyor belt is an eddy current rotor. Non-ferrous metals are thrown forward from the belt into a product bin, while non-metals simply fall of the belt sue to gravity. Eddy current separators may use a rotating drum with permanent magnets or may use an electromagnet depending on the type of separator.

Operating Principles

An Eddy Current Separator consists of a short belt conveyor that has its drive located at the return end and a high speed magnetic rotor system installed at the discharge end. The magnetic rotor, which is positioned within a separately rotating non-metallic drum, revolves at around 3000 revolutions per minute during operation whilst the outer drum cover rotates at the speed of the Eddy Currents’ belt conveyor.

As the rotor spins at these high speeds, an electric current is induced into conducting metals. The induced electric current produces a magnetic field, which opposes the field created by the rotor, repelling the conducting metals over a pre-positioned splitter plate. The remaining materials such as plastics, glass and other dry recyclables will simply free-fall over the rotor, separating them from the repelled metals.