JP2879435B2 - Power conversion circuit and ignition circuit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to all of the controllable valves included in each of one or more other predetermined arms when none of the controllable valves included in each of a plurality of predetermined arms is turned on. And a power conversion circuit controlled to turn on. Therefore, the present invention is applied to a power conversion circuit and a device to which the power conversion circuit is applied, for example, an ignition device including an ignition device for an internal combustion engine, a high voltage generator, an ozonizer, a discharge lamp lighting device, an induction heating device, and the like. Is done.

[0002]

2. Description of the Related Art Japanese Patent Application Laid-Open No. 62-5019 of the present inventor discloses an ignition device to which a series inverter is applied.
In this ignition device, two controllable valves are connected in series between both output terminals of the DC power supply, and a series resonance circuit formed by a primary coil of an ignition coil and a commutation capacitor is connected in parallel to one of the controllable valves. Have been. A spark is generated each time the two controllable valves are turned on alternately. However, the control system is different from the conventional control systems in that the turn-off of one controllable valve triggers the turn-on of the other controllable valve. (Hereafter, such a control method will be referred to as a turn-off trigger method.)

For this purpose, both on / off states are detected, and when one of them is turned off, a turn-on signal for turning on the other is output. As a result, the timing at which these two controllable valves alternately turn on is automatically optimized,
If one turn-off is delayed, the other turns on without any problem, so that no dead time is required. Also, there is no problem even if the on-period changes according to the load current like a thyristor. Such an effect is in the above invention.

However, the above-mentioned invention only discloses a turn-off trigger system when the number of arms including a controllable valve is two. This method when the number of arms is three or more is not disclosed. Further, in the case of a circuit in which the load current is commutated from one arm to the other arm (for example, circuits shown in FIGS. 10, 11, and 13 described below), this control method can be used. Is desired.

Therefore, an object of the present invention is to use a turn-off trigger method when the number of arms including a controllable valve is three or more, or to reduce the load current from one arm to another. An object of the present invention is to provide a power conversion circuit that can use a turn-off trigger method even in a circuit that commutates to an arm.

[0006]

That is, the present invention is a power conversion circuit having the following. Controllable valve S2 and one-way valve S3
Are connected in series, a plurality of arms each having a one-way controllable valve S1 as a component, one or more arms each having a controllable valve S4 as a component, and when each of the controllable valves S2 is on. , Each of the controllable valves S
2 is applied to each controllable valve S2 without passing through each one-way valve S3 in the same direction as the forward direction of each controllable valve S1. And current detection means CS for detecting all the currents
And one or more turns that operate in accordance with the current detection means CS1 and turn on all of the controllable valves S4 when the current detection means CS1 detects that no current is flowing. Turn-on signal generating means TS1 for generating an ON signal. (However, not all controllable valves S2 are necessarily the same type of valve. This is also true for other valves.)

Thus, the current detecting means CS1 detects whether or not all the one-way controllable valves S1 are turned off with respect to the respective forward voltages. By doing so, you know exactly. Further, when all the off states are detected, the turn-on signal generating means TS1 generates one or more turn-on signals for turning on all the controllable valves S4. Therefore, at the optimal timing when the useless time during which power conversion is not performed is minimized or almost zero, and a short circuit does not occur in the power supply or the like, all controllable valves S1 change from on to off, and all controllable valves S1 are turned off. The effect of the present invention is that the valve S4 changes from off to on.

In the case where the present invention is the power conversion circuit described in claim 2, the present invention provides, in addition to the functions and effects described above,
It works as follows and has the following effects. Whether or not all the one-way controllable valves S4 are off with respect to the respective forward voltages is determined by detecting all of the currents according to claim 2 by the current detecting means CS2. I know exactly. Then, when all the off states are detected, the turn-on signal generating means TS2 generates one or more turn-on signals for turning on all the controllable valves S1. Therefore, at the optimal timing when the useless time during which power conversion is not performed is minimized or almost zero and a short circuit does not occur in the power supply or the like, all the controllable valves S4 are changed from ON to OFF, and all controllable valves S4 are turned off. The present invention has an effect that the valve S1 changes from off to on. As a result, the present invention forms an oscillating circuit, for example, even if the on-periods of all controllable valves S1 or S4 may change like a thyristor due to the load, or of these valves, Even if any turn-off is delayed, the present invention can switch the on / off state of these valves at an optimum timing. When there are a plurality of controllable valves S5, these are not necessarily all the same type of valve. The same can be said for the one-way valve S6.

