1. 1 What is Electricity? How do we produce Electricity? What are the different types of current and how are they produced?

2. 2 What is Electricity Electricity involves the interaction of positive and negative chargesElectricity involves the interaction of positive and negative charges Electricity is essentially the movement of chargeElectricity is essentially the movement of charge Electric current is the flow of charge through a conductorElectric current is the flow of charge through a conductor

3. 3 Key Electricity terms: 1.Voltage: Force pushing electrons 2.Current: number of electrons flowing; frequency of e- flow 3.Resistance: how easy or difficult it is for e- to flow 4.Conductors: have low resistance 5.Insulators: have high resistance

4. 4 How do we produce electricity? 1.Static; friction 2.Generators: hydroelectric, nuclear, coal, natural gas, biomass, tidal, hand crank radio 3.Magnetism 4.Solar cells 5. Chemical reactions; batteries 6. Piezoelectricity; using crystalline flux

5. 5 Different types of Electric current: DC= Direct CurrentDC= Direct Current This is current that flows in one direction from positive to negative charged areasThis is current that flows in one direction from positive to negative charged areas AC=Alternating Current This is current that flows back and forth, alternating direction of flow

6. 6 What makes DC? Static dischargesStatic discharges BatteriesBatteries DC converters/DC converters/adapters

7. 7 Static Electricity Made by the transfer of charge due to frictionMade by the transfer of charge due to friction Very dry air promotes static electricity, moist or humid air reduces itVery dry air promotes static electricity, moist or humid air reduces it Lightening is the greatest form of static electric discharge.

8. 8 DC and Batteries Batteries use a chemical reaction to produce a flow of charge.Batteries use a chemical reaction to produce a flow of charge. Batteries can be Wet Cell or Dry Cell in natureBatteries can be Wet Cell or Dry Cell in nature

9. 9 More about Batteries Wet Cells:Wet Cells: Used in cars, lawn mowers, boatsUsed in cars, lawn mowers, boats Often have lead compound anodes and cathodes and use a liquid electrolyteOften have lead compound anodes and cathodes and use a liquid electrolyte Maximum voltage per cell is 2 Volts A simple one can be made with a copper strip, a zinc strip and an electrolyte such as Hydrochloric acid or even Lemon Juice

10. 10 More about Batteries Dry CellsDry Cells Used in small appliances, radios, remote controlsUsed in small appliances, radios, remote controls Often made of a zinc case and carbon center rod and a dry or paste electrolyteOften made of a zinc case and carbon center rod and a dry or paste electrolyte Maximum voltage per cell is 1.5 Volts

11. 11 Dry Cell types: The size AAA, AA, C, and D “batteries” that we use are single dry cells; they are not true batteriesThe size AAA, AA, C, and D “batteries” that we use are single dry cells; they are not true batteries A battery is 2 or more cells wired togetherA battery is 2 or more cells wired together The maximum voltage available from any single dry cell is 1.5 volts, so why so many different types. AAA=1.5V D=1.5V

12. 12 More about batteries and single cells: So how is a 9V built?So how is a 9V built? How does a car battery have 12V?How does a car battery have 12V? How does a camping lantern battery have 6V while the same size hobby battery has 1.5V?How does a camping lantern battery have 6V while the same size hobby battery has 1.5V?

13. 13 More about batteries and single cells… A 9V battery has 6 smaller dry cells in it A car battery has 6 smaller wet cells A lantern battery has 4 dry cells wired in series and a hobby battery has 4 dry cells wired in parallel

14. 14 Good and Bad of Wet and Dry cells: Wet Cells Bad: often use acid electrolytesBad: often use acid electrolytes Bad: tend to be largeBad: tend to be large Good: can be rechargedGood: can be recharged Good: produce more Voltage per cellGood: produce more Voltage per cell Dry Cells Bad: cannot be recharged Bad: only produce 1.5 Volts per cell Good: some can be recharged Good: smaller and lighter and usually do not corrode appliance

15. 15 DC Adapters Used to convert AC to DC for appliance useUsed to convert AC to DC for appliance use Range in sizes from very small Voltages to very large voltagesRange in sizes from very small Voltages to very large voltages A telephone may use 9 V while a laptop computer often uses 18 VA telephone may use 9 V while a laptop computer often uses 18 V

16. 16 What makes AC? Generators: change mechanical energy into electrical energy with the use of magnets It is available through any wall outlet

17. 17 How does a generator work? A generator turns a magnet in between coils of wire and the magnetic field induces an electric charge flow in the coils of wireA generator turns a magnet in between coils of wire and the magnetic field induces an electric charge flow in the coils of wire Different directions of current flow are created as the magnet turns causing the direction changing characteristic of AC

18. 18 More about AC AC is produced at certain frequencies of cycles due to the spinning of the magnets in the generators usedAC is produced at certain frequencies of cycles due to the spinning of the magnets in the generators used The frequency of these cycles varies around the worldThe frequency of these cycles varies around the world

19. 19 AC Stats. The U.S. produces AC at 60Hz (cycles per second) and household outlets are 120 Volts and large appliance outlets are 220 VThe U.S. produces AC at 60Hz (cycles per second) and household outlets are 120 Volts and large appliance outlets are 220 V The UK is at 50Hz and 230V Japan is at 50/60Hz and 100V Australia is at 50Hz and 230V

20. 20 Problems with travel and different AC frequencies If you purchase an appliance that is only set to US it will not work in most other countriesIf you purchase an appliance that is only set to US it will not work in most other countries The plugs are not the same eitherThe plugs are not the same either You would need to purchase a set of adapter plugs and purchase appliances that are adaptableYou would need to purchase a set of adapter plugs and purchase appliances that are adaptable

21. 21 Possible Pros and Cons of AC and DC Pros: AC is easier/cheaper to produce and control in large quantitiesPros: AC is easier/cheaper to produce and control in large quantities Pros: DC is needed for many electronic components and it is easy to transportPros: DC is needed for many electronic components and it is easy to transport Cons: AC production requires a generator and other supplies Cons: DC batteries are expensive and have a limited lifespan