United States Patent (19)
`Grather et al.
`
`(11)
`(45)
`
`4,181,112
`Jan. 1, 1980
`
`73) Assignee:
`
`(54) HIGH-VOLTAGE IGNITION SYSTEM TO
`GENERATEA SPARK FOR AN INTERNAL
`COMBUSTION ENGINE, AND METHOD TO
`GENERATE THE SPARK ENERGY
`75 Inventors: Ginter Grither, Pinache; Josef Wahl,
`Stuttgart; Friedrich Rabus,
`Schwiéberdingen; Bert Wurst,
`Möglingen; Karl-Heinz Adler,
`Leonberg, all of Fed. Rep. of
`Germany
`Robert Bosch GmbH, Stuttgart, Fed.
`Rep. of Germany
`(21) Appl. No.: 776,735
`(22
`Filed:
`Mar. 11, 1977
`30
`Foreign Application Priority Data
`Mar. 19, 1976 (DE) Fed. Rep. of Germany ....... 2611596
`51) int. C.’................................................ F02P 3/04
`52 U.S. Cl. .............. ........... 123/148 E; 123/148 DC
`58) Field of Search ................. 123/148 DC, 148 CA,
`123/148 CB, 148 CC, 148 E; 315/209 CD,208,
`232
`
`(56)
`
`2,977,506
`3,329,867
`3,581,726
`
`References Cited
`U.S. PATENT DOCUMENTS
`3/1961
`Short et al. .................... 123/148 CB
`7/1967 Stearns .......
`... 315/209 CD
`6/1971
`Plume, Jr. ........................ 123/148 E
`
`1/1974 Anderson ......................... 123/148 E
`3,788,983
`6/1975 Hudson ......
`... 123/148 E
`3,889,651
`4,048,543 9/1977 Owen et al. .......................... 315/208
`FOREIGN PATENT DOCUMENTS
`2547397 5/1977 Fed. Rep. of Germany ....... 123/148 E
`Primary Examiner-Charles J. Myhre
`Assistant Examiner-P. S. Lall
`Attorney, Agent, or Firm-Frishauf, Holtz, Goodman &
`Woodward
`ABSTRACT
`57
`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 caus
`ing 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 con
`trolled so that the pauses between sequentially gener
`ated spark pulses and the timing of the spark pulses can
`be matched to the system parameters.
`
`22 Claims, 8 Drawing Figures
`
`
`
`Exhibit 1006
`MOTORTECH v. Altronic - IPR2025-00398
`Page 1 of 12
`
`

`

`U.S. Patent Jan. 1, 1980
`
`Sheet 1 of 4
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`4,181,112
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`
`
`Fig. 3
`U
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`
`E
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`h (h)
`
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`
`t
`
`t
`
`Exhibit 1006
`MOTORTECH v. Altronic - IPR2025-00398
`Page 2 of 12
`
`

`

`U.S. Patent
`Jan. i, 1980
`U.S. Patent Jan. 1, 1980
`
`Sheet 2 of 4
`Sheet 2 of 4
`
`4,181,112
`4,181,112
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`
`
`
`
`
`
`
`
`
`Exhibit 1006
`MOTORTECHv.Altronic - IPR2025-00398
`Page 3 of 12
`
`Exhibit 1006
`MOTORTECH v. Altronic - IPR2025-00398
`Page 3 of 12
`
`

`

`U.S. Patent
`Jan. 1, 1980
`U.S. Patent Jan. 1, 1980
`
`Sheet 3 of 4
`Sheet 3 of 4
`
`4,181,112
`4,181,112
`
`
`
`Fig.5
`
`
`U/J
`
`Exhibit 1006
`MOTORTECHv.Altronic - IPR2025-00398
`Page4 of 12
`
`Exhibit 1006
`MOTORTECH v. Altronic - IPR2025-00398
`Page 4 of 12
`
`

