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Showing papers on "Spark (mathematics) published in 1977"



Journal ArticleDOI
01 Jan 1977
TL;DR: In this article, the effects of gap width, electrode configuration, mixture strength, spark duration, and energy distribution between the two components on the minimum ignition energy were investigated, using a quiescent propane-air mixture.
Abstract: To determine the optimum ignition condition for sparks consisting of a capacitance spark followed by a dc- (glow) or ac-discharge (1 MHz), the effects of gap width, electrode configuration, mixture strength, spark duration, and energy distribution between the two components on the minimum ignition energy were investigated, using a quiescent propane-air mixture. The condition in question is conveniently characterized by the optimum spark duration for which the minimum ignition energy is lowest and the corresponding energy value. For a dc-discharge spark, the well-defined optimum spark duration varies from about 50 to 300 μ sec and the minimum ignition energy for spark durations larger than the optimum increases in different modes, depending on the mixture strength and the quenching effect of spark electrodes. For an ac-discharge spark, the optimum condition for ignition is much the same as for a dc-discharge spark, but the minimum ignition energy and the spark duration are always proportional to each other above the optimum, and therefore the optimum spark duration is easily obtained up to about 5 msec. Flash-schlieren photographic observations of the initial behavior of the spark kernel confirmed that such differences in the mode of minimum ignition energy are related to electrostatic attraction by the negative electrode.

44 citations


Patent
Gene A. West1
22 Apr 1977
TL;DR: In this paper, means are provided for generating a series of alternating coil-on and coil-off signals in accordance with crankshaft rotation and one or more engine operating conditions.
Abstract: In a spark timing system for a spark ignited internal combustion engine, means are provided for generating a series of alternating coil-on and coil-off signals in accordance with crankshaft rotation and one or more engine operating conditions, means are provided for normally passing each coil-on signal immediately to the spark coil to turn on current therethrough and means are provided for passing each coil-off signal to the spark coil to turn off current therethrough with a retard determined in accordance with an additional engine operating condition to generate a spark pulse retarded with respect to the normal spark timing. To ensure a minimum burn time for the spark plugs, means are provided to hold the spark coil in the off condition for a predetermined minimum burn time following each retarded coil-off signal, regardless of the possible appearance of a coil-on signal before the end of this minimum burn time.

38 citations


Proceedings ArticleDOI
24 Jan 1977

36 citations


Patent
Gene A. West1
09 Sep 1977
TL;DR: In this paper, an engine spark timing system includes a first capacitor, a second capacitor, and an apparatus responsive to engine start and one or more other engine operating conditions to substitute selected retarded spark timing pulses for the corresponding conventional spark timing pulse in the firing of the engine spark plugs.
Abstract: An engine spark timing system includes pulse generating apparatus effective to generate conventional spark timing pulses, apparatus, including a first capacitor, effective to vary the voltage across the first capacitor in one direction at a first rate toward a reference voltage and generate a retarded spark timing pulse when the first voltage is reached, apparatus initiated at the time the retarded spark timing pulse is generated to vary the voltage across the capacitor in the opposite direction at a second rate until the next conventional spark timing pulse and apparatus responsive to engine start and one or more other engine operating conditions to substitute selected retarded spark timing pulses for the corresponding conventional spark timing pulses in the firing of the engine spark plugs. In order that the capacitor voltage not reach its maximum value and clip during the slower engine speeds typical of engine start, apparatus responsive to the actuation of engine cranking means is effective to insert a second capacitor parallel with the first capacitor to slow the rates of voltage change across the capacitor in both directions in the same proportion.

21 citations


Proceedings ArticleDOI
01 Feb 1977
TL;DR: In this article, a complete description of the total process from the spark breakdown to the arc and glow phase, resp., in the millisecond range including temperature, local dimensions, energy distribution and radicals which can be formed.
Abstract: Fundamental investigations have been made on processes in common spark plugs useful for ignition of fuel-air mixtures. Development of spark discharge from the early beginnings as well as the initiation of chemical reaction have been studied experimentally by using very high frequency measuring technique, radiation measurements, spectroscopic methods and interferometry by a nitrogen laser (about 300 ps). The measurements have been carried out in non-reacting gases (N2, air) as well as in inflammable mixtures. A complete description will be given of the total process from the spark breakdown to the arc and glow-phase, resp., in the millisecond range including temperature, local dimensions, energy distribution and radicals which can be formed. /SASI/

