Electric Circuits

Electric Circuits

1. Electricity Charge

   • Conventional flow notation
     • Electric charge moves from positive to the negative side of the battery
   • Electron flow notation
     • Electric charges moves from the negative to the positive side of the battery
   • Electric process
     • It is a process of energy transportation
       • The director flow of free electrons through the conduction band of the conductor, represents the electric current
         • 1Ampere=1Coulomb/1seg= 6.24X10 28 Electrones/1 seg
           • It is the force which retains the valence electrons within the atoms nucleus to avoid those electrons becomes in free electrons

2. Atomic theory

   • Molecules are compossed by atoms
     • The atomic number or proton number is the number of protons found in the nucleus of an atom
     • Atoms are compossed by nucleus and valence electron
       • Nucleus are compossed by neutron and proton
       • Atomic stability
         • It has the valence shell complete and it has a full outer Shell of electrons
           • 3 cases in function of the number of valence electrons
             • More than 4 electrons
               • Electrons flow is difficult between atoms
                 • Insulator
             • 4 electrons
               • The bonding between atoms can be covalent, ionic or mixed
                 • Semiconductor
             • Less than 4 electrons
               • Electrons flow easily between atoms
                 • Conductor

3. Sources of electric power

   • Voltage
     • Is a two-terminal devine which can maintain a fixed voltage, of the load change, the current of the source varies
   • Current
     • Is a two-terminal devine which can maintain a fixed current, of the load change, the Voltage of the source varies
   • Power plants
     • Industrial facility that generates electricity from primary energy
       • Most power plants use one or more generators that convert mechanical energy into electrical energy
       • Examples
         • Hydroelectric power plants
           • Is produced by harnessing the gravitational force of flowing water
         • Coal-fired power plants
           • Use steam coal as a source to generate electricity and consequently emit a significant amount of harmful gases into the atmosphere
         • Wind power plants
           • Wind power harvests the primary energy flow of the atmosphere generated from the heating of the Earth’s surface by the Sun
         • Nuclear power plant
           • Use the process of nuclear fission in order to generate electricity
             • They do this by using nuclear reactors in combination with the Rankine cycle, where the heat generated by the reactor converts water into steam, which spins a turbine and a generator

4. Laws

   • Kirchhoff´s
     • “ The algebraic sum of the currents in the connected branches at any node of an electrical circuit is equal to zero"
       • To apply
         • Is necessary to take in cosideration the directions of current´s arrows and branch voltages´s directions, in conventional sense
       • Voltage Law
         • ”The algebraic sum of the branch voltajes in any closed loop of a circuit is equal to zero
           • Knwing the branch voltaje arrows and identyfing the loops, the loop is traversed in any direction considering the voltaje arrows of the positive branches in favor of the path and negative against the path
     • Kirchhoff´s
   • Ohm´s
     • “When applying a voltage to a passive linear circuit, a current will flow through it, which depends directly on the applied voltaje and inversely on its resistance”
       • I=V/R