`

`U.S. Patent
`Jan. 1, 1980
`U.S. Patent Jan. 1, 1980
`
`Sheet 4 of 4
`Sheet 4 of 4
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`4,181,112
`4,181,112
`
`
`
`
`
`
`
` ul
`
`
`
`
`
`G. W. W2 W
`B
`5
`L
`H Z ZZ
`K%
`s
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`
`Exhibit 1006
`MOTORTECHv.Altronic - IPR2025-00398
`Page 5 of 12
`
`Exhibit 1006
`MOTORTECH v. Altronic - IPR2025-00398
`Page 5 of 12
`
`

`

`O
`
`1.
`HIGH-VOLTAGE IGNITION SYSTEM TO
`GENERATEA SPARK FOR AN INTERNAL
`COMBUSTION ENGINE, AND METHOD TO
`GENERATE THE SPARK ENERGY
`CROSS REFERENCE TO RELATED
`APPLICATIONS
`U.S. Ser. No. 776,739, filed Mar. 11, 1977, now U.S.
`Pat. No. 4,114,585; RABUS et al;
`U.S. Ser. No. 776,740, filed Mar. 11, 1977, now U.S.
`Pat. No. 4,112,890;
`U.S. Ser. No. 776,738, filed Mar. 11, 1977; RABUS et
`al;
`U.S. Ser. No. 776,734, filed Mar. 11, 1977; DECKER
`15
`et al.; all assigned to the assignee of the present inven
`tion.
`The present invention relates to a high-voltage igni
`tion system, particularly to provide ignition energy for
`an internal combustion engine, and to a method to pro
`20
`vide this high-voltage energy to the spark gap of a spark
`plug; and especially to a system in which a controlled
`switch is located in the primary circuit of an ignition
`coil, the secondary being connected to the spark gap of
`a spark plug through a uni-directional current-carrying
`25
`device, such as a diode.
`Ignition systems in which primary current through an
`ignition coil is interrupted are known; to improve igni
`tion, it has also been proposed to generate more than
`one ignition impulse for each ignition event. Such an
`30
`arrangement is usually suitable for complete, or essen
`tially complete, combustion of a combustible fuel-air
`mixture in an internal combustion engine. If, however,
`an extremely high voltage pulse becomes necessary, for
`example due to poor maintenance of the spark plug,
`unfavorable combustion conditions, or the like, ignition
`may not effectively and continuously be provided in
`proper manner, so that ignition failure or misfires result.
`Increasing the ignition current through the ignition coil
`to obtain higher ignition voltages may, under some
`circumstances, be expensive and, additionally, lead to
`increased wear and deterioration of the spark plugs and
`associated equipment, such as switching elements, ca
`bles, connectors, and the like.
`It is an object of the present invention to improve the
`45
`ignition in internal combustion engines in which a multi
`plicity of ignition signals are provided for each ignition
`event and to generate high ignition voltages ensuring
`reliable firing of fuel-air mixtures within the cylinders of
`an internal combustion engine, preferably by multiple
`50
`sparks. Additionally, the system should be capable of
`handling suddenly arising increased voltage require
`ments to effect breakdown of the spark, for example due
`to unfavorable operating conditions, deposits on the
`spark plugs and the like, by reliably insuring that igni
`tion will occur.
`SUBJECT MATTER OF THE PRESENT
`INVENTION
`Briefly, an electronic control switch is repetitively
`60
`operated for each ignition event by multiple sequen
`tially occurring ignition signals. An electronic system so
`adjusts the length of the signals and the gaps between
`signals that a charge accumulation will occur at the
`spark gap of the spark plug until breakdown occurs. A
`65
`high-voltage diode is connected in series with the igni
`tion coil and the spark gap to prevent bleed-off, or
`back-flow of accumulated charge at the spark gap.
`
`4,181,112
`2
`The invention additionally contemplates the steps of
