US3677254A

US3677254A - Thyristor circuit arrangement, especially for periodically switching-in and switching-out a load

Info

Publication number: US3677254A
Application number: US90385A
Authority: US
Inventors: Rudolf Diener
Original assignee: Autoelektronik AG
Current assignee: Autoelektronik AG
Priority date: 1969-11-20
Filing date: 1970-11-17
Publication date: 1972-07-18
Anticipated expiration: 1989-07-18
Also published as: CA926461A; CS149938B2; JPS5032362B1; GB1305639A; FR2068559A1; CH516083A; DE2054133A1; SE377166B; BR7024039D0; NL7016132A; CH505290A; CH518035A; DE2054133B2; AT311132B; FR2068559B1; BR7024040D0; DE2054133C3; SU366623A3; GB1327440A

Abstract

A thyristor circuit arrangement, especially for periodically switching-in and switching-out a load, comprising a thyristor including a control electrode and an ignition circuit electrically coupled with such control electrode. The circuit embodies a control transmitter-switch means capable of being switched into a first and second switching state for controlling the ignition sequence, and upon switching of such control transmitter switch means from its first switching state into its second switching state the thyristor fires. The invention contemplates that the ignition circuit embodies an ignition capacitor electrically coupled with the control electrode of the thyristor in order to fire such thyristor by means of a charging current surge. The ignition capacitor can be connected for charging, by means of an auxiliary control circuit and electronic switch means electrically coupled with said auxiliary control circuit, with a charging voltage source, and for discharging can be connected with a discharge circuit. The control transmitterswitch means controls the auxiliary control circuit and the discharge circuit, so that during switching of such control transmitter-switch means from its first switching state into its second switching state the electronic switch means is switched-in with the discharge circuit open, and in its first switching state closes said discharge circuit.

Description

United States Patent Diener [451 July 18,1972

[s4] THYRISTORICIRCUIT ARRANGEMENT, ESPECIALLY FOR PERIODICALLY SWITCHING-IN AND SWITCHING-OUT A LOAD Rudolf Diener, Zurich, Switzerland Autoelektronik AG, Graubunden, Switzerland [22] Filed: Nov. 17, 1970 [21] Appl. No.: 90,385

[72] Inventor:

[73] Assignees [30] Foreign Application Priority Data Nov. 20, 1969 Switzerland ..l7307/69 [52] U.S. Cl. ..l23/l48 E, 315/209 T ..F02p 3/06 ....123/14s E; 315/209 CD, 209 so [51] lnt.Cl.,'... [58] Field of Search Tada Primary Examiner-Laurence M. Goodridge Assistant Examiner-Cort Flint Attorney-OstrOlenk, Faber, Gerb & Sofi'en ABSTRACT A thyristor circuit arrangement, especially for periodically switching-in and switching out a load, comprising a thyristor including a control electrode and an ignition circuit electrically coupled with such control electrode. The circuit embodies a control transmitter-switch means capable of being switched into a first and second switching state for controlling the ignition sequence, and upon switching of such control transmitter switch means from its first switching state into its second switching state the thyristor fires. The invention contemplates that the ignition circuit embodies an ignition capacitor electrically coupled with the control electrode of the thyristor in order to fire such thyristor by means of a charging current surge. The ignition capacitor can be connected for charging, by means of an auxiliary control circuit and electronic switch means electrically coupled with said auxiliary control circuit, with a charging voltage source, and for discharging can be connected with a discharge circuit. The control transmitter-switch means controls the auxiliary control circuit and the discharge circuit, so that during switching of such control transmitter-switch means from its first switching state into its second switching state the electronic switch means is switched-in with the discharge circuit open, and in its first switching state closes said discharge circuit.

9 Claims, I Drawing Figure Patented July 18, 1972 INVENTOR. H70 01F fl/E/V5A THYRISTOR CIRCUIT ARRANGEMENT, ESPECIALLY FOR PERIODICALLY SWITCHING-IN AND SWITCHING- OUT A LOAD BACKGROUND OF THE INVENTION sequence contains a control transmitter-switch means whichcan be switched into a first and second switching state, and wherein the thyristor ignites each time when switching the control transmitter-switch means from a first into a second switching state.

