US3026863A - Ignition system - Google Patents

Description

March 27, 1962 H. B. REYNOLDS ETAL 3,025,863

IGNITION SYSTEM Filed Sept. 18, 1959 Fig. 5

8 Harold B. Reynolds 30 David A. Ward 24 30 24 INVENTORS United States Patent 3,026,863 IGNITION SYSTEM Harold B. Reynolds, Oneida, and David A. Ward, Canastota, N.Y., assignors to Teletronics Technicians, Inc., Oneida, N.Y.

Filed Sept. 18, 1959, Ser. No. 840,863 6 Claims. (Cl. 123-148) This invention relates to automotive vehicle ignition systems and more particularly to a system which provides a comparatively more intense spark in the combustion chamber of an internal combustion engine.

An object of the invention is, to provide improvements in ignition systems for engines of the type used principally for automotive vehicles, although the principles of the invention are applicable in connection with internal combustion engines used for other purposes. Briefly, the purpose of the invention is to provide a more intense spark in the combustion chamber of the engine, for instance across theelectrodes of the spark plugs thereby causing the fuel to be ignited with greater speed and force and resulting in greater fuel economy and an increase in power output, particularly at high engine speeds.

A further object of the invention is to provide the above improvements in internal combustion engine ignition circuits by the addition of only a minor circuit alteration, although the effect of such an alteration is productive of major improvements in efliciency and operation of the engine.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

FIGURE 1 is a diagrammatic view showing a conventional ignition circuit incorporating the improvements of the invention.

FIGURE 2 is a diagrammatic view showing a wave form which would appear in the operation of the circuit shown in FIGURE 1.

FIGURE 3 is a wholly diagrammatic view showing a resonant circuit formed by the coil and condenser of a conventional ignition circuit for an internal combustion engine.

FIGURE 4 is a wave form typical for the operation of a conventional ignition circuit entailing the resonant circuit only diagrammatically shown in FIGURE 3.

FIGURE 5 is a simplified circuit diagram showing a non-resonant circuit formed by the coil, condenser and a rectifier as embodied in the circuit of FIGURE 1.

In the accompanying drawings reference 'is first made to FIGURE 1. Distributor includes a rotor 12 with which high tension wire 14 is connected, together with a plurality of diagrammatically illustrated contacts 16 with wires 18 extending therefrom and operatively connecting with spark plugs 20. Breaker points 22 are conventional, as is condenser 24 connected across the breaker points and to ground 26. The ignition circuit, to follow convention, has ignition coil 28 including a primany winding 30 and a secondary winding 32 with which high tension wire 14 is connected. Conductor 34 extends from one end of the primary 30' to the breaker points 22, and the other end of the primary winding 30 is connected to battery 36 by way of conductor 38 having ignition switch 40 therein.

In essence a part of the circuit in FIGURE 1 is properly resolved into a resonant circuit 42 including condenser 24 and coil 30. This is a resonant circuit which produces a wave form 44 (FIGURE 4) is. a non-damped wave e.g. representing current fiow in the oscillatory circuit of the primary and secondary.

The circuit in FIGURE 1 as described above, is con- 3,026,863 Patented Mar. 27, 1962 ventional and the production of the wave form 44 is also conventional. But FIGURE 1 shows a departure from conventional practice by the inclusion of rectifier 48 in conductor 34 between capacitor 24 connection therewith and the primary 30. The rectifier may be of any known configuration such as a semi-conductor, e.g. a diode, selenium rectifier, electron tube, or any other known rectifier which is suitable for the purpose. Furthermore, the location of rectifier 48 may be moved so long as it will function to produce a non-resonant circuit 50 dia grammatically shown in FIGURE 5. This is what the invention achieves as far as the circuitry is concerned. It is quite evident, then, that rectifier 48 could be placed between the ignition switch 40 and coil primary 30 with equal success.