In the case where the present invention is the power conversion circuit described in claim 3, the present invention has the two effects described above. In this case, the turn-on signal generating means TS2 works to turn on all controllable valves S1 (including a single controllable valve) that do not include the controllable valve S2a through the turn-on signal generating means TS3 and the like.

When the present invention is the power conversion circuit described in claim 4, the present invention also has the two effects described above. In this case, as long as the controllable valve S2a is on,
The turn-on signal generating means TS3 is controlled by the controllable valve S2.
It works to keep all controllable valves S1 (including singular) not containing a. Therefore, the current detection means CS1 can detect the ON / OFF of the controllable valve S1 including the controllable valve S2a via the controllable valve S1 not including the controllable valve S2a. Therefore, in a circuit configuration in which one of the controllable valves S1 not including the controllable valve S2a is turned on later than the controllable valve S1 including the controllable valve S2a in relation to the load, the present invention has an effect. Demonstrate. This is because when each of the controllable valves S1 not including the controllable valve S2a is completely turned off, the town control valve S1 must be turned off.
This is because the controllable valve S1 including 2a is completely turned off or later. As examples of this, there are embodiments described later with reference to FIGS. 10, 11, and 13. FIG.

In the case of the power conversion circuit according to the fifth aspect of the present invention, the same effect as that of the second, third or fourth aspect is obtained. In this case, the turn-on signal generating means T
S1 acts to turn on all controllable valves S4 (including singular) that do not include controllable valve S5a, such as through turn-on signal generation means TS4.

In the case where the present invention is the power conversion circuit described in claim 6, the same effects as those described in the second, third or fourth claim are obtained. As long as the controllable valve S5a is on,
turn. The ON signal generating means TS4 is controlled by the controllable valve S5
It works so as to keep all controllable valves S4 (including singular) not containing a. For this reason, the current detection means CS1 can detect on / off of the controllable valve S4 including the controllable valve S5a via the controllable valve S4 not including the controllable valve S5a. Accordingly, the present invention is particularly applicable to a circuit configuration in which any of the controllable valves S4 not including the controllable valve S5a turns on later than the controllable valve S4 including the controllable valve S5a in relation to the load. It is effective. This is because when each of the controllable valves S4 not including the controllable valve S5a is completely turned off, the same as when the controllable valve S4 including the controllable valve S5a is completely turned off, Or, later.
As an example of this, there is an embodiment of FIG. 11 described later.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings. First, examples of the configuration of the controllable valve S2 and its current path are shown in FIGS. In these, the rectifier 4 or 204 corresponds to the one-way valve S3, and the thyristor 5 or 205 corresponds to the controllable valve S2. FIG. 2 (a),
In (b), the loop including the DC power supply 1, the resistor 2, the diode 3, and the thyristor 5 is the current path. The diode 3 may be omitted, but the diode 3 prevents unnecessary current from flowing from the rectifier 4 to the resistor 2 and the DC power supply 1. With such a configuration, even if a reverse voltage is applied to the one-way controllable valves 200 and 201, the rectifier 4 accepts the reverse voltage, so that the thyristor 5 is always supplied with the forward voltage by the DC power supply 1. Applied. Therefore,
By detecting a current flowing through the above-described circuit including the DC power supply 1 and the thyristor 5, it is possible to determine whether the thyristor 5 is on or off. However, the magnitude must be smaller than the holding current when the thyristor 5 is turned off so that this current does not prevent the thyristor 5 from being turned off.

On the other hand, in the circuits shown in FIGS. 2C and 2D, there are two current paths,
The current path is switched according to the polarity of the voltage applied to 01. When a forward voltage is applied to the controllable valves 200, 201, the source of the forward voltage, the thyristor 5,
A loop including the resistor 2 and the DC power supply 1 is one of the current paths. Of course, in this case, the main current flows through the thyristor 5 and the rectifier 4. On the other hand, controllable valves 200, 201
When a reverse voltage is applied to the current path, a loop including the DC power supply 1, the rectifier 6, the thyristor 5, and the resistor 2 is the other of the current paths. Therefore, if the current flowing through the DC power supply 1 and the resistor 2 is detected, the ON / OFF state of the thyristor 5 can be determined.

