NGK U5561-49656 Ignition Coil 49656 Pencil Coil [1-output type]

【NGK U5561-49656 Ignition Coil 49656 Pencil Coil [1-output type]】
■Product Description
Role of the Ignition Coil
In internal combustion engines using spark plugs, a high voltage of 20,000 to 35,000V is required to discharge electricity within the combustion chamber during the compression stroke. The ignition coil is a type of transformer that converts the 12V battery voltage into the high voltage necessary for spark plug discharge. It is basically composed 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
There are various types of ignition coils, differing in appearance and the number of output terminals, but 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 creates a bundle of magnetic lines of force called magnetic flux in the core (iron core), which acts as the axis of the primary coil, and the core (iron core) becomes an electromagnet. Afterwards, 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*, according to the turns ratio of the primary coil and the secondary coil. 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.
Since the voltage generated in a coil increases proportionally with the number of turns, ignition coils increase the number of windings in the secondary coil to generate high voltage.
Type: Pencil Coil [1-output type]
Pencil coils are mounted directly on each spark plug, eliminating the need for spark plug wires. This is currently the most commonly adopted type by automobile manufacturers.

■Image Disclaimer
*Images are for illustration purposes only. Includes products with different sizes and colors. Product design and specifications are subject to change without notice. Please be aware.

■Precautions
1. Always stop the engine before inspection or replacement.
2. Please check for any oil adherence or leakage around the plug holes. Oil adherence or leakage can cause malfunction.
3. Perform inspection and replacement according to the service manual of each automobile manufacturer.
4. Please handle the connector carefully when attaching or detaching. Damage to the connector can lead to poor conductivity.
5. Do not use products that have been dropped, as dropping or subjecting them to impact can cause cracks or damage to internal components.
6. Please use the correct part number ignition coil as specified in this document.
7. Do not use the ignition coil described 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 diagnostic (self-diagnosis/OBD) error code before (or after) replacing the ignition coil, according to the service manual or similar. Failure to clear the error code may lead to problems such as the engine check lamp not turning off.