Answering the question in the video. The engine will continue to run if the alternator fails or if the master switch is turned off in flight. Electric power from the batter is only required to get the starter motor going, and once it gets the engine spinning the engine is self-sustaining. There is an engine powered fuel pump and the engine also charges the magnetos which generate the spark necessary for combustion. It’s almost a perpetual motion machine if not for the fuel which is finite in quantity.
Great video! One small note on the sidebar text at 0:42 , in DC current, electrons (negatively charged) flow from negative to positive, not positive to negative as written.
I recently broke my ankle so I've had to stop flying for the time being. I'm a few hours short of having my ppl. In my spare time of not flying, I've been going through all your educational videos and they've been super helpful. I've learned so much stuff from these videos and feel I'll be a better pilot because of it. Thanks so much!
By the way, I did like your video. In electron theory, electrons flow from negative to positive. In convential current flow, non electronic circuits, the current flows from positive to negative as you mentioned, but if there is electronic circuits involved in the circuits, current flows from negative to positive. This is why car repair videos will tell you to disconnect the negative battery terminal instead of the positive terminal when working on your car. I'm old school, so I disconnect both terminals. JOHN
John Novak Another reason to disconnect the negative (ground) terminal is to prevent spits and sparks if your wrench hits the body of the car while you're loosening the cable clamp.. If you are in the process of disconnecting the positive (hot) with the ground still connected and hit something metal, things could get interesting. When you disconnect both, I hope you disconnect the grounded terminal first and reconnect it last.
If the engine is running i believe at that point the magnetos are producing their own electricity for the spark so if you had an alternator failure or both batt and alt failure the engine turning over would keep the magnetos alive
i cant afford this hobby/lifestyle and I would love to be able to fly. but I cant. but you taking the time to explain how they work... is awesome. its the closest Ill ever get to knowing anything about them
If you're outside the US there's really not a lot of scholarships or any other way to become a pilot other than through the air force (very difficult) or flight school (very expensive)@@letslightthiscandle
Electron flow is from the negative terminal through the battery to the positive terminal, through the circuit, then back to negative. So technically, negative to positive. Other than that, GREAT VIDEO!!!!!
Electron flow is negative to positive as a few have already mentioned. That is true outside the source (battery) but is positive to negative inside the source. When engine is running the alternator is the source and the battery becomes a load. not a source so the opposite is true unless the alternator fails, then the battery again becomes the source.
Great educational video, well done. Just adding a fun fact here. A LOWER (6v/12v) voltage electrical system requires larger gauge wire for a given consumer then a HIGHER (24v/48v+) voltage system. A lightweight 24v/48v battery will use thinner wires then 12v. You’re correct though, all the switches and electrical parts on an aircraft are not made for 24v or 48v.
Also the alternator would need to spin twice as fast or be twice the diameter. Both the alternator and any electric motors would need twice as many and half as thick windings with a thicker insulating enamel coating. Since most loads are fairly low wattage a primary concern becomes the physical strength of the conductors, so no point in using moving to 24v if the wires would need to stay the same thickness for mechanical reasons. Now on a large airplane with large loads 24v or even 240v may be a practical system.
Hey Jon, I can't thank you enough for the time you spent putting this together. I was Googling "what would happen if your battery/alternator died in flight AND you turned your key off." From what I'm seeing in your video, turning the key to off with a dead battery would shut off the engine and you wouldn't be able to restart them since the magnetos don't have a power source. Good to know, and you video showed why. (At least I think that's correct)
No. Magnetos (in planes) are designed as fully independent systems(two of them) no relation to the alternator/battery system, they use permanent magnets to build up the charge for a spark. Turning the key off directly grounds them so the charge doesn't build enough to spark. If the fuel system is working the windmilling of the prop will restart the engine. In a typical Lycoming the mags have spring devices so that at low speeds during starting(even slow hand propping) the magnetos wind up then suddenly release to generate a solid burst of electricity, as the engine speeds up to idle rpm the springs disengage via inertial force.
The mags generate their own current and don't need any other source of power to run, this the engine can run with out any battery or power from the electrical system.
