US3504230A - Solid-state ionizing ignition system - Google Patents

Description

March 31, 1970 E. GADDES 3,504,230

SOLID-STATE IONIZING IGNITION SYSTEM '2 Sheets-Sheet 1 Filed Dec. 22, 1966 IN VEN TOR. @M/PO- Q 540055 United States Patent 3,504,230 SOLID-STATE IONIZING IGNITION SYSTEM Edward D. Gaddes, 3717 Crestview Drive, Nashville, Tenn. 37215 Continuation-impart of application Ser. No. 362,219, Apr. 24, 1964. This application Dec. 22, 1966, Ser. No. 613,371

Int. Cl. Hb 37/02, 41/36, 41/13 US. Cl. 315209 7 Claims ABSTRACT OF THE DISCLOSURE The solid-state ignition system having ionization and corona discharges to complete burning of combustion mixtures by use of a circuit.

This application is a continuation-in-part application of Ser. No. 362,219, filed Apr. 24, 1964, now abandoned.

This invention relates generally to ignition systems and more particularly to transistorized ignition systems for internal combustion engines which produce complete burning of combustion mixtures.

One of the major problems associated with internal combustion engines is that of providing complete combustion to the fuel mixtures. Without this complete combustion, fuel consumption increases and carbon deposits result which increase wear of the engine parts. In an effort to overcome this deficiency in present-day engine designs, various devices have been employed within the engine and carburetor structures. For instance, it has been a common practice to roughen the intake manifold walls in an effort to break down and completely mix the airfuel mixtures. Also, various carburetor designs have been employed in an effort to provide complete and thorough mixing of the air-fuel mixtures and to provide ionization of the fuel.

All of these prior attempts have proved either partially or wholly unsuccessful in providing a complete ionization and mixing of the air-fuel mixture. As a result, a considerable amount of waste occurs in the operation of internal combustion engines from lost and unburned fuels and from wearing of parts.

Furthermore, a considerable amount of research and development has been done in recent years to eliminate burning of distributor points by employing solid-state electronics. These structures, although providing larger current arcing in the spark plugs, do not provide complete combustion of the air-fuel mixture. The hotter spark transistorized ignition system simply performs to burn the air-fuel mixture a little more than that provided by previous structures, but does not attempt to condition the air-fuel mixture to be more conducive to complete combustion.

It is, therefore, a primary object of this invention to provide a solid-state ignition system which will provide complete combustion of the air-fuel mixture within an internal combustion engine.

It is another object of this invention to provide a solidstate ignition system which ionizes the fuel in the combustion chamber.

Another object of the present invention is to provide a solid-state ignition system which continues to provide an easy adjustable ionizing discharge throughout the entire power stroke of maximum intensity.

These and other objects of the present invention will be more fully realized from the novel structure thereof which generally includes a set of points or similar structures disposed for synchronous operation, switching means, and oscillating means connected with the switching means and responsive to the operation of the points 3,504,230 Patented Mar. 31, 1970 or similar structure for changing the state of oscillation.

The invention, however, will be more fully realized and understood from the following detailed description when taken in conjunction with the accompanying drawings wherein:

FIGURE 1 is a schematic diagram of one embodiment of the present invention;

FIGURE 2 is a schematic diagram of the embodiment of FIGURE 1 with the exception of the standard ignition system;

FIGURE 3 illustrates a modified form of the novel distributor structure of the present invention;

FIGURE 4 is an elevational view of a set of points employing one feature of the invention;

FIGURE 5 is a perspective detailed view of the point protection structure;

FIGURE 6 is a schematic diagram of another embodiment of the present invention;

FIGURE 7 is a schematic diagram of a modified form of the diagram of FIGURE 6; and

FIGURE 8 is a schematic diagram of the embodiment shown in FIGURE 1 but illustrating its use with structures other than an automobile ignition system.

Like reference numerals throughout the various views of the drawings are intended to designate the same or similar structures.

