Chrysler laser 1990 Technical Information Manual page 174

When the SET (COAST) Switch is Depressed
The vehicle speed at the moment the SET switch
was switched from ON to Of F is memorized as the
"set vehicle speed", and thereafter the actuator is
controlled so that fixed-speed driving at that speed
is possible. The illustration below shows the timing
charts.
The initial pulse is the pulse for opening the
M A I N s w i t c h ON
OFF
Control
unit
power supply
ON
SET switch
OFF
Actuator
(DC motor)
stop
Deceleration
ON
Actuator
(electromagnetic
clutch)
OFF
Manual
driving -*
Auto-cruise control unit
DC motor-drive IC operation
l
Operation is as described in the table below, based upon
control signals from the microcomputer.
Actuator
(DC motor)
PULL
RELEASE
throttle valve to a degree of opening wk,
approximately corresponds
speed; this pulse is output when the auto-cruise
control system is set.
Trim pulse
l
The trim pulse is a control pulse for correcting
the vehicle speed; this pulse is output at
fixed cycle intervals. The output pulse width is
determined based upon the amount of deviation
between the current vehicle speed and the set
vehicle speed, and upon vehicle speed accelera-
tion.
Control pulses
Fixed-speed driving
Output mode
(PULL)
the vehicle
to
certain
I
,
Manual
I
OFF OFF ON