`sequentially applying a charge to the spark gap and
`preventing back-flow of energy away from the spark
`gap to build up a charge accumulation as a result of the
`sequentially applied charges across the spark gap until a
`breakdown of the spark gap occurs. The voltage at
`breakdown may vary, in dependence on then existing
`operating conditions. Under ordinary circumstances,
`multiple breakdowns can be obtained for a single igni
`tion event under design breakdown voltage conditions;
`under unfavorable operating conditions, however, a
`higher voltage will occur at the spark gap, yet still
`providing for breakdown and generation of at least one
`spark to ensure ignition.
`The ignition coil which forms part of the ignition
`system can be constructed in various ways, and
`matched to the components of the ignition system, spe
`cifically to the capacities occurring therein. In accor
`dance with a feature of the invention, the ignition coil is
`constructed to have parameters permitting its operation
`as a current voltage flow transformer. The pulse periods
`of the multiple ignition pulses, during any ignition
`event, are so arranged that the electronic switch is
`closed for a period of time corresponding to the pulse
`period, which is approximately that time which is
`needed to reach maximum voltage at the spark gap. The
`pauses, or time gaps between the pulses, during which
`the switch is opened, correspond in essence to the per
`iod of time which is necessary for the oscillatory swing
`back of the circuit until the voltage at the capacity of
`the winding of the secondary of the ignition coil has
`dropped to a minimum from a maximum.
`The ignition coil can also be operated as a blocking
`element or as a blocking inductance; in accordance with
`another embodiment of the invention, the length of the
`pulses during any ignition event falls within the linear
`range of the rise in current at the primary of the ignition
`coil; the pauses between the signals during any ignition
`event correspond essentially to the period of time
`which is necessary to reach maximum voltage at the
`spark gap.
`The controlled switch preferably is a transistor; the
`transistor can be protected against overload, heating, or
`otherwise difficult operating conditions, in accordance
`with a feature of the invention, by sequential charge
`accumulation, or sequential charging, in steps, by cur
`rent pulse trains in which the current pulses occur in
`groups or bundles. The signal lengths of the multiple
`ignition signals, during which the electronic switch is
`closed, will occur within the linear range of the current
`rise of the primary of the ignition coil; the signal gaps
`between the multiple ignition signals, during any igni
`tion event, and when the switch is open, will be small in
`relation to the signal lengths. This improves efficiency
`of operation.
`In accordance with a feature of the invention, the
`system includes a signal generator which has a signal
`generation repetition rate which is high with respect to
`the duration of a spark impulse during any ignition
`event. The signal generator is connected to control
`opening and closing of the switch. The signal generator
`has a fixed relationship of signal or pulse length to signal
`or pulse gap. The ignition events, themselves, are trig
`gered by a control system, preferably including an elec
`tronic control element which is triggered by the crank
`shaft of the engine.
`In accordance with a further feature of the invention,
`the ignition coil may be constructed as a current-volt
`
`35
`
`55
`
`Exhibit 1006
`MOTORTECH v. Altronic - IPR2025-00398
`Page 6 of 12
`
`