With reference to the drawings in detail and in particular FIGURE 1, there is shown one embodiment of the solid-state ionizing ignition system of the present invention. A 12-volt battery or voltage source 10 is connected from its negative terminal to a ground 12; all ground connections shown in the drawings are connected to this. The positive terminal is connected to the ignition switch. To show the compatibility of the invention with existing ignition coils, a Mallory F12ST coil was modified by winding 250 turns of #28 wire around its plastic case for an inductive feedback coil 20. Coil 18 is the primary 200 turns of #20 wire and coil 22 is 100,000 turns of #36 wire, all of enameled copper. At resonant frequency, the oscillating potential for this coil is 30 kilovolts. One end of each of coils 18 and 20 is connected to battery 10 through switch 14 and through a transient and radio noise suppression capacitor 24 to a ground 26. The other end of coil 18 is connected to an emitter 28 of only one RCA 2N174 PNP transistor 30 and to one end of the secondary coil 22. The other end of coil 22. is connected to the distributor 32 for distributing high voltage to the spark plugs (not shown).

The other end of coil 20 is connected to a base terminal 34 of the transistor and a collector terminal connection 36 is made to ground 38. A neon glow tube is connected across the emitter and collector of transistor 30- for transient protection.

Base terminal 34 is connected through a variable 500-ohm resistor 42 to ground 44. A sliding contact 46 is disposed for changing the capacity reactance to base 34. A 2-mfd., 600-volt condenser 48 is disposed to supply this capacity through ignition points 50 to ground 52. All electrical connections are wired with #18 stranded copper high temperature plastic-covered wire except wire 90, which is high voltage ignition wire.

The operation of this embodiment of the present invention is as follows: When ignition switch 14 and points 50 are closed, the coil and transistor oscillate at an offresonant frequency producing non-igniting ionizing discharges in the spark plugs. Rotor 54 is constructed to provide a voltage from coil 22 to the spark plugs through the entire range of the compression power stroke. The non-igniting ionization begins as the piston of the engine starts on the compression stroke and continues until the points open. At the opening of points 50, the frequency changes to the resonant frequency of the coil and produces an igniting are which fires the gas and air vapor that is ionized by the preceding non-igniting discharge. This discharge consists of a flow of ions in the gas and air vapor between the electrodes of the plugs.

The prevaporizing and ionizing of the mixture by the ionizing discharge provides a condition which is extremely conducive to quick engine starts in very cold weather and to optimum efiiciency and economy of operation.

Resistor 42 is of a value that with regenerative coil 16 and transistor 30 the circuit will oscillate at the resonant frequency of the coil. The phantom line illustration of rotor 54 designated with the reference numeral 70 shows the rotor position when providing an ignition arc or voltage to a contact 72.

The resonant oscillating condition exists when points 50 are open, thus disconnecting condenser 48 from the circuit. Condenser 48 is of such a value that at some setting of the resistance arm 46, with points 50 closed, the circuit is detuned off resonance sufficiently to provide only a non-ignition voltage, that is, a voltage sufficient only to warm and ionize the gas vapor at the spark plug but not to fire it. Adjustment of arm 46 is made easily by mounting the transistor 30 on control 42 on the dashboard of the automobile and connecting them to coil 16 and points 50 by a three-conductor #18 shielded wire. Then arm 46 is set for quickest start and smoothest operation. At this setting, an oscillating ionizing operating potential of about 6 to kilovolts is found by measuring the distance the non-resonant spark will jump from the secondary coil 22 to ground. Motor compression and spark plug gap settings cause this wide voltage spread.

The embodiment of FIGURE 1 is adapted to a system without points or an impulse type ignition system as shown by the schematic diagram of FIGURE 2. The circuit is identical with the exception that points 50 are replaced with a transistor 76 and biasing means therefor. The emiter collector circuit is connected between capacitors 24 and 48. This circuit includes a connection to battery 10 through switch 14. A fixed biasing resistor 84 is connected between the emitter and the base. A synchronous biasing means including a magnet 86 and a coil 88 responsive to the magnet is connected to the base of the transistor. Coil 22 is connected to distributor 32 through a line 90 in the same manner as that of FIGURE 1. This circuit operates identically to that of the circuit of FIGURE 1 with the exception of biasing or triggering by points 50.

Resistor 84 establishes the operating point of transistor 76 by its ohmic value being such that in series with the resistance of coil 88 it will produce a small negative bias on the base of the PNP transistor, thus keeping it turned on. A positive pulse produced by the rotating magnet 86 in coil 88 on the base of the transistor will cause it to turn off, thus in effect dis-connecting capacitor 48 from the oscillating circuit, the same as opening points 50. An unusual condition exists in this circuit in that no collector battery connection is made to transistor 76 as negative pulses supplied through capacitor 48 are all that is needed for its operation.

