D1 Electrochemical cells, generators, and motors

• Electric generator


  device that converts mechanical energy into electrical energy
• Electrochemical cell (voltaic cell)


  Two different electrodes (anode and cathode) and an electrolyte that creates a closed circuit and generates electricity
• anode


  negative electrode - where the electrons travel from (repelled)
• cathode


  positive electrode - where electrons travel to (attracted)
• electrolyte


  substance that conducts electricity --> ionic paste or solution (can be acidic, basic, and neutral)
• primary cell


  cell that cannot be recharged
• secondary cell


  cell that can be recharged
• wet cell


  cell with a liquid electrolyte
• dry cell


  cell with a plastic, paste or ceramic electrolyte
• battery


  several cells connected in series
• electromagnetism


  electricity and magnetism - a moving magnetic field will induce an electric current AND an electric current will induce a magnetic field.
• factors that increase magnetism

  -more wraps of coil

  -increased current

  -larger metal core
• electrical induction


  a moving magnetic field causes an electrical current in a conductor
• alternating current


  current that reverses direction in a regular pattern
• direct current


  current that moves in one direction
• split ring commutator


  reverses the magnetic field polarity so the flow of electrons stays constant for a DC generator OR reverses the current so the magnetic field is constant for a DC motor.
• armature


  rotating coils of wire (electromagnet) in a generator or motor
• brushes


  on a generator, transfers the electrons from the commutator to the terminals
• electric motor


  a device that converts electrical energy into mechanical energy
• How to increase the potential difference of an electrochemical cell

  1. increase electrolyte concentration

  2. increase the surface area of the electrodes

  3. choose two metals that are different (AND the furthest away from each other on the electric potential list)

  
• Electric Energy


  energy carried by an electric current
• kinetic energy


  energy due to motion
• gravitational potential energy


  Potential energy that depends on the height of an object
• light energy


  Energy in the form of moving waves of light
• sound energy


  Energy caused by an object's vibrations
• thermal energy


  The total energy of all the particles of an object.
• Example of the transformation of kinetic energy into electric energy

  wind turbine
• Example of the transformation of chemical energy into electric energy


  electrochemical cell
• Example of the transformation of kinetic energy into electric energy
• thermocouple


  A device for measuring temperature that makes use of the way different metals respond to heat.
• Piezoelectric effect


  electrical current caused by pressure on a crystal
• Devices that use thermocouples

  refrigerators, furnace, water heater, computers
• Device that uses the piezoelectric effect


  pickups for electric guitars and drums, and electric lighters and ignitors for gas BBQs.
• What is the difference between a generator and a motor?

  Nothing structurally, but the input energy for one device is the output energy for the other device. So a motor run backwards can be used as a generator and vice versa.