Honda CX500 1978 Shop Manual page 242

HONDA
TECHNICAL FEATURES
-
To advance timing, the signal from the fixed pulser is replaced by the output signal from the spark advancer pulser. The
output signal applies to SCR,
L
gate through the diode D4 and fires the spark plug, performing the same function as
the conventional system. The faster the engine speed, the faster the SCR,
L
is triggered to advance the timing.
The negative pulse from the fixed pulser balances the positive pulse from the spark advance pulser when the maximum
advance is reached. This limits timing advance.
ADVANCER OPERATION
In C.D.I. ignition, timing advance depends on the build-up time of voltage on the advance pulser, which becomes faster as
engine speed increases. The SCR
L
acts like a switching device, but there is a definite voltage at which it triggers. The overall
operation of the C.D.I. system stems from these two facts. The faster the voltage build-up, the earlier the SCR is triggered,
allowing the system to perform the same function as the conventional system. The fixed pulser controls until the advancer
pulser comes into operation.
SCR TRIGGER VOLTAGE (ON)
SPEED:
NI<Nz<N~<N~
Date of Issue: January, 1978
OHONDA MOTOR CO., LTD.