Nippondenso Co., Ltd.

Denso Corporation

Ryoichi Okuda

Tomoatsu Makino

Noboru Yamamoto

Takeshi Matsui

Yukio Tsuzuki

Yutaka Fukuda

Yoshiyuki Miyase

Hiroshi Sakurai

Katsuteru Miwa

Motoshi Kawai

Kenji Yagi

Norboru Yamamoto

Tomoatsu Mikino

Katuhisa Mase

Koichi Suzumura

A semiconductor switching element driving circuit comprises an overcurrent limiting circuit which instantaneously drops a voltage of a gate terminal of an IGBT when a main IGBT current becomes larger than a predetermined level i1. An overcurrent protection circuit which first decreases the main IGBT current at a first inclination when the main IGBT current becomes larger than the other level i2 lower than the i1 and then reduces the main IGBT current at a steep second inclination when it becomes smaller than another level i3.

Semiconductor switching element driving circuit

In an apparatus for controlling the energization time of an ignition coil of an internal combustion engine, a desired ignition timing is computed in accordance with a load and rotation speed of the engine and an energization starting time of the ignition coil is computed in accordance with the ignition timing. The energization starting time is retarded in accordance with the primary current through the ignition coil and the energization time of the ignition coil is reduced. The primary current flow through the ignition coil is interrupted at the ignition timing.

Ignition control apparatus for internal combustion engines

An improved ignition system for internal combustion engines including a constant current control circuit for effecting constant current control of an ignition coil primary current, further includes a compensating circuit for controlling a reference voltage, which is to be compared with a detection value of the ignition coil primary current, at a constant value irrespective of a decrease of a power supply voltage, thereby controlling the ignition coil primary current at a given value over a wide range of variations of the power supply voltage including a considerable decrease thereof.

Ignition system for internal combustion engines

A circuit arrangement for controlling the duration of a current generated in the primary winding of an ignition transformer comprises a ramp generator responsive to the ignition timing or an internal combustion engine for generating a ramp voltage having a constant peak value and a variable rate of increase in voltage as a function of the speed of the engine. A pulse generating means is provided for successively generating a pulse of which the pulse height is substantially equal to the peak value of the ramp voltage and of which the pulse duration is variable inversely as a function of the speed of the engine. To the pulse generating means is coupled an integrator for integrating the pulses supplied thereto to generate an integrated output. The output of the integrator is supplied to a comparator for making a comparison with the instantaneous value of the ramp voltage to generate an ignition current pulse having a duration corresponding to the difference between the compared input variables.

Circuit for controlling the primary dwell time of ignition transformer

In a knock detecting apparatus for an internal combustion engine, a comparator receives at one input a knock detection signal from a knock sensor and at the other input a knock discrimination level signal produced by a knock discrimination level generator in accordance with the knock detection signal of the knock sensor. A mask circuit inhibits the passage of the comparison output signal of the comparator during a period in which a number of noises are generated from the internal combustion engine and at the same time interrupts the operation of the knock discrimination level generator.

Knock detecting apparatus for internal combustion engine

A contactless ignition system for internal combustion engines controls the closing angle of an engine in response to a signal derived by comparing the AC output of an alternator operated in synchronism with the rotation of the engine with the output of a bias-up circuit adapted to supply a DC bias signal which varies with the speed of the engine. The outputs of the alternator and the bias-up circuit are applied to a voltage comparison circuit and the voltage comparison circuit applies to the bias-up circuit a signal having a frequency which is proportional to the number of revolutions of engine. In response to the signal the bias-up circuit generates a signal proportional to the engine speed and this signal is converted through a non-linear circuit of the bias-up circuit into a DC bias signal whose rate of change is small at low engine speeds but increases with an increase in speed at higher engine speeds.

Growing community of inventors

Kariya, Japan

Ryoichi Okuda