scholarly journals III. On the attractions of magnets and electric conductors

1874 ◽  
Vol 22 (148-155) ◽  
pp. 245-247
Keyword(s):  
Copper Wire ◽  
Platinum Wire ◽  
Electric Currents ◽  
Thin Platinum

Being desirous of ascertaining whether, in the case of two parallel wires conveying electric currents, the attractions and repulsions were between the currents themselves or the substances conveying them, and believing this question had not been previously settled, I made the following experiment:— I passed a powerful voltaic current through the thick copper wire of a large electromagnet, and then divided it equally between two vertical pieces of thin platinum wire of equal diameter and length (about six or seven centimetres), so as to make them equally white-hot, the two wires being attached to two horizontal cross wires of copper.

scholarly journals IV. On a magneto-electric machine

1867 ◽  
Vol 15 ◽  
pp. 404-405
Keyword(s):  
Copper Wire ◽  
Electric Machine ◽  
The Other ◽  
Platinum Wire ◽  
External Work ◽  
Small Machine

In June 1864 I received from Mr. Wilde a small magneto-electric machine, consisting of a Siemens’s armature and six magnets. This I endeavoured to improve upon, my object being to get a cheap machine for blasting with Abel's fusees. This was done by making one of circular magnets, and a Siemens's armature revolving directly between the poles, the armature forming the circles; with this I could send a very considerable power into an electro-magnet, &c. It was then suggested to me by my assistant, that if the armature had two wires instead of one, the current from one being sent through a wire surrounding the magnets, their power would be augmented, and a considerable current might be obtained from the other wire available for external work; or there might be two armatures, one to exalt the power of the magnets, and the other made available for blasting other purposes. Want of time prevented me carrying this out until now; but since the interesting papers of C. W. Siemens, F. R. S., and Proissor Wheatstone, F. R. S., were read last month, I have carried out the idea as follows:— Two bars of soft iron, measuring 7½in. x 2½ in. x ½in., are each wound, round the centre portions, with about thirty yards of No. 10 copper wire; and shoes of soft iron are so attached at each end, that when the bars are placed one above the other there will be a space left between the opposite shoes in which a Siemens’s armature can rotate: on each of the armatures is wound about ten yards of No. 14 copper wire cotton covered. The current generated in one of the armatures is always in connexion with the electro-magnets; and the current from the second armature, being perfectly free, can be used for any purpose for which it may be required. The machine is altogether rudely constructed, and is only intended to illustrate the principle; but with this small machine three inches platinum wire ·01 can be made incandescent.

Measurement of weak electric currents in copper wire phantoms using MRI: influence of susceptibility enhancement

2006 ◽  
Vol 19 (3) ◽  
pp. 124-133 ◽  
Author(s):  
Ruiwang Huang ◽  
Oleg Posnansky ◽  
Abdullah Celik ◽  
Ana-Maria Oros-Peusquens ◽  
Veronika Ermer ◽  
...  
Keyword(s):  
Copper Wire ◽  
Electric Currents

scholarly journals Study on Manual Tin Welding Technology of Platinum Wire-Copper Wire

2019 ◽  
Vol 677 ◽  
pp. 022137
Author(s):  
Zhibin Liu ◽  
Pu Yin ◽  
Zaicheng Wang ◽  
Yu Wang ◽  
Wei Wang
Keyword(s):  
Copper Wire ◽  
Platinum Wire ◽  
Welding Technology

I. On the heating effects of electric currents. No. II

1888 ◽  
Vol 43 (258-265) ◽  
pp. 280-295 ◽  
Keyword(s):  
Royal Society ◽  
Atmospheric Electricity ◽  
Platinum Wire ◽  
Electric Currents ◽  
Heating Effects ◽  
The Wire ◽  
The Law ◽  
Submarine Cables

On March 19th, 1884, I submitted to the Royal Society a paper on the heating effects of electric currents, showing the strength of current necessary to fuse the fine platinum wire employed for protecting submarine cables from the ill effects of atmospheric electricity. The paper proved that the law that regulates the production of heat is one which can be expressed by the formula C = ad 3/2 , “ a ” being a constant dependent on the metal used, and “ d ” the diameter of the wire. The current observed was that which heated the wire up to the point of self-luminosity (525°C.).

High Crystalline Cu2O Thin Films Prepared by Electric Current Heating Using Copper Wire

2014 ◽  
Vol 90 ◽  
pp. 66-71
Author(s):  
Tomoichiro Okamoto ◽  
Ko Yamazaki ◽  
Yuichiro Kuroki ◽  
Masasuke Takata
Keyword(s):  
Thin Films ◽  
Oxygen Partial Pressure ◽  
Partial Pressure ◽  
Electric Current ◽  
Atmospheric Pressure ◽  
Copper Wire ◽  
Time Response ◽  
Controlled Atmosphere ◽  
Electric Currents ◽  
Glass Substrates

Cu wires were heated by electric currents to fabricate Cu2O thin films. The films were successfully deposited on glass substrates placed above the wires at air pressures in the range of 100 - 40 Pa. Then the films were annealed in a controlled atmosphere and investigated the crystallinity, morphology and the time response to illumination of the films. After annealing at 800 °C at atmospheric pressure with oxygen partial pressure of 12 Pa, the crystallinity was increased and the time response of photoconduction was successfully improved.