I used to work on Commercial lawnmowers. Its funny how similar it is to planes. just goes to show, electricity is electricity and engines are engines when you get down to how they work. I would say cars too but the electrical system on your car is much more complex to me.
The engine will still be running even if you lose the alternator or turn off the master switch while in flight. Magnetos will generate electricity for the sparks when the engine is running, which will sustain the combustion of the fuel/air mixture.
Another way to stop the engine when magnetos can’t be grounded Is to pull full rich mixture to the intake, also primer pump on continuously will flood the engine with gas making it stop.
RitchieRich Circuit breakers are protective devices. If too much current flows (like from a short circuit) the breaker will trip, opening the circuit and preventing the wires from overheating and causing damage or possibly a fire. If a breaker opens you can usually get away with resetting it once, just in case it tripped because of some transient fault. If it trips again, *leave it off!!*
No, the engine will not fail if the battery master switch or alternator is turned off in flight because the magnetos, once started from the battery master switch, create their own electrical charge independent of the electrical system and can hence operate on their own due to the rotating magnet.
Yes hi I have a question for you my instructor has a Piper Cherokee 160. we were doing a run-up and we got the RPMs up to 1,800 and the fuse breaker popped on the alternator. We checked the amps. The amps were up to 14.4 and that's when the circuit breaker popped. Any suggestions
Can you trickle charge the battery on the PA28Archer through the 12v external port on the fuselage or does it need to be connected directly to the battery?
There is no effect on the engine/s if either of those turned off or fail because magneto will supply the necessary electricity to create spark by the use of spark plug. Magneto is an independent component. But the other instruments might shutoff like the navigation instruments.
This video is really useful and well explained. However i have 2 questions and it would be great if anyone can answer them 1) why turning off the battery shuts down the alternator ? 2) once the alternator ON, is the battery still supplying the Alternator rotor (to energize the electromagnet ) or the Alternator is suppliying itself from his own output ? thanks.
I know it's been a year but thought I would answer in case someone else had same in their mind, so To turn on the alternator you need a big current flow and that comes from the battery, so once the alternator is on and producing it's own power it will recharge the battery for discharge it had while starting the starter and alternator/ generator. And once the alternator is on battery does not does supply power to alternator, unless the alternator started producing lower power than the battery and in that case we have reverse current cutout system in the voltage regulator system to prevent battery from powering the alternator because that will drain the battery real quick and we need the battery for emergency backup
Trying to troubleshoot my electrical problem and have a question. My hobbs stopped working in the plane but works on a bench. Fuse is not blown and I don't believe it is the pressure switch. If the ground wire on the clock broke it would not effect the hobbs, is that correct since we are dealing with DC current? and therefore the hobbs ground seems to be my issue or am I incorrect and a malfunction in the clock could disrupt the circuit?
Isn't there usually a switch between the primary bus and the avionics bus so the battery isn't loaded down with the radios while it's trying to start the engine?
Less common the older the plane... Yet, most airplanes will provide power only to the starter from the battery when starting, just like the lights in your car go dim when you turn the key...
This isn't for battery loading, it is to protect the avionics from voltage dips and spikes during startup and shutdown. Avionics on last, and off first.
Hi, it is my understanding that when u turn your master switch on and crank the engine, initially power from the bus is fed through the alt field cb and the ALT side of the master switch to the ACU which in turn modulates the field charge fed to Field terminal on the rotor side of the alternator flashing the electromagnetic field back, inducing a certain current into the stator and then through the ALT cb to the busses. Once the output from the generator exceeds the battery output - 28 vs 24vdc - the current flows from the battery via the starter and the battery contactors back to the battery keeping it charged. The ACU modulates the field current to the rotor based on the electrical load and on engine rpms sensed on the bus and fed to the SENSE terminal in such a manner to maintain a constant output. Is the above a correct statement? Thanks
The magnetos power the spark the spark plugs which is powered by the engine crankshaft and allows the combustion of fuel and air in the cylinders. It's independent of the battery and alternator
Opening shot you state electrons flow from positive to negative in a DC circuit. This is incorrect. They flow from negative to positive. Negative means electrons are being released as in lost so negative, positive means electrons are being received as in gained so positive.
