Abstract: An AC ignition system for an internal combustion engine having a voltage source, an ignition coil coupled to the voltage source and at least one spark plug having a spark gap, the ignition coil has a primary winding and a secondary winding, the secondary winding has a high turn ratio with respect to the primary winding. The primary winding is electrically coupled to the voltage source and the secondary winding is electrically connected to the spark gap. A switch is connected in series with the primary winding and is configured for movement between an open position and a closed position the closed position electrically couples the voltage source to the primary winding. The ignition coil generates a make voltage after the primary winding is coupled to the voltage source. The make voltage is sufficient to ionize the spark gap.

Abstract: A method for inhibiting or eliminating case erosion in a pencil ignition coil having an internal primary winding and an external secondary winding and shield. Three alternative means for resisting damage due to the partial discharge phenomenon arising from a high electric field in such coil configurations are provided: (i) applying an ozone resistant coating on the case; (ii) applying a coating on the case for eliminating partial discharge under the shield; and (iii) applying a polyimide tape covering to the case for resisting partial discharge under the shield.

Abstract: An ignition coil assembly includes a core formed of magnetically-permeable material extending along a main axis, a primary winding disposed about the core, a secondary winding disposed on a secondary winding spool wherein at least one of the secondary winding leads is connected to a high-voltage connector terminal portion of the ignition coil assembly configured for connection to a remotely disposed spark plug, a case formed of electrical insulating material, and a magnetically-permeable shield disposed outwardly of the case. The secondary winding is progressively wound on the secondary winding spool, thereby eliminating failure modes associated with the segment-wound secondary windings, and, eliminating the need for pole pieces in the magnetic circuit, thereby reducing components, cost, weight, and size of the ignition coil assembly.

Abstract: An ignition apparatus includes a high resistivity ferrite central core with a secondary winding disposed directly thereon. The ignition apparatus also includes, in a progressively coaxial fashion, a primary spool, a primary winding disposed on the spool, a case, and an outer core or shield of magnetically permeable material. The ignition apparatus exhibits reduced capacitance, and eliminates radial partial discharge at the inside diameter of the secondary winding.

Abstract: An ignition coil is provided for an internal combustion engine. The ignition coil comprises a primary winding and a secondary winding. The primary winding is adapted to be electrically connected to a low-voltage ignition signal. The secondary winding is inductively coupled to the primary winding with more turns than the primary winding so that the secondary winding develops a high-voltage ignition signal in response to switching of the low-voltage ignition signal. The turns of the secondary winding are provided in successive layers. An uncured material is applied to the secondary winding prior to the placement of the successive layers. By using an uncured stage material, the coil can be made without the need for complex, expensive, time-consuming, and potentially unreliable impregnation techniques. The ignition coil can be used as a pencil coil for spark plugs of an internal combustion engine. Also provided is a method of manufacturing an ignition coil.

Abstract: A method for inhibiting or eliminating case erosion in a pencil ignition coil having an internal primary winding and an external secondary winding and shield. Three alternative means for resisting damage due to the partial discharge phenomenon arising from a high electric field in such coil configurations are provided: (i) applying an ozone resistant coating on the case; (ii) applying a coating on the case for eliminating partial discharge under the shield; and (iii) applying a polyimide tape covering to the case for resisting partial discharge under the shield.

Abstract: An ignition apparatus includes a high voltage (HV) terminal formed of stamped sheet metal attached to a secondary winding spool, and to which a high voltage end of the secondary winding is soldered. The ignition apparatus further includes an electrically conductive cup formed of stamped aluminum or brass that is disposed in a case and is configured to receive the high voltage terminal when the secondary winding spool is inserted in the case. The high voltage terminal has a spring tab or the like that is biased radially outwardly into engagement with an inner annular surface of the cup. A bottom outer surface of the cup is arranged to be engaged by a high voltage spring or the like for making the connection to the spark plug. The cup is substantially free of burrs, sharp edges, and the like, and therefore reduces localized occurrences of high electric field concentrations, which could otherwise lead to insulating material, and thus ignition coil, failure.

Abstract: An ignition apparatus includes a high voltage (HV) terminal formed of stamped sheet metal attached to a secondary winding spool, and to which a high voltage end of the secondary winding is soldered. The ignition apparatus further includes an electrically conductive cup formed of stamped aluminum or brass that is disposed in a case and is configured to receive the high voltage terminal when the secondary winding spool is inserted in the case. The high voltage terminal has a spring tab or the like that is biased radially outwardly into engagement with an inner annular surface of the cup. A bottom outer surface of the cup is arranged to be engaged by a high voltage spring or the like for making the connection to the spark plug. The cup is substantially free of burrs, sharp edges, and the like, and therefore reduces localized occurrences of high electric field concentrations, which could otherwise lead to insulating material, and thus ignition coil, failure.

Abstract: An ignition apparatus includes a magnetic circuit comprising a central core and a side core or shield, and primary and secondary windings. The shield is allowed to electrically float, thereby reducing the capacitance of the secondary winding. A housing is external to and surrounds the shield to inhibit arcing. A silicone boot overlaps a housing/case interface to further suppress arcing.

Abstract: An ignition coil assembly includes a cylindrical central core having a main axis, a primary winding outwardly of the central core, a secondary winding outwardly of the primary winding, and a case comprising polyimide material. In one embodiment, a secondary winding spool comprises polyimide material. The overall diameter of the ignition coil assembly is reduced relative to conventional designs.