Resistor 84 is a biasing resistor which sets the transistor operating point very near its cut-off. Any type of impulse signal producing a positive voltage on base 82 will cause the frequency to shift from the non-resonant to the resonant condition momentarily producing an ignition are or voltage from coil 22. Then the circuit shifts back to the non-resonant frequency and the nonignition voltage from coil 22. Condenser 24 is used to suppress radio interference and battery line transients. Tube 40 is a voltage regulator device that ionizes at a preselected value of voltage to protect transistor 30 from transient voltages.

FIGURE 3 illustrates the form of the novel distributor employed in the schematic of FIGURE 1. This configuration of rotor 54 in FIGURE 3 produces a steady increase in the non-igniting ionizing intensit as a piston (not shown) moves to compress the air-fuel mixture. This is desired, because it requires a higher intensity ionizing to break down through a compressed air and gas mixture rather than one at atmospheric pressure. That is, the dielectric constant of the air-fuel mixture increases with increased pressures. As shown therein, the rotor is a thin-edged piece of metal with the leading half as designated by the numeral curved away from contacts 56. As the rotor advances on a particular contact, the space between section 100 and the contact becomes increasingly smaller until at a point 102 it closes thereon. A remaining half section 104 of the rotor maintains contact during rotation past the contact and allows a voltage to be conducted therebetween during the power strokes of the engine. Section 100 provides an ionizing discharge until the circuit is biased to provide an igniting voltage and point 102 comes in contact with one of contacts 56. The spacing between the contacts and section 100 is designed to provide the necessary decreasing air-resistance so that the intensity of the ionizing voltage increases during a compression stroke.

As shown by the dotted line box designated with the reference numeral 74 surrounding points 50, the points are sealed by a novel structure described in detail in the following description.

FIGURE 4 illustrates the novel structure for protecting points 50 of the schematic diagram of FIGURE 1. A plastic tubing 92 is illustrated in section in FIGURE 4 and in perspective in FIGURE 5. Epoxy cement is employed to adhere the tubing to each of points 50. A point support structure 94 maintains points 50 in opening and closing relationship with one another. As shown in FIGURE 5, tubing 92 includes sleeves 96 for engaging each point and a bulbous section 98 intermediate the sleeves. The bulbous section allows sufiicient relative movement between the points for closing and for opening a distance to suppress arcing of the minute currents.

Neon glow lamps are employed for several reasons. They have no leakage below the value of ionizing voltage; however, when this value is attained, it will fire and the voltage quickly drops instead of increasinga desired condition for protecting the transistor against high frequency transients. Furthermore, the voltage only drops to a safe level and the lamp cuts off again. These lamps respond to both *A.C. or DC. voltage with practically no frequency limitations. Zener diodes give protection at high currents and low frequencies, but fail at very high frequencies to protect. These high frequency transients punch through the semiconductor material forming an ion path for the high current low voltage to ride on, thus burning out or shorting the transistor. This is another example of an ionizing voltage being a carrier for a different current and voltage.

The embodiment of FIGURE 1 adapted to condenser discharge type ignition systems is shown by the schematic diagram of FIGURE 6.

With reference to the drawings in detail and in particular FIGURE 6, this shows the same single transistor oscillating circuit as in FIGURE 1 with new coil winding additions. Again to show its compatibility with existing ignition coils, a Mallory F12T coil with a turn ratio of 250 to 1 was used. This coil was modified by first winding turns of #28 wire around its plastic case, then 2,000 turns of #30 wire over this. Then, over both of these, 30 turns #20 wire are wound. All wire was enameled cop per. The new coil transformer now has these connections that differ from FIGURE 1. Coil 18 is the new 30-turn primary, coil 19 is the original coil primary, coil 20 is the inductive feedback coil of 150 turns, coil 21 is the 2,000- turn medium voltage coil, and coil 22 is the high voltage secondary of the original coil. A pulse potential of 50 kilovolts may be obtained from this circuit. One end of each of coils 18 and 20 is connected to battery 10 through switch 14 and through a transient and radio noise suppression capacitor 24 to ground 26. Battery negative is connected to all grounds at 12. The other end of coil 18 is connected to an emitter 28 of a single RCA 2N1100 PNP transistor 30 and to one end of secondary coil 22. The other end of coil 22 is connected to high voltage wire 90 leading to the spark plug distributor for distributing the ionizing voltage and high voltage pulse to the spark plugs (not shown).

