FAA Powerplant Written Practice Test

Where is the primary capacitor located in a high tension magneto?

1. In series with the ignition coil

2. In parallel with the breaker points

3. Connected directly to the spark plugs

4. Attached to the distributor cap

The correct answer is: In parallel with the breaker points

The primary capacitor in a high tension magneto plays a critical role in the ignition system. It is located in parallel with the breaker points. This placement is crucial for several reasons. When the breaker points open, the capacitor discharges its stored energy into the ignition coil, producing a higher voltage output. This higher voltage is necessary to ensure that a strong spark is generated at the spark plugs for ignition. The capacitor also aids in damping the voltage spike caused by the sudden opening of the circuit, which helps to reduce arcing at the points and prolongs their lifespan. Positioning the capacitor in parallel with the breaker points maximizes the synchronization of the capacitor's charge and discharge cycles with the operation of the ignition system, enhancing overall performance and efficiency. This helps to ensure that the ignition system operates smoothly, which is essential for the engine's reliable performance.