Description
a battery operated, fully transistorized breakerless
ignition system. By using magnetic pickup
coils the need for contact breaker
points is eliminated. This adds to the
dependability of the system by eliminating
frequent cleaning and adjustment of
points and ignition timing. This TCI
unit incorporates an automatic advance
circuit controlled by signals generated by
the pick-up coils. This adds to the
dependability of the system by eliminating
the mechanic advancer. This TCI
system consists of two main units; a
pick-up unit and an ignitor unit.
Operation
The TCI functions on the same principle
as a conventional DC ignition system
with the exception of using magnetic
pick-up coils and a transistor control box
(TCI) in place of contact breaker points.
Pick-up unit
This unit consists of two pick-up coils
mounted on the generator case and a
permanent magneto on the rotor which
is mounted to the crankshaft. When the
magneto passes through these pickup
coils, the signals are generated at the
pick-up coils and forwarded to the
ignitor unit as a signal.
The full ignition advance is determined
by the distance (or angle) between two
pick-up coils.
lgnitor unit (TCI)
This unit has such functions of wave
form, duty control, switching, and electrical
ignition advance. The ignition
timing is advanced electrically using two
signals from the pick-up coils.
The duty control circuit is provided to
control the on time period of the primary
ignition current to reduce the
electrical consumption. This unit also
incorporates a protective circuit for the
ignition coil. If the ignition switch is turned
on and the crankshaft is not
turned, the protective circuit stops
current flow to the primary coil within
a few seconds. When the crankshaft is
turned over, the current is turned on
again by the signals generated by the
pick-up coils.
Note: Even though two spark plugs fire at the same
time only one cylinder is on the compression
stroke at a time. The other cylinder is on the
exhaust stroke and the spark in that cylinder
has no effect.