JPH0256518B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an ignition device used to ignite an internal combustion engine, and more particularly to an ignition device for an internal combustion engine that has a function of preventing engine overspeed. It is.

Prior Art Conventionally, as a device to prevent overspeeding of an internal combustion engine, a device that controls the rotation speed by using a mechanical governor to delay the ignition position of the engine in the high-speed region of the engine has been widely used. This type of governor had problems with its lifespan due to wear of the moving parts, and also had the drawback of requiring frequent adjustments. Therefore, various ignition devices have been proposed that detect the rotational speed of the engine and delay the ignition position of the engine or cause a misfire when the rotational speed reaches a control speed to prevent overspeeding. However, in conventional ignition systems of this type, output fluctuations of a generator that rotates synchronously with the engine are detected as fluctuations in rotational speed.
There is a drawback that the controlled rotational speed changes when the detected output changes due to changes in the gap between the rotor and stator due to the way the generator is installed. Especially in the case of a magnet generator, when the magnet is heated by the heat of the engine, the output decreases, and when the coil is further heated, its resistance increases and the output decreases, causing the engine temperature to rise. When the engine temperature rises excessively, the rotational speed is detected to be lower than the actual speed, and when the engine temperature rises excessively, the overspeed prevention operation is delayed and cannot protect the engine from destruction. It was hot.

OBJECT OF THE INVENTION An object of the present invention is to provide an ignition device for an internal combustion engine that can always reliably prevent the engine from over-speeding by preventing the detected value of the rotational speed from changing due to fluctuations in the output of the generator. It is in.

Structure of the Invention The present invention provides an ignition power supply coil that induces an alternating current voltage in synchronization with the rotation of an internal combustion engine, and a main current control transistor switch connected in parallel to the ignition power supply coil. A cutoff control switch is provided to cut off the main current control transistor switch, and when the voltage across the main current control transistor switch reaches a set level, a control terminal of the cutoff control switch is connected to the cutoff control switch. and a signal supply circuit that provides a conduction signal for making the control switch conductive, further boosting the high voltage induced in the ignition power supply coil by cutting off the main current control transistor switch to obtain a high voltage for ignition. The ignition device for an internal combustion engine according to the present invention includes first and second capacitors, and a first capacitor that charges the first capacitor to one polarity by the output of one half cycle of the ignition power supply coil. a capacitor charging circuit;
a second capacitor charging circuit that charges the second capacitor at a constant time constant using the electric charge stored in the capacitor; and a second capacitor charging circuit that conducts when the main current control transistor switch is cut off to discharge the second capacitor. and a reset switch that allows the conduction signal to be supplied to the cutoff control switch when the terminal voltage of the second capacitor reaches a set value. A signal supply control switch is provided for blocking the supply of the conductive signal when the terminal voltage of the capacitor is less than a set value.

In the above configuration, the first capacitor is charged by the output of the ignition power supply coil, and the second capacitor is charged by the charge of the first capacitor at a constant time constant without being affected by fluctuations in the output of the generator. It will be charged. When the terminal voltage of this second capacitor reaches the set value, the signal supply switch becomes conductive, allowing a conduction signal to be given from the signal supply circuit to the control terminal of the cutoff control switch, and the ignition circuit becomes operational. When the rotational speed of the engine is below the control rotational speed, there is sufficient time to charge the second capacitor, so that the voltage across the main current control transistor switch reaches a level that can provide the conduction signal. The terminal voltage of the second capacitor has already reached the set value at a position where the phase is ahead of the position. In this state, after the terminal voltage of the second capacitor reaches the set value, the voltage across the main current control transistor switch exceeds the set level, and the conduction signal is given to the cutoff control switch. At times, the conduction of the cutoff control switch causes the main current control transistor switch to be cut off, thereby performing an ignition operation.

When the rotational speed of the engine exceeds the control rotational speed, the terminal voltage of the second capacitor reaches the set value at a point later than the point at which the voltage across the main current control transistor switch reaches a level that can give the conduction signal. reach. In this state, the terminal voltage of the second capacitor reaches the set value and the supply of a conduction signal to the cutoff control switch is permitted, and at the same time the cutoff control switch becomes conductive and the main current control transistor switch enters the cutoff state. Thus, the ignition operation is performed at the position where the terminal voltage of the second capacitor reaches the set value.
Since the charging time constant of the second capacitor is constant, the position at which the terminal voltage of the second capacitor reaches the set value is delayed as the rotational speed of the engine increases. Therefore, in the region where the engine rotational speed exceeds the control rotational speed, the ignition position is gradually delayed, and finally, while the conduction signal exceeds the trigger level of the cutoff control switch, the terminal voltage of the second capacitor is set. This value cannot be reached and the engine misfires. Due to the retardation of the ignition position and the misfire, an increase in the rotational speed of the engine is suppressed, and overspeeding of the engine is prevented.

