NGK U5305-49025 Ignition Coil 49025 Pencil Coil [Single Output Type]

【NGK U5305-49025 Ignition Coil 49025 Pencil Coil [1-Output Type]】
■Product Description
Role of Ignition Coils
In internal combustion engines that use 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
High Voltage Generation Principle of Ignition Coils
While there are various types of ignition coils, differing in external shape and number of output terminals, their high voltage generation principle is all the same. 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 creates a bundle of magnetic field lines called magnetic flux in the core (iron core), which acts as the axis of the primary coil, making the core (iron core) 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) 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) rapidly disappears, a high voltage is generated in the secondary coil, which shares the same core (iron core) as its axis, due to electromagnetic induction*, according 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).
*Coils have the property of generating voltage when the magnetic flux passing through them changes. This voltage generation phenomenon is called electromagnetic induction.
Furthermore, since the voltage generated in a coil increases proportionally with the number of turns, ignition coils increase the winding of the secondary coil to generate high voltage.
Type: Pencil Coil [1-Output Type]
Ignition coils are directly attached to each spark plug, so spark plug wires are not required. This is currently the most commonly adopted type by automotive manufacturers.

■Image Precautions
*Images are for illustrative purposes only. They may include products with different sizes or colors. Product designs and specifications are subject to change without notice. Please understand.

■Notes
1. Always stop the engine before inspecting or replacing parts.
2. Please check for any oil or other substances adhering to or leaking around the plug hole. Oil adherence or leakage can cause 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 part can lead to poor conductivity.
5. Do not use products that have been dropped, as dropping or impacting them may cause cracks or damage to internal components.
6. Use the correct part number 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 high humidity.
9. When the engine check (MIL) lamp illuminates, be sure to clear (reset) the error code from the diagnostic (self-diagnosis/OBD) system 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.