Further, the circuit shown in FIG.
2 in which the rectifier 7 is connected in reverse parallel to the controllable valve 200 of FIG.
This is a circuit in which the circuit of FIG. 2A and the circuit of FIG. 2D are connected in series. Thyristors 5, 205 control the current in two directions. In this case, the rectifiers 204 and 6 and the thyristor 2 are connected in series with their forward directions facing the same direction.
05 is included in one arm. The same is true for rectifiers 4, 7 and thyristor 5. Further, the circuit of FIG. 2F is also possible.

Then, the circuit shown in FIG.
FIG. 2D shows a circuit in which a rectifier is connected in series in the same direction to the controllable valve 200 shown in FIG. 2D and a circuit shown in FIG. 2A is connected in parallel. Then, the circuit of FIG. 2H is also possible.

Note that the thyristors 5, 2
The current flowing through each of the thyristors 5 and 205 is set smaller than the respective holding currents.
Each turn-off must be unimpeded. This setting may be made only when the thyristors 5 and 205 are about to turn off. That is, except for this case, the respective currents may be larger than the respective holding currents. FIGS. 2A to 2H show an example in which the thyristor 5 or 205 is used for the controllable valve S2.
The controllable valve S2 may be any controllable valve such as a triac, a transistor, a power MOS-FET, or an electrostatic induction transistor. Further, FIGS. 2A to 2H show an example in which the rectifier 4 is used for the one-way valve S3, but the one-way valve S3 may be a one-way thyristor as long as no reverse current flows. . However, in this case,
It is necessary to control this one-way thyristor together with the controllable valve S2.

Next, the circuits of the fourteenth embodiment are shown in FIGS.
This is shown in FIGS. 6, 8 to 15, {FIGS. 16 and 17}. FIG.
2 is an AC-AC converter circuit for passing an alternating current to a load resistor 19 using a series resonance circuit of a reactor 17 and a commutation capacitor 18, and uses the circuit of FIG. The same symbols are connected to the connection terminals t1 to t4, respectively. When the thyristor 5 or 205 is on, a current flows from the transistor 8 to the coil 10, and magnetic energy is stored in the coil 10. Thereafter, when neither of the thyristors 5 and 205 is turned on, the transistor 8 is turned off, so that the current flowing through the coil 10 flows through the emitter junction of the transistor 12, the diode 11, the resistor 9, and the like. Since this current flows through the base of the transistor 12 during a period determined by the time constant of the coil 10 and the resistor 9, the transistors 13 and 14 are turned on during a period corresponding to this. As a result, two thyristors 16 are triggered via the pulse transformer 15.

The trigger period is set to be shorter than a half cycle of the series resonance circuit, and before the resonance current flows through one thyristor 16 during the half cycle and then reverses, the other thyristor 16 is turned off. It is supposed to recover. Therefore, this resonance current flows intermittently every half cycle. The trigger of the thyristors 5 and 205 may be periodically performed at a fixed timing as in the related art, or
The circuit of FIG. 2F may be introduced on the thyristor 16 side, and the thyristors 5 and 205 may be similarly triggered by the turn-off trigger method of the present invention. Incidentally, the pulse transformer 15 is used in a usual manner so that magnetic energy is not accumulated in its core as much as possible. Further, the diode 120 is provided as a measure against surge voltage.

The embodiment of FIG. 3 shows thyristors 5, 205,
16, 216, a reactor, a commutation capacitor 18, and the like, a bridge-type series inverter having start / stop means (switch 38) for controlling start / stop of the inverter. This corresponds to the power conversion circuit described in claim 2. The same symbols are connected to the connection terminals t5 to t8, respectively. Transistors 35 and 36 are thyristor 2
05 and 216 are detected, and the transistor 3
7 and 213 detect on / off of the thyristors 5 and 16. The usage of the pulse transformers 39 and 40 is different from the usual usage, in which the saturation of each magnetic flux is positively used. In the case of the pulse transformer 39, during the on-periods of the transistors 13, 14, the primary and secondary voltages induced until the magnetic flux is saturated trigger the thyristors 5, 16. On the other hand, in the case of the pulse transformer 40, the magnetic energy stored during the ON period of the transistors 213 and 214 is used to trigger the thyristors 205 and 216.
Energy. The switch 38 is the start / stop unit. When this is off, the pulse transformer 39 does not output a trigger signal because the switch 38 prevents the output signal of the transistor 36 from being input to the base of the transistor 13. Therefore, when the switch 38 is turned off, the operation of the bridge-type inverter is stopped or the operation of the bridge-type inverter is stopped. Then, it is started as follows.