As described above, in the present invention, a second capacitor is provided that is always charged at a constant time constant regardless of fluctuations in the output voltage of the generator, and the terminal voltage of this second capacitor is maintained at the set value. Since the supply of a conductive signal that determines the ignition position when the ignition position is reached is allowed, the time required for the second capacitor to charge to the set value (constant regardless of the rotation speed) is controlled by setting an appropriate value. Rotation speed can be set. Therefore, it is possible to prevent the control rotational speed from changing due to fluctuations in the output of the generator, and it is possible to always perform a stable overspeed prevention operation to reliably prevent damage to the engine.

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

FIG. 1 shows an embodiment of the present invention, in which 1 indicates a primary coil 1a and a secondary coil 1a.
A spark plug 2 attached to a cylinder of an engine (not shown) is connected to a secondary coil 1b of the ignition coil 1 via a high-voltage cord. At least the primary coil 1a of the ignition coil 1 is arranged in a magnet generator that rotates in synchronization with the engine, so that an alternating current voltage is induced in the primary coil 1a in synchronization with the rotation of the engine. That is, in this example, the primary coil 1a of the ignition coil also serves as the ignition power supply coil.

One end of the primary coil 1a is grounded, and the collectors of NPN transistors 3a and 3b are connected to one end on the ground side of the primary coil. The emitter of transistor 3a is connected to the other end of primary coil 1a, and the emitter of transistor 3b is connected to the base of transistor 3a. transistor 3
One end of resistor 4 is connected to the base of resistor 4.
At the other end, there is a cathode of a diode 5 whose anode is connected to the non-ground terminal of the primary coil 1a, and a resistor 6 whose one end is connected to the ground terminal of the primary coil 1a.
is connected to the other end. The transistors 3a and 3b constitute a main current control transistor switch 3, and this transistor switch 3 has the following characteristics:
In the half cycle in which a voltage in the direction of the solid arrow shown in the figure is generated in the primary coil 1a (ignition power supply coil), a base current is applied through the resistor 6 and conduction occurs.
The other end of the resistor 4 is also connected to the collector of a transistor 7a, and the emitter of the transistor 7a is commonly connected to the emitter of the transistor 3a. The transistor 7a constitutes a cutoff control switch 7, and when this switch 7 is turned on, the main current control transistor switch 3 is cut off. One end of a resistor 8 is connected to the base of the transistor 7a, and the other end of the resistor 8 is connected to the emitter of the transistor 7a. A transistor 9 is also connected to the base of the transistor 7a.
The emitter of the transistor 9 is connected to one end of the primary coil 1a on the ground side via a resistor 10. The base of transistor 9 is connected to the collector of transistor 12 via resistor 11, and the emitter of transistor 12 is commonly connected to the emitter of transistor 7a.

An anode of a diode 15 is connected to the non-grounded terminal of the primary coil 1a of the ignition coil 1, and one end of a first capacitor 16 is connected to the cathode of the diode 15. The other end of the capacitor 16 is connected to the anode of a diode 17, and the cathode of the diode 17 is connected to one end of the primary coil 1a on the ground side. One end of a second capacitor 19 is connected to the diode 15 side terminal of the capacitor 16 via a constant current circuit 18, and the capacitor 1
The other end of 9 is connected to the anode of diode 15. One end of a resistor 20 is connected to the terminal of the capacitor 16 on the diode 17 side, and the other end of the resistor 20 is connected to the anode of the diode 15. In this example, the primary coil 1
The circuit of a-diode 15-first capacitor 16-diode 17-primary coil 1a causes the first capacitor 16 to be connected to one side by the output of one half cycle of the ignition power supply coil (the half cycle in the direction of the dashed arrow in the figure). A first capacitor charging circuit is configured to charge to the polarity of the first capacitor 16 - constant current circuit - second capacitor 19 - resistor 20 - first
The circuit of the capacitor 16 constitutes a second capacitor charging circuit that charges the second capacitor 19 with the electric charge of the first capacitor 16 at a constant time constant.