The ground that "shorts" the magnetos to disable them and shut down the engine does go through the airframe, but they are otherwise independent of the electrical system as you stated.
it's pretty iffy as to actual direction, there is a flow from positive to negative called "Hole Flow". Also, considering the diagrams for solid-state devices like diodes and transistors, the arrows on those devices are pointing as though electricity does flow from positive to negative. In a diode, if the arrow points toward the negative pole of the battery, electricity will flow through it, but if the diode points the other way, there is no flow of electricity. Aircraft circuits use a LOT of diodes, and it's actually easier to understand the circuitry and troubleshoot if you just imagine the flow as going from positive to negative, then you see it going through the diode if the arrow is in that direction, and see it blocked if it is the other way. Notice the external charging circuit with the diode pointing to the battery that allows current to flow from the external charger into the aircraft battery, but it will block current from flowing from the battery to the external plug circuit. Also, the diode across the relay is installed "reversed" preventing it from shorting the relay except when the switch is turned OFF there will be a momentary spike generated across the relay coil that is reversed from normal polarity, the diode absorbs that momentary spike preventing the switch from burning out prematurely. If the diode was not there, that momentary spike would create a spark across the switch contacts as it was turned OFF. Sometimes a capacitor is used to absorb that spike as seen across the contact points in the magneto to extend the life of the points. It basically extends the life of the point from a factor of ten min without it to ten years with it.
The statement in the video is that "electrons flow from positive to negative", which is wrong. "electrical flows from negative to positive", is not accurate. The accurate statement is that electrons flow from negative to positive. Alternately one could accurately say that negative charge carriers flow from negative potential to positive potential and that positive charge carriers flow in the opposite direction, this is because the charge carriers are not necessarily free electrons in every case for example an electrolyte solution[salt water] where many charge carriers are actually positive and negative ions migrating through the liquid. In metallic conductors electrons are the primary negative charge carriers and the particle that actually moves. In advance electronics such as semiconductor design, positive carriers are called holes [a missing electron] as the true positive charges are protons and protons are locked in to the crystal structure of a solid and removing the matched electron leaves a net positive charge. Standard schematic symbols were developed before electron theory was widespread and so they use positive charge-carrier flow as the convention. Many vehicles prior to the 1950s had the positive side of the battery connected to ground, they work just as well, but for parts compatibility it is best for an industry to pick just one. --- The reason that electrons are labeled negative goes allllll the way back to Ben Franklin's time when they rubbed fur on amber to generate a static charge. The theory at the time was that the [rough]fur was scraping charge particles off of the [smooth] amber, and as I recall electricity was at this time viewed as an actual substance, so if you have more of it on the fur after rubbing then that is a "positive" amount of electricity.(which could be compared to other electrical sources using the old likes repel opposites attract test) Years later it was shown that the actual physical charged particle exchange is electrons moving to and collecting on the surface of the amber from the fur(just the opposite) but by the time enough products and research literature had used the amber=charge donor convention that it wasn't feasible to introduce the corrected amber=charge receiver notion and so electrons were labeled negative and we still have confusion in classrooms over a hundred years on.
@@TheDuckofDoom. correct. This is covered in any Physics, Chemistry, or EE course. Either way, his description of power flow through the circuits is incorrect; for example, you don't need power to operate a ground switch...you simply interrupt or complete the circuit.
Most lawn mower/small engines do not need battery nor alternator to run, magnetos are similar as they produce their own electricity to spark as they rotate, they need to be grounded (short circuited) in order for them to stop producing sparks that's why we see on the diagram a ground symbol on each magneto and a ground symbol on the ignition switch, so plane engines keep running without battery, electricity or alternator. Electrons are negative charged so from the physics standpoint current (electron flow) flows from negative to positive, before we learned about electrons negative charge, electric diagrams were written as current flowing from + to - and we continue with that wrong practice, in reality it does not matter as long as we close the circuit. You are wrong explaining the alternator circuit as he ALT switch does not connect with the BAT switch cable, the cable between the battery contactor and the BAT switch is negative when the BAT switch is in the on position. We need to have the BAT switch on in order to have electricity flowing through the ALT switch into the Alternator control unit and the alternator control unit will energize the alternator field. The Starter contactor has a ground symbol underneath that should not be there, ground to it comes from the ignition switch. Thanks for all the videos, I am learning a lot.
