Patent EP0369236A2 successfully refreshed from Google Patents.
EP0369236A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Apparatus and method for providing ignition to a turbine engine
Assignee: Unison Industries LLC
•
Filing: 1989-10-31
•
Granted: —
•
Expires: 2009-10-31
Abstract
Abstract A unipolar ignition of the invention provides a current waveform at the ignitor plug which initially rises relatively slowly, followed by a transition to a fast rising current which quickly peaks and thereafter slowly dissipates. Such a current waveform provides an initially hotter and longer lasting spark which does not harm the ignitor plug of the system or shorten its life expectancy. Neither does the spark create stress on the solid state circuitry which delivers the energy to the ignitor plug. To provide the foregoing spark and current characteristics, an inductor having a saturable core is in series with the ignitor plug, and it provides an initially high inductance which limits the rate of current rise at the plug as energy is transferred from an energy storage device to the plug. As the current through the inductor increases, its core begins to saturate and the effective inductance begins to decrease, allowing the current to rise more quickly. As energy is transferred to the ignitor plug, the increasing saturation, decreasing inductance and increasing current complement one another, causing the rate of current rise to increase quickly to a high value desirable for ignition. Related features of the invention provide for easy diagnostics of the spark and for timing an ignition sequence and providing a repetition rate which aids in a successful ignition.
Inventors
- 👤 John R. Frus
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-30 10:21
CPC Classifications
F; F02; F02P; F02P3/00; F02P3/06; F02P3/10; F02P15/00; F02P15/001; F02P15/003; F02P15/10; F02P3/08; F02P3/0853; F02P3/0861; F02P3/0869; F02P3/0876; F02P3/0884; F02P9/00; F02P9/002; F02P17/00; F02P17/12; F02P2017/003; F02P2017/125; F02P3/02
Claims Analysis
Total Claims: 42
Claim 1
Independent Claim
166 words
In a system for igniting engine fuel, a unipolar ignition comprising: a voltage converter for receiving a low voltage from a system source and converting it to a high DC output voltage; a capacitor coupled to said voltage converter for accumulating energy delivered from said voltage converter; an inductor wound about a magnetically saturable core and connected in series with a spark gap device; solid state means including a switch means for transferring said predetermined energy from said capacitor to said series connected inductor and spark gap device such that the following sequence of event occurs: (a) the voltage of the spark gap device creates a plasma, (b) a relatively slow current rise (di/dt) is initiated during transition of said switch means from a first state to a second state; and (c) saturation of said magnetically saturable core occurs and a relatively fast di/dt occurs across the spark gap device; and a unidirectional device connected in parallel with said series connected inductor and spark gap device.
Claim 2
Dependent Claim
166 words
In a system for igniting engine fuel, a unipolar ignition comprising: a voltage converter for receiving a low voltage from a system source and converting it to a high DC output voltage; a capacitor coupled to said voltage converter for accumulating energy delivered from said voltage converter; an inductor wound about a magnetically saturable core and connected in series with a spark gap device; solid state means including a switch means for transferring said predetermined energy from said capacitor to said series connected inductor and spark gap device such that the following sequence of event occurs: (a) the voltage of the spark gap device creates a plasma, (b) a relatively slow current rise (di/dt) is initiated during transition of said switch means from a first state to a second state; and (c) saturation of said magnetically saturable core occurs and a relatively fast di/dt occurs across the spark gap device; and a unidirectional device connected in parallel with said series connected inductor and spark gap device.
Claim 3
Dependent Claim
19 words
A unipolar ignition as set forth in claim 1 wherein said spark gap device is a semiconductor ignitor plug.
Claim 4
Dependent Claim
64 words
A unipolar ignition as set forth in claim 1 wherein said solid state means includes means for initiating ignition of said engine fuel by repeatedly generating sparks at said spark gap device for a predetermined period of time and thereafter continuing the repetition of sparks at an average rate that is less than the average rate of said sparks during said predetermined time period.
Claim 5
Dependent Claim
43 words
A unipolar ignition as set forth in claim 1 wherein said switch is responsive to a means external of said ignition for generating at least the initial spark of an ignition sequence at a time when engine conditions are most favorable for ignition.
Claim 6
Dependent Claim
22 words
A unipolar ignition as set forth in claim 1 wherein said core is composed of an iron powder material of high permeability.
Claim 7
Dependent Claim
52 words
A unipolar ignition as set forth in claim 1 wherein said solid state means includes a logic circuit which is responsive to the presence of a predetermined energy stored in said capacitor for closing said switch means so as to couple said capacitor to said series connected inductor and spark gap device.
Claim 8
Dependent Claim
28 words
A unipolar ignition as set forth in claim 6 wherein said logic circuit includes an output for disabling said voltage converter for providing a delay between successive sparks.
Claim 9
Dependent Claim
44 words
A unipolar ignition as set forth in claim 1 wherein said inductor incorporates a sensor for providing a diagnostic signal representing the phenomenon occurring in the series connected inductor and spark gap device during the period of energy transfer to said spark gap device.
