Ignition System Utilizing Transistor For Internal Combustion Engines

Abstract

A transistor has a control electrode connected to the feedback winding of an ignition transformer. A storage capacitor is connected to the primary winding of the ignition transformer via the input-output path of the transistor and a starting stabilization diode.

Description

DESCRIPTION OF THE INVENTION

The present invention relates to an ignition system for internal combustion engines. More particularly, the invention relates to an ignition system utilizing a transistor for internal combustion engines.

Electronic ignition systems have been developed due to more stringent requirements for the output performance of high-speed internal combustion engines having a high compression ratio and more stringent requirements for increasing the operational reliability of ignition circuits and for reducing control and maintenance requirements.

Since electronic ignition systems or circuits of newly developed type are not yet widely used, primarily due to economic reasons, battery and magneto ignition systems having contacts are in use. Although the better quality of electronic ignition systems is not in doubt, the advantages of such systems do not outweigh the high production costs thereof.

Ignition systems of known type utilizing a mechanical contact breaker or interrupter have a number of disadvantages which are particularly pronounced in small cylinder capacity internal combustion engines which provide greater power primarily by an increase in speed. A mechanical interrupter functions very unreliably at higher speeds such as, for example, 10,000 revolutions per minute. The use of two interrupters has not proven to be of advantage. The unreliability of a mechanical interrupter is due to pitting and fouling of the interrupter contacts and cam and arm vibration. These disadvantages are overcome by electronic ignition systems, especially of the contact type.

There are three basic known types of electronic ignition systems. A first, transistorized ignition system, is controlled by a mechanical interrupter. A second, transistorized ignition system, is controlled by an electrical pulse which is produced electromagnetically, photoelectrically or piezoelectrically. A third, capacitive ignition system, utilizes a capacitor which discharges into the primary circuit of an ignition coil. There are other types of ignition systems which are not in general use such as, for example, various oscillatory systems and the like. Each type of electronic ignition system has advantages and disadvantages.

A transistorized ignition system of the type controlled by a mechanical interrupter is the most simple in design, may be adapted to internal combustion engines of current type with facility and does not require more considerable adaptations and equipment, except a special ignition coil having a greater step-up ratio. However, transistors meeting considerable requirements are necessary for reliable operation of the system. In a system of this type, the transistor only relieves the usual mechanical interrupter by providing the switching-in interruption function of electrical currents of large magnitudes of 8 to 12 amps. There are also high-voltage peaks which exceed the permissible magnitude and must be eliminated by, for example, Zener diodes. The transistor may be severely damaged or destroyed. Thus, for example, the mechanical vibration of contacts may cause the emitter-collector junction of the transistor to become loaded with considerably higher electrical magnitudes. Furthermore, if the ignition system is disconnected by the ignition key-operated switch at an instant when the mechanical interrupter is switched on, there is a considerable strain.

For various reasons, the transistor is required to have high parameters. Since the transistor must be carefully selected, it is costly. An electronic ignition system of the first type is unsuitable for internal combustion engines operating at very high speeds, because the mechanical interrupter is unsatisfactory for mechanical reasons, even if it is not under an electrical strain. There are also inaccuracies in spark advance at high speeds. The entire system, including the transistor, is heated by a high power loss and the space occupied by said system is increased by the inclusion of the required cooling areas.

The second type of ignition system is controlled without contacts. This requires additional amplifying units, and therefore increases the circuit complexity and cost, and reduces reliability. The principal advantage of the second type of system is its desirable operation in the entire speed range. Another advantage is a reduced possibility of severe damage or destruction of the transistor.

Neither of the first and second type of ignition system provides a solution for the problem of increasing the rate of increase of the ignition voltage required for igniting partly fouled spark plugs. This problem is solved by the third type of electronic ignition system which functions on the principle of capacitor discharge. The capacitor is charged to a voltage of 300 to 1,000 volts via either a mechanical contact or an electronic switch such as, for example, a thyristor or thyratron or gas-filled discharge tube, and discharges into an ignition coil. Although the third type of system is the best of the three types, it is also the costliest. The cost may be reduced by utilizing a gas-filled discharge tube instead of a more costly thyristor. A discharge tube has a shorter life than a thyristor and requires a considerably higher voltage such as, for example, approximately 220 volts, for the starting pulse. Although the pulse current and power are small, a voltage of 220 volts may be produced only by additional amplifying units or a mechanical interrupter. A mechanical interrupter is less expensive than amplifying units and is therefore more frequently utilized.

