The Standard Electrical Dictionary Part 17

(b) Upward's Chlorine Battery and any battery of that type (see Battery, Upward's,) is sometimes termed a gas battery.

64 STANDARD ELECTRICAL DICTIONARY.

Battery Gauge.

A pocket or portable galvanometer for use in testing batteries and connections.

Battery, Gravity.

A battery of the Daniell type, in which the porous cup is suppressed and the separation of the fluids is secured by their difference in specific gravity. A great many forms have been devised, varying only in details.

The copper plate, which is sometimes disc shaped, but in any case of inconsiderable height, rests at the bottom of the jar. Near the top the zinc plate, also flat or of slight depth, is supported. As exciting liquid a strong solution of copper sulphate lies at the bottom of the jar. This is overlaid by a solution of zinc sulphate, or sodium sulphate, which must be of considerably less specific gravity than that of the copper sulphate solution. In charging the jar one-tenth of a saturated solution of zinc sulphate mixed with water is sometimes used as the upper fluid. This may be first added so as to half fill the jar.

The strong solution of copper sulphate may then be added with a syphon or syringe underneath the other so as to raise it up. From time to time copper sulphate in crystals are dropped into the jar. They sink to the bottom and maintain the copper sulphate solution in a state of saturation.

Fig. 43. GRAVITY BATTERY OF THE TROUV?-CALLAUD TYPE.

If the battery is left on open circuit the liquids diffuse, and metallic copper precipitates upon the zincs. This impairs its efficiency and creates local action. As long as the battery is kept at work on closed circuit work but little deposition, comparatively speaking, occurs.

From time to time, in any case, the zinc plates are removed and sc.r.a.ped, so as to remove the copper which inevitably forms on their surface. Care must be taken that the zinc sulphate solution, which is constantly increasing in strength, does not get so strong as to become of as high specific gravity as the copper sulphate solution. From time to time some of the upper solution is therefore removed with a syphon or syringe and replaced with water. An areometer is useful in running this battery.

65 STANDARD ELECTRICAL DICTIONARY.

Battery, Grenet.

A plunge battery with zinc positive and carbon negative electrodes.

Electropoion or other chromic acid or bichromate solution is used as depolarizer and excitant. The zinc plate alone is plunged into and withdrawn from the solution.

Fig. 44. GRENET'S BATTERY.

Fig. 45. GROVE'S BATTERY.

Battery, Grove's.

A two fluid galvanic battery. A porous cup has within it a riband of platinum, which is the negative plate; amalgamated zinc in the outer jar is the positive plate. Dilute sulphuric acid (10 per cent. solution) is placed in the outer jar, and strong nitric acid (40? B.) as a depolarizer in the porous cups. Its E. M. F. is 1.96 volts.

It is objectionable, as it gives off corrosive nitrous fumes. These are produced by the oxidation of the nascent hydrogen by the nitric acid, by the following reaction:

3 H + H N O3 = 2 H2 O + N O. There are other reactions, one of which results in the formation of ammonia by the reduction of the nitric acid radical by the hydrogen. Ammonium can be detected in the spent liquids.

66 STANDARD ELECTRICAL DICTIONARY.

Battery, Hydrochloric Acid.

A battery in which hydrochloric acid is used as the excitant. Many attempts have been made to use this acid in batteries, but the volatile nature of the acid causes the production of so much odor with corrosive fumes that it has never come into use.

Battery, Lead Chloride.

A battery of the lead sulphate type in which lead chloride is the depolarizer. It has had no extended use.

Battery, Lead Sulphate.

A battery similar to Mari? Davy's battery or the gravity battery, but using lead sulphate as depolarizer and excitant. Lead, copper or tin is the material of the negative plate. Becquerel used the lead sulphate as a solid cylindrical ma.s.s surrounding a lead rod 1/5 to 1/4 inch in diameter. One part of common salt may be mixed with 5 parts of the lead sulphate. The electro-motive force is about 0.5 volt. The resistance is very high.

Battery, Leclanch?.

An open circuit battery with porous cup. In the outer jar is a zinc rod; a carbon plate is placed in the porous cup. The latter is packed with a mixture of clean powdered manganese binoxide as depolarizer, and graphite in equal volumes. A strong solution of ammonium chloride (sal ammoniac) is placed in the outer jar. It is only used on open circuit work. Its electromotive force is 1.48 volts, when not polarized.

The reaction is supposed to be about the following:

2 N H4 Cl + 2 Mn O2 + Zn = Zn Cl2 + 2 N H3 + H2 0 + M2 O3

The battery rapidly weakens on open circuit, but quickly recuperates.

There is another form of this battery, termed the agglomerate battery.

(See Battery, Leclanch? Agglomerate.)

Fig. 46. LECLANCH? BATTERY.

Battery, Leclanch? Agglomerate.

A form of the Leclanch? in which the porous jar is suppressed. Cakes made of a mixture of carbon, 52 parts; manganese binoxide, 40 parts; gum lac, 5 parts; pota.s.sium bisulphate, 3 parts, compressed at 300 atmospheres, at a temperature of 100? C. (212? F.), are fastened by India rubber bands or otherwise against the carbon plate. These const.i.tute the depolarizer. Various shapes are given the carbon and depolarizing agglomerates.

Battery, Local.

A battery supplying a local circuit (see Circuit. Local). The current is governed by the relay situated on the main line and operated by its current.

Battery, Main.

The battery used in operating the main line. It is usually applied to telegraphy. Its function is then to supply current for working relays, which in turn actuate the local circuits.

Main and local circuits and batteries are also used in the automatic block system of railroad signalling.

67 STANDARD ELECTRICAL DICTIONARY.

Battery, Mari? Davy's.

A two fluid porous cup battery with carbon negative plate, zinc positive plate, and mercury sulphate, a nearly insoluble salt, as depolarizer and excitant. Mercurous or mercuric sulphates have been used in it. Its electromotive force is 1.5 volts. The local action and waste, owing to the slight solubility of the mercury compounds, is very slight. If used on close circuit it becomes polarized. It is also subject under extreme circ.u.mstances to reversal of polarity, zinc becoming deposited upon the carbon, and there forming a positive electrode.

In using the cells in series the level of liquid in all must be the same, otherwise the cell in which it is lowest will become polarized and exhausted.

Modifications of this battery on the lines of the gravity battery have been constructed.