Lawnmower Coil Sparking System - How it Actually Works - Finally Understand the Basic Principles!

hello again it's craig and i want to thank you so much for being here the channel's growing at a nice steady pace and it's all because of you and in this video i'm going to go through how a lawnmower magneto coil pack works so here goes [Music] as we turn the engine the fixed magnet on the flywheel rotates with it and each time the magnet passes the electronic coil pack it generates an electric charge within it and the way it does this is all about how the magnet passes over the copper coiled wire in the coil pack and so showing this in very basic terms if we could see inside the coil pack it would look something like this there would be an a shaped iron core and a copper wire wound in the middle with around 70 turns this wire is insulated so that the coils are not in direct contact with each other so if we took a cross-sectional view of the wire we'd see we've got the copper part of the wire and then the insulation on the outside and then wound over this coil is another coil with thinner wire with many thousands of turns and now they're together there's a better appreciation of the differences between the two the one on the left which we call the primary coil has far fewer turns but the wire is much thicker than the one on the right which has far more turns but the wire is much thinner this is the one referred to as the secondary coil and this coil is much much longer than the primary coil and this secondary coil wire is also insulated in the same way as the primary coil wire and so although they exist like this together on the iron core there is also space between the two of them they're not in direct contact and to better show that if we were to slice one of these coils in half like this and have a look from this perspective it would look exactly like this this is indeed one of those coils dissected we can clearly see the iron core in the center which is insulated from the primary coil and the primary coil is insulated from the secondary coil and the secondary coil as an outer insulation which is encasing everything and it's the primary and secondary coils that are vital in producing the electrical current that is going to produce a spark this part's also referred to as the transformer and you'll see that very shortly but how does this happen then how does this create electricity for the spark plug well it needs a kick start from something very similar but much smaller this is known as the trigger coil or the initiator and this basically is also insulated copper coiled wire wrapped around an iron core in fact you can see the iron core of this trigger coil protruding at the bottom of the coil pack here and it's this trigger coil that's wired to the small primary coil and has no contact with the larger secondary coil and it's this whole system that's designed to work with the fixed magnet on the flywheel like any fixed magnet the fixed magnet on the flywheel has a north and a south pole and its magnetic field is orientated just like so with the flow running through the center and out like this and this magnetic field on the fixed magnet is constant it's always there it always exists meaning it's never turned on or off it's always on and that's exactly what's needed to fulfill its job because when everything's fixed in place and it's attached to the flywheel on the engine and the flower wheel turns past the coil pack firstly one of the things that happens when the magnets aligned to the iron core is that the iron core picks up the magnetic field remember though that the flywheel is moving so fast that the fixed magnet would pass over the coil in a split second this is just a moment in time frozen to explain my point but as the flywheel continues to turn the magnetic field from the fixed magnet is also felt by the trigger coil and the way the fixed magnet affects the trigger coil is all about what the copper coiled wire is made of simply put billions and billions of copper atoms and it's the structure of copper atoms that makes it so good at reacting to a magnetic field to create an electric current and to understand how this happens we need to take a look at the basic structure of the atom itself so what's it made of well in its center nucleus there's 29 positively charged protons and in there amongst them are 35 neutrons called neutrons because they are neutral in charge meaning they're neither positive nor negative so basically this 29 positive particles and 35 neutral particles makes up the center nucleus of the copper atom but remember at the moment we've only got positive charge here because the neutrons aren't negative charge they're no charge and so what does it do well it attracts the equal proportion of its opposites so it attracts 29 negatively charged electrons this now means that the atom has equaled out its own charge so it's neither too negative nor too positive this is known as a stable atom and that's because it's got all the particles it needs it doesn't need to attract anything it's wholesome and so all of these 29 electrons are constantly orbiting round and round the nucleus and they never stop and if you notice all 29 electrons there are existing at different levels and in fact like all atoms each level has a specific number of electrons and so with copper atoms there are always two electrons at this lower state closest to the nucleus and at this level the electrons are said to be at their ground state so at their lowest level of energy and that's because these are the two most drawn into that positive pull of the nucleus being at this level it means that the pull towards the nucleus is at its strongest and this force means that there's a certain amount of drag for the electrons so they can't quite move as quickly and as erratically as the other electrons and as we go outwards to the other levels each level has less of a drag less of a force pulling it into the nucleus and the more freedom to move quicker and more erratic the electrons have so that means that these eight electrons have more freedom to move and these 18 electrons have even more freedom to move all of which while still being caught up in the electrical pull of the nucleus so the role in the nucleus is orbit just moving at different paces and that brings me on to the highest level and the reason i wanted to explain everything so far because it's this level that occupies just one electron which is the reason the copper wire can produce an electrical current and that's because this one outer electron having the least amount of attraction to the nucleus and therefore the least amount of drag can behave in a way that's more erratic than all of the other electrons and to better explain that let's take a look at how these atoms make up the copper wire and how the electrons behave within it okay so here's some copper wire and in reality there'd be many billions and billions of atoms making up the wire but so we can see things a little better i'll bring it in so that we can see each atom okay so we have our copper atoms and the all-important outer electrons which i shall highlight it's important to say now that the atoms don't orbit the nucleus in this uniformed way like this they actually do so more like this like a swarm of bees buzzing around so it makes more of a cloud as they move somewhere near the speed of light and of course each level is doing the same and the further up we go the more erratically they're doing it until we get up to the one electron at the highest level which is moving the most freely and whilst these electrons in these first three levels caught up in that electrical pull of the nucleus stay local to the nucleus this lone electron at the outer level with the least gravitational pull doesn't stay local it moves about from one atom to another and that of course means there isn't one outer electron doing this from one atom there is billions of them doing it all at