A first reset switch 21 is connected to both ends of the first capacitor 16, and a trigger signal is applied to the control terminal of the reset switch 21 from the ground terminal of the primary coil 1a via a resistor 22. There is. Also, a second capacitor 19 is connected to both ends of the second capacitor 19.
A reset switch 23 is arranged in parallel, and a trigger signal is input to the control terminal of the switch 23 from the ground side of the primary coil through a resistor 24.

A terminal voltage of the second capacitor 19 is applied between the base and emitter of the transistor 12 via an electronic circuit 25 having a predetermined threshold value. Here, the electronic circuit 25 is composed of, for example, a Zener diode, and is conductive while the terminal voltage V2 of the second capacitor 19 exceeds a set value Vz, allowing a base current to flow through the transistor 12.

In this embodiment, the voltage Ve' across the main current control transistor switch 3 is detected by the transistors 9, 12, the resistors 8, 10, 11, and the electronic circuit 25, and the voltage across the transistor switch 3 is set to the set level Vt. The control terminal of the cut-off control switch 7 (base of the transistor 7a)
A signal supply circuit 26 is configured to provide a conduction signal to. This signal supply circuit includes transistors 9 and 12, a resistor 11, and an electronic circuit 25.
Therefore, when the terminal voltage V2 of the second capacitor 19 reaches the set value Vz, the conduction signal is allowed to be supplied to the cut-off control switch 7, and when the terminal voltage of the second capacitor 19 is less than the set value, the conduction signal is not supplied. Signal supply control switch 27 that blocks supply
is configured.

In the above embodiment, the first capacitor 16
The capacitance of the second capacitor 19 is set to be sufficiently larger than that of the second capacitor 19. Further, the charging time constant of the second capacitor 19 is determined at a point (where the voltage Ve' across the transistor switch 3 reaches a set level Vt that can trigger the cut-off control switch 7 when the engine rotation speed is less than the control rotation speed). The terminal voltage of the second capacitor at a position where the phase is more advanced than the position where the conduction signal is given to the cutoff control switch.
When V2 reaches the set value Vz (level that triggers the transistor 12) and the rotation speed is higher than the control rotation speed, the main current control transistor switch 3
The terminal voltage V2 of the second capacitor 19 is set to reach the set value Vz at a position whose phase is delayed from the position where the voltage Ve' across the terminal reaches the set level Vt. The first reset switch 21 and the second reset switch 23 are used to reset the primary coil 1 when the main current control transistor switch 3 changes from a conductive state to a cutoff state and an ignition operation is performed.
The respective trigger levels are set so that conduction occurs when the voltage across a increases.

FIGS. 2A to 2D are voltage and current waveform diagrams for explaining the operation of the above embodiment, and FIGS.
represent the voltage Ve across the primary coil 1a and the waveform of the primary current 1 flowing through the primary coil, respectively. In addition, FIG. 2 C and D are the terminal voltages of the first and second capacitors 16 and 19, respectively.
The waveforms of V1 and V2 are shown. In these figures, the waveforms indicated by symbols a, b, and c indicate the waveforms when the engine starts, when the rotational speed reaches the control rotational speed at high speed, and when the overspeed prevention operation is performed, respectively. .

