The system can be naturally divided into three main functional loops: Power Generation & Regulation, Engine Control & Ignition, and the Chassis Output Loads.
1. Power Generation & Regulation Loop
This section acts as the primary energy plant of the motorcycle, converting mechanical rotation from the engine crankshaft into stable electrical power.
Magneto Stator (
U4): Spun by the engine, it outputs three high-power AC voltage phases from terminals A, B, and C. It also features a separate P and PG terminal set that provides an isolated trigger signal to the pickup coil sensor.Rectifier Regulator (
U6): The three chaotic AC phase lines enter pins 1, 2, and 3. Inside this block, the AC is rectified into DC and regulated down to a safe charging voltage (typically around $14.4\text{V}$), exiting through+Vand-V(Ground).12V Battery (
BAT2): Connected directly across the regulated+Vand-VDC bus bar. When the engine is off or idling low, the battery supplies current to the system; when the engine spins fast, the Rectifier Regulator recharges the battery.
2. Engine Control & Ignition Loop
This loop manages the critical microsecond timing required to keep the internal combustion engine running smoothly.
Pickup Coil: Reads the magnetic pulse from the stator flywheel and sends a clean, low-power AC timing wave (
Pout) straight into the ECU.Electronic Control Unit (ECU): The computer brain of the circuit.
It takes direct power from the main DC bus via its
V+andGNDpins to turn on.It processes the engine speed from the
RPMinput pin.It sends timed execution signals out of its
Inj(Injector) pin andHT(Ignition) pin.
Injector / Purge Valves: Receives the low-voltage command from the ECU to open and close its internal solenoid, controlling raw fuel delivery into the engine cylinder.
High Tension (HT) Coil: Receives the low-voltage pulse from the ECU into
HTIN. It functions as a step-up transformer, converting that low-voltage pulse into an ultra-high voltage blast ($20,000\text{V}+$) which fires out ofHTOUT.Spark Plug: Connected in series after the HT Coil, it receives the high-voltage spike to jump its air gap, creating a hot spark to ignite the compressed fuel-air mixture.
3. Chassis Bus & Auxiliary Loads
This section represents everything else on the bike that relies on a steady diet of $12\text{V}$ DC power to operate.
Digital Dashboard / Display Unit: Connected directly across the positive and negative rails, representing the electronic instrument console that displays speed, fuel level, and diagnostics to the rider.
Switch Matrix: The momentary push buttons represent your handlebar switches (such as turn signal, horn, pass light, or starter switches) that complete the circuit path when pressed.
Lighting Network (
L1toL5): These lamps model the actual physical illumination loads on the chassis, including the headlamp, tail/brake light, and turn indicators, drawing current directly from the regulated DC bus.
