The Cathode Ray Tube site
electronic glassware
History and Physics Instruments
electronic glassware
History and Physics Instruments
Ruhmkorff coils
Fuel for tubes
Fuel for tubes
Heinrich Daniel Ruhmkorff a German engineer working in Paris, gave his name to this high tension coil in 1850, it works like the same principle as the spark coil in a car. It consist of a small primary coil and a large secondary coil where the high tension is formed by a mechanical breaker system. In the wooden base there is room for an capacitor made of paper and metal foil. Ruhmkorff or spark coils were used to lighten the Crookes and Geissler tubes. Most of the coils come from the beginning of the 20th Century, the dimensions vary from small to huge ones, depending on the amount tension that was needed.
The tension of the spark was expressed in centimeters! The coils are real beauties with nice lacquered mahogany base and brass connections or switches. A lot of companies produced this coils like Max Kohl, Radiguet, Leybold, Newton, and were also used as spark transmitters and in medical equipment.
The tension of the spark was expressed in centimeters! The coils are real beauties with nice lacquered mahogany base and brass connections or switches. A lot of companies produced this coils like Max Kohl, Radiguet, Leybold, Newton, and were also used as spark transmitters and in medical equipment.
Heinrich Daniel Ruhmkorff
1803-1877
1803-1877
Early advertisement of Ruhmkorff coils and Geissler tubes.
This is a German Ruhmkorff mini coil from the beginning of the 20th Century.
It measures 8x15cm.
It measures 8x15cm.
French Radiguet Ruhmkorff coil
early 20th Century. 22x12cm
early 20th Century. 22x12cm
Close-up of the breaker system.
PREV
HOME
NEXT
In the wooden bottom (box) of the old Ruhmkorff or spark
coil you will find a capacitor witch consists out of paper
and metal foil. In one of my coils the paper sheets were
old book pages with photographs of pre WW I soldiers!
coil you will find a capacitor witch consists out of paper
and metal foil. In one of my coils the paper sheets were
old book pages with photographs of pre WW I soldiers!
The paper capacitor build in the wooden box.
A very nice and big English Ruhmkorff coil, Newton Apps 1890.
Pictures courtesy of Alastair Wright.
Pictures courtesy of Alastair Wright.
The early power source, the Grenet Cell
Induction Coil C&M Aussmann Germany
This nice restored coil from the beginning of 1900 uses a Deprez interrupter. Size: 41cm L x23cm W x 30cm H
Pictures courtesy of Ingo Buchmann
This nice restored coil from the beginning of 1900 uses a Deprez interrupter. Size: 41cm L x23cm W x 30cm H
Pictures courtesy of Ingo Buchmann
This interrupter invented by Marcel Deprez, a French inventor (1843-1918) was a much more stable model for use in laboratories.
Deprez interrupter from a German catalog 1909
The Grenet Cell or pile invented by the German
Johann Christian Poggendorff (1796-1877)
It is a galvanic battery filled with an acid solution
Potassium Bichromate.The electrodes are made
of zinc and carbon and generates 1,96 Volts, in
practice many cells were coupled to make a
workable powersource.
The voltage rapidly dropped when the cells were
used.The zinc element which is positioned in the
middle can be shifted upwards or lowered by the
middle connection on top.
Johann Christian Poggendorff (1796-1877)
It is a galvanic battery filled with an acid solution
Potassium Bichromate.The electrodes are made
of zinc and carbon and generates 1,96 Volts, in
practice many cells were coupled to make a
workable powersource.
The voltage rapidly dropped when the cells were
used.The zinc element which is positioned in the
middle can be shifted upwards or lowered by the
middle connection on top.
Two small French Ruhmkorff coils early 20th century.
Sizes 15x9 and 7x12cm. These two coils are from the same manufacturer and were mainly used for lightning small Geissler tubes and other Physics experiments. Often sold as a complete kit including Geissler rotator for education.
Sizes 15x9 and 7x12cm. These two coils are from the same manufacturer and were mainly used for lightning small Geissler tubes and other Physics experiments. Often sold as a complete kit including Geissler rotator for education.
Two Small Ruhmkorf coils with sliding secondary coil.
With the sliding secondary coil the high tension can be regulated.
They have ivory switches in order to change the polarity.
Measures 25x10 cm. and 35x12 cm
With the sliding secondary coil the high tension can be regulated.
They have ivory switches in order to change the polarity.
Measures 25x10 cm. and 35x12 cm