Thyristor circuit arrangements of this type are oftentimes used in capacitor-ignition devices for internal combustion engines in order, during each ignition operation, to discharge by means of a thyristor a storage capacitor charged predominantly by an inductive storage means through the primary winding of an ignition transformer and in the secondary winding thereof to induce a voltage which is high enough to produce an ignition spark at the electrodes of a spark plug. In this regard, there can be used as the control transmitter-switch means either a mechanical interrupter, whereby generally when the interrupter contacts are open the thyristor is fired to bring about discharge of the capacitor, or else there can be used a contactless electromagnetic transmitter which, for instance, is driven by the distributor shaft, and during each revolution of one of the number of cylinders delivers an appropriate number of control pulses to the ignition circuit of the thyristor. Generally, the control pulses initially act upon an electronic switch and by means of the latter the ignition circuit is then controlled.

More specifically, it is here mentioned that, for instance, with a known ignition device for controlling a thyristor arranged in the discharge circuit of a storage capacitor there is provided a transistorized pulse generator circuit possessing a control transformer equipped with two secondary windings. One secondary winding serves to control charging of the capacitor, and the other secondary winding is coupled with the control electrode of the thyristor. By means of a control pulse produced upon opening the interrupter contacts the pulse generator circuit causes a current to flow through the primary winding of the control transformer, and in the second secondary winding there is induced a voltage for an ignition pulse, so that the thyristor ignites and the storage capacitor is able to discharge. Upon discharge of the storage capacitor, the resonance in the discharge circuit causes blocking of the thyristor, so that the storage capacitor can again be charged.

it is also known to equip a charging transformer with a second secondary winding. This second secondary winding is then electrically coupled with the control electrode of a thyristor, so that a transistorized circuit arrangement controls the current flow through the primary winding of a charging transformer and the circuit arrangement, in turn, is controlled by the control transmitter.

It should be understood that an electronic ignition mechanism must be designed so as to be compact for reasons of utility and housed in a sealed or closed housing. The ignition mechanism should be mounted at the vehicle at the region of the engine beneath the hood. However, beneath the engine hood there generally prevail temperatures which range almost up to the maximum temperatures permissible to be used for the semiconductor elements used in the ignition mechanism. Such construction and mounting of the ignition mechanism is therefore generally only possible if the ignition mechanism does not additionally heat up itself during operation, that is to say, at the ignition device or mechanism no appreciable power losses should occur. Of course, for the entire power loss of an ignition mechanism which has been designed to possess a compact construction the power losses of the ignition circuit are also of importance for the thyristor. With known thyristor circuit arrangements the power losses are generally not negligibly low, so that their use in ignition devices leads to unsatisfactory results.

The foregoing will be better understood if it is appreciated that especially in the case of mechanical control transmitterswitches which are actuated in a rapid sequence, for instance mechanical interrupters, the movable contact after having been opened does not immediately remain in its open position, rather strikes one or more times back against the stationary contact. This chattering or fluttering of the movable contact can lead to faulty ignition of the thyristor. Hence, it is necessary to resort to measures which render ineffectualthis switch chattering or restriking of the stationary contact by the movable contact. Similar experiences can also be encountered with contactless control transmitters.

SUMMARY OF THE INVENTION Accordingly, there is still present a real need in the art for an improved type of thyristor circuit arrangement, especially for periodically switching-in and switching-out a load, which is not associated with the aforementioned drawbacks and disadvantages of the prior art circuitry. Hence, a primary objective of the present invention is to provide a thyristor circuit arrangement for this purpose which effectively and reliably fulfills the existing need of the art. 7

Another and more specific object of the present invention relates to the provision of a new and improved thyristor circuit arrangement for switching-in and switching-out a load, exhibiting a negligibly low power loss in the ignition circuit while possessing a simple construction and design and is economical to manufacture, and wherein the faulty ignition of the thyristor owing to the above-discussed chatter or restriking effect can be effectively prevented without any additional expenditure.

