Magneto-based ignition system for reciprocating internal combustion engine having a capacitive discharge booster for aiding engine starting
AssigneeUnison Industries Limited Partnership
InventorsBradley D. Mottier, J. Norman MacLeod
Life of this patent
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Abstract
A capacitative discharge device is provided as part of a magneto-based ignition system for enhancing the starting performance of the ignition system for an internal combustion engine. The ignition system incorporating the invention is applicable to conventional mechanically timed magnetos, including those intended to incorporate impulse coupling or inductive vibrators as starting aids. Although the ignition system incorporating the invention is primarily intended for aerospace applications, its relative small size the light weight make it also ideal for any type of portable application.
Claims18
An ignition system for providing spark energy to a spark plug of an internal combustion engine having at least one reciprocating piston, the ignition system comprising in combination:
- a magneto having a primary coil, a rotary magnet driven by the engine and generating energy in the primary coil having a voltage of alternating polarity and a single breaker for timing a discharge of the energy from the coil to the spark plug;
- a capacitor for concentrating energy from a source of energy;
- an output circuit for delivering the concentrated energy to the primary coil of the magneto as discrete pulses whose timing is independent of the reciprocating motion of the piston;
- a converter responsive to the source of energy for pumping increments of energy from the source into the capacitor at a rate of at least several thousand increments per second;
- and a start switch for starting the internal combustion engine that enables the converter while the engine is being started and disables the converter thereafter.
A method of using a capacitive discharge circuit in a starting system for an internal combustion engine having at least one reciprocating piston, the method comprising:
- connecting an energy output of the capacitive discharge circuit to a primary coil of the magneto;
- cranking the engine and applying an energy source to the capacitive discharge circuit;
- concentrating energy from the energy source within the capacitive discharge circuit by metering incremental amounts of energy into a storage capacitor at a frequency of more than several thousand increments per second;
- delivering pulses of the concentrated energy from the capacitive discharge circuit to the primary coil at a rate and relative timing independent of a rotational frequency and phase of a crankshaft of the cranking engine;
- and transferring energy from a rotating magnet to the primary winding of the magneto so as to induce a first voltage at the primary winding that alternates between positive and negative values that are less than a value of a second voltage induced at the primary winding by the pulses of concentrated energy, which first and second voltages consistently sum to a value (1) sufficient to reliably initiate combustion and (2) having a same polarity across the primary winding.
A portable starting system for an internal combustion engine having at least one reciprocating piston comprising:
- a source of energy;
- a capacitive discharge circuit responsive to the source of energy for concentrating energy from the source and discharging the concentrated energy to an output;
- a converter in the capacitive discharge circuit for pumping incremental amounts of energy into a storage capacitor at a frequency of at least several thousand increments per second in order to concentrate the energy;
- an output cable connected to the output of the capacitive discharge circuit whose distal end includes a coupling for making an electrical connection to a primary winding of a magneto;
- a user operable switch for selectively applying the energy source to the capacitive discharge circuit;
- and a housing containing (1) the source of energy, (2) the capacitive discharge circuit and (3) a coupling for attaching a proximal end of the output cable to the output of the capacitive discharge circuit.
An ignition system for an internal combustion engine comprising a magneto driven by the engine for delivering energy to a primary coil of the magneto, a secondary coil of the magneto for coupling energy stored in the primary coil to a spark plug for generating an ignition spark, a capacitive discharge device for concentrating energy from a battery and delivering the concentrated energy to the primary coil independent of engine position and speed, a breaker switch responsive to the position and speed of the engine for timing a discharging of energy stored in the primary coil into the plug by way of the secondary coil, an impulse coupling for retarding the timing of the breaker during cranking of the engine and a start switch for enabling the capacitive discharge device during cranking of the engine and disabling the device after the engine has started.
An ignition system for an engine of an aircraft comprising:
- first and second magnetos, each having primary and secondary coils a rotating magnet driven by the engine for imparting energy to the primary coil, each of the magnetos providing energy to one of two spark plugs associated with each piston of the engine, and a capacitive discharge device enabled by a starter switch when the engine is cranking for delivering pulses of energy to the primary coil of at least one of the magnetos at a timing and rate independent of the speed and position of the cranking engine;
- and the capacitive discharge device including a converter responsive to a battery for concentrating energy from the battery into a storage capacitor by pumping the energy into the capacitor in incremental amounts at a frequency of more than several thousand increments per second.
Dependencies are inferred from the claim text.