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Electrical System - Engine (Coupe): Overview Smart Fortwo II

Engine Control Systems 3 illustrations ~486 words

Component description for ignition coils - GF15.10-P-2100MCC

ENGINE 132.9 in MODEL 451.3 /4

Scheme 1

Scheme 1: Component description for ignition coils - GF15.10-P-2100MCC

Location

Ignition coils sit vertically in the valve cover above the respective cylinder.

Task

The ignition coil generates the ignition voltage for the respective spark plug (R4).

Design

The ignition coils consist of a primary coil and a secondary coil with its own power supply and actuation by the ME control unit (N3/10).

Function

When the primary coil is switched on, a self-induction voltage is produced in the secondary circuit. The primary current flow is interrupted at the moment of ignition timing point. The sudden collapse of the magnetic field generates the ignition voltage in the secondary coil which is fed directly to the spark plugs.

In order to suppress any additional ignition spark while cutting out the output stage a high voltage diode is installed in every ignition coil.

Scheme 2

Scheme 2: On-board electrical system power supply Location of components - GF15.40-P-0001-02MCU

Table of contents for function description On-board electrical system power supply - GF15.40-P-0999MCU

ENGINE 132.9 in MODEL 451.3 /4

On-board electrical system power supply, function GF15.40-P-0001MCU On-board electrical system power supply Location of components GF15.40-P-0001-02MCU Wiring diagram for starter, alternator PE15.00-P-2000MCU Overview of system components On-board electrical system power supply GF15.40-P-9999MCU

Component description for the alternator - GF15.40-P-2000MCU

ENGINE 132.9 in MODEL 451.3 /4

Scheme 3

Scheme 3: Component description for the alternator - GF15.40-P-2000MCU

Location

The alternator is located on the suction side on the right on the engine.

Task

The alternator driven by a poly-V belt delivers an adequate amount of energy to the on-board electrical system for all rotational speed occurring during driving and thus ensures the on-board electrical system supply and charging of the battery (G1).

Design

The alternator is designed as a three-phase alternator with integrated regulation.

Control

Regulation of alternator takes place by integral electronics depending on the rotational speed and on-board power supply voltage. The alternator is directly connected with the ME-SFI [ME] control unit (N3/10).

Functional principle

Voltage generation in the alternator is based on the principle of induction. If a conducting loop (coil or winding) changes a magnetic field, an electrical voltage will be induced in the conducting loop.

If a coil has a rotating, magnetic field running through it with a north and south pole then a sinusoidal alternating voltage is produced. The alternating voltage is rectified by diodes.

For an alternator one differentiates between three electric circuits

Preexcitation power circuit

The preexcitation power circuit builds up a magnetic field in the excitation coil. After starting the engine the alternator excites itself. If the excitation current flows, the charge control and alternator warning lamp(A1e5) is switched off by the instrument cluster (A1).

Excitation power circuit

The excitation current builds up the magnetic field in the excitation coil of the rotor.

Charge power circuit

The charge power circuit supplies the on-board electrical system with electrical energy.

Overview of system components On-board electrical system power supply - GF15.40-P-9999MCU

ENGINE 132.9 in MODEL 451.3 /4

Instrument cluster, component descriptionA1GF54.30-P-6000MCU
Component description for the alternatorG2GF15.40-P-2000MCU
ME-SFI [ME] control unit, component descriptionN3/10GF07.61-P-6000MCU
Table of contents for function description On-board electrical system power supplyGF15.40-P-0999MCU