NGK U5555-49648 Ignition Coil 49648 Pencil Coil [1-Output Type]

【NGK U5555-49648 Ignition Coil 49648 Pencil Coil [1-Output Type]】
■Product Description
The Role of the Ignition Coil
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 in the case between these parts to ensure insulation.

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, 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, causing current to flow through the primary coil. This generates a bundle of magnetic field lines called magnetic flux in the core (iron core) that serves 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 within the core (iron core) also disappears. When the magnetic flux inside the core (iron core) suddenly disappears, 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 gap of the spark plug, igniting 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.
Furthermore, since the voltage generated in a coil increases in proportion to the number of turns, ignition coils increase the winding of the secondary coil to generate high voltage.
Type: Pencil Coil [1-Output Type]
Since ignition coils are attached directly to each spark plug, spark plug wires are not necessary. This is the type most commonly adopted by automotive manufacturers today.

■Image Disclaimer
*Images are for illustration purposes only. They may include products of different sizes or colors. Product design and specifications are subject to change without notice. Please be aware.

■Precautions
1. Always turn off the engine before inspection or replacement.
2. Please check for any oil or other residue/leaks around the spark plug holes. Oil residue/leaks can cause malfunctions.
3. Perform inspection and replacement according to the service manual of each automobile manufacturer.
4. Please handle connector removal and attachment carefully. Damaging the connector part can lead to poor conductivity.
5. Do not use products that have been dropped, as dropping them or subjecting them to impact may cause cracks or damage to internal components.
6. Use the correct part number of the ignition coil 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 codes according to the service manual or similar before (or after) replacing the ignition coil. Failure to clear the error codes may lead to problems such as the engine check lamp not turning off.