| 摘要 |
A circuit for use in conjunction with the fuel injection controller of an internal combustion engine in which fuel injection valve control pulses are generated on the basis of engine information, for example, engine speed and air flow rate. When the engine is being operated at negative torque (downhill operation, engine braking) the valve control pulses are suppressed. This condition is detected by comparing the length of preliminary control pulses with a reference pulse generated by a monostable multivibrator which is triggered by pulses synchronous with engine speed. A first comparator circuit sets a bistable multivibrator when the preliminary pulses are shorter than the reference pulse and a second comparator circuit resets the bistable multivibrator in the opposite case. The bistable multivibrator controls an output elemet which can suppress the valve control pulses in one of the two states. A hysteresis-inducing feedback path is provided so that pulse suppression occurs at a slightly different pulse length than does pulse transmission in order to prevent oscillations.
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