B19-History of Transformers -Timelines- Part 1

1800

• Alessandro Volta (Italy) produced continuous electrical energy (as opposed to spark or static electricity produced so far) from a stack of silver and zinc plates, the first battery in the world.

1820

• Andre Marie Ampere (French) invented the cylindrical coil (solenoid)
• Hans?Christian?Oersted?(Denish)?finds?the?generation?of?a?magnetic?field?by? electric?currents?by?observing?the?deflection?of?a?compass?needle.?This?was? the first?time?a?mechanical?movement?was?caused?by?an?electric current.? Danish Physicist shows that an electric current flowing through a conducting material created a magnetic field around the conductor.

1825?

• Georg Simon Ohm, a German Physicist discovered the relation between the current in a circuit and the voltage applied (Ohm's Law) using a galvanic battery and galvanoscope. Published results in "Preliminary notice of the law according to which metals conduct contact electricity."

1831, August, 29

• Michael Faraday (English physicist) discovered electromagnetic induction using two independent coils wound over a circular iron ring (i.e. closed magnetic path). Interrupting the direct current flow in the primary coil induced a voltage pulse across the secondary coil.
• Faraday introduced the first transformer to the world through his early experiments with electromagnetic induction. Using two coils of wire wrapped around an iron core, he showed that an alternating current flowing through one coil could induce a current in the second coil, even without a direct connection. This foundational principle is the origin of transformers found around the world today.

• Photographed from the original, preserved in the Museum of the Royal Institution, London. (Frontispiece of the book by John Ambrose Fleming, The Alternate Current Transformer in Theory and Practice –Vol1-Induction of Electric Currents, The Electrician Printing &Publishing Co Ltd, London 1889)

1831??

• Independently of Faraday, Joseph Henry, carried out similar experiments at the Academy in Albany, New York State, and succeeded in drawing a spark between two electrodes by interrupting the direct current circuit of a solenoid.

1832 ?? ?

• Discovery of self-inductance in coils during change of current.

1836 ??

• Rev. Nicholas J Callan of Maynooth College, Ireland invents the induction coil. High voltage is generated by induction using a two-coil converter. Nicolas Callan, a physics student (Ireland) generates a spark across the secondary terminals of the high-voltage coil by interrupting a DC in the primary coil. A magnetic circuit was formed by a ductile iron bar. (Open iron core) He was the first to use a thicker wire for the LV coil and fine wire for the HV coil. These were called spark inductors- forerunners of today's transformers.

1836 -1842

• J C. Page (Washington DC, America), and Masson (France) make similar spark inductors / high voltage pulse transformers.?

?1837 ??

• Masson prevents eddy currents in stacked laminated cores by insulating thin steel?sheet ribbons.

1840's

• Direct Current Electricity came to be used commercially in telegraphy. Many European companies are incorporated to make LV electric equipment for telegraphy. Siemens & Halske (Germany) were the major ones and interested in High Voltage electric technology.

1848??

• Heinrich Ruhmkorff (Paris) built a spark inductor in Europe – A type of high-voltage transformer.

1852-55

• C T Bright & E B Bright (England) modify the induction coils developed by Page and Ruhmkorkf by introducing a closed magnetic path and coils connected in parallel.

1856?

• C F Varley reversed the direction of direct current at each switching and used a closed magnetic core to obtain a more powerful spark (British Patent)

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1856

• Werner Siemens (German)-built an electric generator with a double-T armature winding; the first inventor to place a winding into slots.

1857??

• French Company Alliance makes alternating current generators. Engineers are?faced with the question of how to feed several arc lamps from a single AC alternator.? (subdivision of electric light)

?1866

• Werner Siemens (German)-developed the dynamo-electric machine based on the double-T armature. A power generator became available with the advent of electricity.

1868??

• W R Grove applies alternating current to one of the windings of an open-core inductor (2f)1870s Russian engineer Jablochkoff planned for the “distribution of light “–a single current source supplies several lamps simultaneously and independently of each other. He used induction coils with open rod cores and induction coils in series both on the primary and secondary sides. He introduced the arc candle - ‘Jablochkoff’ candle - Flame arc lamps fed by AC generators driven by steam engines.? Lamps of 35-40V rating were connected in series, i.e. 1.5 kV Generator voltage could feed 20 ~ 30 lamps.? But if connected in parallel, the distance between the generator and lamps could not exceed 100 - 200 metres due to heavy line drop.1871
• Gramme (France) develops a continuous current (DC) dynamo (generator) with commutation (developed by A.C. Pacinotti). This improved dynamo replaces crude Wild / Ladd generators used so far.

1872

• Friedrich von Hefner-Alteneck (German)-started the development of the anchor drum motor.

1873

• Clark Maxwell (UK) Publishes 2 Volume book "Treatise on Electricity and????? Magnetism" containing his famous Maxwell's equations connecting the relationship between the magnetic field and electric current.

1876

• Pavel N Jablochkov, a retired Russian military engineer uses induction coils in his lighting system. His lamp consisted of two carbon rods put side by side, separated by insulating material. These ‘candles’ were fed with alternating current through open-core induction coils, with primary windings connected in series (Fig 2 g)

1878

• Pavel Yablochkov (Russian)-implemented high voltage AC power for electrical distribution of lighting in the Paris Exhibition over the longest distance of the time.
• Machinenfabrik Oerlikon (MFO) was established in Zurich district of Oerlikon. They started with electric locomotives. The company was taken over by Brown Boveri &Cie in 1967.
• Many experiments, concepts, and patents were developed on induction apparatus using alternating current by de Mertens, C T Bright, E. Edwards, A. Normandy, J B Fuller, R Kennedy, Deprez, Carpentier and W Siemens. But only the system developed by L Gaulard and E D Gibbs found a practical application (Fig 2 h),
• Bright Brothers used induction coils for lighting purposes by using alternating currents. (English Patent 4212) A secondary apparatus with induction coils was placed where lights were required. Primary coils were connected in series, and secondary coils fed the lights at each place.
• ?Similar patents were taken by Strumbo (France), Harrison and Meritens (England) for modified induction machines.
• ?Jim Billings Fuller took a patent (No.210317) for lighting using secondary generators (transformers) in America. He used two horseshoe magnets with secondary coils in the middle and primary coils outside of these magnets. Secondary coils connected in series fed the arc lamp. Before developing his potential system further, Fuller passed away in 1879.

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