21 citations


Patent
Gunter Grather1, Friedrich Rabus1
25 Jan 1977
TL;DR: In this article, an ignition coil is constructed to have two secondary winding portions, one providing a highvoltage output and the other providing high energy level or current output, to provide a sharp voltage pulse to break down the spark gap of a spark plug.
Abstract: To provide a sharp voltage pulse to break down the spark gap of a spark plug, an ignition coil is constructed to have two secondary winding portions, one providing a high-voltage output and the other providing high energy level or current output. The high current output portion is connected through a diode to charge a capacitor which is further connected through an additional blocking diode to the spark gap, to which also the high voltage portion is connected, so that the spark gap will be supplied by a circuit common to both winding portions of the ignition coil, the high voltage pulse breaking down the spark gap and the high energy pulse, of lower voltage, however, providing spark energy for an extended period of time after initial breakdown of the gap. Preferably, the system is transistor-controlled, with the ignition instant being determined by a digital counter counting forward and reversely under control of a rotation-pulse transducer coupled to the crankshaft of the engine.

21 citations


Journal ArticleDOI
TL;DR: In this paper, the electrical conditions necessary for reliable operation of sliding-spark arrays have been determined and the emission from an array can be considerably enhanced by critically damping the spark discharge circuit.
Abstract: The electrical conditions necessary for reliable operation of sliding-spark arrays have been determined The emission from an array can be considerably enhanced by critically damping the spark discharge circuit When used to pre-ionize a CO2 laser there must be a delay between the array and main discharge pulses, but this delay may be as small as 100 ns and less than the array discharge pulse width

18 citations


Patent
13 Jul 1977
TL;DR: In this article, a flame detection system responsive to an arc triggering voltage in a spark gap having at least a portion located in a flame is used to control spark generating equipment, and a pulse generator used to trigger the arc is inhibited upon detection of a lowered spark triggering voltage resulting from ignition of a flame.
Abstract: A flame detection system responsive to an arc triggering voltage in a spark gap having at least a portion located in a flame is used to control spark generating equipment. A pulse generator used to trigger the arc is inhibited upon detection of a lowered spark triggering voltage resulting from ignition of a flame.

18 citations


Journal ArticleDOI
TL;DR: In this paper, a family of new, electronically-controlled spark sources which routinely operate at repetition rates up to 10 kHz and show high spark positional stability (± 0.1 mm) for specific site analytical sampling is described.

17 citations


Journal ArticleDOI
Georges Charpak1
01 Dec 1977-Nature
TL;DR: Proportional counters, which were superseded in high-energy physics by developments such as spark and bubble chambers, have recently undergone modifications which have considerably increased their space and time resolution.
Abstract: Proportional counters, which were superseded in high-energy physics by developments such as spark and bubble chambers, have recently undergone modifications which have considerably increased their space and time resolution. These modified counters are finding applications not only in high-energy and nuclear physics but also in biology and medicine.

Journal ArticleDOI
TL;DR: In this article, a physically-compact digitally actuated spark source employing a quarter-wave transmission line is described, and the spark discharge's spectral, electrical and positional stability and reproducibility are examined experimentally.

Patent
20 Apr 1977
TL;DR: In this paper, a solid state inductive ignition system for a solid-state engine with a spark of up to 48 to 50 KV occurring at the most desirable position of the pistons for maximum mileage and power with a minimum of undesirable exhaust emissions is presented.
Abstract: A solid state inductive ignition system for igniting the mixture in the cylinders of an associated engine with a spark of up to 48 to 50 KV occurring at the most desirable position of the pistons for maximum mileage and power with a minimum of undesirable exhaust emissions. Exceptionally wide spark plug gaps are used to aid in igniting extra lean mixtures. The invention includes a novel high voltage spark distribution system utilizing, if desired, a conventional diameter distribution cap while providing sufficient clearance between adjacent spark plug cable outlets to prevent crossfire. Multiple sparks are provided while cranking to insure the ignition of overly rich or lean mixtures and a constant dwell of extremely short duration is used when running to saturate the core of the ignition coil.

01 Jan 1977

Journal ArticleDOI
TL;DR: The adjustable waveform, high-voltage spark source has found application in several production situations in the alloy industry as mentioned in this paper, where the pulsating unidirectional waveform is used to produce a high voltage spark current.
Abstract: The adjustable-waveform, high-voltage spark source has found application in several production situations in the alloy industry. Commercial versions of this source have appeared using an auxiliary air-gap, or a hydrogen thyratron, for controlling spark formation. It would appear that some of the practical utility of these sources is associated with increased precision and reduced Matrix effects, as compared to other forms of excitation, arising from use of the pulsating unidirectional spark current that they produce as one of a variety of readily-adjustable waveforms. It is not yet clear that a particular mode Of triggering is more critical to improved spectrochemistry than is the pulsating unidirectional waveform, which suggests that traditional air-gap or rotary-gap high-voltage spark sources that are already in production use could be modified to produce this, and other, waveforms with attendant analytical benefits.