In the above embodiment, when the engine is rotated, a voltage Ve as shown in FIG. 2A is generated in the primary coil 1a. Such a waveform can be obtained by a magnet generator with a three-pole magnet rotor. When a negative half cycle of the voltage Ve starts at an angle θ1 (a half cycle in the direction of the dashed arrow in FIG. 1), the first capacitor 16 is charged to the polarity shown through the diodes 15 and 17, and its terminal voltage V1 increases as shown in Figure 2C. When the voltage Ve reaches a negative peak value at the angle θ2, charging of the capacitor 16 ends, and the charge of the capacitor 16 becomes constant in the path of capacitor 16 - constant current circuit 18 - second capacitor 19 - resistor 20 - capacitor 16. The terminal voltage V2 of the second capacitor 19 rises as shown in FIG. 2D.
When the terminal voltage V2 of the second capacitor 19 reaches the set value, the electronic circuit 25 causes the base current to flow through the transistor 12. Therefore, at angle θ3 the voltage Ve
When the positive half cycle (the half cycle in the direction of the solid arrow in FIG. 1) starts, transistor 12 becomes conductive, and thereby transistor 9 becomes conductive. At this time, a conduction signal is allowed to be applied from the primary coil 1a side to the transistor (interruption control switch 7) 7a through the resistor 10 and the transistor 9. On the other hand, when a positive half cycle of voltage Ve starts at angle θ3, a base current flows to main current control transistor switch 3 through resistors 6 and 4, and transistor switch 3 becomes conductive. Therefore, the primary coil 1a is in a substantially short-circuited state,
A large primary current 1 flows from the primary coil 1a through the transistor switch 3. At this time, between both ends of the primary coil 1a and between the transistor switch 3
The voltage Ve' across the transistor switch 3 decreases to a low value corresponding to the collector-emitter voltage drop of the transistor switch 3, as shown by the broken line in FIG. 2A. When starting the engine, when this voltage Ve' reaches its peak value at angle θ5, it reaches the set level Vt that can trigger the cutoff control switch 7, and the resistor 1
A conduction signal is applied to the cutoff control switch 7 through the transistor 9 and the transistor 9. As a result, the cutoff control switch 7 becomes conductive, the main current control transistor switch 3 is cut off, and the primary current 1 is cut off. By interrupting this current 1, the primary coil 1a
A high voltage is induced in the ignition coil 1, and this voltage is stepped up by the ignition coil 1 to generate a high voltage for ignition on its secondary side. Since this high voltage is applied to the ignition plug 2, a spark is generated in the ignition plug and the engine is ignited. In this manner, when starting the engine, ignition is performed at an angle θ5 where the voltage across the transistor switch 3 reaches its peak. The first and second reset switches 21 are activated by the rise in voltage across the primary coil 1a when the ignition operation is performed.
and 23 conduct, and the first and second capacitors 1
6 and 19 are discharged almost instantaneously.

When the rotational speed of the engine is less than the control rotational speed, the terminals of the second capacitor 23 are connected to the terminals of the second capacitor 23 at a position before the voltage across the main current control transistor switch 3 reaches a level that makes the cutoff control switch 7 conductive. The ignition position of the engine is determined by the voltage across the transistor switch 3, since the voltage reaches the trigger level of the transistor 12, which makes the transistor 12 conductive, and the transistor 9 conducts, allowing the supply of a conduction signal to the cut-off control switch. Ignition occurs when the current reaches a set level that can cause the cutoff control switch 7 to conduct. As the engine rotational speed increases, the phase at which the voltage across the transistor switch 3 reaches the set level Vt advances, so the ignition position advances as the engine rotational speed increases.

When the rotational speed of the engine increases to a certain degree, the voltage across the transistor switch 3 reaches the set level Vt.
Since the advance of the phase that reaches this point is small, the advance angle of the ignition position is small, and the ignition position remains constant (in this embodiment, at the angle θ4 shown in FIG. 2).

The charging time constant of the second capacitor 19 is constant, and the phase at which the terminal voltage V2 of the capacitor reaches the set value Vz is constant regardless of the rotational speed of the engine. The angle at which the set value is reached becomes delayed as the rotational speed of the engine increases.

When the engine rotation speed reaches the control rotation speed Ns,
The position where the terminal voltage V2 of the second capacitor 19 reaches the set value coincides with the position where the voltage across the transistor switch 3 reaches the set level Vt, and when the rotation speed further increases, the terminal voltage of the second capacitor 19 reaches the set value. The position at which this value is reached is delayed from the position at which the voltage across the transistor switch 3 reaches the set level. Therefore, in the region above the control rotation speed, the transistors 12 and 9 become conductive at the position where the terminal voltage V2 of the second capacitor 19 reaches the set value Vz, allowing the supply of a conduction signal to the cut-off control switch. Shutdown control switch 7
A conduction signal is given to the ignition operation. Since the phase in which the terminal voltage of the second capacitor 19 reaches the set value is delayed as the rotation speed increases,
In the region above the control rotational speed, the ignition position is delayed as the rotational speed increases, and eventually, even when the terminal voltage of the second capacitor 19 reaches the set value, no conduction signal is given to the cutoff control switch. This caused the engine to misfire. The ignition position at a rotational speed at which the engine is on the verge of misfire is at an angle θ6 at which the voltage Ve' across the transistor switch 3 passes its peak and then falls below the set level Vt. The advance and retard characteristics of the ignition position obtained in the above embodiment are as shown by solid lines in FIG.