`

`10
`
`4,181,112
`3.
`4.
`age transformer element in combination with an elec
`introduced into stage 12. Stage 12, as such, is known
`tronic control system which includes a differentiator
`and need not be described in detail. The output of stage
`coupled to the ignition coil and a polarity recognition
`12, available at terminal 13, is connected to one input of
`circuit, likewise coupled to the ignition coil, which is
`an AND-gate 14. Two frequency generators 15, 16 are
`connected over a logical connecting network with the
`likewise connected to terminal 13 and have their out
`control input of the controlled switch.
`puts, respectively, connected to further inputs of AND
`The charge accumulation at the spark gap permits
`gate 14. The terminals to the frequency generators 15,
`ignition voltages of various levels. The ignition coil thus
`16 from terminal 13 are start terminals or gate terminals
`of the frequency generators so that output signals from
`can be constructed to have a relatively low transform
`ingratio. This results in a high re-charge current, at low
`the frequency generators 15, 16 are applied to AND
`primary current, and a low inner resistance. Operation
`gate 14 only when terminal 3 has a signal appear
`can be obtained with extremely high spark repetition
`thereat. The output of AND-gate 14 is formed by a
`frequency although the transforming ratio of the igni
`terminal 17 which is connected to the control input of
`tion or spark coil is low. The spark repetition frequency
`an electrical switch 18, preferably a transistor. The
`can be increased if there is an additional air gap. The
`AND-gate 14 and the two frequency generators 15, 16
`15
`system can be so designed that the voltage during the
`form an electronic control system 19 to control the
`first control pulse is just sufficient to effect ignition.
`interrupter switch 18. Power is supplied from a source
`Upon ignition failure, however, ignition will occur at
`of voltage connected to terminal 20, for example the
`the next pulse. Upon continued failure, ignition will
`battery of the vehicle. The main path of the switch 18,
`occur at subsequently occurring pulses. The sequential
`typically the emitter-collector path of a transistor, is
`20
`charging, in steps, results in stepped increase in the
`connected to a further terminal 21, which is connected
`ignition voltage. The stepped charging by means of
`through the primary of an ignition coil 22 to ground or
`current pulse trains or current pulse bundles results in
`chassis forming the negative terminal of the source of
`low current flow through the electronic switch. This
`supply 20. The secondary of the ignition coil 22 is con
`protects the electronic switch which usually is a transis
`nected through a high-voltage diode 23 with the spark
`25
`tor and, additionally, results in high efficiency of opera
`gap, in case of an internal combustion engine, typically
`tion.
`the spark plug of one of the cylinders. The second elec
`Drawings: illustrating an example:
`trode of the spark gap is connected to ground or chassis.
`FIG. 1 shows a schematic block diagram of a system
`Both windings of the coil 22 are likewise connected to
`in accordance with the invention;
`ground or chassis. A distributor can be interposed be
`30
`FIG. 2 is a detailed diagram of a portion of the system
`tween diode 23 and the spark gap 24, or between the
`of FIG. 1 or FIG. 7;
`coil 22 and diode 23. Ignition cable 23' connects diode
`FIG. 3 is a timing diagram showing pulses, and used
`23 to spark plug 24.
`in connection with explanation of the operation of the
`FIG. 2 is the equivalent circuit diagram of a portion
`system;
`of FIG. , illustrating, specifically, the circuit compo
`35
`FIG. 4 is a voltage diagram illustrating one form of
`nents between terminals 17 and the spark gap 24. The
`operation of the system of FIG. 2;
`reference numerals of FIG. 2 are identical to those of
`FIG. 5 is a voltage diagram illustrating another form
`FIG. 1.
`of operation of the system of FIG. 2, in which the sys
`The spark gap 24 has, in parallel thereto, the capacity
`tem has different parameters than those resulting in the
`of the ignition cable 23". This capacity is shown as an
`operation in accordance with FIG. 4;
`equivalent capacitor C2. The ignition coil 22, and par
`FIG. 6 is a current-voltage diagram illustrating oper
`ticularly its secondary, is shown in detailed equivalent
`ation with bundles of pulses or with rapidly recurring
`circuit. The turns ratio of the secondary W2 with re
`pulses of a pulse train;
`spect to the primary W1 is represented by an ideal trans
`FIG. 7 is a fragmentary detailed diagram of another
`former 220. The main inductance Lh is shown in paral
`45
`embodiment of the system in accordance with the pres
`lel to the secondary. The leakage or stray inductance Ls
`ent invention; and
`is shown connected in series with the output of the
`FIG. 8 is a series of graphs used in connection with
`secondary winding W2 and the output of the coil 22.
`explanation of the operation of the system of FIG. 7.
`The winding capacity is shown as equivalent capacitor
`The crankshaft of an internal combustion engine,
`C1. The resistances of the windings have been ne
`50
`typically an automotive-type gasoline internal combus
`glected in this diagram since they are not material to an
`tion engine, is coupled to a transducer 10 (FIG. 1) pro
`understanding of the operation of the present invention.
`viding an output pulse whenever the crankshaft has
`Operation, with reference to FIGS. 2 and 3: A signal
`reached a predetermined angular position with respect
`from transducer i0 is shaped in stage 11 to provide a
`to the upper dead center (UDC) position of a piston
`square wave pulse shown in graph A of FIG. 3; letters
`55
`thereof. The output from transducer 10 is coupled to a
`corresponding to the graphs of FIG.3 have been added
`wave-shaping circuit 11, typically a Schmitt trigger.
`to FIG. i to show where the respective signals occur.
`The transducer 10 may be of any suitable type, for ex
`The ignition timing stage 12 shifts the signal of graph. A
`ample an inductive transducer, a cam-operated breaker
`by a time To, to appear as the signal B, shown in FIG.
`switch, or the like. The output of wave-shaping stage 11
`3 in graph B at terminal 13. The first frequency genera
`60
`is connected to a circuit 12 providing for adjustment of
`tor 15 provides a sequence of pulses shown in graph C
`the timing of the pulse with respect to the angular posi
`of FIG. 3. The second frequency generator 16 provides
`tion of the crankshaft in accordance with operating
`a sequence of signals shown in graph D. As can be seen,
`parameters of the engine, such as engine speed (n), in
`the repetition rate of the signals D is substantially
`duction-type pressure or, rather, vacuum (p), engine or
`higher than that of the signals of graph A. The output of
`65
`other temperature conditions (T) and deflection angle
`the AND-gate 14, appearing at terminal 17, then will
`(a) of the throttle of the engine. Other operating, ambi
`have a signal as shown in graph E if, simultaneously, the
`ent or operation parameters of the engine may also be
`signal of graphs B, C and D are applied thereto. Sequen
`
`Exhibit 1006
`MOTORTECH v. Altronic - IPR2025-00398
`Page 7 of 12
`
`

