An ignition control system for an internal combustion engine includes a controller, which includes an IGT generating section and an IGW generating section and is connected to ignition devices through an IGT signal line and an IGW signal line. The IGW signal line includes bifurcated portions, which sequentially bifurcate from a common main signal line. The bifurcated portions each correspond to one of the ignition devices and include a branched line, which is connected to an energy supply circuit inside the corresponding ignition device.

Circuits and methods to control a current in a coil are disclosed. The circuit and methods provide over-dwell protection and soft shut-down functionality to safely discharge the coil. The safe discharge of the coil is facilitated by a soft-start ramp signal that reduces the coil current gradually by controlling a switching device according. A profile of the soft-start ramp signal over time determines the gradual reduction. The profile of the soft-start ramp signal can be adjusted to set (i) an over-dwell period of the coil current, after which the coil current is shut down, and (ii) a soft shut-down period, over which the coil current is gradually reduced.

A hand-held power tool comprising an internal combustion engine (4), a working tool (6), a centrifugal clutch (8), and a control system (10) is disclosed. The engine (4) has a clutch-in speed, above which the engine (4) drives the working tool (6). The control system (10) comprises a rotation speed sensor (12), and a speed limitation controller (14), which is configured to limit an engine speed at a limitation speed below the clutch-in speed. It is active or activated during a starting procedure of the internal combustion engine (4). The control system (10) is configured to deactivate the speed limitation controller (14) upon sensing at least one acceleration at a level above the limitation speed and sensing at least one deceleration at a level above the limitation speed, such that the engine (4) is rotatable above the limitation speed to drive the working tool (6).

A hand-held power tool comprising an internal combustion engine (4), a working tool (6), a centrifugal clutch (8), and a control system (10) is disclosed. The engine (4) has a clutch-in speed, above which the engine (4) drives the working tool (6). The control system (10) comprises a rotation speed sensor (12), and a speed limitation controller (14), which is configured to limit an engine speed at a limitation speed below the clutch-in speed. It is active or activated during a starting procedure of the internal combustion engine (4). The control system (10) is configured to deactivate the speed limitation controller (14) upon sensing at least one acceleration at a level above the limitation speed and sensing at least one deceleration at a level above the limitation speed, such that the engine (4) is rotatable above the limitation speed to drive the working tool (6).

A control device for controlling the operation of an internal combustion engine and of an electrical machine in a hybrid drive assembly, which permits a mechanical coupling of the engine and the machine in a drive train. An engine control part controls the internal combustion engine and an electrical machine control part controls the electrical machine. A monitoring part monitors proper operation of the control parts and, in the event of a malfunction, takes over a control function within a reaction time span. An engine false-start prevention part detects a transition of the internal combustion engine from stopped to running and, in the event of such a transition, checks if a proper start of the internal combustion engine was requested within a predefined past time span in order to prevent a fuel supply release and/or an ignition release if such a start was not requested.

In at least some implementations, a control and communication system for a light-duty combustion engine includes a circuit card, an ignition circuit carried by the circuit card and configured to control an ignition timing of the engine, and a short range wireless communication circuit carried by the circuit card. The communication circuit may include a Bluetooth Low Energy antenna. The ignition circuit may include an ignition capacitor that when drained induces an ignition pulse adapted to fire a spark plug. The system may further include a microprocessor that is coupled to and controls the ignition and communication circuits, and/or a clocking circuit adapted to provide a clocking frequency associated with the timing of the ignition circuit and associated with the communication circuit via a short range wireless communication protocol. The clocking circuit may include a crystal oscillator.

In at least some implementations, a control and communication system for a light-duty combustion engine includes a circuit card, an ignition circuit carried by the circuit card and configured to control an ignition timing of the engine, and a short range wireless communication circuit carried by the circuit card. The communication circuit may include a Bluetooth Low Energy antenna. The ignition circuit may include an ignition capacitor that when drained induces an ignition pulse adapted to fire a spark plug. The system may further include a microprocessor that is coupled to and controls the ignition and communication circuits, and/or a clocking circuit adapted to provide a clocking frequency associated with the timing of the ignition circuit and associated with the communication circuit via a short range wireless communication protocol. The clocking circuit may include a crystal oscillator.

A vehicle kill switch assembly includes a switch that is coupled to a vehicle. The switch is positioned beneath a driver's seat of the vehicle and the switch is electrically coupled to the ignition system of the vehicle. The ignition system is turned off when the switch is disengaged. A biasing unit is coupled to the vehicle and the driver's seat is coupled to the biasing unit. The biasing unit biases the driver's seat upwardly in the vehicle and the biasing unit is compressed when the driver sits in the driver's seat. The switch is engaged when the biasing unit is compressed to facilitate the vehicle to be driven. Conversely, the switch is disengaged when the biasing unit biases the driver's seat upwardly to inhibit the vehicle from being driven.

A vehicle kill switch assembly includes a switch that is coupled to a vehicle. The switch is positioned beneath a driver's seat of the vehicle and the switch is electrically coupled to the ignition system of the vehicle. The ignition system is turned off when the switch is disengaged. A biasing unit is coupled to the vehicle and the driver's seat is coupled to the biasing unit. The biasing unit biases the driver's seat upwardly in the vehicle and the biasing unit is compressed when the driver sits in the driver's seat. The switch is engaged when the biasing unit is compressed to facilitate the vehicle to be driven. Conversely, the switch is disengaged when the biasing unit biases the driver's seat upwardly to inhibit the vehicle from being driven.

A system for monitoring and cleaning a spark plug is disclosed. In one example, rim firing of a spark plug is detected according to characteristics of a voltage of a primary coil of an ignition coil. The system may institute spark plug cleaning after rim firing of a spark plug is detected.