Claim 10
Dependent Claim
37 words
A unipolar ignition as set forth in claim 8 wherein said saturable core is a toroid and said sensor is one or more turns of winding over said toroid and separate from the windings of said inductor.
Claim 11
Dependent Claim
208 words
In a system for igniting engine fuel using a unipolar ignition having a storage device for delivering energy to a spark gap device by way of an inductor wound about a magnetically saturable core connected in series with said spark gap device and a unidirectional device connected in parallel with said series connected inductor and spark gap device, a method comprising the steps of: delivering energy to said storage device; transferring said predetermined amount of energy from said storage device to said series connected inductor and spark gap device; applying a high D.C. voltage across said spark gap for a sufficient time to create a plasma; allowing a relatively low D.C. current to initially flow through said plasma and inductor so as to saturate said magnetically saturable core and thereafter allowing a high D.C. current flow through said plasma; conducting energy from said storage device and through said inductor and spark gap device and collecting energy in said inductor until virtually all energy has left said storage device; and providing for the virtual instantaneous reversal of the polarity of said inductor when all energy has left said storage device such that the energy stored in said inductor is released through said spark gap device and said unidirectional device.
Claim 12
Dependent Claim
208 words
In a system for igniting engine fuel using a unipolar ignition having a storage device for delivering energy to a spark gap device by way of an inductor wound about a magnetically saturable core connected in series with said spark gap device and a unidirectional device connected in parallel with said series connected inductor and spark gap device, a method comprising the steps of: delivering energy to said storage device; transferring said predetermined amount of energy from said storage device to said series connected inductor and spark gap device; applying a high D.C. voltage across said spark gap for a sufficient time to create a plasma; allowing a relatively low D.C. current to initially flow through said plasma and inductor so as to saturate said magnetically saturable core and thereafter allowing a high D.C. current flow through said plasma; conducting energy from said storage device and through said inductor and spark gap device and collecting energy in said inductor until virtually all energy has left said storage device; and providing for the virtual instantaneous reversal of the polarity of said inductor when all energy has left said storage device such that the energy stored in said inductor is released through said spark gap device and said unidirectional device.
Claim 13
Dependent Claim
67 words
A method as set forth in claim 10 including the sequential steps of: initiating ignition of said engine fuel by repeating the steps of claim 6 for a predetermined period of time; and continuing the repetition of the steps of claim 6 after said predetermined period of time at an average rate that is less than the average rate of repetition during said predetermined period of time.
Claim 14
Dependent Claim
42 words
A method as set forth in claim 10 wherein said step of transferring said energy from said storage device to said series connected inductor and spark gap device occurs in response to the sensing of predetermined conditions external of said unipolar ignition.
Claim 15
Dependent Claim
44 words
A method as set forth in claim 10 including the step of stopping said delivering of energy to said storage device when said predetermined amount of energy has been reached and continuing delivering of energy to said storage device after a predetermined time delay.
Claim 16
Dependent Claim
180 words
In a system for igniting engine fuel, a unipolar ignition comprising: a voltage converter for receiving a low voltage from a system source and converting it to a high DC output voltage; a capacitor coupled to said voltage converter for accumulating energy delivered from said voltage converter; an inductor connected in series with a spark gap; a solid state switch interposed between said capacitor and said series connected inductor and spark gap for transferring the energy accumulated by said capacitor to said inductor and spark gap; a unidirectional device connected in parallel with said series connected inductor and spark gap for directing energy away from said solid state switch after said capacitor is substantially fully discharged; an energy sensing device responsive to a predetermined energy level at said capacitor for disabling said voltage converter so that said capacitor is not charged beyond said predetermined energy level; and a logic circuit responsive to a signal external from said unipolar ignition for initiating transfer of energy from said capacitor to said series connected inductor and spark gap by said solid state switch.
Claim 17
Dependent Claim
180 words
In a system for igniting engine fuel, a unipolar ignition comprising: a voltage converter for receiving a low voltage from a system source and converting it to a high DC output voltage; a capacitor coupled to said voltage converter for accumulating energy delivered from said voltage converter; an inductor connected in series with a spark gap; a solid state switch interposed between said capacitor and said series connected inductor and spark gap for transferring the energy accumulated by said capacitor to said inductor and spark gap; a unidirectional device connected in parallel with said series connected inductor and spark gap for directing energy away from said solid state switch after said capacitor is substantially fully discharged; an energy sensing device responsive to a predetermined energy level at said capacitor for disabling said voltage converter so that said capacitor is not charged beyond said predetermined energy level; and a logic circuit responsive to a signal external from said unipolar ignition for initiating transfer of energy from said capacitor to said series connected inductor and spark gap by said solid state switch.
Claim 18
Dependent Claim
37 words
A unipolar ignition as set forth in claim 14 wherein the source of said external signal is from a means for determining an ignition time window when a spark at said gap will most likely cause ignition.
Claim 19
Dependent Claim
31 words
A unipolar ignition as set forth in claim 15 wherein said means for determining is from an engine control unit for an engine whose fuel is ignited by said unipolar ignition.
Claim 20
Dependent Claim
17 words
A unipolar ignition as set forth in claim 14 wherein said inductor has a magnetically saturable core.