Patent
Robert I. Masta1
24 Jan 1977
TL;DR: In this article, a spark timing control system for an internal combustion engine is described, where the spark timing of the engine is controlled by a signal generating device driven in synchronism with the engine which develops signals that represent engine crankshaft position.
Abstract: A spark timing control system for an internal combustion engine. The spark timing of the engine is controlled by a signal generating device driven in synchronism with the engine which develops signals that represent engine crankshaft position. The signal generating device has mechanisms for phase shifting the signal as a function of engine speed and engine manifold vacuum. The system includes a spark timing controller connected to the signal generating device which is capable of retarding spark timing from that set by the signal generating device in a plurality of crankshaft angle steps. The ignition timing provided by the spark timing controller is controlled by an electronic spark selection device which responds to engine operating parameters such as engine speed, engine manifold vacuum and engine temperature. The electronic spark selection device is capable of controlling the system to select the spark timing provided by the signal generating device or at a spark timing retarded from that provided by the signal generating device.

Patent
13 Apr 1977
TL;DR: The air-fuel mixture in each combustion chamber of a dual spark plug ignition engine is ignited with two spark plugs during normal engine operation, but is ignited only one of the two spark plug during high power output engine operation as mentioned in this paper.
Abstract: The air-fuel mixture in each combustion chamber of a dual spark plug ignition engine is ignited with two spark plugs during normal engine operation, but is ignited with only one of the two spark plugs during high power output engine operation. The spark timing in the ignition with one spark plug is advanced relative to that in the ignition with two spark plugs.

Patent
11 Mar 1977
TL;DR: In this paper, a diode is used to prevent back-flow of energy applied to the spark gap, the capacity of the ignition cable, or a capacitor, until the gap breaks down; the breakdown voltage, therefore, will be determined by the conditions of the gap.
Abstract: Sequentially generated charge pulses are applied to the spark gap through a diode which prevents back-flow of energy applied to the spark gap, the capacity of the ignition cable, or a capacitor, and of the spark gap causing a build-up of charge accumulation as a result of the sequentially applied charges, until the gap breaks down; the breakdown voltage, therefore, will be determined by the conditions of the gap. The pulses are generated at a pulse repetition rate which is high with respect to the rate of generation of spark impulses through a circuit in which the respective capacities and winding ratios and inductances of the ignition coil and the cabling are controlled so that the pauses between sequentially generated spark pulses and the timing of the spark pulses can be matched to the system parameters.

Journal ArticleDOI
TL;DR: In this article, a method of controlling the growth process of a sliding spark along the surface of a film dielectric by introducing emission centers from chemical compounds with a low electron work function into the surface is presented.
Abstract: A method of controlling the growth process of a sliding spark along the surface of a film dielectric by introducing emission centers from chemical compounds with a low electron work function into the surface is presented. It is shown that it is possible, by using this method, to produce a spark channel with sharp corners, such as a Z-shaped channel, and an ordered system of parallel channels, as well as a strictly rectilinear channel up to 2 m long. It is established that the rate of growth of the sliding spark is nonuniform. The mean rate is heavily dependent on the overvoltage, which is related to a reduction in the pauses in its growth.

Patent
30 Aug 1977
TL;DR: In this paper, the relays are divided into two groups and, with a periodicity dependent on generator output, a selected relay in each group is closed immediately prior to generation of voltage in the winding and opened when the voltage has been dissipated.
Abstract: A spark ignition engine has a crankshaft speed pulse generator and a plurality of cylinders each cylinder containing a spark plug. Each plug is connectable to a high voltage ignition winding by way of a reed relay. The relays are divided into two groups and, with a periodicity dependent on generator output, a selected relay in each group is closed immediately prior to generation of voltage in the winding and opened when the voltage has been dissipated. Although both plugs connected to the selected relays produce a spark only one of the cylinders contains fuel mixture and, consequently, one one power stroke occurs.


Patent
17 Nov 1977
TL;DR: In this paper, an engine is equipped with an EGR system in which the amount of recirculated exhaust gases is controlled in response to an intake vacuum in an intake passage.
Abstract: An engine is equipped with an EGR system in which the amount of recirculated exhaust gases is controlled in response to an intake vacuum in an intake passage The spark timing of the engine is controlled to advance in accordance with the increase of the amount of the recirculated exhaust gases so as to maintain stable engine running even under a considerably high EGR rate

