High Tension Magneto System Flashcards
What is a single magneto and a dual magneto
Single magneto is 2 magnetos in 2 separate housing.
Dual Magneto is 2 magnetos in 1 housing.
High Tension Magneto System
An AC generator driven by crankshaft rotation whose purpose is to produce a large instantaneous voltage to fire the spark plug.
Three circuits of the high tension magneto system
Magnetic- power generation
Primary- spark generation
Secondary- distribution
Magnetic circuit
Purpose is to provide a constant source of magnetism to induce a voltage. Acts as a voltage source.
Components of a Magnetic circuit
Rotating Magnet, pole shoes, and coil core
Rotating Magnet
Consist of 4 poles that are 180 degrees apart radially aligned. On magneto drive shaft.
Pole shoes
Laminated strips of soft iron that act as a magnetic conductor. Mounted on both sides of the rotating magnet.
Coil Core
Solid Bar of soft iron that connects the top of the pole shoes and completes the circuit.
Magnet Alignment
Full, Neutral, E-gap (efficiency gap), Reverse Register.
Full register
Poles are aligned with pole shoes, Max magnetic force (Max lines of flux). Lines of flux go left to right.
Neutral Register
Poles out of alignment, lines of flux shortcut through the pole shoes so there’s no lines of flux through the coil core.
E-gap
5-25 degrees beyond neutral register
Maximum induced voltage
Breaker points must be open at E gap
Spark plugs fire at E gap
Reverse Register
Poles are aligned right to left.
Therefore current flows in the opposite direction, producing A/C current within the primary circuit.
Primary Circuit
Its purpose is to act as an AC generator via electromagnetic induction.
Voltage is induced within the circuit as the magnet rotates from full register to neutral.
Induced voltage pushes current whenever the breaker points are closed.
