05
Letrika keeps abreast of all technical
innovations in the field of alternators. New
solutions are regularly applied to the design
of new alternators. Energy conservation
in vehicles is an absolute necessity. We
are working continuously to optimize the
design, increase specific output power and
efficiency, and to incorporate the latest
technology. The Letrika R&D laboratories
are equipped to perform the majority of
tests required in our and our customer’s test
specifications. Outside laboratory facilities
are used for other specific test requirements.
RESEARCH AND DEVELOPMENT
Voltage Regulator
The voltage regulator with brush holder
and brushes is fitted on the alternator rear
bracket. It is electrically connected to the
field winding, and rectifier. Different types are
available and can be divided with regard to:
•
Electrical design:
14
V, 28V and 48V
regulating voltage
•
Functions:
Mono-function with local
or remote sensing, battery-less,… and
Multi-function with local or remote
sensing, bus interface…
•
Technology:
Thick-Film Hybrid,
Microelectronic,
•
Brush holder design
(
different alternator
families, different connection terminals, ...).
Different Regulation voltages and
Temperature coefficients are available in
order to match different applications.
Bearings
A range of specially sealed roller bearings
makes it possible to design alternators
for specific applications, operating in the
harshest conditions whilst achieving long,
maintenance free life. Different bearings
types and dimensions are used on different
alternator families taking into account the
mechanical load, required rotational speed
and operating temperature. In addition
special needle bearings are used on the AAT
alternator family.
Mounting Brackets -
Protection covers - Pulleys
A wide range of different standard and
special mounting brackets and pulleys are
available. A variety of plastic protection
covers for different electrical terminal
configurations are also available. New
designs, if necessary, are made according to
customers' requirements.
Electrical terminals
Electrical terminals can be screw or
blade type in different configurations,
alternatively connectors are offered. The
main electrical terminals (B+, D+(L), W)
may also be positioned on the side of
protection covers. The position and the
design of the electrical terminals can be
adapted to the specific requirements of the
customers. Output terminal B+ is a stud,
M6, M8 and M10 are available.
ALTERNATORS
MAIN FEATURES
Cooling
Efficient alternator cooling is a very
important design issue, which allows high
specific output power, lower operating
temperatures, high reliability and a long
alternator life. There are two different basic
alternator designs due to the position of
cooling fans:
•
External fan (classic alternators) - the
fan provides effective through cooling
of the alternator and its subassemblies.
Protection covers with the facility to
mount additional hoses for clean air
intake and trash screens for difficult
environments are available,
•
Internal fans (compact alternators) – two
internal fans, positioned on the front
and rear of the claw poles, provide more
effective cooling particularly of the stator
winding, allowing higher alternator
rotational speed and lower acoustic noise.
Greater protection against accidental
contact is assured. Trash screens for
protection against harsh environments
are also available.