Definitely yes, because magnetos are engine driven, losing alternator or turn off master switch will only effect the electrical system only, so as long as mixture is rich enough to power the engine and ignition position is still in "both", it will still able to run. P.S. I got my checkride fail because of unable to answer this question. :D
Answering the question in the video. The engine will continue to run if the alternator fails or if the master switch is turned off in flight. Electric power from the batter is only required to get the starter motor going, and once it gets the engine spinning the engine is self-sustaining. There is an engine powered fuel pump and the engine also charges the magnetos which generate the spark necessary for combustion. It’s almost a perpetual motion machine if not for the fuel which is finite in quantity.
Great video! One small note on the sidebar text at 0:42 , in DC current, electrons (negatively charged) flow from negative to positive, not positive to negative as written.
I've been teaching and flying for a long long time and this is hands down the best instructional video i've ever seen. Thanks for that!
Ha. I was just reading in my pilot book and got stuck on the electrical system. This video sure as hell helped a lot.
I recently broke my ankle so I've had to stop flying for the time being. I'm a few hours short of having my ppl. In my spare time of not flying, I've been going through all your educational videos and they've been super helpful. I've learned so much stuff from these videos and feel I'll be a better pilot because of it. Thanks so much!
Hope you feel better !
i realize Im kind of off topic but does anyone know of a good place to stream newly released movies online ?
@Angelo Hank Flixportal =)
@Sean Sterling thank you, I went there and it seems like they got a lot of movies there :D I appreciate it !
@Angelo Hank No problem xD
By the way, I did like your video. In electron theory, electrons flow from negative to positive. In convential current flow, non electronic circuits, the current flows from positive to negative as you mentioned, but if there is electronic circuits involved in the circuits, current flows from negative to positive. This is why car repair videos will tell you to disconnect the negative battery terminal instead of the positive terminal when working on your car. I'm old school, so I disconnect both terminals.
JOHN
John Novak Another reason to disconnect the negative (ground) terminal is to prevent spits and sparks if your wrench hits the body of the car while you're loosening the cable clamp.. If you are in the process of disconnecting the positive (hot) with the ground still connected and hit something metal, things could get interesting. When you disconnect both, I hope you disconnect the grounded terminal first and reconnect it last.
Great explanation. The description with gradual build up of the visual schematic made it easy to understand. Thanks.
You’re the best in the business, as always, sir. Nice video on a confusing topic!
Glad it helps! Be sure to share us with your friends on facebook and around the airport!
Glad it helps! Be sure to share us with your friends on facebook and around the airport!
I agree 💯 percent. Am an A&P graduate and this is very useful. Thanks
I know this is tailored towards pilots but this Info will help me on my O&P Technician, thank you
If the engine is running i believe at that point the magnetos are producing their own electricity for the spark so if you had an alternator failure or both batt and alt failure the engine turning over would keep the magnetos alive
i cant afford this hobby/lifestyle and I would love to be able to fly. but I cant. but you taking the time to explain how they work... is awesome. its the closest Ill ever get to knowing anything about them
There are a million scholarships available! I've learned to fly completely on scholarships; I never would have been able to either. Good luck!
If you're outside the US there's really not a lot of scholarships or any other way to become a pilot other than through the air force (very difficult) or flight school (very expensive)@@letslightthiscandle
Excellent; the lesson is clear, and easy to understand. Thanks very much.
Thanks Jon for the videos!
They are really helpful.
Thanks! Hope the checkride went well! Check out the new site when you get a chance and let me know what you think of the new courses! -Jon
Electron flow is from the negative terminal through the battery to the positive terminal, through the circuit, then back to negative. So technically, negative to positive. Other than that, GREAT VIDEO!!!!!
Correct. Electrons have a negative charge, and therefore attracted to the positive side of the battery. Flow is negative to positive.