Now, in order to implement these and still further objects of the invention, which will become more readily apparent as the description proceeds, the inventive thyristor circuit arrangement is manifested by the features that the ignition circuit contains an ignition capacitor which is electrically connected with the control electrode of a thyristor in order to ignite such by a charging current surge. The ignition capacitor is connectable by means of an electronic switch coupled with an auxiliary control circuit with a charging voltage source and is connectable for discharging with a discharge circuit. To this end, the auxiliary control circuit and the discharge circuit are controlled by the control transmitter-switch means in order that upon switching thereof from the first into the second switching state there can be switched-in the electronic switch with the discharge circuit being interrupted and in the first switching state to close the discharge circuit.

The electronic switch or switch means can preferably be constituted by a thyristor, whereby then the auxiliary control circuit is designed as an auxiliary ignition circuit for the control-thyristor.

In contrast to the previously mentioned prior art circuit arrangements the inventive circuit arrangement does not possess as components thereof any windings possessing inductance. The power loss of the ignition circuit is essentially limited to the power loss of the electronic switch i.e. the controlthyristor, which however can be maintained so low by appropriately dimensioning the chargingand discharging circuit for the ignition capacitor, that such is no longer sufficient to bring about an additional heating-up of the circuit arrangement.

' By appropriately selecting a suitable resistance value for the discharge circuit it is possible to spread the discharge time of the ignition capacitor over a time interval in which the chattering or restrike effect occurring at the control transmitterswitch is ineffectual. Hence, charging of the ignition capacitor to a value sufficient for generating an ignition pulse for the thyristor is only then possible when the control transmitterswitch has finally switched without chattering into its second switching state.

A direct-current voltage source can be provided for operating the control-thyristor. Moreover, as the auxiliary ignition circuit for the control-thyristor there can be used a conventional voltage divider with two resistors which can be connected to the direct-current voltage source and connected in parallel to the control-thyristor, with the control electrode of the control-thyristor being coupled with the center tap of the voltage divider.

Now, in order to even further simplify the circuit arrangement it is possible to simultaneously also utilize the voltage divider of the auxiliary ignition circuit consisting of both of the series connected resistors as the discharge circuit for the ignition capacitor in that, the positive pole of the direct-current voltage source is coupled via a diode poled in the conductive direction with the voltage divider and such is connected via the control transmitter-switch with the negative pole of the direct-current voltage source. Furthermore, the control electrode of the control-thyristor with the resistor of the voltage divider connecting such to its cathode has connected in parallel thereto a diode in the blocking direction, so that in the first switching position of the control transmitter-switch the discharge current circuit for the ignition capacitor is closed, and in the second switch position thereof the discharge current circuit is interrupted and the auxiliary ignition circuit for the control-thyristor is excited.

The charging voltage source for the ignition capacitor can consist of a charging capacitor with a charging circuit controlled by the control transmitter-switch. In the first switching condition of the control transmitter-switch the charging capacitor is charged via the charging circuit from an auxiliary voltage source and upon switching-over into the second switching state or condition of the control transmitter-switch is discharged into the ignition capacitor.

The inventive thyristor circuit arrangement for generating ignition sparks for an internal combustion engine can be used to particular advantage, especially in a circuit arrangement in which there are provided a storage capacitor, a charging transformer for charging the storage capacitor and an ignition transformer. The thyristor circuit arrangement then control the momentary discharge of the storage capacitor through the primary winding of the ignition transformer and, furthermore, wherein there is provided a transistorized control circuit with a feedback element. in order to control the current flow through the primary winding of the charging transformer, and via such to control the momentary charging-up of the storage capacitor. In such an arrangement the charging-voltage source for the ignition capacitor of the thyristor circuit arrangement can be constituted by a capacitor, one electrode of which is connected with ground and the other electrode of which is coupled with the electronic switch and connected with the primary winding of the charging transformer. When the electronic switch is turned-off the capacitor forming the charging voltage source is charged through the primary winding of the charging transformer, and when the electronic switch is turnedor switched-on the ignition capacitor is charged by means of the capacitor forming the charging voltage source.