`

`10
`
`4,181,
`112
`5
`6
`tial signals E, applied through switch 18 to coil 22 and
`the spark gap, that is, which is sufficient to cause firing
`through diode 23 to the spark gap 24, result in a charge
`of the spark plug. The cycle will then repeat if signals E
`accumulation across the spark gap 24. This charge accu
`are still present.
`The system can operate differently as well, with dif
`mulation will continue until the spark gap breaks down
`and discharge of the spark gap occurs, and then starts 5
`ferent system parameters; as illustrated in FIG. 5, the
`again. During a sequence of pulses of graphs E, one or
`ignition coil 22 can also operate as a blocking element,
`more ignition sparks can be generated depending on the
`or blocking inductance. To effect blocking, the main
`requirements of the ignition voltage, that is, how many
`inductance Lh must have a relatively low value to store
`charges must be accumulated. Ignition is indicated by
`magnetic energy and the leakage or stray inductance Ls
`the ignition arrows beneath graph E of FIG. 3.
`should be as small as possible so that the transistors will
`The frequency of the pulse sequence D is constant
`not be excessively loaded by peaks arising during turn
`and substantially higher than the frequency of the trans
`off of the current through the coil.
`ducer 10, that is, of the signal of graph A. The fre
`The winding ratio W2 to W1 for a coil operating
`quency of frequency generator 15 is intermediate that of
`under those conditions should be small and is limited by
`the transducer 10 and of frequency generator 16. Vary
`the breakdown voltage of transistor 18, operating as the
`15
`ing the frequency and signal duration of signals of fre
`electrical interrupter switch. The relationship of wind
`quency generator C can be used to set the number of
`ings is determined by equation (3) wherein Ut is the
`ignition sparks for any ignition event.
`maximum permissible transistor voltage, and Ub is the
`supply voltage.
`Charge accumulation, in accordance with a feature of
`the invention, is obtained by so adjusting the signals of 20
`When the coil operates as a blocking transducer, the
`graph E and graph D, respectively, which control the
`current Ib through coil 22 rises during signal E. This
`opening and closing of the switch 18, to have a prede
`current rise, initially, is linear. The duration of the signal
`termined signal length and signal pause and thereby
`1 is preferably limited so that the current rise of the
`effect build-up of charge accumulation, in the light of
`current Ib remains in the linear range. During the subse
`the electrical parameters of the system.
`quent gap in pulses for the duration p, the presence cf
`25
`Referring now to FIG. 4, which illustrates voltage
`the capacity in the circuit will cause an oscillation and
`diagrams when using an ignition coil 22 constructed as
`transfer of charge from the main inductance Lh (FIG.
`a low current high voltage transformer. Such a coil will
`2) to the two capacities C1, C2. Current Ib drops, and
`have a high winding ratio, that is, will have a large
`the voltages at the capacities rise, particularly the volt
`number of windings W2 with respect to the number of 30
`age U2 at the capacity C2, which is the voltage across
`turns of winding W1. This results in a high main induc
`the spark gap 24 and the voltage of interest for purposes
`of the present invention. The rise in voltage is delayed
`tance Lh, and one in which the main inductance Lh is
`large in relation to the leakage inductance Ls. Voltage
`by a time t1 due to the presence of the capacity C1. To
`U1 at the secondary winding of the ignition coil 22 rises
`obtain maximum voltage accumulation, the signal pause