Proceedings ArticleDOI
16 Mar 1977
TL;DR: In this article, a correlation between the time at which a particular event in the ignition sequence occurs and the RFI produced at that time is made by obtaining synchronization signals from the engine's ignition system, which are used to view the video output of an RFI receiver or spectrum analyzer as a function of time on an oscilloscope.
Abstract: Due to increasing concern about emissions from internal combustion engines that cause radio frequency interference (RFI), investigations are being made to identify sources of the interference and into possible methods of remedying them. In the investigations, it is useful to have a system by which a correlation can be made between the time at which a particular event in the ignition sequence occurs and the RFI produced at that time. See. Fig. 1 for a definition of the ignition events. A system is described in the paper which permits this correlation by obtaining synchronization signals from the engine's ignition system. The synchronization signals are used to view the video output of an RFI receiver or spectrum analyzer as a function of time on an oscilloscope. This allows for discrimination of the ignition related RFI to a time resolution determined by the bandwidth of the receiver being used. A particular advantage of this technique is that it permits a more accurate assessment of the effect of individual component modification in a complex system and, in addition, it permits discrimination against RFI sources unrelated to the automobile being tested.

Patent
12 Dec 1977
TL;DR: In this article, a spark indication apparatus connectable between the secondary winding tower of an ignition coil or a spark plug distribution tower of a car distributor or a wire coming from the distributor, and chassis ground having, preferably, a transmission cable including two separated portions, provided a spaced air gap or spark gap space for the generation of an electric spark by current passing through the transmission cable.
Abstract: A spark indication apparatus connectable between the secondary winding tower of an ignition coil or a spark plug distribution tower of an auto distributor or a spark plug wire coming from the distributor, and chassis ground having, preferably, a transmission cable including two separated portions, the intermittent connection thereof may provide a spaced air gap or spark gap space for the generation of an electric spark by current passing through the transmission cable; and having a housing which may encase part of each transmission cable portion and the spark gap space, this housing preferably having a cavity defining a spark chamber, wherein the spark chamber may be vented to the atmosphere through the housing.

Patent
12 Dec 1977
TL;DR: In this article, the authors proposed to improve engine performance by providing sufficient igniting energy by maintaining sufficient energy and spark duration under high speed operation of an engine as well as checking spark energy fall off due to high voltage electric system.
Abstract: PURPOSE:To improve engine performance providing sufficient igniting energy by maintaining sufficient igniting energy and spark duration under high speed operation of an engine as well by checking spark energy fall off due to high voltage electric system.

DOI
14 Sep 1977
TL;DR: In this paper, the luminous ionized plasma channel of an electric spark discharge is used as an indicator for the acceleration of a gas flow. But the luminosity of the plasma channel is not mass-free, unlike the material of the gas discharge.
Abstract: In studying gas flow, the physical motion of the medium, is normally made visible by blowing in smoke or lightweight particles. These methods are limited to the observation of more complicated phenomena like turbulence, boundary layer flow or three-dimensional flow. In spark tracing, the luminous ionized plasma channel of an electric spark discharge is the indicator. This offers the particular advantage that it is comparatively mass-free, because the luminous ions of a gas discharge consist of the material of the flowing medium. This method has special advantages with three-dimensional or nonstationary flows, as well as processes of air mixtures in classifiers. The first discharge generates a spark path between two points of wires. If high voltage pulses are now fed to the same electrodes at such high repetition rates that during the interval between two pulses the plasma of the spark has not yet completely deionized, then every subsequent voltage pulse will trace the path of the first spark, which in the meantime has been moved away by the air current.

Patent
20 Apr 1977
TL;DR: In this paper, the authors proposed a method to prevent spark produced by operning/closing contacts when switching from driving condition to braking condition, which can be used to prevent fires.
Abstract: PURPOSE:To prevent spark produced by operning/closing of contacts when switching from driving condition to braking condition.

Patent
23 May 1977
TL;DR: In this article, a time delay circuit is connected to control a frequency generator for generation of a plurality of spark pulses, the first spark pulse, however, being controlled through a differentiating network, for positive generation of the first pulse.
Abstract: To generate a plurality of spark pulses for a multi-spark breakdown for each ignition event for ignition of a combustible mixture in an internal combustion engine, while providing for positive generation of the first spark at a predetermined time instant, a time delay circuit is connected to control a frequency generator for generation of a plurality of spark pulses, the first spark pulse, however, being controlled through a differentiating network, for example an R/C network, for positive generation of the first pulse.

Patent
25 Apr 1977
TL;DR: In this article, the authors proposed a compact lighter in which firing gas is ensured and unnecessary spark is prevented by combining an ignition device for generating repeated spark and a timer, which can be used to provide a more compact lighter.
Abstract: PURPOSE:To provide a compact lighter in which firing gas is ensured and unnecessary spark is prevented by combining an ignition device for generating repeated spark and a timer.