Battery, Meidinger's.
A variety of Daniell cell of the gravity type. The plates are
cylindrical. The zinc plate lies against the upper walls of the vessel.
The copper plate of smaller diameter rests on the bottom. A large tube,
with an aperture in its bottom, is supported in the centre and is
charged with copper sulphate crystals. The cup is filled with a dilute
solution of Epsom salts (magnesium sulphate) or with dilute sulphuric
acid.
Battery Mud.
A deposit of mud-like character which forms in gravity batteries and
which consists of metallic copper precipitated by the zinc. It indicates
wasteful action.
Battery, Multiple-connected.
A battery connected in parallel, all the positive plates being connected
to one electrode, and all the negative to another.
Battery, Nitric Acid.
A battery in which nitric acid is used as the excitant. Owing to its
cost and volatility this acid has been but little used in batteries,
other than as a depolarizer. In Grove's battery (see Battery, Grove's)
it has been thus used.
Battery of Dynamos.
A number of dynamos may be arranged to supply the same circuit. They are
then sometimes termed as above, a Dynamo Battery. They may be arranged
in series or in parallel or otherwise combined.
Battery of Leyden Jars.
To produce the quantity effect of a single large Leyden jar with a
number of small ones they are often connected in parallel and termed a
battery. In such case the inner coatings are all connected by regular
bar conductors, and the outside coatings are also all in connection.
They are conveniently placed in a box or deep tray whose inner surface
is lined with tinfoil, with an outside connection for grounding, etc.
The cascade, q. v., arrangement is not so generally termed a battery.
Battery, Open Circuit.
A battery adapted for use in open circuit work. Its main requirement is
that it shall not run down, or exhaust itself when left on open circuit.
The Leclanché battery is very extensively used for this work. Its action
is typical of that of most open circuit batteries. It is without any
action on open circuit. It is very quickly exhausted on closed circuit,
but recuperates or depolarizes quite soon when on open circuit. It is
always in condition for a momentary connection, but useless for steady
work.
Battery, Oxide of Copper.
A battery with zinc positive and iron negative electrodes. The excitant
is a 30 or 40 per cent. solution of sodium or potassium hydrate (caustic
soda or caustic potash). The depolarizer is copper oxide. In action the
copper is gradually reduced to the metallic state. The iron element is
often the containing vessel. The battery is practically inactive on open
circuit.
Its electro-motive force varies from .75 to .90 volt. To prevent the
formation of sodium or potassium carbonate the cell should be closed, or
else the liquid should be covered with mineral oil.
Synonyms--Lalande & Chaperon Battery--Lalande-Edison Battery.