The other end of inductive feedback coil 20 is connected to base terminal 34 of the transistor and a collector terminal connection 36 is made to ground 38. Base terminal 34 is connected through a variable l50-ohm resistor 40 to ground 52. A 1-mfd., l000-volt condenser 48 has one connection made to ground at 44. The other connection is made to resistor 40 through sliding contact 46 that changes capacity reactance to transistor base 34. The transistor is doubly protected from transients by a neon glow tube 40 and Zener diode 120 across the emitter 28 collector terminals 36. It is also protected from burn-out by having base connection 34 of the transistor connected to a positive voltage supply through coil 20 to battery 10. Should the circuit fail to oscillate, this positive voltage on base terminal 34 will turn off the transistor.

Coil 21 is the medium voltage coil. An oscillating voltage from coil 21 is rectified to DC. by bridge diode rectifier 120. This direct current charges capacitor 136 from 100 to 500 volts depending on the setting of contact 36 which can vary the non-resonant frequency from 15 to 20 kilohertz. This pulse circuit works well within this voltage range. Below 100 volts, little energy is supplied to the pulse circuit and therefore a 100-volt, lO-watt rating Zener diode 159 limits the minimum voltage charge in the 2-mfd., 600-volt capacitor 136 to 100 volts. This also prevents the circuit from going out of oscillation. Resistor 114 limits the maximum voltage to about 500 volts by loading the circuit; 250,000 ohms is its value, with a 2- watt heat dissipating rating.

Condenser 136 charges instantaneously as the circuit goes into operation with the closing of battery switch 14. Pulse transformer 15, an Argonne type 119 output transformer, controls the high voltage pulse as follows. When points 50 are opened by the distributor cam, the interruption of the 70-milliamp current through coil 125 on this transformer causes a low voltage pulse in coil 126 by induction. This pulse is rectified by diode 122 and applied to gate control electrode 2 of the silicon control rectifier 158. This causes it to turn on and fire the voltage in capacitor 136 through coil 19 to common grounds 126 and 110. This medium voltage pulse in coil 19 induces a high voltage pulse in coil 22 which distributes it through wire 90 by means of the distributor to the spark plug to be fired (not shown). This high voltage pulse rides the ionizing voltage across the gap of the plug, thus firing the cylinder. The extremely short time, a few microseconds, required for the voltage to reach its peak gives it the ability to fire very dirty or even fouled-out plugs that would not fire in standard ignition. Fast starting and smooth running, even -in extremely cold weather, is assured by at least 50 kilovolts on the plug electrodes at every start. This voltage drops to 30 kilovolts at maximum speed.

A modified diagram of FIGURE 6 is shown in FIGURE 7. If pulse transformer 15 is removed from the circuit in FIGURE 6 and electro-magnetic distributor transformer 17, FIGURE 7, connected as shown by dotted lines and connections 108 and 111, the circuit is then converted to an ignition system without points which operates as follows. As distributor rotor vane 13 interrupts the electromagnetic field in the core of transformer 17 that is supplied by the current flow from battery through coil 123, a pulse voltage is induced in coil 124, rectified by diode 122 and applied to the trigger electrode 2 of SCR 158 to operate it the same as described in FIGURE 6. Resistor 108 of 100 ohms value is used to bleed off any negative voltage that might accumulate on trigger electrode 2 in FIGURE 6 that might stop its operation.

A novel feature of this circuit in FIGURE 7 is the variable voltage supplying resistor 8. By varying the voltage and thus the current with movable are 7, the timing can be advanced or retarded from inside the car by mounting the arm on the dash and connecting it to transformer 17 through coil 123 to ground 113. Pulse coil 124 is also connected to ground 113. Weak current, and thus low magnetic flux in transformer core 17, causes vane 13 to have to come in almost complete alignment with core 17 before a pulse is generated suflicient to fire a plug. This would be the retard setting. Advancing rotor, and thus increasing the current through coil 123, causes a greater magnetic flux in transformer core 17. Now vane 13, as it rotates, will cause a trigger pulse to be generated in coil 124 before it is in complete alignment with core 17, thus advancing the plug firing. (Vane 13 is made of soft iron.)

