Month: March 2018

Electric Motor Trajectory

In the middle of 1879, the company Siemens and Halske presented the first electric locomotive in Berlin at an industrial fair, with an average power of 2 KW. It had a DC motor, which had advantages over the water wheel, animal power, and steam engine. However, due to its high manufacturing cost and its vulnerability due to the commutator, these factors led several scientists to focus on the design of an electric motor that was cheaper, stronger and easier to maintain.

In 1885, electrical engineer Galileo Ferraris sketched a two-phase alternating current motor, and although he invented the rotating field motor, he concluded incorrectly that motors designed in accordance with this principle could yield a maximum efficiency 50% in relation to the power consumed.

Among the researchers involved with this idea are the Yugoslavian Nikola Tesla, the Italian Galileo Ferraris and the Russian Michael von Dolivo-Dobrovolski. Their efforts were not limited only to the refinement of the direct current motor, but also to alternating current systems, where the advantages were already known in 1881.

 

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Aplicativos para condomínios

Que muitos aplicativos vieram para facilitar nossas vidas você já sabe. Mas a grande novidade da vez é que aplicativos para condomínios estão surgindo para abrir novos horizontes.

Confira na íntegra tudo sobre o assunto com as dicas do condominio acapulco guarujá:

Aplicativos para condomínios possuem objetivos específicos

Todos sabemos que disputas por áreas de lazer, barulhos e discórdias podem acontecer em qualquer condomínio. Entretanto, é sempre interessante buscar novas formas que sejam democráticas para evitar esse tipo de situação.

E é exatamente dessa forma, com o pedido por parte dos síndicos, que aplicativos para condomínios estão surgindo. Eles são baixados pelos moradores e podem ser utilizados para reservar as áreas de lazer, tirar extratos, receber avisos importantes e até mesmo relatórios sobre as rondas e reuniões sobre a segurança.  condominio acapulco guaruja

Usabilidade

Nem mesmo o acesso a portaria fica de fora de alguns desses aplicativos! Existem aplicativos para condomínio como o Interbind, Nobi e CondomínioApp. Cada um deles possui funcionalidades diferentes, com valores e serviços mensais prestados aos condomínios.

O mercado de segurança residencial está continuamente crescendo, mas não é em função de um aspecto positivo. Infelizmente, os índices de homicídio e de segurança pública despertam cada vez mais medo na população. Dessa forma, o setor privado tenta a todo custo nos oferecer novas soluções em segurança, tal como os aplicativos para condomínio.

Esperemos que o cenário melhore!

Rotation of the Motor

The rotor of the electric motor needs a torque so that it is able to start its rotation and this moment of torque is usually promoted by magnetic forces generated between the rotor and the stator magnetic poles. Forces acting on the attraction or repulsion, generated between stator and rotor, are able to pull or push the movable poles of the rotor, and this produces torques, which cause the rotor to rotate faster, until the frictions or charges attached to the axis can reduce the resulting torque to zero.

An engine can not function if it is made with permanent magnets only and this is simple to note since it will not present the initial torque to start the movement and if they are already in their equilibrium positions, they will only hesitate around that position if they receive a stimulus external.

After that moment, the rotor starts to turn at a constant angular speed and the rotor in the same way as the motor stator, must be magnetic, since it is these forces between poles that are able to give the necessary torque to make the rotor rotate. In the same way, even if permanent magnets are used frequently, especially on smaller motors, remembering that at least some of the magnets on a motor need to be electromagnets.

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Engine Mounting – Vibrations

The standard motor is schematized to act with horizontal axis and in case of

vertical axis or even other inclinations, it is imperative that the electric motor built specifically for this purpose, usually equipped with a thrust bearing. Correctly, we can say that an engine should never be fixed on any inclination of its axis, without knowing exactly its own characteristics and designs. 7800 OLS SS

In order to control some factors, it is necessary to adopt some preventive measures, such as observing the state of the bearings, as well as the useful life, observing and controlling the vibrations by placing any tool on the bearing and approaching the ear, to detect some failures by produced noises. Be cautious when replacing one bearing for another and at long-term stops, we should frequently change the resting position of the rotors of the electric motors in the same way as the moving parts of the machines.

Vibrations considered to be out of order may cause a reduction in engine performance, and may result from a misalignment, insufficient or even faulty engine attachment at its base, excessive bearing clearances, or poor balance made in the rotating parts.