Average PPG Electrical system

[Capotec2015]

Hope everyone is safe and well.

I am looking to learn about the electrical system of a paramotor. How it works, what it does etc. My youtube search just gives me stuff about electric paramotors. I am thinking that it wont be too far removed from other 2 stroke motors electrical setup but would like to take the forum advice in the first instance. Thanks.

[ChrisO]

I’d Imagine it’s a very minimal system, no battery or ancillaries. It’ll just be a magneto providing the energy for the spark.

[Capotec2015]

I have found some youtube videos on 2 stroke electrical systems. I wanted to know what each component does and the flow from pull start to spark.... its starting to make sense now..

[Blackburn Mark]

I'm no expert.... 
As far as I know there are two main types of ignition system where one stores energy in a coil and one in a capacitor (CDI)
They both basically gain a charge via a magnet on the crank passing a stationary coil.
They both trigger a release of that energy via a trigger (contact breakers [points] are rarely used these days but they are easer to visualise)

So... Magnet >>> Coil (or capacitor)>>> Plug       /// with a trigger [points] acting as a gate between the coil and the plug.

There are many many ways of implementing those basic functions which can really muddy the waters in gaining a basic perspective on what is occurring.

Retarding the timing is something else that is required as the RPM increases // in a simple system, this almost occurs naturally because the voltage rises as the RPM rises causing it to trigger early.
You may be able to get away without this timing shift but it would be a bitch to start or inversely, it would be easy to start but would run poorly.
 

[Capotec2015]

so...the videos I am seeing have the magnet but also have a condenser -is that the same as a capacitor?

[Blackburn Mark]

3 minutes ago, Capotec2015 said:

so...the videos I am seeing have the magnet but also have a condenser -is that the same as a capacitor?

No, the condenser is an ancillary device used with "points" to minimise arcing between the contacts which wears out the contacts (spark erosion) and causes a lot of electromagnetic noise (interference with analogue tv, radio etc)

Most modern systems will use some sort of transistor in place of points so the EMF is dealt with via a free-wheeling diode (I think).

[Blackburn Mark]

Work your way back from the spark plug:
IF the smaller coil has a voltage across it, as soon as you remove the voltage, the plug will see a massive voltage spike... if you grasp that, you will see that everything else in the circuit is for maintaining that voltage then removing when you need the spark.

There are no "points" in this system, instead SCR (a transistor) brakes that smaller coil out of the circuit causing the collapsing magnetic field of the smaller coil to cause the larger secondary coil to output a massive spike in voltage (spark)

The timing shift on this schematic is either omitted for simplicity or the "Pulse Rotor" coil will trigger SCR earlier due to the higher velocity at higher RPM.... I dunno, I only just grasp what's going on myself