The invention will now be more fully explained in detail in conjunction with an exemplary embodiment of circuit arrangement serving to generate ignition sparks for an internal combustion engine.

BRIEF DESCRIPTION OF THE DRAWING The invention will be better understood and objects other than those set forth above will become apparent when consideration. is given to the following detailed description thereof. Such description makes reference to the annexed drawing, wherein the single figure thereof shows an exemplary embodiment of circuit diagram of a thyristor circuit arrange ment designed according to the invention and containing an ignition device, wherein for preserving clarity in illustration of this circuit diagram there has only been shown therein the spark path of a single cylinder and a mechanical interrupter serving as the interrupter switch means which is driven in synchronism with the motor shaft.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Describing now the drawing, in the single Figure illustrated therein there isdepicted a preferred embodiment of ignition device constituted by a circuit arrangement containing a first circuit portion SA which serves for the actual generation of the ignition sparks, and apart from the ignition transformer 7 and a storage capacitor C; also contains a charging transformer 1. This charging transformer 1 possesses a conventional iron core carrying a primary winding la and a secondary winding 1b, and which is used in the circuitry as inductive storage means.

The one end of the primary winding 70 of the ignition transformer 7 which is bridged by a diode D, is electrically coupled through the agency of the storage capacitor C and a charging diode D with one end of the secondary winding lb of the charging transformer l. The other ends or terminals of the primary winding 7a of the ignition transformer 7 and the secondary winding lb of the charging transformer l are connected with ground. The one end of the primary winding la of the charging transformer l is connected via an ignition switch Z with the positive pole of a direct-current voltage source B2, namely the vehicle battery, and additionally is coupled with the third circuit portion SC, the thyristor circuit arrangement.

Continuing, it will be observed that the other terminal of the primary winding la of the charging transformer 1 leads to a second circuit portion SB serving to control the current flow through the primary winding 1a and containing a transistor T as well as a feedback 2. In the illustrated embodiment the feedback element 2 possesses a main winding 2a and a first secondary winding 2b and a second secondary winding 2c. The primary winding 1a is connected with the collector-emitter path of the transistor T and the main winding 2a in series with the poles of the direct-current voltage source Bt. A current surge through the second control winding 2c of the feedback element 2 causes the transistor T to conduct and current to begin to flow through the primary winding 1a of the charging transformer 1. Upon reaching a certain current intensity the transistor T should block. Circuit arrangements suitable for this purpose are well known to those versed in the art, and therefore need not be explained in greater detail, since such operation, beyond that which has been stated herein, is not completely necessary for understanding the underlying concepts of the present invention. Upon interruption of the current flow through the primary winding 1a the magnetic field of the charging transformer 1 collapses andvoltages are induced both in the primary winding 10 as well as in the secondary winding lb thereof. As mentioned, the charging capacitor C: is charged-up by means of the secondary winding lb. To discharge the storage capacitor C there is provided a thyristor circuit arrangement with the thyristor 6 and an ignition circuit, which forms the third circuit portion SC of the ignition device.

The illustrated ignition circuit SC contains an ignition capacitor C the one electrode of which is connected via a resistor R to ground and via a connection terminal 11 is coupled by means of a conductor 10 with the control electrode G of the thyristor 6. A Zener diode ZD is connected parallel with the resistor R for voltage stabilization purposes. The other electrode of the ignition capacitor C is connected via a charging resistor R with the cathode of a control thyristor 5. The anode of the control thyristor 5 is coupled via the second control winding 20 of the feedback element 2 both with the one electrode of a capacitor C, as well as also via a diode D the primary winding 1a of the charging transformer 1 and the ignition switch 2 with the positive pole of the direct-current voltage source Bt. The other electrode of the capacitor C is connected with ground. The capacitor C together with the diode D and the primary winding 1 a of the charging transformer l defining an inductive storage means forms the charging-voltage source for the ignition capacitor C as will be still further more fully explained hereinafter.

