Yablochkov candle
Encyclopedia
A Yablochkov candle is a type of electric carbon arc lamp
, invented in 1876 by Pavel Yablochkov
.
blocks, approximately 6 by 12 millimetres in cross-section, separated by a block of inert material such as plaster of paris or kaolin. There is a small piece of fuse wire or carbon paste linking the two carbon blocks at the top end. The assembly is mounted vertically into a suitable insulated holder.
On application of the electric supply, the fuse wire 'blows' and strikes the arc. The arc then continues to burn, gradually consuming the carbon electrodes (and the intervening plaster) as it does so. The first candles were powered by a Gramme machine
.
On disconnecting the supply, the arc extinguishes. It cannot be restarted, as there is now no fuse wire between the electrodes. Once switched off or consumed, the candle must be replaced. Electrodes last about two hours.
The advantage of the design over other carbon arc designs is that it removes the need for a mechanical regulator to maintain the appropriate distance between the carbon blocks to sustain the arc.
Arc lamp
"Arc lamp" or "arc light" is the general term for a class of lamps that produce light by an electric arc . The lamp consists of two electrodes, first made from carbon but typically made today of tungsten, which are separated by a gas...
, invented in 1876 by Pavel Yablochkov
Pavel Yablochkov
Pavel Nikolayevich Yablochkov was a Russian electrical engineer, the inventor of the Yablochkov candle and businessman.-Biography:...
.
Design
A Yablochkov candle consists of a sandwich of two long carbonCarbon
Carbon is the chemical element with symbol C and atomic number 6. As a member of group 14 on the periodic table, it is nonmetallic and tetravalent—making four electrons available to form covalent chemical bonds...
blocks, approximately 6 by 12 millimetres in cross-section, separated by a block of inert material such as plaster of paris or kaolin. There is a small piece of fuse wire or carbon paste linking the two carbon blocks at the top end. The assembly is mounted vertically into a suitable insulated holder.
On application of the electric supply, the fuse wire 'blows' and strikes the arc. The arc then continues to burn, gradually consuming the carbon electrodes (and the intervening plaster) as it does so. The first candles were powered by a Gramme machine
Gramme machine
A Gramme machine, Gramme ring, Gramme magneto, or Gramme dynamo is an electrical generator which produces direct current, named for its Belgian inventor, Zénobe Gramme, and was built as either a dynamo or a magneto. It was the first generator to produce power on a commercial scale for industry...
.
On disconnecting the supply, the arc extinguishes. It cannot be restarted, as there is now no fuse wire between the electrodes. Once switched off or consumed, the candle must be replaced. Electrodes last about two hours.
The advantage of the design over other carbon arc designs is that it removes the need for a mechanical regulator to maintain the appropriate distance between the carbon blocks to sustain the arc.