Søren Hjorth
Søren Hjorth , (born October 13, 1801 in Vesterbygaard near Kalundborg in the west of Zealand (Denmark) , † August 28, 1870 in Copenhagen ) was a Danish railway engineer and inventor . He discovered the dynamo-electric principle before Werner von Siemens and received the first patent for a self-excited dynamo machine in 1854 .
Life
Søren Hjorth was born on Vesterbygaard Manor, where his father was the manager. Since his parents had intended him to work in agriculture, he grew up without any special schooling. Nevertheless, he managed to pass a law exam.
In 1821 he became the manager of the Bonderup estate near Korsør (West Zealand). Since this did not fill him out, he joined the Treasury as a volunteer in 1828, where he became secretary and chamber clerk in 1836 (also in his later work as an engineer he was usually called "Secretary Hjorth"). Since this activity did not fill him, he also attended lectures at the Polytechnic, especially with Hans Christian Ørsted on electricity and magnetism.
In 1839 he became the manager of a piano factory and in 1844 the technical director of the railway company he founded . In 1845 he married Vilhelmine Ancker, b. Hansen, who brought two children into the marriage; the couple did not have children together. In 1848 he had to give up the post of director for health reasons. For the next few years he worked on his dynamo in England .
Since 1857 he has worked in various positions, as a representative of an English steel mill, as a translator and as a patent advisor. From 1861 he received a pension for his services in building the first Danish railway. He died on August 28, 1870.
Services
Steam car
Mechanical problems fascinated him throughout his life. In 1832 he designed a rotary steam engine that was built by the mechanic Schiødt and then bought by the king for the Polytechnic. In the same year he published the draft of a steam car that should be powered by this machine. However, a construction grant was rejected and the car was probably never built.
A trip to England in 1834, during which he studied the experiments there with steam vehicles on rails and roads, stimulated him to new experiments. A small steam wagon proved itself on the flat streets of Copenhagen, but failed on the smallest hills in the area.
railroad
In 1839 a trip to England, France and Belgium convinced him that steam vehicles had to be more successful on rails than on roads. In 1840, together with the accountant Schram, he presented a detailed plan for a railway from Copenhagen to Roskilde . This idea was laughed at at first, but after a tough battle they were awarded the royal concession in 1843. In 1844 shares were issued and all subscribed within one month (mostly in Hamburg, interest in Denmark was low).
Det Sjællandske Jernbaneselskab was founded on July 2nd, 1844; Hjorth became technical director, Johan Christian Gustav Schramm general director. On June 27, 1847, the line from Copenhagen to Roskilde was the first railway in Denmark (apart from the Kiel - Altona line in the Danish-ruled Duchy of Holstein ). Only with a state guarantee could the extension to Korsør be built in 1852 .
electricity
After the discovery of electromagnetism (generation of a magnetic field by means of an electric current) by Ørsted in 1820 and electromagnetic induction (generation of an electric voltage by changing a magnetic field) by Faraday in 1831 , there were many attempts to find practical applications for it. Hjorth has also designed various electric motors since 1842. In 1848 he applied for a grant to have such a machine built according to his plans in England. At this point he had already recognized that the magnetism in a piece of iron was increased if it was wrapped with a current-carrying wire, but only up to a saturation limit; his new machine should take advantage of this principle.
In their test report, Ørsted and Forchhammer doubted this observation (which is now a matter of course in school), but supported the application because the ingenious machine, even if it barely performs well, will at least provide the inventor with new knowledge for further inventions. Two versions of this engine, the performance of which was comparable to steam engines of the same size at the time, were built in England and caused a sensation. A patent was granted in 1849.
However, the invention had the disadvantage that there were no power sources other than low-power batteries (wet cells). Hjorth therefore wanted to develop a generator for his engine, which he called a "dry battery". On May 1, 1851, he formulated the dynamo-electric principle of self-excitation in his notebook :
"When the current flows around the electromagnets in this way, they are naturally excited in proportion to their strength, and the more they are excited, the more the disks will be excited by the magnets and mutual reinforcement will occur."
In the spring of 1854 he built a 3 hp generator in Copenhagen and in October of the same year received the English patent No. 2198 for it - 12 years before Werner von Siemens .
Failed plans
Fascinated by the principle of self-excitation, in which a small initial magnetism generates a current, which in turn amplifies the magnetism further and further, he said that the generator-motor combination would have to generate more and more energy based on a small amount of starting energy. That such a perpetual motion machine is impossible was only formulated in the law of conservation of energy in 1847 and was not yet generally recognized, not even among scientists.
For years he tried in vain to raise money for the construction of larger and more sophisticated machines in order to still fulfill his dream of the perpetual motion machine .
literature
- Sigurd Smith: Søren Hjorth. Inventor of the Dynamo-Electric Principle . Elektrotekniske Forening, København 1912 ( archive.org ).
- Søren Hjorth . In: Carl Frederik Bricka (Ed.): Dansk biografisk Lexikon. Tillige omfattende Norge for Tidsrummet 1537-1814. 1st edition. tape 7 : I. Hansen – Holmsted . Gyldendalske Boghandels Forlag, Copenhagen 1893, p. 483 (Danish, runeberg.org ).
Individual evidence
| personal data | |
|---|---|
| SURNAME | Hjorth, Søren |
| ALTERNATIVE NAMES | Secretary Hjorth (nickname) |
| BRIEF DESCRIPTION | Danish railway engineer and inventor |
| DATE OF BIRTH | October 13, 1801 |
| PLACE OF BIRTH | Vesterbygaard near Kalundborg in the west of Zealand (Denmark) |
| DATE OF DEATH | August 28, 1870 |
| Place of death | Copenhagen |