EY35, EY40 - Small Engine Discount

8. ROBIN SOLID STATE IGNITION ENGINE (OPTION)
8-1 FEATURES
The S.S.I. system is free of the weak points of the conventional point type ignition system, that is, ignition failure due to a
dirty or burnt contact point, oxidation during long storage,and mechanical wear,and featuresmaintenance-free performance,
proper sparking, and freedom from the ill effects of water, oil dust, and moisture.
8-2 BASIC CIRCUIT and OPERATING THEORY of
S.S. I. SYSTEM
1) As the flywheel and magneto rotate, a voltage is in-
duced in the exciter coil, and flows through the pri-
mary wire to the transistor base. A
2) At the same time, the transistor is energized to form a
circuit between the exciter coil and the transistor. B
3) At the ignition time, electric power flows from the
pulser coil to the SCR gate to energize the SCR. C
Thus the current flowing to the transistor is cut off,
and the exciter current suddenly rushes to the prima-
ry side of the ignition coil. D Thus, a high voltage is
generated on the secondary side of the ignition coil to
produce a spark in the spark plug. E
L
IGNITION UNIT
Fig. 50
"-1
IGNITION COIL
8-3 CHECKING IGNITION UNIT with TESTER
The ignition unit can be checked with an ordinary circuit
tester.
Checkit as shown in the table at right, and if the test results
are as specified, the ignition unit is in normal condition. If
any of the test results is not satisfactory, replace the whole
ignition unit.
NOTE: Use a circuit tester, not a megger or other
tester that requires high ovltage. ON in the
table indicates the forward characteristic of
the diode, and if the tester pointer moves to
a certain extent, it is good.
OFF in the table indicates ma.
8-4 MEASURING RESISTANCES of EXCITER COIL and PULSER COIL
Connect (+) terminal of tester.
I
Exciter Coil
Pulser Coil
A - t B
A + B
STD
150W
0.97Q * 20%
4.5R * 20%
66Q * 20%
t
Fig. 51
* Values in the table above apply where ambient temperature 20°C. is
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