Oxygen radical density measurement in O2-N2 gas mixture plasma by means of a thin platinum wire

2004 ◽  
Vol 149 (4) ◽  
pp. 14-20 ◽  
Author(s):  
Nobuyuki Haraki ◽  
Saiensu Nakano ◽  
Shigeru Ono ◽  
Shinriki Teii
Keyword(s):  
Density Measurement ◽  
Oxygen Radical ◽  
Platinum Wire ◽  
Gas Mixture ◽  
Thin Platinum ◽  
Mixture Plasma

On the increase in resistance to the passage of an electric current produced on certain wires by stretching

1878 ◽  
Vol 26 (179-184) ◽  
pp. 401-410
Keyword(s):  
Electric Current ◽  
Copper Wire ◽  
Lower Extremities ◽  
The Other ◽  
Platinum Wire ◽  
Sliding Scale ◽  
The Mean ◽  
The Wire ◽  
Two Sides ◽  
Permanent Increase

The object of this inquiry was (1) to determine the relation between increased resistance to the passage of an electric current and stretching-force; (2) to ascertain how much of the increased resistance in each case is produced by mere increase of length and diminution of section. In order to determine the increase of resistance from stretching, the wires were each divided into two parts about 14 feet or more in length. One end of each part was fastened to a stout hook, firmly fixed into a block of wood, the two hooks used being about 8 inches apart, and the block of wood in which they were fixed securely fastened across two strong uprights, which were placed resting against the wall, so that the weights attached to the wires might swing clear of the table on which the uprights were placed. A loop was made at the other end of each part of the wire, and to this the weights were attached by means of strong hooks. The two parts of the wire were joined at the top, about 2 inches below each hook, by a piece of copper wire, which was securely soldered on to each part of the wire, so as to connect them; and toward the lower extremities of the two parts, about 5 inches above the points of attachment of the weights, two copper wires were soldered so as to connect the wires with a Wheatstone’s bridge. The increase of resistance of the wires was measured by means of a sliding scale of platinum wire divided into millimetre divisions, each equal to ·00166 ohm. As the object was to obtain the temporary and not the permanent increase of resistance (which permanent increase was found more or less with al the wires), weights slightly heavier than those intended to be used were first put on and taken off. Afterwards the wire was balanced as nearly as possible by German-silver wire, without the sliding scale, and then very exactly with the sliding scale, which was connected with one of two resistance-coils of 100 ohms each, which formed the other two sides of the bridge. The weights used were then carefully put on to the wires and the increase of resistance measured by means of the sliding scale the weights were next taken off again, and the sliding scale used for balancing once more. If there was any slight difference, as sometimes occurred, between the readings of the sliding scale before the weights were put on and after they were taken off, the mean of the two readings was taken.

scholarly journals II. On an electrodynamic balance

1881 ◽  
Vol 32 (212-215) ◽  
pp. 39-40
Keyword(s):  
Internal Friction ◽  
Copper Wire ◽  
Thin Sheet ◽  
The Other ◽  
Electric Currents ◽  
Fixed Position ◽  
Chemical Balance ◽  
Electrodynamic Balance ◽  
A Current ◽  
Satisfactory Manner

In order to avoid the disturbances produced by the variations of direction and intensity of terrestrial magnetism in measuring the intensity of galvanic currents by their electromagnetic effects, I have tried to construct an electrodynamic balance. I have suspended at the ends of the lever of a smaller chemical balance, instead of the scales, two coils of copper wire, their height being equal to the diameter of the cylinder around which the wire is coiled up. Their axis is vertical, and they are suspended in such a manner that they cannot turn around this axis. Two larger spirals of the same height, but of greater radius, are placed into a fixed position, borne by a horizontal metallic rod, the middle of which is fixed on the column bearing the balance. The connexions of the wires are arranged in such a way that one of the movable coils is attracted by the fixed coil, the other is repelled. Both the fixed coils are placed a little higher than the movable coils. The attracted coil rises, the other sinks down as soon as a current passes through the circuit. There are two difficulties to be overcome in the construction of such a balance. At first, the current must be introduced into the movable spirals without diminishing their mobility, and without introducing places of contact of too small a pressure, which would make the resistance variable. I have succeeded to do this in a very satisfactory manner by using a kind of very thin sheet-brass, used for playthings of children, called in German “Rauschgold” (tinsel), because it looks like gold, and makes a crackling noise when it is moved, btrips of this, about 30 centims. long and 6 or 7 millims. broad, are very flexible, and show no signs of internal friction, their resistance to electric currents is very moderate, and they are not easily heated even by strong currents, because they have a relatively large surface in con­tact with air. I have connected each of the movable spirals with the other wires conducting the current by two such strips hanging loosely down from four pieces of brass fixed at the upper parts of the case of the balance. I may be allowed to remark, that strips of the same kind, and of greater length, are very useful to demonstrate the action of a magnet on a movable cnrrent. If you suspend the strip so that it hangs down in a curve, it is attracted, repelled, even raised against gravity, or coiled up around the magnet with great rapidity, in a very striking way.

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