NGK U5381-49149 Ignition Coil 49149 Pencil Coil [1-Output Type]

【NGK U5381-49149 Ignition Coil 49149 Pencil Coil [1-output type] 】
■Product Description
Role of Ignition Coils
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 parts.

Specifications
High Voltage Generation Principle of Ignition Coils
While there are various types of ignition coils with differences in appearance and number of output terminals, the principle of high voltage generation is the same for all. 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), which is the axis of the primary coil, and the core (iron core) becomes an electromagnet. Then, 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) is no longer 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*, in proportion to the turns ratio of the primary and secondary coils. The high voltage generated in the secondary coil causes a spark to jump across the spark plug gap, 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 voltage generation phenomenon 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 windings of the secondary coil.
Type: Pencil Coil [1-output type]
Since ignition coils are installed directly on each spark plug, spark plug wires are not required. This is currently the most commonly adopted type by automotive manufacturers.

■Notes on Images
*Images are for illustration purposes only. They may include products with different sizes and colors. Product designs and specifications are subject to change without notice. Please understand.

■Precautions
1. Always inspect and replace parts after stopping the engine.
2. Please check for any oil adhesion or leakage around the plug hole. Oil adhesion or leakage can cause malfunctions.
3. Please perform inspection and replacement according to the service manuals of each car manufacturer.
4. Please be careful when attaching and detaching the connector. Damage to the connector part can lead to poor conductivity or other problems.
5. Do not use products that have been dropped, as dropping them or subjecting them to impact can cause cracks or damage to internal components.
6. Please use the correct part number ignition coil as described in this document.
7. Do not use the ignition coil in this document for purposes other than its intended use.
8. When storing, avoid high temperatures and high 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, etc., 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.