FIGURE 8 illustrates a circuit identical with that of FIGURE 1 except coil 16 which is made to operate a 22-w. fluorescent tube on a 12-v. DC. voltage supply. The coil is made as follows: the coil 22 is 2,000 turns of #30 enameled wire, coil 18 is 60 turns of #20 enameled wire, and coil 20 is turns of #30 enameled wire. These coils are wound on a powdered iron core x /8" x 3" in this order18, 20 and 22. This circuit operates in the 10 to 20-kilohertz region with high efficiency using 30 battery watts to produce 22 w. of light. Capacitor 133, a .05-mfd., 660-v. unit in this circuit, is necesary for this high efficiency as it causes a current to flow through the filaments of tube 134 keeping them hot. The transistor is also protected by this capacitor from high voltage open circuit transients in case the lamp fails.

If points 50 are replaced by a switch, if desired, such switch may be of the rotating or thermal type as indicated by the reference numeral 134, and will cause the light to flash using a very small current across the flasher points. A condenser 48 and variable resistor 42 provide a variation from ver dim to full brightness of the light. Rotation of resistance arm 46 causes the current to vary from minimum to maximum.

In each of these embodiments or configurations, with a negative ground a PNP transistor is employed. For changing from negative ground to positive ground or vice versa, an NPN type transistor may be substituted.

The principles of the invention explained in connection with the specific exemplifications thereof will suggest many other applications and modifications of the same. It is accordingly desired that, in construing the breadth of the appended claims, they shall not be limited to the specific details shown and described in connection with the exemplifications thereof.

What is claimed is:

1. A solid-state ignition circuit comprising a transitor having an emitter, collector and base; means for regulating a voltage directly between said emitter and collector; a first coil connected to said emitter and voltage source; means for biasing said transistor between at least two values of biasing potential; a mutual inductance means; voltage source connected to said coil, a second coil coupled for inductive feedback from said base to said first coil through said mutual inductance means; and distribution means connected to a third coil for distributing a voltage developed in said third coil, said second and third coils being coupled by said mutual inductance means, said distribution means including a rotor and a plurality of contacts, said rotor providing by its contact contour a variable air resistance path between said third coil and said contacts.

2. The ignitor circuit of claim 1 wherein said biasing means includes a pair of points disposed for opening and closing with respect to one another.

3. The ignitor circuit of claim 1 wherein said biasing means includes a second transistor; means for changing an operating point of said second transistor from conducting to nonconducting; and magnetic means for actuating said operating point changing means.

4. The circuit of claim 1 wherein said distribution means includes a rotor and a plurality of contacts, said rotor including a crescent-shaped element and an arm connected at a mid-point of said element, said element of such contour presenting a Wide air gap at the leading end and no air gap at the midpoint thereof.

5. A solid-state ignitor circuit comprising a transistor having an emitter, collector and base; means for regulating a voltage between said emitter and collector; a mutual inductance means; a first coil connected to said emitter and voltage source; a second coil coupled for inductive feedback to said first coil through said mutual inductance means; means for biasing said transistor for non-resonant oscillation; a third coil; means for developing ionizing voltage in said third coil; a fourth coil developing medium DC. voltage through rectifying diodes; means for storing said voltage; means for discharging said voltage through a fifth coil; means for preventing complete discharge of said voltage; and means for producing high voltage pulses from said third coil, said second and third coils being coupled by said mutual inductance means, said high voltage producing means including a 20 rotor and a plurality of contacts, said rotor providing by its contact contour a variable air resistance path between said third coil and said contacts.

6. The circuit of claim 5 wherein said providing means includes a pulse transformer, and said altering means includes a pair of points.

7. The circuit of claim 5 wherein said providing means includes an electromagnetic transformer having no points; means for varying the magnetic field in said transformer; means for plusing the transformer, and means for varying pluse timing.

References Cited UNITED STATES PATENTS 2,898,392 8/1959 Jaeschke 315-209 X 3,016,476 1/1962 Bataille 315-135 3,016,477 1/1962 Naborowski 315-206 3,018,413 1/1962 Neapolitakis 315-206 3,035,108 5/1962 Kaehi 315-209 X 3,152,281 10/1964 Robbins 315-201 3,263,124 7/1966 Stuermer 315-224 X 3,383,555 5/1968 Minks 315-224 X 3,383,556 5/1968 Tarter 315-218 X FOREIGN PATENTS 583,553 10/1958 Italy.

JOHN W. HUCKERT, Primary Examiner R. F. POLISSACK, Assistant Examiner US. Cl. X.R. 315-218, 219

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