Furthermore, the positive pole of the direct-current voltage source Bt is coupled via the ignition switch Z, a current limiting resistor R a diode D which is poled in its conductive direction and two series connected resistors R and R forming a voltage divider, with the cathode of the control-thyristor 5. This circuit portion forms the auxiliary ignition circuit for the control-thyristor, with the control electrode thereof being connected with the center tap of the voltage divider R and R Now, for the purpose of stabilizing the ignition voltage for the control-thyristor 5 and the operating voltage for the ignition device the junction point of the ignition switch 2 and the current limiting resistor R, as well as the junction point of the current limiting resistor R and the diode D are connected via a respective Zener diode 2D: and ZD and a ground conductor 9 with ground. The negative pole of the direct-current voltage source Bt is connected with ground and is coupled with the movable contact 3b of the mechanical interrupter or switch used here as the control transmitter-switch means U. The stationary contact 3a of the interrupter is coupled via a diode D, with the junction point of the diode D and the voltage divider R R,,. A diode D is connected in parallel with the resistor R of the voltage divider R R coupling the control electrode of the control-thyristor with its cathode. When the

interrupter contacts

3a, 3b are closed, then, there is formed for the ignition capacitor C a discharge current circuit consisting of the resistor R the diode D and the resistor R, as well as the diode D and the

interrupter contacts

3a, 3b.

If the ignition switch 2 is closed during such time as the capacitor C is charged and the

interrupter contacts

3a, 3b are open, then the ignition capacitor C begins to charge through the agency of the current limiting resistor R the diode D and the resistors R R of the voltage divider as well as the resistor R Due to the current flow through the voltage divider connected in parallel with the control-thyristor 5, this controlthyristor 5 begins to conduct and, as will be explained more fully hereinafter, the capacitor C which is at a higher voltage completely charges the ignition capacitor C through the agency of the second control winding of the feedback element 2, the fired or ignited control thyristor 5 and the resistor R The pronounced current pulse charging the ignition capacitor C generates via the resistor R, an ignition pulse for the thyristor 6. As a result, thyristor 6 ignites and the storage capacitor C discharges through the primary winding 7a of the ignition transformer 7 and produces via the secondary winding 7b of this ignition transformer 7 an ignition spark.

Due to the current fiow through the second control winding of the feedback element 2, there is simultaneously induced in its first control winding 21; a voltage which fires the transistor T. As a result, current begins to flow through the primary winding 1a of the charging transformer 1. When a certain current intensity has been reached, the transistor T again blocks, so that the magnetic field of the charging transformer l collapses and the capacitor C, is charged via thediode D owing to the induced voltage at its primary winding la, since previously the control-thyristor 5 was again blocked during charging of the ignition capacitor C The ratio of the number of turns of the primary and secondary windings of the charging transformer is chosen such that the storage capacitor C charges to approximately 370 volts and the capacitor C to about 40 volts. This voltage at the capacitor C is sufficient to also charge the ignition capacitor C to about volts, so that a sufiiciently high voltage appears at the open interrupter contacts 30, 3b for preventing the previously mentioned faulty closure during closing of the contacts.

Upon closing the

interrupter contacts

3a, 3b the ignition capacitor C discharges on the one hand through the resistor R and, on the other hand, via the resistor R the diode D and the resistor R as well as the diode D whereby the direct-current voltage source Br is short-circuited across the current limiting resistor R but, however, owing to the magnitude of the current limiting resistance only a very small current flows.

As already explained, the ignition pulse for the thyristor 6 of the circuit arrangement is generated by the charging current virtue of static charging brought about due to disturbing or i of the ignition capacitor C So that a sufficient voltage droppulse can appear at the resistor R for igniting the thyristor 6, it is necessary that the capacitor C prior to charging possesses a certain free charging capacity. If upon ignition of the control-thyristor 5 the ignition capacitor C has not sufficiently discharged, then the voltage drop-pulse at the resistor R is not sufficient for igniting the control-thyristor 6. In order to prevent erroneous or faulty ignitions due to the previously explained chattering or restriking of the interrupter contacts 30, 3b, the resistance values of the resistors R, and R,,, R, are dimensioned or chosen such that an ignition operation is only then effective when the interrupter contacts have been closed for a certain period of time, so that the ignition capacitor C, can discharge to a desired degree.