Electron flow is negative to positive as a few have already mentioned. That is true outside the source (battery) but is positive to negative inside the source. When engine is running the alternator is the source and the battery becomes a load. not a source so the opposite is true unless the alternator fails, then the battery again becomes the source.
Great educational video, well done.
Just adding a fun fact here. A LOWER (6v/12v) voltage electrical system requires larger gauge wire for a given consumer then a HIGHER (24v/48v+) voltage system. A lightweight 24v/48v battery will use thinner wires then 12v.
You’re correct though, all the switches and electrical parts on an aircraft are not made for 24v or 48v.
Also the alternator would need to spin twice as fast or be twice the diameter. Both the alternator and any electric motors would need twice as many and half as thick windings with a thicker insulating enamel coating. Since most loads are fairly low wattage a primary concern becomes the physical strength of the conductors, so no point in using moving to 24v if the wires would need to stay the same thickness for mechanical reasons. Now on a large airplane with large loads 24v or even 240v may be a practical system.
Love your channel.
Thank you for this! Although I'd really hoped that apart from the Amp meter, that other meter would be discussed also..
A very nice explained and detailed video. Thanks, John
Needed this
Many thanks, great job.
How to perform an electrical load analysis to determine the percentage of rated capacity?
great video.
Hey Jon, I can't thank you enough for the time you spent putting this together. I was Googling "what would happen if your battery/alternator died in flight AND you turned your key off." From what I'm seeing in your video, turning the key to off with a dead battery would shut off the engine and you wouldn't be able to restart them since the magnetos don't have a power source. Good to know, and you video showed why. (At least I think that's correct)
No. Magnetos (in planes) are designed as fully independent systems(two of them) no relation to the alternator/battery system, they use permanent magnets to build up the charge for a spark. Turning the key off directly grounds them so the charge doesn't build enough to spark. If the fuel system is working the windmilling of the prop will restart the engine. In a typical Lycoming the mags have spring devices so that at low speeds during starting(even slow hand propping) the magnetos wind up then suddenly release to generate a solid burst of electricity, as the engine speeds up to idle rpm the springs disengage via inertial force.
The mags generate their own current and don't need any other source of power to run, this the engine can run with out any battery or power from the electrical system.
Good refresher!
Great video!
PS. Are your parents Polish ?
Thanks! Yup!
I used to work on Commercial lawnmowers. Its funny how similar it is to planes. just goes to show, electricity is electricity and engines are engines when you get down to how they work. I would say cars too but the electrical system on your car is much more complex to me.
The engine will still be running even if you lose the alternator or turn off the master switch while in flight. Magnetos will generate electricity for the sparks when the engine is running, which will sustain the combustion of the fuel/air mixture.
No. The engines rotation operates the magnetos, which is what creates the spark to ignite the fuel.
No, You have magnetos that will keep the engine hot.
Another way to stop the engine when magnetos can’t be grounded Is to pull full rich mixture to the intake, also primer pump on continuously will flood the engine with gas making it stop.
Nice way to start a fire. Ffs
Hey, John can you please tell me whats the purpose of a circuit breaker I'm not sure exactly what they do ? Thanks in advance.
RitchieRich Circuit breakers are protective devices. If too much current flows (like from a short circuit) the breaker will trip, opening the circuit and preventing the wires from overheating and causing damage or possibly a fire.
If a breaker opens you can usually get away with resetting it once, just in case it tripped because of some transient fault. If it trips again, *leave it off!!*
No, the engine will not fail if the battery master switch or alternator is turned off in flight because the magnetos, once started from the battery master switch, create their own electrical charge independent of the electrical system and can hence operate on their own due to the rotating magnet.
Yes hi I have a question for you my instructor has a Piper Cherokee 160. we were doing a run-up and we got the RPMs up to 1,800 and the fuse breaker popped on the alternator. We checked the amps. The amps were up to 14.4 and that's when the circuit breaker popped. Any suggestions
Can you trickle charge the battery on the PA28Archer through the 12v external port on the fuselage or does it need to be connected directly to the battery?