The common disadvantage of the three types of electronic ignition systems is their high production costs. A suitable ignition system must therefore be economical in cost as well as technically advantageous.

The principal object of the present invention is to provide a new and improved ignition system.

An object of the present invention is to provide an ignition system which combines the advantages of the three types of electronic ignition systems.

An object of the present invention is to provide an ignition system of which the transistor cannot be damaged or destroyed.

An object of the present invention is to provide an ignition system which provides a rapid increase of the ignition voltage and thereby provides ignition for partly fouled spark plugs.

An object of the present invention is to provide an ignition system the transistor of which may be made conductive by applying a voltage pulse of approximately 0.5 volt and a current of approximately 10 ma. to a starting diode.

An object of the present invention is to provide an ignition system having an auxiliary feedback winding on the ignition transformer for providing positive feedback to the control electrode of a transistor thereby rapidly switching the transistor to its conductive condition, so that there is no need for amplifying units and miniature starting induction coils may be utilized for starting.

An object of the present invention is to provide an ignition system utilizing components of nonexacting tolerances and having low production costs, which are comparable with those of known mechanical interrupter systems.

An object of the present invention is to provide an ignition system of low cost which may be used in low-cost vehicles.

An object of the present invention is to provide an ignition system which may utilize with reliability transistors of lower quality and looser tolerances than the usual rated tolerances.

An object of the present invention is to provide a transistorized ignition system having a high efficiency of operation.

An object of the present invention is to provide an ignition system having very low energy consumption, such as 0.3 watts with 600 sparks and 6 watts with 12,000 sparks, such energy being dissipated by the components of the system and producing a magnetic field in the ignition transformer.

An object of the present invention is to provide an ignition system having a transistor whose temperature, for practical purposes, is not increased above the ambient temperature, so that no cooling is required.

An object of the present invention is to provide an ignition system including a transistor which functions reliably when heated by an external source to 80.degree. C., so that it operates reliably under an engine hood of a vehicle.

An object of the present invention is to provide an ignition system for low-capacity, high-speed engines which functions perfectly, starts the engine at low ambient temperatures and has an ignition accuracy of .+-.0.5 percent over the entire speed range.

An object of the present invention is to provide an ignition system which operates to fire an engine in a manner whereby the engine runs regularly and elastically, starts well with direct transmission from a low speed without jerking, is immune to engine vibrations, requires practically no maintenance and the functional life of the spark plugs is considerably lengthened.

Another object of the present invention is to provide an ignition system which functions with efficiency, effectiveness and reliability.

In accordance with the present invention, an ignition system comprises a supply circuit, starting pulse means an ignition transformer having a primary winding connected to an igniting device, a secondary winding and a feedback winding. A semiconductor switching device has input and output electrodes, an input-output path and a control electrode connected to the feedback winding of the ignition transformer. A storage capacitor supplied by the supply circuit is connected in parallel to the primary winding of the ignition transformer via the input-output path of the semiconductor switching device and a starting stabilization diode connected to the starting pulse means. The semiconductor switching device comprises a transistor.

A shaping capacitor is connected in parallel with the starting stabilization diode. A starting pulse circuit is connected in parallel with the starting stabilization diode for providing a starting pulse. The starting-pulse circuit comprises an alternator having a starting coil connected via a diode to the shaping capacitor. The alternator of the starting pulse circuit has a supply coil, and the supply coil and the starting coil of the alternator are positioned in operative inductive proximity with each other. The alternator of the starting pulse circuit has a supply coil connected to the ignition transformer in the first half cycle of the alternator current via a rectifying diode and the storage capacitor and in the second half cycle of the alternator current via a diode, the starting stabilization diode of the starting-pulse circuit and the shaping capacitor.

In one embodiment of the invention, the alternator of the starting-pulse circuit has a galvanomagnetic resistor connected to the storage capacitor via the primary winding of the ignition transformer.

In another embodiment of the invention, a variable capacitor is mechanically coupled to the alternator of the starting pulse circuit and is connected to the storage capacitor via the primary winding of the ignition transformer.

In another embodiment of the invention, a variable capacitor is mechanically coupled to the alternator of the starting pulse circuit and is connected to the storage capacitor via the input-control path of the transistor and the starting stabilization diode and the primary winding of the ignition transformer.