If the

interrupter contacts

3a, 3b again open, then the above-described procedure repeats. The Zener diode ZD prevents erroneous ignitions which would occur during fiuctuations of the voltage.

The diode D prevents-faulty ignition which might occur by stray fields.

The thyristor circuit arrangement described herein in conjunction with an ignition device and for switching-in and switching-out a load is also readily usable for other purposes, to which end changes in circuit design essentially will be limited to the construction of the control transmitter-switch means and the charging-voltage source for the ignition capacitor.

The thyristor circuit arrangement of the present invention is quite simple in construction and design and its power loss during operation is so slight that an inherent heating-up of the semiconductor components practically does not occur.

While there is shown and described present preferred embodiment of the invention, it is to be distinctly understood that the invention is not limited thereto, but may be otherwise variously embodied and practiced within the scope of the following claims.

Accordingly what is claimed is:

l. A thyristor circuit arrangement, especially for periodically switching-in and switching-out a load, comprising a thyristor including a control electrode, an ignition circuit electrically coupled with said control electrode of said thyristor, a control transmitter-switch means capable of being switched into first and second switching states for controlling the ignition sequence, said control transmitter-switch means when switched from its first switching state into its second switching state causing firing of said thyristor, said ignition circuit incorporating an ignition capacitor electrically coupled with said control electrode of said thyristor in order to fire said thyristor by means of a charging current surge, auxiliary control circuit means including a resistor and a capacitor which define a timing circuit and electronic switch means electrically coupled with said auxiliary control circuit means, means defining a charging voltage source, said ignition capacitor being electrically connected in series with said electronic switch means for charging by means of said electronic switch means coupled with said auxiliary control circuit with said charging voltage source, means defining a discharge circuit, said ignition capacitor being connectible with said discharge circuit for discharge thereof, said control transmitter-switch means controlling said auxiliary control circuit means and said discharge circuit such that at a given time after switching of said control transmitter-switch means from its first switching state into its second switching state said electronic switch means is turnedon with the discharge circuit open and such that said control- 7 transmitter switch means in its first switching state closes said discharge circuit.

2. The circuit arrangement as defined in claim 1, wherein said electronic switch means comprises control thyristor means, and wherein said auxiliary control circuit means provides an auxiliary ignition circuit for said control thyristor means.

3. The circuit arrangement as defined in claim 2, wherein said control thyristor means includes an anode, control electrode and cathode, said auxiliary ignition circuit for said control thyristor means defining said electronic switch means incorporating voltage divider means connected parallel to its switching path, said voltage divider means comprising a first resistor which connects said control electrode of said control thyristor means with its cathode, a direct-current voltage source, and a second resistor of said voltage divider means coupled with one pole of said direct-current source.

4. The circuit arrangement as defined in claim 1, wherein said discharge circuit comprises at least one resistor having a resistance value which extends the discharge time of said ignition capacitor over a timespan during which said control transmitter switch means switches without chatter.

5. The circuit arrangement as defined in claim 3, wherein said voltage divider means of said auxiliary ignition circuit forms part of said discharge circuit for said ignition capacitor, said voltage divider means being connected via said control transmitter-switch means with the other pole of said directcurrent source, and blocking diode means for forming a charging circuit for said ignition capacitor during the second switching state of said control transmitter switch means, upon charging of said ignition capacitor firing said control thyristor means and when said ignition capacitor is charged blocking said control thyristor means, and for freeing said discharge circuit when said control transmitter-switch means assumes its first switching state.

6. The circuit arrangement as defined in claim 1, wherein said means defining a charging voltage source for charging said ignition capacitor comprises a charging capacitor, and an auxiliary voltage source for charging said last-mentioned charging capacitor.