When the switch 38 is turned on at the time of the start, the thyristors 205 and 216 and the transistor 35,
Since 36 is off, transistors 13 and 14 are turned on. Until the magnetic flux of the pulse transformer 39 is saturated, the back electromotive force generated in the primary coil and the secondary coil is applied between the gate and cathode of the thyristors 5 and 16. Therefore, the thyristors 5 and 16 are turned
Turning on, the series resonance circuit of the reactor 17, the commutation capacitor 18, and the load resistor 19 oscillates only for a half cycle. During the ON period of the thyristor 5 or 16, the transistor 213,
Since 214 is on, magnetic energy is stored in the pulse transformer 40 for triggering the thyristors 205 and 216. Thereafter, when both the thyristors 5 and 16 are not turned on and the transistors 213 and 214 are turned off, the magnetic energy is supplied to the thyristors 205 and 216 as a trigger current. As a result, the thyristors 205 and 216 are turned on, and the series resonance circuit oscillates again for the half cycle.

On the other hand, during the ON period of the thyristor 205 or 216, the transistors 35 and 36 are ON and the transistors 13 and 14 are OFF, so that the pulse transformer 39 transfers the accumulated magnetic energy to the primary side Zener diode or the like. Consumes and releases with resistance. Thus, the next trigger of the thyristors 5 and 16 is prepared. Thereafter, if switch 38 is on when both thyristors 205 and 216 are no longer on and transistor 36 is turned off, transistors 13 and 14 are turned on and thyristors 5 and 16 are triggered. In the same manner, the inverter repeats the same operation, but continues as long as the switch 38 is on. The pulse transformers 39 and 40 are used in the same manner as the pulse transformer 1 shown in FIG.
Unlike the method of No. 5, each magnetic flux is actively saturated and magnetic energy is stored. Therefore, if it is attempted to set the trigger period of each of the thyristors 5, 205, 16, and 216 to be shorter than a half cycle of the resonance circuit, each of the exciting inductances becomes equal to the pulse transformer 15.
Smaller than that of. Then, the four sets of the series circuit of the resistor 112 and the capacitor 113 are snubber circuits.

The embodiment shown in FIG. 4 corresponds to the power conversion circuit described in claims 3 and 5, and is a bridge type series inverter. In this embodiment, the triggers of the thyristor 5 and the triac 31 or the triggers of the thyristor 205 and the triac 231 are different. When the transistors 41, 42 and the like detect that the thyristor 5 is turned on, the triac 31 is triggered. The transistors 43 and 44 turn the thyristor 205
When ON is detected, the triac 231 is triggered. When the capacitor 46 is charged, the transistor 21
4 triggers thyristor 5 and transistors 13 and 14 trigger thyristor 205 when capacitor 45 discharges.

The operation of the whole inverter is as follows. The start and stop are performed by a start and an input to the input terminal t9.
This is performed by a stop signal. When this signal rises at the time of activation, the thyristor 205, the triac 231 and the transistors 37 and 43 are off, so that the transistor 47 is turned on and the charging current of the capacitor 46 flows to the base of the transistor 214. The transistor 214 triggers the thyristor 5 only during a period corresponding to the charging period, and the triac 31 is turned on in association with the thyristor 5. Thereafter, the resonance current flowing through the thyristor 5 and the triac 31 is reversed, and the two rectifiers 4
Thyristor 5 and Triac 31 immediately after starting to flow to 8
At the same time, the transistor 41 is turned off. Then, the capacitor 4 charged during these ON periods is
5 begins to discharge through the bases of transistors 13,14 and the like. During the period corresponding to this discharge, the transistor 1
3 and 14 trigger the thyristor 205, and the triac 231 turns on in cooperation with the thyristor 205. Therefore, the resonance current flowing through the two rectifiers 48 starts flowing through the thyristor 205 and the triac 231.

