Perpetual motion machine of the first kind produces work without the input of energy. It thus violates the first law of thermodynamics: the law of conservation of energy.
Perpetual motion machine of the second kind is a machine which spontaneously converts thermal energy into mechanical work. When the thermal energy is equivalent to the work done, this does not violate the law of conservation of energy. However it does violate the more subtle second law of thermodynamics . The signature of a perpetual motion machine of the second kind is that there is only one heat reservoir involved, which is being spontaneously cooled without involving a transfer of heat to a cooler reservoir. This conversion of heat into useful work, without any side effect, is impossible, according to the second law of thermodynamics.
Perpetual motion machine of the third kind, usually (but not always) defined as one that completely eliminates friction and other dissipative forces, to maintain motion forever (due to its mass inertia). Third in this case refers solely to the position in the above classification scheme, not the third law of thermodynamics. Although it is impossible to make such a machine as dissipation can never be 100% eliminated in a mechanical system, it is nevertheless possible to get very close to this ideal (see examples in the Low Friction section). Such a machine would not serve as a source of energy but would have utility as a perpetual energy storage device.
SOME PERPETUAL MOTION MACHINE PLANS
The “Overbalanced Wheel”. It was thought that the metal balls on the right side would turn the wheel because of the longer lever arm, but since the left side had more balls than the right side, the torque was balanced and the perpetual movement could be achieved.
The “Float Belt”. The yellow blocks indicate floaters. It was thought that the floaters would rise through the liquid and turn the belt. However pushing the floaters into the water at the bottom would require more energy than the floating could generate.
The “Capillary Bowl”. It was thought that the capillary action would keep the water flowing in the tube, but since the cohesion force that draws the liquid up the tube in the first place holds the droplet from releasing into the bowl, the flow is perpetual.
Steam power plant:
For that consider the steam power plant. It is proposed to heat the steam by resistance heaters that are placed inside the boiler instead of energy input from fossil or nuclear fuels. Part of the electricity that is generated by the plant is to be used to power the resistors as well as the pump. Remaining electrical energy is to be supplied to the electric networks as the network output. Inventor claims that once the system starts, the power plant will produce electricity indefinitely without requiring any energy input from the outside.