7. The circuit arrangement as defined in claim 5, wherein said means defining a charging voltage source for charging said ignition capacitor comprises a charging capacitor, and an auxiliary voltage source for charging said last-mentioned charging capacitor and wherein said charging capacitor can be charged by said auxiliary voltage source to a higher voltage than the voltage of said direct-current source.

8. A circuit arrangement as defined in claim 7, particularly for use in an electronic ignition device for internal combustion engines in which there is provided a storage capacitor, a charging transformer including a primary winding and a secondary winding, a charging rectifier means, said storage capacitor being charged via said secondary winding of said charging transformer and said charging rectifier means, an ignition transformer having a primary and second winding, said storage capacitor discharging through said primary winding of said ignition transformer, a transistor circuit arrangement including feedback means for controlling the current flow through said primary winding of said charging transformer, said thyristor being connected in parallel with said storage capacitor in order to control discharge thereof, said auxiliary voltage source for said charging capacitor comprising said primary winding of said charging transformer, and wherein a terv minal of said charging capacitor coupled with said electronic switch means is connected via a diode with one end of said primary winding of said charging transformer.

9. The circuit arrangement as defined in claim 8, wherein said charging capacitor can be charged by means of said primary winding of said charging transformer to 40 volts and said ignition capacitor can be charged by said charging capacitor to 30 volts.

Claims

1. A thyristor circuit arrangement, especially for periodically switching-in and switching-out a load, comprising a thyristor including a control electrode, an ignition circuit electrically coupled with said control electrode of said thyristor, a control transmitter-switch means capable of being switched into first and second switching states for controlling the ignition sequence, said control transmitter-switch means when switched from its first switching state into its second switching state causing firing of said thyristor, said ignition circuit incorporating an ignition capacitor electrically coupled with said control electrode of said thyristor in order to fire said thyristor by means of a charging current surge, auxiliary control circuit means including a resistor and a capacitor which define a timing circuit and electronic switch means electrically coupled with said auxiliary control circuit means, means defining a charging voltage source, said ignition capacitor being electrically connected in series with said electronic switch means for charging by means of said electronic switch means coupled with said auxiliary control circuit with said charging voltage source, means defining a discharge circuit, said ignition capacitor being connectible with said discharge circuit for discharge thereof, said control transmitter-switch means controlling said auxiliary control circuit means and said discharge circuit such that at a given time after switching of said control transmitter-switch means from its first switching state into its second switching state said electronic switch means is turned-on with the discharge circuit open and such that said control-transmitter switch means in its first switchIng state closes said discharge circuit.

4. The circuit arrangement as defined in claim 1, wherein said discharge circuit comprises at least one resistor having a resistance value which extends the discharge time of said ignition capacitor over a time-span during which said control transmitter switch means switches without chatter.

5. The circuit arrangement as defined in claim 3, wherein said voltage divider means of said auxiliary ignition circuit forms part of said discharge circuit for said ignition capacitor, said voltage divider means being connected via said control transmitter-switch means with the other pole of said direct-current source, and blocking diode means for forming a charging circuit for said ignition capacitor during the second switching state of said control transmitter switch means, upon charging of said ignition capacitor firing said control thyristor means and when said ignition capacitor is charged blocking said control thyristor means, and for freeing said discharge circuit when said control transmitter-switch means assumes its first switching state.

8. A circuit arrangement as defined in claim 7, particularly for use in an electronic ignition device for internal combustion engines in which there is provided a storage capacitor, a charging transformer including a primary winding and a secondary winding, a charging rectifier means, said storage capacitor being charged via said secondary winding of said charging transformer and said charging rectifier means, an ignition transformer having a primary and second winding, said storage capacitor discharging through said primary winding of said ignition transformer, a transistor circuit arrangement including feedback means for controlling the current flow through said primary winding of said charging transformer, said thyristor being connected in parallel with said storage capacitor in order to control discharge thereof, said auxiliary voltage source for said charging capacitor comprising said primary winding of said charging transformer, and wherein a terminal of said charging capacitor coupled with said electronic switch means is connected via a diode with one end of said primary winding of said charging transformer.