The principal feature of the ignition system of the present invention is that it includes a storage capacitor which is connected to the primary winding of the ignition transformer via a transistor and a starting stabilization diode. The control electrode of the transistor is connected to a feedback winding of the ignition transformer. The starting pulse circuit is connected in parallel with the starting stabilization diode.

The charged storage capacitor of the ignition system of the present invention discharges via the transistor. The ignition is started without contacts and without additional amplifying units, by electrical pulses. The transistor may be of the most inexpensive type available.

The entire ignition system of the present invention may be embedded in plastic to protect it from the heat of its environment.

In order that the present invention may be readily carried into effect, it will now be described with reference to the accompanying drawings, wherein:

FIG. 1 is a circuit diagram of an embodiment of the ignition system of the present invention;

FIG. 2 is a circuit diagram of another embodiment of the ignition system of the present invention;

FIG. 3 is a circuit diagram of another embodiment of the ignition system of the present invention;

FIG. 4 is a circuit diagram of another embodiment of the ignition system of the present invention;

FIG. 5 is a circuit diagram of another embodiment of the ignition system of the present invention;

FIG. 6 is a circuit diagram of another embodiment of the ignition system of the present invention; and

FIG. 7 is a circuit diagram of still another embodiment of the ignition system of the present invention.

In the FIGS., the same components are identified by the same reference numerals.

In FIG. 1, the supply coil and the starting coil of an alternator are in independent circuits, separated electrically and spatially, but synchronized with each other. In FIG. 1, a storage capacitor C1 is connected to the collector or output electrode of a transistor T. If the transistor T is of PNP type, as in the example of FIG. 1, the collector electrode is negative. A rectifying diode D1 in the supply circuit is therefore connected in the forward direction for the negative half wave of the supply voltage from a supply coil L1 of an alternator A.

One end of the supply coil L1 is connected to a point Z at ground potential. The point at ground potential may comprise, for example, the engine frame (not shown in the FIGS.). The rectifying diode D1 is connected between the other end of the supply coil L1 and the collector electrode C of the transistor T. One plate of the storage capacitor C1 is connected to a common point in the connection between the rectifying diode D1 and the transistor T. The other plate of the storage capacitor C1 is connected to ground Z via the primary winding L2 of an ignition transformer TR1. The ignition transformer TR1 also has a secondary winding L3 and an auxiliary feedback winding L4.

An electrical voltage is produced in the supply coil L1 of the alternator A during rotation of the rotor R of said alternator. The voltage produced in the supply coil L1 stores energy in the storage capacitor C1 during each negative half wave, by charging said capacitor. The circuit parameters are so selected that the voltage across the storage capacitor C1 corresponds to the cutoff voltage V.sub.CBO of the transistor T. The input or emitter electrode E of the transistor T is connected to ground Z via a starting stabilization diode D2.

The starting stabilization diode D2 is connected in series circuit arrangement with the auxiliary feedback winding L4 of the ignition transformer TR1 in the emitter-base or input-control path of the transistor T. The starting stabilization diode D2 performs two functions. The first function of the starting stabilization diode D2 is the production of a small voltage of approximately 0.5 volt, provided by the supply of a residual current I.sub.CBO through the transistor T from the charged storage capacitor C1 at a time when said transistor is blocked or in its nonconductive condition. This small voltage, which is positive in the case of the present example, is applied to the control or base electrode B of the transistor T via the feedback winding L4 of the ignition transformer TR1.

The application of the voltage of approximately 0.5 volt to the base electrode B of the transistor T reduces the residual current I.sub.CE to I.sub.CBO and the cutoff voltage V.sub.CE of said transistor is substantially reduced to V.sub.CBO. The second function of the starting stabilization diode D2 is the provision of a very simple and reliable source of starting pulses. The source of starting pulse is the starting circuit, which comprises a starting coil L5 of the alternator A. The starting coil L5 is connected at one end to ground Z and is connected at its other end to the emitter electrode E of the transistor T via a diode D3 and a capacitor C2.

The starting coil L5 of the alternator A is spatially positioned and connected with such polarities relative to the supply coil L1 of said alternator, that, in the case of the present example, said starting coil produces a positive starting pulse when there is a positive supply voltage in said supply coil, so that the rectifying diode D1 is blocked or in its nonconductive condition. The diode D3 transfers a positive starting pulse only if the magnitude of such starting pulse is greater than the characteristic threshold voltage of said diode such as, for example, approximately 0.5 volt for a ceramic diode. This eliminates undesirable pulses which may occur in the alternator A.

