Power Summary Magneto-Electric Holmes (1856) Alliance (1857) Dynamo-Electric Gramme (1873) Siemens (1873) Type Speed (rpm) Approx. Output (kw) AC AC 400 400 2.0 2.3 51 36 550 494 DC DC 420 480 3.2 5.5 25 11 320 265 Weight Cost Alternator Background de Meritens Gramme Wilde & Siemens Ferranti Gordon Mordley Alternator Early Dynamos Constant Maintenance Commutators Brush-Gear Could not Be Design For AC Alternating Current Better Wave Form - Efficiency Alternator Back To Work Of Holmes Non Continuous Winding - Distributed Winding Baron A. de Maritens Manufactured - 1880 Permanent Magnets Magneto-Electric Type Installations Trinity House - S. Foreland Lizard Lighthouses Still In Use In 1947 4.5 kw At 830 rpm Gramme (1878) Rotating Field Exciter - Built Into Alternator Carcass 2-Polar Dynamo With Ring Armature Wilde (1878) Armature Coils Bobbins Similar To Holmes Siemens Eliminated Iron cores On Bobbins Sebastian Ziani de Ferranti 1881 Rotor Winding Copper Ribbon Advantage Free To Expand J. E. H. Gordon (1852-1893) Power Plants Largest Alternators Of The Time (1885) Alternator 600 hp At 146 rpm 10 ft Diameter 22 tons Problem Overheating - Laminated Cores Power Source Steam At 160 psi Paddington Great Western Railway Station (1885) Gordon Alternators W. M. Mordey (1856-1938) 1886 Rotating Field Magnet Coil Between Two Steel Plates Fixed Stator Electric Lighting Lighthouses Limelight (1850) Lime Incandescent In Oxy-Hydrogen flame Electric Arc-Lamps, “Jablochkoff Candles” (1857) Street Lighting - Electric Arc Paris (1875) Llondon (1878) Domestic Lighting Electric Arc-Lamps - Too Powerfull Filament Lamp (1881) Electric Power Stations Background Transformers Deptford Power Station DC Or AC Parallel Operation Of Alternators Background First Power Station (1882) Supplied Private Customers Holborn Viaduct Station - Edison Co. Brighton & Godalming Grosvenor Gallery (1883) AC @ High Voltage Customers Given Series Transformers Ferranti Replaced Seimens Alts. With 2400 V Alternators Switch From Series To Parallel - Gibbs Brighton Power Station (1887) Transformers Faraday (1831) Principle Of AC Transformer Mutual Induction Of Windings Gaulard & Gibbs (1883) Adjustable Core Series Circuit Ferrenti Or Westinghouse Parallel Circuit Deptford Power Station (1991) Intended To Supply London Ferranti Transmission At High Voltage (10,000 V) Mains 20 ft Copper Tubing (Inner & Outer) Separated By Paper Used In London For 40 Years Power Output Four Ferranti Generators (10,000 V Windings) One 10,000 hp Steam Engine Led To Small Power Stations Maiden Lane (1889) Deptford Power Station (1891) Maiden Lane D.C. Or A.C. Pro A.C. England Ferranti, Gordon, Mordley, Thompson U.S. Westinghouse, Tesla, Sprague, Steinmetz Pro D.C. England Lord Kelvin, Crompton, Kennedy, Hopkinson U.S. Edison D.C. Or A.C. (Continued) A.C. Advantages High Voltage Generation & Transmission Less Main Loss Disadvantages Electrocution D.C. Advantages Large Storage Batteries During Light Load Safe Disadvantages High Voltage Transmission (No H.V. Machines) Battery Maintenance D.C. Or A.C. (Continued) Arguments Brown & Edison Death Penalty By Lethal Electrocution Bought Generators From Westinghouse (1889) Westinghouse Contact For Niagara Falls Power Scheme Bitter Fights Between Edison & Westinghouse Change-Over Equal Number Of D.C. & A.C. In 1890 London (1958) Some Areas & Provincial Towns Are Still D.C. Batteries Primary Batteries Non reverseable Chemical Reaction Single Or Two Fluid Classes Single Fluid Class Voltaic Cell - Zinc & Copper Problem - Variable Voltage Subject To Polarizartion Hydrogen At Positive Pole Two Fluid Class Constant Electromotive Force Batteries - Single Fluid Helm (1850) Carbon Replaced Copper Warren de la Rue (1868) Lead Dioxide Silver Chloride G. Leclanche (1866) Lead Acid R. W. Bunsen (1844) Carbon & Zinc Plates With Chromic Acid Grenet (1859) - Shown Carbon & Zinc Plates With Potassium Dichromate Batteries - Two Fluid Used For Telegraph Daniell Cell Electrolyte - Dilute Sulfuric Acid Constant Voltage Plates Did Not Waste Active For Long Periods No Unpleasant Fumes Minotto Cell Replaced Pot With Sand Fuller Cell 12 Cells Telegraph (1875)