Chemical Sources of Electricity Types of Sources Circuit

Chemical Sources of Electricity • • Types of Sources Circuit Combinations Rechargeable vs. Disposable Assembly

Types of Chemical Sources 1. Cells – Contains 1 Positive and 1 Negative Terminal 2. Battery – Contains Several Positive and Negative Terminals 3. Fuel Cell – Produces Variable Electrical Power

Cells Schematic Symbol Sizes (all produce 1. 5 volts) 1. AAA 2. AA 3. C 4. D

Batteries Schematic Symbol • When cells are combined they produce batteries – (2 or More Cells)

Composition Positive Terminal Electrolytic Fluid Negative Terminal

Series Combination Connection the + terminal of 1 cell to the – terminal of another - 1. 5 V + - + 1. 5 V + = 3. 0 V

+ 1. 5 V What's the Point? - 1. 5 V - + Parallel Combination = 1. 5 V

+ + Why bother if it doesn’t seem to do anything? 1. 5 V • Longer Life - - • More Amps – The amps from each batter get added together

Rechargeable Batteries • Types – Ni Cad (Nickel Cadmium) – Nickel Metal Hydride • Expensive • Require Special Chargers • Bad for Environment • Less Time Between Charges

Disposable Batteries • Types – Alkaline • Duracell • Energizer • Less Expensive • Long Life • Bad for Environment

Battery Assembly • Combine the appropriate cells below to make a battery with these specifications: 1. 5 v @ ¼ amp • 6 volts with at least a ¼ amp 3 v @ ½ amp

6 volts with at least a ¼ amp Answer: Combine two of the 3 v @ ½ amp cells in Series 1. 5 v @ ¼ amp 3 v @ ½ amp

Battery Assembly • Combine the appropriate cells to make a battery with these specifications: • 3 volts with at least 2 amps 1. 5 v @ ¼ amp 3 v @ ½ amp

3 volts with at least 2 amps Answer: 1. 5 v @ ¼ amp Combine four of the 3 v @ 2 amp cells in Parallel 3 v @ ½ amp