Law of Conservation of Energy
The law of conservation of energy states that energy can neither be created nor destroyed. It is transformed from one form to another. The total input energy is equal to the sum of the energy that is dissipated, stored, and output as useful energy.
Electromechanical Devices
Electromechanical devices are used to convert mechanical energy into electrical energy, and vice versa. When mechanical energy is converted into electrical energy, the device is referred to as a generator. When electrical energy is converted into mechanical energy, the device is referred to as a motor. Electromagnetic phenomena are used to facilitate the conversion of energy from one form to another.
Generators
Generators are electromechanical devices that convert mechanical energy into electrical energy. This conversion process is facilitated by electromagnetic phenomena in which a magnetic field induces an electrical current in a coil. Generators are used in a wide range of applications, including power plants, electric cars, and portable devices.
Motors
Motors are electromechanical devices that convert electrical energy into mechanical energy. This conversion process is facilitated by electromagnetic phenomena in which a current in a coil produces a magnetic field, which interacts with a permanent magnet to create a force that drives the motor ‘s shaft. Motors are used in a wide range of applications, including automobiles, pumps, and robots.
The conversion of energy occurs via two types of electromagnetic phenomena.
- When a conductor carrying a current moves through a magnetic field, a voltage is induced in the conductor.
- A magnetic field is generated when a current-carrying conductor is placed within it.
The converter typically uses a magnetic field to link the electric and magnetic systems together due to its higher energy storing capacity than an electric field. This magnetic field acts as a coupling medium between the two systems, allowing energy to be stored and transferred.
The energy balance equation for motor action is given as:
Energy Input = Energy Output + Energy Storage.
In motor action, electricity from the main power source is taken as an input. This input is then converted into mechanical energy, however, not all of the energy is used. A portion of the energy is lost due to friction and windage, resulting in frictional losses.
The energy balance equation for generator action is written as follows:
Electromechanical devices, such as electric motors and generators, store energy in multiple forms. The total energy stored in these devices can be calculated by summing the energy stored in the magnetic field, the energy stored in the mechanical system, and the potential or kinetic energy of the system. This energy is used to power the device, allowing it to operate and perform its intended function.
The energy dissipated in an electric circuit is the total of the energy lost in electrical, magnetic and mechanical systems. This energy loss is the result of ohmic losses in the electrical system, hysteresis and eddy current losses in the magnetic system, and friction and windage losses in the mechanical system. All these losses contribute to the overall energy that is dissipated in the circuit.