| 摘要 |
PURPOSE:To reduce an equipment cost by using a heat ray type flow meter as an air flow meter. CONSTITUTION:A pulse width arithmetic operational circuit is composed of a nonlinear circuit 1 which receives an output signal of a heat ray flow meter as an input and generates an output which is proportional to an intake air flow measured by this heat ray flow meter, a specified value detector circuit 3 which detects a specified value, e.g. an average, of the output signal from the nonlinear circuit 1 in a specified period, a capacitor C0, a charging control circuit 9 which supplies a charging current to the capacitor C0 according to an engine speed signal, a discharging control circuit 8 which controls a discharging current of the capacitor C0 according to the output signal of the specified value detector circuit and a pulse generator circuit 10 which generates a basic pulse tp according to a discharging time of the capacitor. |