The capacitor C2 is connected in parallel with the starting stabilization diode D2 and functions to substantially reduce the magnitude of the required starting pulse. The capacitor C2 shapes the pulses in a suitable manner and, with the inductance of the starting coil L5 of the alternator, produces a spark or flash. The inductance of the starting coil L5, at the instant of starting, cancels the bias voltage produced across the starting stabilization diode D2 which increases the residual current suddenly from I.sub.CBO to I.sub.CE via the transistor T. At the same instant, the positive starting current pulse, applied to the input electrode E and the control electrode B of the transistor T, switches said transistor to its conductive condition.

The starting current pulse, which is greater in magnitude than the residual current I.sub.CBO, passes through the primary winding L2 of the ignition transformer TR1 and produces in the iron core of said transformer a magnetic field which induces a pulse in the auxiliary feedback winding L4 of said ignition transformer. The pulse induced in the feedback winding L4 has a polarity which is such that there is positive coupling which tends to make the transistor T more conductive. This function is very rapid.

All the energy stored in the storage capacitor C1 is transformed into a magnetic field in the ignition transformer TR1. This results in the production of a high voltage, of approximately 25 kilovolts, in the secondary winding L3 of the ignition transformer TR1, due to the large number of turns of said winding. The 25 kilovolt voltage produced by the secondary winding L3 produces a spark in the spark plug SP. At such time, the rectifying diode D1 is blocked or in nonconductive condition, so that no energy is transferred from the supply coil L1 of the alternator A to the circuit of the transistor T. This prevents the circuit comprising the transistor T, the storage capacitor C1 and the ignition transformer TR1 from oscillating and said transistor is switched to its nonconductive condition. The circuit is then in its deenergized or inactive condition and the storage capacitor C1 is ready for charging with energy form the supply coil L1 of the alternator A via the rectifying diode D1 when the negative half wave of the supply voltage forms. The process is repeated when a positive pulse is produced by the starting coil L5 of the alternator A.

In the embodiment of FIG. 1, the supply voltage and the starting pulse are synchronized by the positions or locations and polarities of the supply coil L1 and the starting coil L5 relative to each other. The internal impedance of the supply coil L1 of the alternator A may therefore be as small as required and is determined only by the admissible magnitude of the current pulse of the rectifying diode D1.

It may be seen that the principle of operation of the circuit arrangement of FIG. 1 is such that the maximum voltage which may be produced in the circuit of the transistor T is the voltage of the storage capacitor C1. The storage capacitor C1, however, has a capacitance of several microfarads, and random pulses would have to have considerable magnitude to increase the voltage on the collector and emitter electrodes of the transistor T to an undesirable extent. Since the ignition system of the present invention is completely separated from the general network of the vehicle in which it is utilized, the voltage cannot increase to an undesirable magnitude. The number of turns of the auxiliary feedback winding L4 of the ignition transformer TR1 is selected so that the transistor T is switched to conductive condition within a minimum period of time and to prevent the pulse voltage between the emitter and base electrodes of said transistor from exceeding the required magnitude. This is achieved without difficulty.

Very good operation of the ignition system of the present invention was attained, even with a transistor having a cutoff voltage V.sub.CE =25 volts at R.sub.BE =0, with a current I.sub.CE =2 ma., at a temperature of 25.degree. C., and with a current I.sub. CE =5 ma. at R.sub.VE =0, V.sub.CE =40 volts, at a temperature of 25.degree. C. It is thus seen that even low-quality transistors function successfully at a voltage of 130 volts on the storage capacitor C1.

If for any outside reason whatsoever, a voltage appears at the storage capacitor C1 which may damage the transistor T, the residual current I.sub.CE is suddenly increased in magnitude. Under the effect of the positive feedback in the auxiliary feedback winding L4 of the ignition transformer TR1, the increased residual current I.sub.CE causes spontaneous conduction of the transistor T, so that the storage capacitor C1 commences to discharge instantaneously and the voltage is reduced to zero. This prevents damage to or destruction of the transistor T. The internal impedance of the supply coil L1 of the alternator A is always at least large enough that, in such a special case, damage of the transistor T by short circuit current is prevented. Such a situation does not occur under practical operating conditions, but is described in order to illustrate the protection of the transistor from damage, as well as the reliability of operation of the ignition system of the present invention.

