Group
28
Igni
t
ion sys
t
ems
Design and function
-
Components
A
Distributor
Function
The function of the distributor
is
to
conduct
the high-tension pulse from the
ignition coil
to
the appropriate spark
plug
.
A distributor fitted with
a
Hall
generator also
provides
information on engine speed
with the aid of the trigger
rotor driven
the
distributor shaft.
Construction and variants
The distributor consists of a
cap
rot
or
arm
(2),
shaft (3) and, in applicable cases, a
Hall
genera
t
or (
4
) and
trigger
rotor
(5). (Older systems employ either
contact
breaker points or
some
form of pulse genera
t
or.)
A
. 'Vertical'
distributors are driven by
an
intermediate
shaft
through bevel
gearing.
B
. 'Horizontal'
distributors
are driven
directly from the
camshaft, minimizing
the play
in
the transmission mechan
-
ism.
This
,
in
turn
,
affords
more
accurate control of
the timing
in systems in
which
speed information is supplied
by a Hall generator
.
700 series models from 1985
on (with
the exception of the 740 with the B230A engine) are fitted with camshaft
-
driven
units.
In
the
case of distributors which are not
equipped
with a Hall generator and
,
as a
result, are fitted
only
with a rotor
arm
,
the timing cannot be
varied
by
rotating
the
unit.
In
systems of
th
is
type
,
since crankshaft position signals
are
supplied
by an
inductive
p
ick-up
at the flywheel
,
only the position of
the rotor
in
relation
to the
contacts
in
the
cap
is
altered by this procedure
.
•
TZ-28H
system employs
with
advan
ce
un
i
t
to
supply
load
in
f
o
rmation
.
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