The three main characteristics of a DC shunt generator are the open circuit or magnetic characteristic, the internal or total characteristic, and the external characteristic. These characteristics are represented by graphed curves.Know More
As the generator turns, the spinning armature creates an electromagnetic field. The EMF is proportionate in strength to the speed of the spinning armature and creates a resistance within the generator. This effect is the open circuit or magnetic characteristic. It shows that at a fixed speed, there is a relationship between the generated EMF and the field current with zero load on the generator.
When a load is applied to the generator, its voltage output is decreased. Therefore, generated voltage under a load drops below that of the electromagnetic field when there is no load. The relation of the generated voltage and the load current is referred to as the internal or total characteristic. When graphed, this curve drops below the open circuit characteristic curve.
The relationship between the load current and the terminal voltage is the external characteristic. The external characteristic curve shows a greater drop than the internal one because it includes the voltage drop of the armature circuit while under a load. Determining a generator's external characteristic, or its output compared to its load, is very important when deciding which application it is best suited for.Learn more about Electricity
A typical wind power generator produces approximately 30 percent of the theoretical maximum power it could produce on average, as reported by the European Wind Power Administration and Global Wind Energy Council. Losses of efficiency due to the mechanical action of the generator are already included in the theoretical maximum.Full Answer >
Resistance in AC and DC currents is the ability of a material, normally a circuit or a resistor, to oppose or restrict the flow of current through it. The amount of resistance that a material gives is referred to as an ohm. Several common materials with high resistance levels include wood, tungsten, air, glass and rubber.Full Answer >
Ohio Electric Motors indicates that the main difference between AC and DC motors is the power source. AC motors are powered by an alternating current while DC motors use a direct current as a power source.Full Answer >
DC current is direct current, which means electricity only flows in one direction; AC current is alternating current, which means it flows in both directions. Batteries run on DC current, while AC current is what comes in through an electrical plug in the wall.Full Answer >