In direct current (or DC) circuits, electricity flows in one direction. In alternating current (or AC) circuits, the electricity switches directions, sometimes going forward and sometimes going backward.Continue Reading
A magnet near the wire in a DC circuit attracts the electrons on its positive side and repels the electrons on its negative side. This causes the electricity to flow in one direction only; DC power from a battery works this way. However, it is not an efficient way to transfer electricity over long distances because it begins to lose energy.
AC circuits use rotating magnets instead of applying magnetism along the wire. When the magnet is facing one direction the electricity flows in that direction. When the magnet is flipped, the flow of electricity changes direction as well. Direct current can be stored in batteries, but alternating current cannot be stored. The voltage oscillates in AC circuits but is constant in a DC circuit.
Alternating current voltage can be increased or decreased using a device called a transformer. Transformers reduce the high voltage of AC to a lower voltage that is used in home appliances. Thomas Edison's work led to the DC battery system. Nikola Tesla came up with the AC generator by using a rotating magnet.Learn more about Electrical
A synchronous AC motor is an electric motor that operates at constant speed and is synchronized with the AC line that provides electricity to it. These motors are extremely useful in applications where accurate timing is needed, such as the timers of clocks.Full Answer >
A rectifier diode is used to force electricity to flow only in one direction. These components are commonly used to change alternating current into direct current.Full Answer >
Double pole sockets operate two separate electrical circuits in a single circuit. Double pole sockets switch the live and neutral conductors. Double pole sockets are often used in home lighting situations where red wires are live, and black are neutral and the green wires are Earth or grounding wires.Full Answer >
To use a Megger insulation tester, first turn off the power that supplies the circuits to be tested. Use a voltage tester to ensure that the circuits have no power running to them. Choose the test voltage on the Megger, which, depending on the model, should be 500 or 1000 volts. Put the probes on the terminals located where the insulation is tested and turn on the Megger for at least a minute. Record the value produced.Full Answer >