In this video, we're going to do a quick overview of the Magneto. The magneto is part of the ignition system. Basically, the magneto supplies a high voltage to the spark plugs for ignition.

Let's take a closer look and see how the magneto actually works.

So here we have a Magneto. Let's break it down. Let's start with the rotor. The rotor is a permanent magnet, and it rotates. It is rotated by an engine drive gear.

Next, we have the coil assembly. Let's take it apart to see what it's made up of.

Okay, so in the middle we have an iron core. Next, we have the primary coil, which is around 200 turns of heavy copper wire. Then, we have the secondary coil, which is a 100 times step-up, around 20,000 turns of fine copper wire.

Some important connections that the coil assembly has are first, a hot wire leaving from the primary coil going to ground. Also, there's a high voltage tab that leaves from the secondary coil going to the spark plugs.

When the rotor permanent magnet rotates, it induces a continuously changing flowing current in the primary coil, which creates a powerful magnetic field in the iron core. This magnetic field expands outwards, encircling the entire coil assembly.

When ignition is required, the grounding of the hot wire leaving the primary coil is disconnected. The flow of current is stopped, and this causes the magnetic field to collapse suddenly, cutting across the secondary coil. This induces a huge voltage spike in the secondary coil of around 20,000 to 30,000 volts.

This huge voltage spike leaves the secondary coil through the high voltage tab and goes to the spark plug, where the high voltage drives current across the gap in the spark plug, creating the spark required for ignition.

Now, let's cover a couple of select details before I wrap things up.

First detail: the disconnecting of ground on the hot wire from the primary coil is accomplished through breaker points. The contacts are opened, disconnecting the ground connection, which leads to the voltage spike in the coil assembly.

The last detail: there is more than one spark plug to consider. Well, this is where the distributor comes in. The distributor directs the high voltage to the spark plugs in proper sequence.

A cool thing to observe is that the magneto is its own little electrical powerhouse. The magnet in the magneto rotates off engine power. The magneto itself is completely independent of the alternator and battery in the airplane. So, if you have an aircraft electrical failure, the magneto won't be affected, and the engine will continue to run.