This paper represents the study of different types of single phase AC to DC step down converter. Performances and outputs have analyzed depending on the equations. Different parameters such as voltage gain, harmonic contents in input current, and parameters of changing output voltage are compared different type of single phase AC to DC converters. AC to DC converter is defined as rectifier. The main power supply system is alternating in nature. Rectification action is required to obtain DC supply from the main power supply which issinusoidal.

These factors play roles to various degrees (but not 100%) of importance.  For example, the confinement and the coherent effects are not as complete as that in an atom.  Both the crystalline (bulk) states and the surface/interface states cannot be ignored in nanoscale structures.  The different mixture of atomic/molecular, mesoscopic and macroscopic characters make the properties of nanostructures vary dramatically. Nanostructural materials are often in a metastable state.  Their detailed atomic configuration depends sensitively on the kinetic processes in which they are fabricated.  Therefore, the properties of nanostructures can be widely adjustable by changing their size, shape and processing conditions.

The transistor has ranking in 20th century technology.  It is finding the application in all electronic devices as radios, computers.  Integrated circuits are containing various transistors, which are made by silicon. The transistors are used to handle large current and/or large voltages. As example, the final audio stage in the stereo system used a power transistors amplifier to drive the various speakers. Transistors are device, which are utilizes a change in current to produce a large change in voltage, current, or power.

Photovoltaic cells are converts about 15% of the solar energy falling into the useful electricity. The increase in the temperature increases the resistance of these cell and in turns decreases the cell efficiency. So, cooling these panels is the effective way of increasing the cell efficiency. The performance of the solar panel increases by reducing the temperature. This cooling is done by air cooling or water cooling on the self-designed modified panel. The solar panels are cooled by passing air with the help of blower.

The difference between conductors, insulators and semiconductors is to plot the available energies for electrons in the materials. Instead of having discrete energies as in the case of free atoms, the available energy states form bands. Energy bands occur in solids where the discreet energy levels of the individual atoms merge into bands which contain a large number of closely spaced energy levels.