52
ENGLISH
perpendicular to the magnetic field lines moves in a uniform magnetic field, an induced electromotive
force generated in the wire. If the wire and other external circuit form a closed loop, the induced current is
generated in the wire, and the direction of the current is judged by the Right-hand Rule.
[2.]Structure and principles of alternators
Alternators can be divided into flywheel alternators, magnet rotor alternators and three-phase
alternators.As with DC magnetos, alternators also work by principles of electromagnetic induction. An
alternator does not produce currents by use of a wire perpendicular to the magnetic field lines moving in
a uniform magnetic field. Instead, the rotor made of the permanent magnet continuously rotates so as to
form a rotating magnetic field. Magnetic lines intermittently alternate through the fixed coil, resulting in
inducted alternating current.
[3.]Structure and working principles of storage batteries
The battery has a light weight and small size. It is of good sealing and anti-vibration performance. A
lead-acid battery also has other merits such as small internal resistance, voltage stability and so on. It
consists mainly of shell, cover, polar plate, electrolyte and separator. The shell is made of hard rubber or
plastic that resists acid, heat and vibration. According to rated voltages, batteries can be divided into three
different or six independent parts. The outside of the shell is generally marked with two upper and lower
lines, marked
“
H
”
for the upper line and
“
L
”
for the lower, indicating the upper and lower limits of
the battery. Meanwhile, it is also marked with positive
“
+
”
and negative
“
-
“
to indicate the positive
and negative poles..
The polar plate is the main working material to charge and discharge. A polar plate is made by
electrificating a lead-antimony alloy grid plate coated with active material. The plate is divided into positive
plate and negative plate. The active material on the positive plate is lead dioxide PbO2, while the active
material on the negative plate is sponge-like pure lead Pb.
The electrolyte is a special sulfuric acid and distilled water mixture. The electrolyte density shall be
measured at the standard measurement temperature of 20
℃
. At the standard temperature and in the
condition that it is fully charged, the battery has a density generally between 1.24 ~ 1.29g/cm3. In
each separate part of the shell are equipped with a group of plates and electrolytes. Each group of plates
produces chemical reaction with electrolytes, constituting a separate single cell. The voltage is about 2V.
3 or 6 single cells in series constitute a battery at a rated voltage of 6V or 12V. The cover is made of hard
rubber or hard plastic with high insulation properties, forming a complete interior space with the shell.
2. Demolition and Maintenance of the Power Supply Portion
[1] Remove the fuse plate and check it for any
burn-out. Install a new fuse plate of the same
model.
Fuse plate model: 12V/20A
Install a new protective tube of the same model if
it is damaged.
Caution
Check the fuse plate