`during any signal as illustrated in graph E (FIG. 3),
`or gap p must be so timed or adjusted that a new signal
`causing a rise in voltage U2 at the spark gap 24 (see
`E (FIG. 3) begins when the current Ib is approximately
`FIG. 4). The signal length 1 is so adjusted that the end
`again at zero level, that is, when the voltage U2 has
`of the signal will occur when the voltage U2 approxi
`reached its maximum. The time of the signal gap can,
`essentially, be determined by the relationship of equa
`mately has reached its maximum, that is, when the ca
`pacities represented by the capacitors C1, C2 have been 40
`tion (4).
`charged through the leakage inductance Ls. The time of
`The high-voltage diode 23 holds the voltage U2 dur
`a signal E can thus be calculated, approximately, by
`ing the subsequent signal E during which current Ib
`equation (1) of the table of equations forming part of
`(FIG. 5) again rises. At the next signal gap p, current Ib
`this specification.
`drops and voltage is again accumulated, causing a rise in
`The interrupter switch 18 is opened during the subse- 45
`voltage U2. The voltage accumulation of the voltage
`quent signal pause. The charge of the capacity C1 will
`U2 increases until the necessary ignition voltage across
`thus oscillate back to the main inductance Lh. The
`the spark gap 24 has been reached and the spark breaks
`duration of the signal pause p thus must be so deter
`down which, in effect, for an internal combustion en
`mined that a new signal will start when the voltage U1
`gine means that the spark plug has fired.
`has, approximately, reached its minimum. The timing of 50
`Coil 22, operating as a current/voltage transformer as
`the signal pause p thus can be determined, approxi
`explained in connection with FIG. 4, can also be used to
`mately, by equation (2).
`effect stepped charge accumulation by groups of cur
`The equivalent capacity C2 of the ignition cable 23'
`rent pulses, or by current pulse trains, or bundles of
`cannot discharge during the signal pause due to the
`current pulses. The signals E are slightly changed from
`blocked high-voltage diode 23. Voltage U2 thus re
`the illustration of FIG. 5; referring to FIG. 6, the
`55
`mains essentially constant. The next subsequent signal
`charge accumulation of voltage U2 is obtained by short,
`rapidly recurring current pulses Ib through the switch
`illustrated at graph E in FIG. 3 thus causes a rise in the
`voltage U1 until, again, a maximum or approximately a
`ing path of the interrupter switch 18, and thus to the
`primary winding of ignition coil 22. The length l of a
`maximum has been reached. Due to the resonance effect
`of this oscillation, the maximum will be higher than the
`signal E (FIG. 6) is so adjusted that the current rise Ib
`maximum of the preceding wave of the oscillation.
`remains in the linear range. During the rise in current,
`When the voltage exceeds the level of the voltage at
`voltage U2 across the spark gap 24 also rises. The gap p
`which U2 previously had been held, then voltage U2
`between pulses is set to be very short so that the switch
`will rise, parallel to voltage U1, until, at the next gap
`18 opens only for a short period of time. Current Ib
`immediately drops to zero but immediately again starts
`between pulses, a level will be established as previously
`65
`described. This accumulation of charge, or accumula
`to rise due to the next recurring signal E. Upon subse
`tion of voltage, at the spark gap 24 continues until the
`quent current rise, voltage U2 likewise rises again. The
`voltage U2 reaches a value which causes breakdown of
`voltage U2 is held at its previous level by the high-volt
`
`35
`
`Exhibit 1006
`MOTORTECH v. Altronic - IPR2025-00398
`Page 8 of 12
`
`