the same time so that means with billions and billions of outer electrons moving round and round from atom to atom at something like close to the speed of light there's a constant c of electrons surrounding all of the atoms and this is indeed called the electron c and at the moment these electrons are moving everywhere backwards and forwards side to side and what's needed to create an electrical current is to put some order in there and have them move together in one direction and that's where the magnetic field of a fixed magnet comes in because when the magnetic field on the flywheel's fixed magnet passes over the trigger coil inside the coil pack the electrons inside the copper wire react to the magnetic field in such a way that the magnetic field pushes them all in one direction so they're no longer moving randomly in different directions they're all uniformly moving together so as the engine turns and the magnet passes and passes and passes it moves them and moves them and moves them so each time the magnetic field passes the trigger coil it moves those electrons forward inside the coil and because all electrons are negative in charge they're all repelling each other so as some electrons are being pushed forward by the magnetic field those electrons that are being pushed forward repel the electrons in front of them and that pushes those forward a bit like the flow of a river when the water's moving it's pushing the water in front of it downstream and this flowing movement of electrons is indeed what we refer to as an electrical current so the electron flow of this electrical current takes this regular route out through the copper wire it would like to take this route but it comes up against a resistor so it goes this way and passes a transistor which is a voltage gate that directs the flow this way and when it's past that it flows to another transistor which it passes and continues to flow to a degree back to the coil but there is a huge amount of flow which goes up this route to the primary coil all of this of course is happening in a split second but as the current flows out of the primary coil the current can't go back on itself because as it comes up against the transistor which is the one-way voltage gate it's redirected back into the same current circuit and if it tries to take this route the same will happen it comes up against the other transistor and the flow is put back into the flow of the circuit and so the electron flow of the current stays largely in a loop like this that means that the primary coil momentarily maintains a decent electrical current within it and if a copper coiled wire surrounding an iron core has an electrical current passed through it that itself becomes a magnet an electromagnet and so this primary coil takes on a magnetic field of its own which is very much like the fixed magnet and so this electromagnetic field of the primary coil is large enough to be felt by the whole of the secondary coil and this magnetic field and indeed all of the electron flow is all happening whilst the fixed magnet on the flywheel is passing over the trigger coil pack creating the electron flow it has to pass over it fast to do so the magnet can't simply stand over it static but as soon as the magnetic field has passed everything instantly changes and that is because there's no longer an electron flow creating an electrical current the electromagnetic field of the primary coil instantly collapses down to the iron core at a speed near the speed of light so let's take a look at what's happened here on the cross-sectional view of the actual coil pack so the electron movement was causing the electrical current within the primary coil and that was creating the electromagnetic field and that electromagnetic field was covering the secondary coil as the electrical current flow through the primary coil stopped the electromagnetic field collapsed down to the iron core as it collapsed that electromagnetic field passed the secondary coil at the speed of light as it passed the secondary coil windings at the speed of light this was the same as a magnet moving past a coil but because this magnetic field moved past the coils much faster than the fixed magnet move past the trigger coil and for the fact that the secondary coil winding is much longer than the primary coil winding with many thousands and thousands of turns this created a charge that went from just a few hundred volts to many many thousands of volts so going from just a few hundred volts in the primary coil to many thousands of volts in the secondary coil where it transforms the voltage from lower voltage to a higher voltage up regulating it this is known as a transformer and so now what happens to this thousands of voltage of electron flow current inside the secondary coil while this current only exists in the split second that the electromagnetic current is collapsing when the magnetic field collapsed this electrical current needed to go to ground in other words all of these negative charged electrons are attracted to something more positive because opposites attract and so the attraction for these negatively charged electrons is to flow out of the secondary coil through the ht lead which is connected to it and over to the spark plug to find the ground of the engine and in doing so it creates the spark and so in a nutshell each time the fixed magnet on the flywheel passes the trigger coil this is what's happening we can see there from fixed magnet to spark how this is all created but how exactly does the spark itself occur how do these electrons trying to find a ground actually create a spark well when the electrical current from the secondary coil arrives at the spark plug it then travels down a specially designed electrode at the center of the spark plug and right down to the end of the electrode but when it gets here it can't go any further because there's an air gap this air acts as an insulator stopping the electrical current from going any further than the end of the electrode but as the pressure of this current builds up and up inside the electrode here which we call voltage this changes the composition of the air in that gap as this high concentration of electrons build up they push forward the outer electrons in the atoms that make up the air towards the ground electrode this momentarily turns the atoms in the air into ions basically atoms that need electrons in other words it's ionized the air and so these electrons now have a gap to fill which they then move into and continue to flow to the positive attraction of the ground electrode and as they pass through the air we see this as a spark and they instantly move through the outer grounded area of the spark plug and into the engine body where it's not necessarily positively charged but because it's more positively charged than all of those negatively charged electrons bunched together that's why they're attracted to it and for that reason this is what's known as a ground and so here are the basics again in their working capacity i really hope you've benefited from this video and you feel like you've learned something if you have please can i ask that you give me a thumbs up and comment to let me know what you think exactly of the video and in the meantime i'll be back soon thank you so much for watching you

Channel: TheRepairSpecialist

Views: 399,728

Rating: 4.9298382 out of 5

Keywords: craig kirkman, the repair specialist, ignition coil test, lawn mower coil test, lawn mower magneto testing, briggs and stratton magneto replacement, briggs and stratton magnetron 5hp, briggs and stratton magnetron 3hp, lawn mower coil gap, lawn mower sparking, lawn mower not sparking, how a magneto ignition system works, how a magnetron works, how does a lawn mower coil work, how a lawn mower coil, how a lawn mower coil works, briggs and stratton coil replacement, magnetron

Id: NNlYbvDY6pI

Length: 16min 14sec (974 seconds)

Published: Thu May 27 2021