In FIG. 2, a single alternator coil functions as the supply coil and the starting coil. The embodiment of FIG. 2 differs from that of FIG. 1 only in the manner of producing a starting pulse. The supply coil L1 of the alternator A functions also to provide a starting pulse. When a positive voltage is produced and the rectifying diode D1 is blocked, the starting pulse is transmitted via the diode D3 to the shaping capacitor C2 and the starting stabilization diode D2. If the preceding negative half wave from the supply coil L1 of the alternator A has charged the storage capacitor C1 via the rectifying diode D1, the positive half wave may switch the transistor T to its conductive condition. Thus, during one revolution, as many sparks are provided as there are pairs of poles N and S on the rotor R2 of the alternator A2. In the embodiment of FIG. 2, the rotor R2 of the alternator A2 has two pairs of poles N and S, so that two sparks are produced in each revolution.

In FIG. 3, the alternator and the spark distributor form a single unit. In the embodiment of FIG. 3, the rotor R of the alternator A has four pairs of poles N and S, so that four sparks are produced in each revolution. The alternator A is directly coupled mechanically to a spark distributor SD. This provides an ignition system for a four stroke, four cylinder engine. The systems of FIG. 2 and FIG. 3 require, apart from the engine frame, which functions as the ground lead, only a single electrical conductor to interconnect the supply and starting coil L1 of the spark distributor SD with the transistor circuit. This is of great importance regarding service and maintenance.

In FIG. 4, the ignition system is supplied with power from one phase of a standard three-phase alternator and the voltage is increased to the required magnitude by a transformer. The starting coil is included with the spark distributor. In the embodiment of FIG. 4, the power is supplied by a single phase X of a standard three-phase alternator A3. A transformer TR2 has a primary winding L6 and a secondary winding L7 which replaces the supply coil L1 of the embodiment of FIG. 1.

The starting coil L5 is independent from the supply transformer TR2 and is included with the spark distributor SD. Since it is impossible to synchronize the supply voltage provided by the secondary winding L7 of the transformer TR2 with the voltage pulse provided by the starting coil L5 of the spark distributor SD, the internal impedance of said secondary winding has to be at least 400 ohms, to prevent the transistor circuit from oscillating under the influence of the positive feedback.

The current from the secondary supply winding L7 must not exceed a magnitude which maintains the positive feedback. This may be accomplished by the proper selection of the transformer TR2. Operation is then as reliable as in the embodiments of FIGS. 1, 2 and 3. Therefore, any suitable voltage and power source may be utilized in the embodiment of FIG. 4 if said source has an internal impedance greater than 400 ohms, and it is not necessary that the supply voltage and the starting pulse be synchronized. A suitable power source may comprise, for example, a transistor converter or an oscillatory or vibratory converter.

In FIG. 5, the starting circuit comprises a galvanomagnetic resistor rather than a starting coil, said resistor having a resistance value which depends upon the intensity of the magnetic field. In the embodiment of FIG. 5, a galvanomagnetic resistor GR is positioned in the magnetic field of the rotor R of the alternator A. The ohmic resistance value of the galvanomagnetic resistor GR is dependent upon the intensity of the magnetic field.

The galvanomagnetic resistor GR is connected to the storage capacitor C1 and to the starting stabilizing diode D2. When the resistance value of the galvanomagnetic resistor GR varies due to a variation in the magnetic field of the rotor R, an electrical pulse is transmitted from the storage capacitor C1 through said galvanomagnetic resistor and the primary winding L2 of the ignition transformer TR1. Such pulse, with the assistance of the feedback winding L4 of the ignition transformer TR1, switches the transistor T to its conductive condition, and the storage capacitor C1 discharges into the primary winding L2 of said ignition transformer. In other respects, the embodiment of FIG. 5 is the same as the other described embodiments of the present invention in operation.

In FIG. 6, a variable capacitor is connected between the storage capacitor and the starting stabilization diode. In the embodiment of FIG. 6, a variable capacitor C3 having a variable capacitance is mechanically coupled to and rotates with the rotor R of the alternator A and is electrically connected between the storage capacitor C1 and the starting stabilization diode D2. If the capacitance of the variable capacitor C3 varies rapidly, for example, if said capacitance increases, said variable capacitor is charged by current from the storage capacitor C1 via the primary winding L2 of the ignition transformer TR1.