6:11 no the engine is fine without them
There is no effect on the engine/s if either of those turned off or fail because magneto will supply the necessary electricity to create spark by the use of spark plug. Magneto is an independent component. But the other instruments might shutoff like the navigation instruments.
Is this applicable to pipers as well?
This video is really useful and well explained. However i have 2 questions and it would be great if anyone can answer them
1) why turning off the battery shuts down the alternator ?
2) once the alternator ON, is the battery still supplying the Alternator rotor (to energize the electromagnet ) or the Alternator is suppliying itself from his own output ?
thanks.
I know it's been a year but thought I would answer in case someone else had same in their mind, so
To turn on the alternator you need a big current flow and that comes from the battery, so once the alternator is on and producing it's own power it will recharge the battery for discharge it had while starting the starter and alternator/ generator.
And once the alternator is on battery does not does supply power to alternator, unless the alternator started producing lower power than the battery and in that case we have reverse current cutout system in the voltage regulator system to prevent battery from powering the alternator because that will drain the battery real quick and we need the battery for emergency backup
Trying to troubleshoot my electrical problem and have a question. My hobbs stopped working in the plane but works on a bench. Fuse is not blown and I don't believe it is the pressure switch. If the ground wire on the clock broke it would not effect the hobbs, is that correct since we are dealing with DC current? and therefore the hobbs ground seems to be my issue or am I incorrect and a malfunction in the clock could disrupt the circuit?
Got an interview for aircraft maintenance as an electrical engineer. Can you please assist me? Thank you very much
Isn't there usually a switch between the primary bus and the avionics bus so the battery isn't loaded down with the radios while it's trying to start the engine?
Less common the older the plane... Yet, most airplanes will provide power only to the starter from the battery when starting, just like the lights in your car go dim when you turn the key...
Ok, thanks. As an electronics guy, it bugs me that they label them as two separate busses when they can't be isolated.
This isn't for battery loading, it is to protect the avionics from voltage dips and spikes during startup and shutdown. Avionics on last, and off first.
Hi, it is my understanding that when u turn your master switch on and crank the engine, initially power from the bus is fed through the alt field cb and the ALT side of the master switch to the ACU which in turn modulates the field charge fed to Field terminal on the rotor side of the alternator flashing the electromagnetic field back, inducing a certain current into the stator and then through the ALT cb to the busses. Once the output from the generator exceeds the battery output - 28 vs 24vdc - the current flows from the battery via the starter and the battery contactors back to the battery keeping it charged. The ACU modulates the field current to the rotor based on the electrical load and on engine rpms sensed on the bus and fed to the SENSE terminal in such a manner to maintain a constant output.
Is the above a correct statement?
Thanks
6:11 no. Because you still have the battery as back up power. Correct me if im wrong
The magnetos power the spark the spark plugs which is powered by the engine crankshaft and allows the combustion of fuel and air in the cylinders. It's independent of the battery and alternator
@@zc8992 thank you so much for the info sir
Opening shot you state electrons flow from positive to negative in a DC circuit. This is incorrect. They flow from negative to positive. Negative means electrons are being released as in lost so negative, positive means electrons are being received as in gained so positive.
No, magnetos system is independent of airframe eletrical system.
The ground that "shorts" the magnetos to disable them and shut down the engine does go through the airframe, but they are otherwise independent of the electrical system as you stated.
Your electrical "flow" is backwards. The ground is negative and electrical flows from negative to positive.
Robert Seida thank you fot the correction. I'm confused haha
it's pretty iffy as to actual direction, there is a flow from positive to negative called "Hole Flow". Also, considering the diagrams for solid-state devices like diodes and transistors, the arrows on those devices are pointing as though electricity does flow from positive to negative. In a diode, if the arrow points toward the negative pole of the battery, electricity will flow through it, but if the diode points the other way, there is no flow of electricity. Aircraft circuits use a LOT of diodes, and it's actually easier to understand the circuitry and troubleshoot if you just imagine the flow as going from positive to negative, then you see it going through the diode if the arrow is in that direction, and see it blocked if it is the other way. Notice the external charging circuit with the diode pointing to the battery that allows current to flow from the external charger into the aircraft battery, but it will block current from flowing from the battery to the external plug circuit. Also, the diode across the relay is installed "reversed" preventing it from shorting the relay except when the switch is turned OFF there will be a momentary spike generated across the relay coil that is reversed from normal polarity, the diode absorbs that momentary spike preventing the switch from burning out prematurely. If the diode was not there, that momentary spike would create a spark across the switch contacts as it was turned OFF. Sometimes a capacitor is used to absorb that spike as seen across the contact points in the magneto to extend the life of the points. It basically extends the life of the point from a factor of ten min without it to ten years with it.
