Honda CM400A - Advancer Operation

HONDA
CB4OOT 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 as 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
is 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 is a definite voltage at which it 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
is triggered,
allowing the system to perform the same function as 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.