`

`4,181,112
`8
`7
`threshold, therefore, a signal F will be generated at the
`age diode 23. Charge accumulation, that is, accumula
`tion of the voltage U2, requires more charging steps
`output of the inverter stage 270.
`If the change-over point is in the positive region,
`when following this sequence in order to obtain suffi
`cient ignition voltage; the pulse repetition rate of the
`diode 260 is conductive and resistor 261 will have a
`positive voltage applied thereto which appears as the
`pulses E can be selected to be higher, however. This
`arrangement has the advantage that the switch 18 is
`output signal G at terminal 262. Simultaneously, no
`better protected since a comparatively smaller current
`signal is present at terminal 264 due to the presence of
`flows through its switching path and the transistor usu
`the inverter stage 263. If the voltage at terminal 21 is
`ally operates in saturation. The efficiency of operation
`negative, so that diode 260 blocks, the output terminal
`of the switch is also improved.
`262 will have a zero signal and output terminal 264 will
`10
`Embodiment of FIG. 7: Generally, the system of
`have the signal H. If, simultaneously, there is a signal F
`FIG. 7 corresponds to that of FIGS. 1 and 2. The elec
`and H, the SET input of FF 273 will have the signal K.
`tronic control system 19', however, is differently con
`If, simultaneously, there is a signal F and a signal G, the
`structed and here includes a differentiator 25 and a
`RESET input of the FF 273 will have the signal L.
`polarity recognition stage 26. The inputs of differenti
`During a clock signal B at terminal 13, FF 273 is en
`ator 25 and of stage 26 are connected together and to
`abled and then can be set by a signal K and reset by a
`terminal 21 (FIG. 1); the outputs are connected over a
`signal L. As a consequence, the output signal at FF 273
`logic circuit 27 to the control input of the interrupter
`will be the sequence of pulses shown at M in FIG. 8.
`switch 18. Differentiator 25 uses a well-known differen
`The operation of the signal sequence M with respect to
`tiating circuit formed by the series circuit of a capacitor
`ignition voltage U2 is similar to that of the sequence E,
`250, a resistor 251, an inverting operational amplifier
`as explained in connection with FIG. 4. The voltages
`252 and a feedback path consisting of a parallel con
`U1 and U2 are shown also in FIG. 8.
`nected resistor-capacitor network 253,254.
`The control voltage for the control unit 19 can be
`The polarity recognition stage 26 has an input diode
`either the primary voltage U1' of the coil or the second
`260 and a resistor 261, serially connected to ground or
`25
`ary voltage U. The example in accordance with FIG.
`chassis. The junction between diode 260 and resistor
`7 does not need to particularly consider the different
`261 is connected to an output 262 and, through an in
`secondary capacities since the switch-over points of the
`verter 263, to a second output 264.
`voltages U1 or U1' are recognized in each instant by the
`The output of differentiator 25 is connected through
`electronic control system directly. The signal sequence
`an inverter 270 to one input each of two AND-gates
`B (FIG. 2) has superimposed thereon a signal sequence
`271, 272; the second inputs of the AND-gates 271, 272
`C so that a plurality of ignition sparks are generated for
`are, respectively, connected to the outputs. 264, 262 of
`any ignition event; this is also advantageous for the
`the polarity recognition stage. The output of the first
`example of FIGS. 7, 8. The signal lengths C or B, re
`AND-gate 271 is connected to the SET input of an RS
`spectively, vary and can lead to a plurality of ignition
`flip-flop (FF) 273; the output of the second AND-gate
`35