In this way, in the present invention, the ignition position is delayed at a rotational speed higher than the control rotational speed, and the engine eventually misfires, so that overspeeding of the engine can be prevented. In the present invention, the first capacitor is once charged with the output of the generator, and then the first capacitor is charged with the output of the generator.
By charging the second capacitor with the charge of the capacitor, the second capacitor
The second capacitor is charged with a constant time constant, and the time it takes for the terminal voltage of the second capacitor to reach the set value (constant regardless of the rotation speed)
Since the control rotation speed is set by setting the value of This has the advantage of being able to reliably prevent the destruction of the engine.

FIG. 4 shows an embodiment of the constant current circuit 18, the reset switches 21 and 23, and the electronic circuit 25 shown in FIG. A resistor 31 is connected between the gate and source of the field effect transistor, and an electronic circuit 25 is a Zener diode. The first reset switch 21 includes a thyristor 32 connected in parallel to both ends of a capacitor 16 with its anode facing the diode 16 side, a capacitor 33 connected in parallel between the gate and cathode of the thyristor 32, and a gate of the thyristor 32. It consists of a diode 34 whose cathode is connected to the diode 34, and a Zener diode 35 inserted between the diode 34 and the resistor 22 with its anode facing the diode 34 side. The thyristor 32 of the reset switch 21 is triggered to conduct when the main current control transistor switch 3 is cut off and a high voltage is generated across the primary coil 1a, and instantly discharges the charge in the capacitor 16. .

The second reset switch 23 is connected to the capacitor 1.
A transistor 36 with a collector-emitter circuit connected in parallel to both ends of the transistor 9;
The anode is connected to the base of the resistor 2, and the cathode is connected to the resistor 2.
4, and a Zener diode 37 connected to one end of the ground side of the primary coil 1a via a zener diode 37.

Further, in this embodiment, a Zener diode 38 is connected in parallel between the collector and emitter of the transistor 9 with its anode facing toward the collector of the transistor 9. By connecting the Zener diode 38 in this manner, the transistor 9 can be protected from surge voltage. In other respects, the structure is similar to that of the embodiment shown in FIG. 1, and the operation is similar to that of the embodiment shown in FIG.

In the above embodiment, if the capacitance of the capacitor 33 of the first reset switch 21 is set appropriately, the voltage of the second negative half cycle of the voltage Ve in FIG. The voltage of this second negative half cycle does not charge the first capacitor 16 since the thyristor 32 can be held conductive until this occurs. Therefore, unnecessary charging of the capacitor 16 can be prevented. In some cases, the first reset switch 21 may be omitted.

FIG. 5 shows another embodiment of the present invention,
In this embodiment, the transistor 36, Zener diode 37 and resistor 24 used in the embodiment of FIG.
is coupled to the anode of thyristor 32 via. Other points are similar to the embodiment shown in FIG.

In this embodiment, when the thyristor 32 conducts, the charge on the second capacitor 19 is transferred to the diode 4.
0, discharge through the thyristor 32, diode 17 and primary coil 1a. Therefore, thyristor 3
2 to the first and second capacitors 16 and 19
can be discharged (reset) at the same time, and the circuit configuration can be simplified. That is, in this embodiment, the thyristor 32, the diode 17,
34, 40, the capacitor 33, and the Zener diode 35 constitute a second reset switch for resetting the second capacitor.

FIG. 6 shows another embodiment of the present invention,
In this embodiment, a collector-emitter circuit of a transistor 41 is connected in parallel with the second capacitor 19 of the circuit shown in FIG. Positive feedback has been given. In other respects, the structure is similar to that of the embodiment shown in FIG.

In the configuration shown in FIG. 6, as the potential across the main current control transistor switch 3 increases and the potential at the emitter of the transistor 9 increases accordingly, the transistor 41 enters the active region. A portion of the charge on second capacitor 19 is discharged through transistor 41 . Therefore, the terminal voltage of the second capacitor 19 is delayed in reaching the set value, and the ignition position is delayed further than in the embodiments of FIGS. 1, 4, and 5. Therefore, according to this embodiment, the ignition position can be rapidly delayed in the rotational speed range above the control rotational speed, and the characteristics shown by the broken line in FIG. 3 can be obtained.

In the embodiment shown in FIG. 6, the resistor 42 may be replaced by a Zener diode with its anode directed toward the base of the transistor 41. With this configuration, as shown by the chain line in FIG. 3, it is possible to obtain a characteristic in which the retardation speed of the ignition position rapidly increases at a predetermined rotational speed equal to or higher than the control rotational speed Ns.