Rectifier 48 serves to damp the circuit by producing the non-resonant circuit 50 formed by the coil, condenser and rectifier. The wave form 52 is drawn on the same ordinate as wave form 44 'to facilitate comparison. Wave form 52 is that which may be read on an oscilloscope tuned to depict the wave form of the primary and secondary of the special damped circuit 50. Notice that there is only a very small oscillation due to the capacity across the primary only. The self-capacitance ordinarily produced at capacitor 24 for wave form 44 is clamped out of the circuit or essentially so, by rectifier 48 so that the electrical pulse produced has a greater peak in wave form 52 in comparison to that of wave form 44.

In operation current from the source, for instance battery 36, flows through the primary winding 30, but when the points 22 open the normal damped oscillation which takes place in primary winding 30-condenser 24 circuit cannot take place. The rectifier 48 damps the unwanted oscillation, and this is particularly important at high distributor speeds, as the time of opening of the breaker points 22 is not always great enough to completely collapse the field of the ignition coil (transformer). Since the condenser 24 is in the circuit this creates an oscillating circuit (simplified in FIGURE 3) which tends to have the effect of premature burning of the distributor points due to arcing. Some energy is lost due to the fact that the oscillatory circuit tends to preserve the magnetic field rather than letting it collapse instantly. Accordingly, the secondary voltage is greater with the increased collapse speed. There is no reversal of voltage in the secondary winding of the coil so that the spark plug firing is not killed due to the reverse voltage and termination of the spark is governed only by the completion of the field collapse.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as claimed.

What is claimed as new is as follows:

1. In an ignition circuit for an internal combustion engine wherein the ignition circuit includes an electrical energy source, an ignition coil having a primary and a secondary winding, breaker points, a condenser connected in shunt with the breaker points, and a conductor serially connecting said breaker points with the primary winding, thereby producing a resonant circuit, the improvement comprising means connected in the resonant circuit to damp the oscillation thereof and convert the resonant circuit to a non-resonant circuit.

2. In an ignition circuit for an internal combustion engine wherein the ignition circuit includes an electrical energy source, an ignition coil having a primary and a secondary winding, breaker points, a condenser connected in shunt with the. breaker points, and a conductor serially connecting said. breaker points with. theiprimary Winding, thereby producing a resonant circuit, the improvement comprising means connected in the resonant circuit to damp the oscillation thereof andconvert the resonant circuit toa non-resonant circuit, said means comprising a rectifying component.

3. In an, internal combustion engine. ignition circuit wherein there is a source of electrical energy together with a distributor, a coil including a primary and secondaryv and operatively connected with the distributor, said secondary having a conductor connected therewith and also operatively connected with the source of electrical potential, conventional breaker points connected with said conductor and a conventional capacitor connected inshuntwith the breaker points, a rectifier connected in circuit with said source and said primary and saidbreaker 7 points and said condenser tocooperate therewith and form a non-resonant circuit thereby causing the current to peak and damping. the. oscillation resulting from the resonant circuit formed by the coil and condenser.

4. In, combination with a conventional internal combustion engine ignition system including a primary circuit comprising a primary coil winding connected in series with a set of breaker points having a capacitor connectedthereacross; a rectifier connected in series with:

said. winding reducing. oscillations in the normally resonant circuit formed by saidtwinding and said capacitor. 5. In, combinationwith a single path primary circuit g 4 having a primary winding connected in series with a circuit interrupter for intermittent interruption of the primary circuit as a variable function independent of the primary circuit current, and an are preventing capacitor connected across the interrupter arranged to produce a resonant oscillating waveform for the primary circuit for obtaining a maximum peak voltage in the primary winding at a predetermined time lag with respect to interruption of the primary circuit and wave form modifying means connected in said primary circuit to, render it non-resonant for reducing said fixed time lag at which said peak voltage occurs.

6. The combination of claim 5, wherein said modifying means comprises rectifier means for isolating the oscillating effect of the capacitor on the primary circuit wave form. 4

Referencesfiited in the file of this. patent UNITED STATES PATENTS Q HER REFERENCES Electronics, April 1945, pages 106-112.

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