`events since the voltage accumulation or build-up of the
`272 is connected to the RESET input of the FF 273.
`voltage U2 will begin again after each ignition firing
`The output of FF 273 is connected to the control input
`from zero level if a signal B or C continues to be ap
`of the interrupter switch 18. The clock or enabling input
`plied.
`of FF 273 is connected to terminal 13 (FIG. 1), and has
`Various changes and modifications may be made, and
`the signal B (FIG. 3) applied thereto.
`features explained in connection with any one of the
`In the previously explained examples, the switching
`embodiments may be used with any of the others.
`instants of the interrupter switch 18 were fixed, so that
`the switch-over of the voltage curve U1 was fixed by a
`EQUATIONS
`predetermined frequency having a fixed ratio of signal
`L(C-C2)
`duration to signal pause, that is, a fixed duty cycle.
`45
`Frequency generator 16, therefore, operated in accor
`dance with a predetermined fixed mode. The system of
`FIG. 7, however, provides recognition stages which
`recognize the occurence of a switch-over instant and
`then initiate the switch-over of the switch 18. The crite
`50
`rion to recognize the switch-over is the slope of the
`curve U' (FIG. 8) which slope will become zero at the
`switch-over point; and, additionally, the polarity of the
`voltages at the switch-over points. The voltage U1'
`(FIG. 8) is the primary voltage of the ignition coil 22
`which, essentially, is similar to that of the secondary
`voltage U1.
`OPERATION, WITH REFERENCE TO FIG. 8
`Differentiator 25 provides a signal at its output only if
`a voltage change is present at the input thereof. If the
`input at the voltage remains constant, the output volt
`age drops to zero. Since the rate of change, that is, the
`slope of the curve of the voltage U", becomes zero
`when it approaches the switch-over point, that is, when
`65
`the first re-charging cycle of the capacities formed by
`capacitor C1, C2 is terminated, the output voltage of the
`differentiator 25 will go to zero. At a predetermined
`
`We claim:
`1. In an internal combustion engine ignition system
`having an ignition coil (22);
`a spark gap (24);
`connecting means (23) serially connected with the
`secondary winding of the ignition coil (22) and the
`spark gap (24) and providing an energy storage
`means connected to the spark gap;
`and a controlled interrupter switch (18) serially con
`nected with the primary winding of the spark coil
`(22),
`a method to generate a high-voltage ignition spark
`and to cause an ignition event, comprising the steps
`of
`sequentially, in repetitive pulse cycles, applying a
`charge to the spark energy storage means con
`nected to the spark gap (24);
`
`5
`
`20
`
`55
`
`60
`
`st
`
`p = 7TV LiC
`
`W2/W1 - U2 max/OU - U)
`
`(1)
`
`(2)
`
`(3)
`
`(4)
`
`Exhibit 1006
`MOTORTECH v. Altronic - IPR2025-00398
`Page 9 of 12
`
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`10
`
`15
`
`30
`
`4,181,112
`10
`very small leakage inductance (W2/W1 small, Lh small,
`preventing back-flow of energy away from the en
`Ls very small);
`ergy storage means connected to the spark gap
`the pulse duration (1) of the multiple pulses (E) is
`(24);
`timed to fall within the linear range of the rise in
`and building up an energy accumulation in said en
`primary current (Ib) through the coil (22), the gaps
`ergy storage means in form of a charge voltage
`(p) between sequential pulses (E) being timed to
`accumulation as the result of said sequentially ap
`correspond essentially to the period of time that
`plied charges to the energy storage means until the
`maximum voltage, corresponding to said rate of
`energy stored therein causes breakdown of the
`change of current, is accumulated across said spark
`spark gap,
`gap (24).
`wherein the s