The charging current of the variable capacitor C3 provided by the storage capacitor C1 and the auxiliary feedback winding L4 of the ignition transformer TR1 switch the transistor T to its conductive condition. When the transistor T is conductive, the storage capacitor C1 discharges into the primary winding L2 of the ignition transformer TR1. In other respects, the ignition system of FIG. 6 functions in the same manner as the previously described embodiments.

In FIG. 7, a variable capacitor is electrically connected between the collector and base electrodes of the transistor. In the embodiment of FIG. 7, the variable capacitor C3 is mechanically coupled to and rotates with the rotor R of the alternator A and is electrically connected between the collector and base electrodes of the transistor T. If the capacitance of the variable capacitor C3 increases rapidly, the charging current of the storage capacitor C1 flows through the control or base electrode B and the input or emitter electrode E of the transistor T and through the starting stabilization diode D2 to the primary winding L2 of the ignition transformer TR1.

The charging current pulse of the variable capacitor C3 and the auxiliary feedback winding L4 of the ignition transformer TR1 switch the transistor T to its conductive condition. When the transistor T is conductive, the storage capacitor C1 discharges into the primary winding L2 of the ignition transformer TR1. Otherwise, the ignition system of FIG. 7 functions in the same manner as the previously described embodiments.

If the transistor T is of NPN type, the polarities of the diodes D1, D2 and D3 must be reversed. The positive half wave of the current provided by the supply coil L1 of the alternator A is utilized. The starting pulse then has a negative polarity.

The ignition system of the present invention reveals some functional deficiencies of engines such as, for example, the engine filling with a mixture, faults in the fuel system, and the like. This permits further improvements to be made in the engine. Some of the deficiencies may be due to operation with an ignition system of known type, because it is difficult to determine the actual nature of the deficiency, especially in engines which have already run a considerable distance and in which decrease in output power is due to a variety of reasons.

While the invention has been described by means of specific examples and in specific embodiments, we do not wish to be limited thereto, for obvious modification will occur to those skilled in the art without departing from the spirit and scope of the invention.

Claims

What we claim is:

1. An ignition system, comprising

a supply circuit,

starting pulse means,

an ignition transformer having a primary winding, a secondary winding connected to an igniting device and a feedback winding,

a semiconductor switching device having input and output electrodes, an input-output path and a control electrode connected to the feedback winding of said ignition transformer,

a starting stabilization diode connected to said starting pulse means, and

a storage capacitor supplied by said supply circuit and connected in parallel to the primary winding of said ignition transformer and the input-output path of said semiconductor switching device and said starting stabilization diode.

2. An ignition system as claimed in claim 1, wherein said semiconductor switching device comprises a transistor.

3. An ignition system as claimed in claim 2, further comprising a starting pulse circuit connected in parallel with said starting stabilization diode for providing a starting pulse.

4. An ignition system as claimed in claim 2, further comprising a shaping capacitor connected in parallel with said starting stabilization diode, a diode and a starting pulse circuit connected in parallel with said starting stabilization diode for providing a starting pulse, said starting pulse circuit comprising an alternator having a starting coil connected via said diode to said shaping capacitor

5. An ignition system as claimed in claim 4, further comprising a variable capacitor mechanically coupled to the alternator of said starting pulse circuit and connected to said storage capacitor via the primary winding of said ignition transformer.

6. An ignition system as claimed in claim 4, wherein said transistor has an input-control path, and further comprising a variable capacitor mechanically coupled to the alternator of said starting pulse circuit and connected to said storage capacitor via the input-control path of said transistor and said starting stabilization diode and the primary winding of said ignition transformer.

7. An ignition system as claimed in claim 4, wherein the alternator of said starting pulse circuit has a supply coil, said supply coil and the starting coil of said alternator being positioned in operative inductive proximity with each other.

8. An ignition system as claimed in claim 4, further comprising a rectifying diode and wherein the alternator of said starting pulse circuit has a supply coil connected to said ignition transformer in the first half cycle of the alternator current via said rectifying diode and said storage capacitor and in the second half cycle of said alternator current via said diode, the starting stabilization diode of said starting pulse circuit and said shaping capacitor.

9. An ignition system as claimed in claim 4, wherein the alternator of said starting pulse circuit has a galvanomagnetic resistor connected to said storage capacitor via the primary winding of said ignition transformer.