Friedrich von Hefner-Alteneck

Friedrich von Hefner - Alteneck (* April 27, 1845 in Aschaffenburg, † January 6, 1904 in Biesdorf at Berlin; Complete name Friedrich Franz Heinrich Philipp von Hefner - Alteneck ) was a German engineer, electrical technician and engineer and one of the closest collaborators of Werner from Siemens. Known to a wider public Friedrich von Hefner - Alteneck by the eponymous lamp candlepower, which served from 1890 to 1942 in Germany, Austria and Scandinavia as luminous intensity unit Hefner candle ( HK).

Friedrich Franz Heinrich Philipp was the youngest of the three sons of his father Jacob Heinrich. The was an art historian and director of the Bavarian National Museum. However, this had no influence on the career choice, but Friedrich began very early to tinker all sorts of equipment. So the school was followed by the Technical University of Munich and the Polytechnic of Zurich, where he was interested mainly lectures on the design of machinery rather than mathematical considerations. This is followed by a short time interns joined in Munich.

Siemens & Halske

At the World Exhibition in 1867 impressed by Hefner Alteneck the " Telegraphenbauanstalt Siemens & Halske " whereupon, at this he applied as a draftsman. One could for him but no use, but engineers had at this time a lot more workshop practice. So he started just decided on 17 June 1867 in this company as a laborer, where he made quick attention and was treated already on September 30, the new design office. He quickly became leader of the but consisting of only two man offices. After Siemens in 1868, the construction of which runs from London to Calcutta Indo-European telegraph line had been transferred, contributed by Hefner Alteneck essential to their success. During this time he also promoted significantly the safety of railway operations through the design of a bell signal station and a speedometer and registrar. 1872, with 27 years, he was assistant to the chief engineer Carl Fischer ( 1830-1890 ), who headed the general technical management of the company. It was responsible for the design and testing of designs and working drawings for the manufacture of all of Hefner Alteneck. From 1880 to the end of 1890 he was General Manager and Head of the Charlottenburg station by Siemens & Halske. Werner von Siemens had handed over management of the company to his sons, also withdrew from Hefner Alteneck from the company. He has received numerous honors, including membership of the Academy of Sciences in 1897 and an honorary doctorate from the Technical University of Munich. In the same year he participated in a supervisory board seat at AEG.

Doses writer

The breakthrough came from Hefner Alteneck with his cans writer who brought the telegraph being a major step forward. It was a kind of typewriter, the transposed letters in Morse code, so that the operator of a telegraph station can not Morse code had to. It consisted of a horizontally arranged box were attached to the pins, which could be shifted by a keyboard. Wronged you a letter, the corresponding pins generated by scanning a shorter or longer current pulses, the Morse code accordingly. This apparatus was greatest attention, Werner von Siemens wrote to his brother William about it in April 1873: " ... Hefner has struck with his cans Schreiber Schreiber my chain again by several nose lengths The thing works remarkably accurate and beautiful ... Anyway, we have. Wheatstone completely antiquated. "

The doses followed by other writers in telecommunication equipment, including flood curve printers, remote water level indicator and command equipment for ships and mines.

Drum anchor

With the invention of the electromagnetic self-excitation Werner von Siemens laid in 1866 the foundation stone for the power engineering: Well motors and generators could be built with acceptable efficiency. However, the first machines were not yet perfect. One problem posed her double T- anchor, were unfavorable at the numerous turns of the coil. They did little for energy conversion and produced with their electrical resistance unnecessary heat that led to overheating. From Hefner in 1872 introduced a much improved version, which allowed a use for a long time the first time. The anchor drum, there was only a solid cylinder, which has been wound such that the coils were parallel to the axis of the cylinder jacket. So it was virtually only external coils, the proportion of ineffective turns was significantly lower. This design is still in use today.

Air coil machine

One problem remained with the drum anchor receive: The induced eddy currents strong heating of the armature core. It meant a great loss of energy and prepared such large problems that past was no way to water cooling. From Hefner met him with the air reel machine at the World Exhibition in Vienna in 1873 learned a lot of attention. In this design, the anchor stood still, the windings to the commutator circulated magnetic coils and armature core alone. For this purpose, a wire drum had quickly turning into a narrow gap, which is a highly accurate production demanded. But could now dispense with a water cooling system and yet the performance can be increased by more than fivefold. This design was for a decade the art, then you had to go back to the old design for even larger engines. Now we used isolated iron turns later today known laminated electrical sheets to reduce the eddy current losses.

Differential arc lamp

In the early days of electric power technology light always had to be produced by carbon arc lamps, and due to the time necessary for the operation of complex control mechanism, each lamp demanded its own generator. Here created by Hefner Alteneck 1878 with a self-regulating arc lamp remedy, it was in 1879 at the Berlin Trade Exhibition, then at the Berlin Kaiser Passage ( intersection of Unter den Linden / Friedrichstraße ) demonstrated and was aroused by a great sensation. Although the electric light only with the serial production developed by Thomas Edison light bulb gaslight largely replaced, so it turned to the differential arc lamp, already constitute an equal competition

Hefner candle

The competition between gas and electric light required for a suitable unit for photometric studies. From Hefner Alteneck this hit 1884 the electrical engineering club before a luminous flame as a comparison that could be reproduced at any time. The physico- technical Reichsanstalt certified the new light unit, which was named after him, Hefner candle.

Mignon

From Hefner Altenecks last major invention was not electro-technical nature: the pointer Mignon typewriter.

Honors

In his memory, a street was named in Aschaffenburg. In Berlin -Siemens city street Hefner trail was named after von Hefner - Alteneck. His grave, a grave of honor of the State of Berlin, located on the Old St.Matthäus Cemetery in Berlin -Schöneberg.