Abstract: An ignition apparatus includes a suppression device comprising a suppression winding that is in series with the secondary winding and is further located outside of a magnetic circuit. The suppression winding is made from the same wire as used in the secondary winding and is wound on a reduced diameter portion of a secondary winding spool. A carbon resistor is disposed in series with the suppression winding in another embodiment. Nickel wire may be substituted for the suppression winding and carbon resistor in order to obtain both inductance and resistance characteristics for the suppression device.

Abstract: An ignition apparatus includes a suppression device comprising a suppression winding that is in series with the secondary winding and is further located outside of a magnetic circuit. The suppression winding is made from the same wire as used in the secondary winding and is wound on a reduced diameter portion of a secondary winding spool. A carbon resistor is disposed in series with the suppression winding in another embodiment. Nickel wire may be substituted for the suppression winding and carbon resistor in order to obtain both inductance and resistance characteristics for the suppression device.

Abstract: An ignition apparatus includes a magnetic circuit comprising a central core and a side core or shield, and primary and secondary windings. The shield is allowed to electrically float, thereby reducing the capacitance of the secondary winding. A unitary boot surrounds the shield to inhibit arcing, and further includes a seal configured to seal a spark plug well or the like.

Abstract: An ignition coil (10) has a core (16) composed of a plurality of laminations (46) and about which is directly disposed an insulating layer (22). A primary winding (24) is wound directly on the insulating layer (22), thereby eliminating the need for a primary winding spool and recovering the space conventionally occupied by such a primary winding spool for use in allocating greater space to the core (16) and/or windings.

Abstract: An interface device for interfacing a pencil coil to a spark plug is provided. The interface device comprises a substantially C-shaped spring adapted to mechanically and electrically engage a pencil coil shield and also adapted to make electrical contact with a spark plug ground while the spring remains mechanically and electrically engaged to the pencil coil shield. Also provided is a pencil coil shield assembly for interfacing a pencil coil to a spark plug. The pencil coil shield assembly comprises a substantially cylindrical pencil coil and a spring. The substantially cylindrical pencil coil shield is adapted to surround the pencil coil. The spring is mechanically and electrically engaged with the pencil coil shield and is adapted to make electrical contact with a spark plug ground while the spring remains mechanically and electrically engaged to the pencil coil shield.

Abstract: An ignition coil assembly adapted to be mounted directly in a plug hole of an internal combustion engine. The coil assembly includes a primary coil and a secondary coil. The spool upon which the secondary coil is wound is cylindrical in shape and has ramp structures provided at each end thereof. The ramps decrease voltage concentration between the secondary and primary windings, decrease the voltage gradient along the end wall of the secondary spool, and minimize adverse effects of gaps created during thermal expansion/contraction.

Abstract: An ignition coil for a spark ignition engine generally includes primary and secondary windings disposed about a magnetic core. The secondary winding is wound around a spool. The spool includes a cylindrical body having opposite first and second ends and a winding section between the ends. A conical winding surface at one of the ends tapers from a large diameter at the one end to a smaller diameter. A grooved surface extends axially toward another of the ends of the body and extends to adjacent the smaller diameter of the conical surface. The grooved surface contains longitudinally spaced continuous circular grooves that have unequally angled sides. The sides toward the one end are sloped at a greater angle relative to a radial direction than are the sides toward the other end. The secondary winding is wound around the winding section forming a plurality of turns of wire wound one over the other at a desired angle. The grooves are sized such that only one turn of the wire is disposed within each groove.

Abstract: An ignition coil for an internal combustion engine improves high-voltage sealing performance and moreover reduces housing outer diameter. The ignition coil for an internal combustion engine is made up of a transformer portion of cylindrical configuration housed within a housing chamber of a case, a control-circuit portion, that is positioned on one end portion of this transformer portion, causing primary current of the transformer portion to be intermittent, and a connecting portion that is positioned on another end portion of the transformer portion, supplying secondary voltage of the transformer portion to a spark plug. A silicone rubber injection molding serves as the encapsulant while forming the high voltage boot to the plug.

Abstract: An ignition control system for an internal combustion engine includes a control circuit, an ignition coil, a switch, and a sensing circuit. The control circuit is configured to interrupt a primary current, thereby establishing a secondary current which is discharged to cause a spark plug coupled to the secondary winding to produce a first spark. The sensing circuit is configured to generate a secondary current signal representative of a level of secondary current. The control circuit is responsive to the secondary current signal to terminate the discharge by closing the switch to cause the primary current to again flow in preparation of a second spark. The termination of the discharge occurs when the secondary current level reaches a secondary current threshold which is determined as a function of engine speed and ambient temperature.

Abstract: An ignition coil for a spark ignition engine includes a cylindrical magnetic core having opposite first and second ends. Preferably, the magnetic core has a circular cross section. Permanent magnets similarly shaped as the core are disposed at the ends of the magnetic core. The magnets are made from a microencapsulated magnetic material, resulting in increased resisitivity and decreased eddy current loss. By using the microencapsulated magnets, the voltage output of the ignition coil is increased while requiring no additional input energy. A primary winding is wound about the magnetic core between the first and second ends. A secondary winding assembly is disposed about the primary winding and the core. The secondary winding assembly includes a spool and secondary winding wound thereon. The secondary winding is inductively coupled to the primary winding. An outer case is disposed about said magnetic core, magnets and the primary and secondary windings.