NGK U5556-49649 Ignition Coil 49649 Pencil Coil [1-output type]

【NGK U5556-49649 Ignition Coil 49649 Pencil Coil [1-Output Type]】
■Product Description
Role of the Ignition Coil
In an internal combustion engine using spark plugs, a high voltage of 20,000 to 35,000V is required to discharge electricity in the combustion chamber during the compression stroke. An ignition coil is a type of transformer that converts the 12V battery voltage into the high voltage necessary for spark plug discharge. It basically consists of a primary coil, a secondary coil, and a core (iron core), and epoxy resin is filled into the case to ensure insulation between these components.

Specifications
Principle of High Voltage Generation in Ignition Coils
While there are various types of ignition coils, differing in external shape and number of output terminals, the principle of high voltage generation is the same for all of them. The primary coil is connected to the battery via an igniter (switch). First, the ECU (Engine Control Unit) turns the igniter ON, allowing current to flow through the primary coil. This generates a bundle of magnetic field lines called magnetic flux in the core (iron core) that acts as the axis of the primary coil, turning the core (iron core) into an electromagnet. Subsequently, when the ECU determines the engine ignition timing, it switches the igniter to the OFF state, stopping the current to the primary coil. As a result, the core (iron core) ceases to be an electromagnet, and the magnetic flux inside the core (iron core) also disappears. When the magnetic flux inside the core (iron core) suddenly disappears, a high voltage is generated in the secondary coil, which shares the same core (iron core) as its axis, due to electromagnetic induction*, proportional to the turns ratio between the primary and secondary coils. The high voltage generated in the secondary coil causes a spark to jump across the gap of the spark plug, initiating the combustion of the air-fuel mixture (gasoline + air).
*A coil has the property of generating voltage when the magnetic flux passing through it changes. This phenomenon of voltage generation is called electromagnetic induction.
Since the voltage generated in a coil increases in proportion to the number of turns, ignition coils generate high voltage by increasing the winding of the secondary coil.
Type: Pencil Coil [1-Output Type]
Ignition coils are directly attached to each spark plug, eliminating the need for plug wires. This is currently the most commonly adopted type by car manufacturers.

■Image Precautions
*Images are for illustration purposes only. Products with different sizes and colors are included. Product design and specifications are subject to change without notice. Please be aware of this.

■Precautions
1. Always turn off the engine before inspection or replacement.
2. Please check for any oil adhesion or leakage around the plug hole. Oil adhesion or leakage can lead to malfunctions.
3. Perform inspection and replacement according to the service manual of each automobile manufacturer.
4. Please handle the connector carefully when attaching or detaching it. Damaging the connector can lead to poor conductivity or other issues.
5. If the product is dropped or subjected to impact, cracks or internal component damage may occur. Do not use products that have been dropped.
6. Please use the correct part number of ignition coil as specified in this document.
7. Do not use the ignition coil in this document for any purpose other than its intended use.
8. When storing, avoid high temperatures and humidity.
9. When the engine check (MIL) lamp illuminates, be sure to clear (reset) the diagnostic (self-diagnosis/OBD) error code according to the service manual or similar, either before or after replacing the ignition coil. Failure to clear the error code may lead to problems such as the engine check lamp not turning off.