The statement in the video is that "electrons flow from positive to negative", which is wrong.
"electrical flows from negative to positive", is not accurate.
The accurate statement is that electrons flow from negative to positive. Alternately one could accurately say that negative charge carriers flow from negative potential to positive potential and that positive charge carriers flow in the opposite direction, this is because the charge carriers are not necessarily free electrons in every case for example an electrolyte solution[salt water] where many charge carriers are actually positive and negative ions migrating through the liquid. In metallic conductors electrons are the primary negative charge carriers and the particle that actually moves. In advance electronics such as semiconductor design, positive carriers are called holes [a missing electron] as the true positive charges are protons and protons are locked in to the crystal structure of a solid and removing the matched electron leaves a net positive charge.
Standard schematic symbols were developed before electron theory was widespread and so they use positive charge-carrier flow as the convention. Many vehicles prior to the 1950s had the positive side of the battery connected to ground, they work just as well, but for parts compatibility it is best for an industry to pick just one.
---
The reason that electrons are labeled negative goes allllll the way back to Ben Franklin's time when they rubbed fur on amber to generate a static charge. The theory at the time was that the [rough]fur was scraping charge particles off of the [smooth] amber, and as I recall electricity was at this time viewed as an actual substance, so if you have more of it on the fur after rubbing then that is a "positive" amount of electricity.(which could be compared to other electrical sources using the old likes repel opposites attract test) Years later it was shown that the actual physical charged particle exchange is electrons moving to and collecting on the surface of the amber from the fur(just the opposite) but by the time enough products and research literature had used the amber=charge donor convention that it wasn't feasible to introduce the corrected amber=charge receiver notion and so electrons were labeled negative and we still have confusion in classrooms over a hundred years on.
@@TheDuckofDoom. correct. This is covered in any Physics, Chemistry, or EE course. Either way, his description of power flow through the circuits is incorrect; for example, you don't need power to operate a ground switch...you simply interrupt or complete the circuit.
No voltage regulator ?
Hola leonardo
Most lawn mower/small engines do not need battery nor alternator to run, magnetos are similar as they produce their own electricity to spark as they rotate, they need to be grounded (short circuited) in order for them to stop producing sparks that's why we see on the diagram a ground symbol on each magneto and a ground symbol on the ignition switch, so plane engines keep running without battery, electricity or alternator.
Electrons are negative charged so from the physics standpoint current (electron flow) flows from negative to positive, before we learned about electrons negative charge, electric diagrams were written as current flowing from + to - and we continue with that wrong practice, in reality it does not matter as long as we close the circuit.
You are wrong explaining the alternator circuit as he ALT switch does not connect with the BAT switch cable, the cable between the battery contactor and the BAT switch is negative when the BAT switch is in the on position. We need to have the BAT switch on in order to have electricity flowing through the ALT switch into the Alternator control unit and the alternator control unit will energize the alternator field.
The Starter contactor has a ground symbol underneath that should not be there, ground to it comes from the ignition switch. Thanks for all the videos, I am learning a lot.
Definitely yes, because magnetos are engine driven, losing alternator or turn off master switch will only effect the electrical system only, so as long as mixture is rich enough to power the engine and ignition position is still in "both", it will still able to run. P.S. I got my checkride fail because of unable to answer this question. :D
No magnetos are self sustaining they dont need outside power to generate spark
It would take 30 minutes 6:11
No, if the alternator fails you will still have limited battery power left to operate the aircraft.
And even when that battery goes totally dead you'll still get spark from the magnetos to keep the engine running! Pretty smart design!
You must have not been paying attention
A little convoluted. Lacks simplicity.