Claim 21
Dependent Claim
22 words
A unipolar ignition as set forth in claim 17 wherein said core is composed of an iron powder material of high permeability.
Claim 22
Dependent Claim
51 words
A unipolar ignition as set forth in claim 17 wherein a current of said energy discharged through said series connected inductor and spark gap has a characteristic waveform shape where a rate of current rise (di/dt) initially increases monotonically and thereafter converts to a monotonically decreasing rate that goes to zero.
Claim 23
Dependent Claim
64 words
A unipolar ignition as set forth in claim 19 wherein the current of said initially increasing di/dt is of a magnitude to ensure said solid state switch is substantially unstressed during a transition of said switch from an off state blocking transfer of said energy from said capacitor to said series connected inductor and spark gap to an on state for transferring said energy.
Claim 24
Dependent Claim
76 words
In ignition system using an ignitor plug for igniting fuel of an engine, an ignition sequence comprising the steps of: initiating ignition by repeating spark discharges at said ignitor plug for a predetermined time period which best assures combustion of said fuel; and continuing the repeating of spark discharges at said ignitor plug after said predetermined time period at an average rate which is less than the average rate of spark discharges during said time period.
Claim 25
Dependent Claim
76 words
In ignition system using an ignitor plug for igniting fuel of an engine, an ignition sequence comprising the steps of: initiating ignition by repeating spark discharges at said ignitor plug for a predetermined time period which best assures combustion of said fuel; and continuing the repeating of spark discharges at said ignitor plug after said predetermined time period at an average rate which is less than the average rate of spark discharges during said time period.
Claim 26
Dependent Claim
33 words
An ignition sequence as set forth in claim 21 wherein the step of continuing the repeating of spark discharges is maintained until said engine is turned off or said ignition sequence is restarted.
Claim 27
Dependent Claim
30 words
An ignition sequence as set forth in claim 21 wherein the step of continuing the repeating of spark discharges occurs at an instantaneous rate which remains substantially constant in time.
Claim 28
Dependent Claim
36 words
An ignition sequence as set forth in claim 21 wherein each spark has a characteristic current waveform which has a monotonically increasing rate of current rise (di/dt), followed by monotonically decreasing di/dt that ends in zero.
Claim 29
Dependent Claim
24 words
An ignition sequence as set forth in claim 21 wherein the initiation of said sequence is in response to predetermined conditions of said engine.
Claim 30
Dependent Claim
24 words
An ignition sequence as set forth in claim 21 wherein the occurrence of each spark is in response to predetermined conditions of said engine.
Claim 31
Dependent Claim
27 words
An ignition sequence as set forth in claim 21 wherein the initiation of said sequence is in response to the application of power to said ignition system.
Claim 32
Dependent Claim
25 words
An ignition sequence as set forth in claim 21 including the step of: providing a diagnostic signal in association with each of said spark discharges.
Claim 33
Dependent Claim
80 words
In a system for igniting engine fuel, an ignition comprising: an energy source; an energy storage device; a first means for transferring energy from said source to said energy storage device; an ignitor plug in series with an inductive device; a second means for transferring energy from said energy storage device to said inductive device and said ignitor plug; and a sensor incorporated into said inductive device for providing a diagnostic signal representing the phenomenon occurring at said ignitor plug.
Claim 34
Dependent Claim
80 words
In a system for igniting engine fuel, an ignition comprising: an energy source; an energy storage device; a first means for transferring energy from said source to said energy storage device; an ignitor plug in series with an inductive device; a second means for transferring energy from said energy storage device to said inductive device and said ignitor plug; and a sensor incorporated into said inductive device for providing a diagnostic signal representing the phenomenon occurring at said ignitor plug.
Claim 35
Dependent Claim
15 words
An ignition as set forth in claim 29 where said inductive device is an inductor.
Claim 36
Dependent Claim
18 words
An ignition as set forth in claim 30 where said inductor is wound about a magnetically saturable core.
Claim 37
Dependent Claim
21 words
An ignition as set forth in claim 31 wherein said core is composed of an iron powder material of high permeability.
Claim 38
Dependent Claim
29 words
An ignition as set forth in claim 31 where said sensor includes a winding wrapped about said magnetically saturable core and electrically insulated from the winding of said inductor.
Claim 39
Dependent Claim
24 words
An ignition as set forth in claim 30 where said sensor is a winding of wire magnetically coupled but electrically insulted from said inductor.
Claim 40
Dependent Claim
45 words
An ignition as set forth in claim 30 where said ignition is a unipolar ignition with said first means including a DC-to-DC converter and said second means including a switch for selectively coupling said energy storage device to said series connected inductor and ignitor plug.
Claim 41
Dependent Claim
20 words
An ignition as set forth in claim 35 where said switch is responsive to a signal external from said ignition.
Claim 42
Dependent Claim
77 words
An ignition as set forth in claim 29 where said second means includes means for initiating ignition by transferring energy to said series connected inductive device and ignitor plug a plurality of times so as to generate a series of sparks at said ignitor plug for a first predetermined time period and thereafter continuing repetition of sparks at said ignitor plug at an average rate that is less than the average rate of said series of sparks.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.