A method for manufacturing an ignition coil for an internal combustion engine includes manufacturing a containment body provided with a containment chamber, defining an internal volume, and with a lateral seat facing outwards, and preparing an electronic board provided with a first face and a second face, opposite the first. The electronic board is positioned inside said lateral seat and a polymeric material with high thermal conductivity is then printed on the electronic board so as to cover it.

A method for manufacturing an ignition coil for an internal combustion engine includes manufacturing a containment body provided with a containment chamber, defining an internal volume, and with a lateral seat facing outwards, and preparing an electronic board provided with a first face and a second face, opposite the first. The electronic board is positioned inside said lateral seat and a polymeric material with high thermal conductivity is then printed on the electronic board so as to cover it.

A switch control circuit controls a switch element connected to a primary coil of an ignition coil in accordance with an ignition signal. The switch element includes a transistor and a protection element connected between a collector and gate of the transistor. The switch control circuit uses a voltage at a gate terminal controlling the transistor or a voltage corresponding to a collector current of the transistor as a detection voltage and generates a status detection signal corresponding to a change in the detection voltage.

A switch control circuit controls a switch element connected to a primary coil of an ignition coil in accordance with an ignition signal. The switch element includes a transistor and a protection element connected between a collector and gate of the transistor. The switch control circuit uses a voltage at a gate terminal controlling the transistor or a voltage corresponding to a collector current of the transistor as a detection voltage and generates a status detection signal corresponding to a change in the detection voltage.

Energization abnormality of a switch element of an internal combustion engine ignition device is detected appropriately. To this end, in an internal combustion engine ignition device that includes an ignition coil and an ignition plug, the ignition coil includes a primary coil including a main primary coil and a sub primary coil and a secondary coil that generates secondary current in response to a voltage variation generated in the primary coil. The internal combustion engine ignition device includes a main switch element that performs energization/deenergization of the main primary coil in a first direction, a sub primary coil magnetic flux generation state switching unit capable of switching between a forward direction magnetic flux generation state in which energization of the sub primary coil in the first direction is performed and an opposite direction magnetic flux generation state in which energization of the sub primary coil in a second direction is performed, and an abnormality detection section that detects energization abnormality to the sub primary coil. The abnormality detection section is configured so as to detect energization abnormality on the basis of overlap between energization in the first direction and energization in the second direction of the sub primary coil.

An ignition coil control device includes: an energization control unit that controls to energize an ignition coil by first energization control and second energization control shorter in energization time than the first energization control; a cruise area determination unit that determines that a driving area of a vehicle is located in a cruise area on the basis of a throttle opening and an engine speed; and an integration counter that is incremented every predetermined time when the first energization control is being executed in the cruise area and is decremented every predetermined time in other cases. When a counter value of the integration counter reaches an upper limit value, a cooling process of switching from the first energization control to the second energization control is executed. Such ignition coil control device can appropriately switch energization time while preventing excessive heating of an ignition coil without using a current sensor.

An ignition coil control device includes: an energization control unit that controls to energize an ignition coil by first energization control and second energization control shorter in energization time than the first energization control; a cruise area determination unit that determines that a driving area of a vehicle is located in a cruise area on the basis of a throttle opening and an engine speed; and an integration counter that is incremented every predetermined time when the first energization control is being executed in the cruise area and is decremented every predetermined time in other cases. When a counter value of the integration counter reaches an upper limit value, a cooling process of switching from the first energization control to the second energization control is executed. Such ignition coil control device can appropriately switch energization time while preventing excessive heating of an ignition coil without using a current sensor.

A circuit configured to control a switching device to reduce a current in a charged coil is disclosed. The circuit is configured to monitor a kickback voltage generated by the decreasing current in the coil. The circuit is further configured to adjust a rate at which the current is reduced in order to limit the kickback voltage. Limiting the kickback voltage during shutdown can prevent a spark at a spark gap that is inductively coupled to the coil and can allow for greater flexibility in the time taken to shut down the coil without overheating components or generating an unwanted spark. Additional, limiting the kickback voltage during shutdown can allow for a pseudo ramp wave to control the circuit during the shutdown because voltage spikes cause by abrupt changes in the pseudo ramp wave are limited.

In an ignition apparatus, a deterioration determination circuit performs a deterioration determination task of (i) monitoring an absolute increase in a temperature parameter during a predetermined deterioration detection period that has been started since an energization command signal being inputted to a control circuit, and (ii) performing a comparison between the absolute increase in the temperature parameter and a predetermined deterioration detection threshold to thereby determine whether a level of deterioration of a switching circuit is within an acceptable level.

An igniter includes a switch element with input, output control electrodes, a first lead in contact with the input electrode and connected to a primary coil of an ignition coil, a second lead that is grounded, a third lead spaced apart from the first and second leads, a first bonding wire connecting the output electrode and the third lead, a second bonding wire connecting the third lead and the second lead, and a control IC that drives the switch element based on an ignition instruction signal from an engine control unit. The control IC generates an ignition confirmation signal based on the voltage of the third lead, and outputs the signal to the engine control unit.