Ignition module for use with a light-duty internal combustion engine
AssigneeWalbro Engine Management, L.L.C.
InventorsMartin N. Andersson, Cyrus M. Healy
Life of this patent
Estimating the term…
Abstract
A capacitive discharge ignition (CDI) system that can be used with a variety of light-duty internal combustion engines, including those typically employed by lawn, garden, and other outdoor equipment. According to one embodiment, the CDI system includes an ignition module having a first switching device that shorts a charge coil during an initial portion of a charge cycle. Subsequently, the first switching device is turned ‘off’ so that a flyback charging technique charges an ignition capacitor. A second switching device is then used to discharge the ignition capacitor and initiate the combustion process.
Claims25
An ignition module for use with a capacitive discharge ignition (CDI) System comprising:
- a charge coil being mounted in the ignition module to induce electrical energy in response to one or more rotating magnetic element(s);
- an ignition capacitor being coupled to the charge coil to receive electrical energy from the charge coil;
- a first switching device being coupled in parallel with the charge coil;
- a second switching device being coupled to the ignition capacitor;
- and
- an electronic processing device being coupled to the first switching device to provide it with a charge control signal and to the second switching device to provide it with a discharge control signal, wherein activation of the first switching device creates a ground path between the charge coil and ground so that electrical current flows through the parallel coupled first switching device and bypasses the ignition capacitor.
A method of operating an ignition module, comprising the steps of:
- (a) inducing electrical energy in a charge coil in response to one or more rotating magnetic element(s), wherein a switching device is coupled in parallel to the charge coil;
- (b) shorting the charge coil with the switching device during a first stage of a charge cycle so that electrical current flows between the charge coil and ground through the parallel coupled switching device and bypasses the ignition capacitor;
- (c) interrupting the short with the switching device during a second stage of the charge cycle so that electrical current flows between the charge coil and the ignition capacitor, wherein an electronic processing device controls the switching device according to an engine input signal;
- and
- (d) charging the ignition capacitor according to a flyback charging technique.
A method of operating an ignition module, comprising the steps of:
- (a) inducing electrical energy in a charge coil in response to one or more rotating magnetic element(s), wherein the charge coil has a relatively low inductance of about 2-10 mH, inclusive;
- (b) using a flyback charging technique to charge an ignition capacitor with electrical energy from the low inductance charge coil, wherein the flyback charging technique is used when an engine is operating in a lower speed range;
- and
- (c) using a non-flyback charging technique to power an additional electrical device with electrical energy from the same low inductance charge coil, wherein the non-flyback charging technique is used when the engine is operating in a higher speed range.
A method of operating an ignition module, comprising the steps of:
- (a) inducing electrical energy in a charge coil;
- (b) monitoring an engine input signal with an electronic processing device, wherein the engine input signal is representative of at least one of the position or speed of an engine;
- (c) shorting the charge coil during a first stage of a charge cycle so that electrical current flows between the charge coil and ground;
- and
- (d) interrupting the short during a second stage of the charge cycle so that electrical current flows between the charge coil and an ignition capacitor, wherein the electronic processing device uses the engine input signal to determine the timing for at least one of the shorting or interrupting steps.
Dependencies are inferred from the claim text.