In each of the above embodiments, a constant current circuit 18 consisting of a field effect transistor 30 and a resistor 31 was used, but when a constant current circuit is used as a charging circuit for the second capacitor 19 in the present invention, its configuration is as follows. For example, as shown in FIG. 7, a transistor 45, a resistor 46 connected between the collector and base of the transistor, a resistor 47 with one end connected to the emitter of the transistor, and the other end of the resistor 47 are optional. A known constant current circuit 18 including a resistor 48 connected between the base of the transistor 45 and the base of the transistor 45 can also be used.

Note that the second capacitor 19 only needs to be charged at a constant time constant, and the constant current circuit 18 in the above embodiment can also be replaced by a resistor.

In each of the embodiments described above, each semiconductor element can of course be replaced with another semiconductor element if there is another semiconductor element having an equivalent function for each semiconductor block. For example, the transistor 7a constituting the cutoff control switch can be replaced by a thyristor. Further, the thyristor 32 constituting the first reset switch 21 can be replaced with a transistor, and the transistor 36 constituting the second reset switch 23 can be replaced with a thyristor.

In the above embodiment, the primary coil of the ignition coil also serves as the ignition power supply coil, but the present invention also applies when the ignition coil is placed outside the magnet generator and the ignition power supply coil is used separately from the ignition coil. Of course, it is possible to apply In this case, the ignition power supply coil and the primary coil of the ignition coil are connected in parallel, and the main current control transistor switch is connected in parallel to both coils.

Effects of the Invention As described above, according to the present invention, the ignition position is delayed at a rotation speed higher than the control rotation speed, and the engine eventually misfires, so that over-speeding of the engine can be prevented. In particular, in the present invention, the first capacitor is once charged with the output of the generator, and then the first capacitor is charged with the output of the generator.
By charging the second capacitor with the charge of the capacitor, the second capacitor
The second capacitor is charged with a constant time constant, and the time it takes for the terminal voltage of the second capacitor to reach the set value (constant regardless of the rotation speed)
Since the control rotation speed is set by setting the value of This has the advantage of being able to reliably prevent the destruction of the engine.

[Brief explanation of drawings]

Figure 1 is a circuit diagram showing an embodiment of the present invention, Figure 2 is a circuit diagram showing an embodiment of the present invention.
The figure is a waveform diagram showing the voltage or current waveform of each part of the embodiment of Fig. 1, Fig. 3 is a line diagram showing the advance angle and retard angle characteristics obtained by the embodiment, and Fig. 4 is the diagram of the figure 1. 5 and 6 are circuit diagrams showing other different embodiments of the present invention, and FIG. 7 is a circuit diagram showing a modified example of the constant current circuit used in the present invention. FIG. 1...Ignition coil, 2...Spark plug, 3...
Main current control transistor switch, 4, 6,
8, 10, 11, 22, 24...Resistance, 5, 1
5, 17... Diode, 7... Cutoff control switch, 9, 12... Transistor, 16... First
capacitor, 19... second capacitor, 23
...Reset switch, 27...Signal control switch.

Claims (1)

[Claims] 1. An ignition power supply coil that induces an alternating current voltage in synchronization with the rotation of the internal combustion engine, a main current control transistor switch connected in parallel to the ignition power supply coil, and a main current control transistor switch connected in parallel to the ignition power supply coil; a cutoff control switch provided to cut off the main current control transistor switch; and a conduction switch for making the cutoff control switch conductive when the voltage across the main current control transistor switch reaches a set level. and a signal supply circuit for supplying a signal, the ignition device for an internal combustion engine obtains a high voltage for ignition by boosting a high voltage induced in the ignition power supply coil by interrupting the main current control transistor switch. a second capacitor; a first capacitor charging circuit that charges the first capacitor to one polarity by the output of one half cycle of the ignition power supply coil; A second capacitor that charges a second capacitor with a constant time constant.
a capacitor charging circuit; and a reset switch that becomes conductive to discharge the second capacitor when the main current control transistor switch is cut off, and the signal supply circuit includes a terminal of the second capacitor. a signal supply control switch that allows the supply of the conduction signal to the cutoff control switch when the voltage reaches a set value and blocks the supply of the conduction signal when the terminal voltage of the second capacitor is less than the set value; An ignition device for an internal combustion engine, comprising: