this system, the clock signal keeping the microcomputer
working is generated by the external clock circuit.
5.4. Actuator and its processing circuit
5.4.1. Fuel injector driving circuit
In order to preciously control the amount of hydrogen injection,
the pulse width modulation (PWM) output is used to
control the width of fuel injection pulse. In the microcomputer,
PWM signal can be generated by the PWM output
module existed in the interior of the microcomputer. The high
level pulse width of PWM pulse directly reflects the injected
amount of hydrogen, but the high level pulse width does not
equal to the real injected amount of hydrogen, because we
have to consider the lag time of the open and close of fuel
injector. So the diving circuit of peak-hold type is designed in
Fig. 7.
5.4.2. The driving circuit of ignition system
Driving circuit of ignition system is also called ignition
controller. Its function is to link or unlink the current of
primary winding of the ignition coil according to the signal
input by ECU, and to make the secondary winding of the
ignition generate electricity with high voltage, and break
down the gap of spark plug, realize ignition. Ignition signal is
realized by the input capture/output compare of