Advancer Operation - Honda CB400T Shop Manual

HONDA
C B 4 O O T
TECHNICAL FEATURES
3. To advance timing, the signal from the fix-
ed pulser is replaced by the output signal
from the spark advance pulser. The output
signal applies to SCR gate through diode
3 and fires the spark plug, performing
the same function a s the conventional
system. The faster the engine speed, the
faster the SCR is triggered to advance the
timing.
4. The negative pulse from the fixed pulser
balances the positive pulse from the spark
advance pulser when the maximum ad-
vance i s reached. This limits timing
advance.
ADVANCER OPERATION
In C.D.I. ignition, timing advance depends on the buildup time of voltage on the advance pulser, which becomes faster as
the engine speed increases. The SCR acts like a switching device, but there i s a definite voltage at which i t turns on. The overall
operation of the C.D.I. system stems from these two facts. The faster the voltage buildup, the earlier the SCR i s triggered,
allowing the system to perform the same function a s the conventional system. The fixed pulser controls timing until the
advance pulser comes into operation.
SCR TRIGGER VOLTAGE
SPEED:
N,<N2<N3<N4
Date of Issue: September. 1977
O
HONDA MOTOR CO., LTD.