Dynamo how does it work

However batteries were not reliable or cost effective for any regular electrical use, it was the dynamo that radically changed electricity from a curiosity into a profitable, reliable technology.

How it Works 2. Brief History of Dynamos and Generators 3. Videos of generators. First you need a mechanical power source like a turbine powered by water falling , wind turbine, gas turbine or steam turbine. A shaft from one of these devices is connected to a generator to make power. Dynamos and generators work using the wild complex phenomena of electromagnetism. Understanding the behavior of electromagnetism, its fields and its effects is a large subject of study.

We will keep things simple to help introduce you to the interesting subject of power generation. You cannot see a magnetic field, but it is often illustrated using lines of flux. In the illustration above lines of magnetic flux would follow the lines created by the iron filings. When the rotor cuts through lines of magnetic flux it makes electricity. Due to Faraday's Law of Induction if you take a wire and move it back and forth in a magnetic field, the field pushes on electrons in the metal.

Copper has 27 electrons, the last two in the orbit are easily pushed on to the next atom. This movement of electrons is electrical flow.

See the video below showing how current is induced in a wire:. If you take a lot of wire such as in a coil and move it in the field, you create a more powerful "flow" of electrons. The strength of your generator depends on:. See the video to see all of this demonstrated:. Above: a simple electromagnet referred to as a solenoid. The term "solenoid" actually describes the tubular shape created by the coiled wire.

The magnets are usually not made of natural magnetite or a permanent magnet unless it is a small generator , but they are copper or aluminum wire coiled around an iron core. Each coil must be energized with some power to make it into a magnet.

This coil around iron is called a solenoid. Solenoids are used instead of natural magnetite because the solenoid is MUCH more powerful. A small solenoid can create a very strong magnetic field. Above: The coils of wire in the generators must be insulated. Generator failure is caused by temperatures rising too high which results in a breakdown of insulation and a short between to parallel wires.

Commutator - Learn more detail about them here Torque - force in a rotational motion. Also see our page on Induction. Dynamo is an older term used to describe a generator that makes direct current power.

DC power sends electrons in only one direction. The problem with a simple generator is that when the rotor rotates it eventually turns completely around, reversing the current. Early inventors didn't know what to do with this alternating current, alternating current is more complex to control and design motors and lights for.

Early inventors had to figure a way to only capture the positive energy of the generator, so they invented a commutator. The commutator is a switch that allows current to only flow in one direction. See the video below to see how the commutator works:.

The Dynamo consists of 3 major components : the stator, the armature, and the commutator. Brushes are part of the commutator, the brushes must conduct electricity as the keep contact with the rotating armature. The first brushes were actual wire "brushes" made of small wires. These wore out easily and they developed graphic blocks to do the same job. The stator is a fixed structure that makes magnetic field, you can do this in a small dynamo using a permanent magnet.

Large dynamos require an electromagnet. The armature is made of coiled copper windings which rotate inside the magnetic field made by the stator. When the windings move, they cut through the lines of magnetic field. This creates pulses of electric power.

The commutator is needed to produce direct current. In direct current power flows in only one direction through a wire, the problem is that the rotating armature in a dynamo reverses current each half turn, so the commutator is a rotary switch that disconnects the power during the reversed current part of the cycle.

Since the magnets in an dynamo are solenoids, they must be powered to work. So in addition to brushes which tap power to go out to the main circuit, there is another set of brushes to take power from from the armature to power the stator's magnets. That's fine if the dynamo is running, but how do you start a dynamo if you have no power to start? Sometimes the armature retains some magnetism in the iron core, and and when it begins to turn it makes a small amount of power, enough to excite the solenoids in the stator.

Voltage then begins to rise until the dynamo is at full power. If there is no magnetism left in the armature's iron, than often a battery is used to excite the solenoids in the dynamo to get it started.

This is called "field flashing". Below in the discussion of wiring the dynamo you will notice how power is routed through the solenoids differently. There are two ways of wiring a dynamo: series wound and shunt wound. See the diagrams to learn the difference. Below, video of a small simple dynamo similar to the diagrams above built in the s :. The generator differs from the dynamo in that it produces AC power.

Electrons flow in in both directions in AC power. It wasn't until the s that engineers had figured out how to design powerful motors, transformers and other devices which could use AC power in a way that could compete with DC power. The end of the dynamo has two terminals. The other end of the field coil internally connected to the dynamo case. If you have followed the explanation so far, you have probably worked out that there are two things that affect the maximum power any given dynamo can generate.

To stop a battery being over charged the dynamo output needs to be regulated. This is done by, not surprisingly, the regulator sometimes called a controller or control box which changes the field coil current as needed.

This diagram is a very simplified explanation of a complex electro-mechanical unit. The dynamo earth connection is via its case, mount and vehicle chassis. Anglo Agriparts nor any such reviewers or contributors of content provides any warranty or guarantee as to the accuracy of any information on this website and cannot accept liability for any errors or omissions.

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How Does a Dynamo Work? How does a Dynamo Work? How Does A Dynamo Work Andrew grew up on a dairy farm and completed his first tractor engine rebuild around 50 years ago. With a degree in engineering Andrew, now retired, has time to pursue his interest in tractor restoration. Power is always power. This is equivalent to switching something OFF.

Switch closed — opposite to switch open. Allows electricity to flow, equivalent to switching something ON. First Principles Dynamos convert external power to electrical power. A Simple Dynamo This is a simplified representation of a dynamo. A Real Dynamo The armature could be almost any shape — Fig 1 is quite short along the rotational axis but the types of dynamo in cars and tractors it tends to be long relative to its diameter as shown in Fig 2.