Further, as soon as the resonance current is inverted and starts to flow through the two rectifiers 248, the thyristor 205,
The transistors 43 and 37 are turned off together with the triac 231. At this time, if the start / stop signal is at a high level, the transistor 47 is turned on, and the capacitor 46 discharged during the ON period of the thyristor 205 and the like is charged via the transistor 214 and the like. Thus, when the thyristor 5 and the triac 31 turn on together with the transistor 214, the resonance current flowing through the two rectifiers 248 starts flowing through the thyristor 5 and the triac 31. In the same manner, this inverter repeats the same operation, but the repetition continues as long as the start / stop signal is at the high level. However, the transistor 4 together with the thyristor 205 and the triac 231
When the start / stop signal is low when 3, 37 is turned off, the inverter stops operating.

As described above, in this embodiment, the start and stop are controlled by the start and stop signals input to the input terminal t9. If the input terminal t9 is connected to the DC power supply 220
, The thyristor 5 and the triac 31 can be triggered by turning off both the thyristor 205 and the triac 231, although this method cannot be used. In other words, conversely, if one end of the resistor 110 is disconnected from its positive power supply line and the start / stop signal is input from this one end (that is, the input terminal t9), the start / stop means can be easily implemented. It can be configured. This method without using the switch 38 is also possible in the circuit of FIG. Of course, in this case, the phase of the start / stop signal is
The opposite of the stop signal.

The embodiment shown in FIG. 5 corresponds to the power conversion circuit described in claims 4 and 6, and is a bridge type series inverter. The same symbols are connected to the connection terminals t10 to t13, respectively. In this embodiment, the thyristor 16 is kept on as long as the transistors 29, 30 and the like detect the on state of the thyristor 5. Therefore, the turn-off of the thyristor 16 is always the turn-off of the thyristor 5
The same as or after turning off, the transistor 214
Can detect on / off of both thyristors 5 and 16 by detecting on / off of thyristor 16. Similarly, transistors 129, 130, etc., are thyristor 2
The thyristor 216 is kept on as long as the on state of the thyristor 05 is detected. Therefore, since the turn-off of the thyristor 216 is always the same as or later than the turn-off of the thyristor 205, the transistor 36 can detect the on / off of both the thyristors 205 and 216 by detecting the on / off of the thyristor 216. it can. Thyristor 1
Instead of 6 or 216, a controllable valve having no self-holding function, for example, a transistor, may be used. The operations of the pulse transformers 49 and 50 are almost the same as those of the pulse transformers 39 and 40 in FIG. FIG.
The flow of the resonance current flowing through the load resistor 19 is the same as that of the circuit of FIG.

The overall trigger operation is roughly as follows. The start and stop of the inverter are performed by a start / stop signal input to the input terminal t14. When this signal falls at the time of startup, the thyristors 205, 216
Since the transistor 36 is off, the transistor 14
Triggers the thyristor 5 via the pulse transformer 49. At the same time, transistors 29 and 30 are thyristor 1
Turn 6 on. After that, thyristors 5, 16
Are turned off, the magnetic energy stored in the pulse transformer 50 triggers the thyristor 205, while the transistors 129, 130 turn the thyristor 216 on. After that, thyristor 2
When the start / stop signal is low when transistor 36 turns off along with
Transistor 14 turns on. In the same manner, this inverter repeats the same operation, but the repetition continues as long as the start / stop signal is at the low level. on the other hand,
When this signal is high when transistor 36 turns off, the inverter stops operating.

The embodiment of FIG. 6 is similar to the embodiment of FIG.
Although it is a C-AC converter, the circuits shown in FIGS. 2 (g) and 2 (h) are used. However, in the case of this embodiment, the thyristors 5 and 16 are triggered simultaneously, and the thyristors 205 and
216 are triggered simultaneously. In the figure, 51 is a rectifier,
Reference numeral 52 denotes a DC constant voltage circuit, and reference numerals 53 and 54 denote photocouplers (TLP550, manufactured by Toshiba Corporation). Connection terminal t
The same reference numerals are connected to each other from 15 to t22. The photo coupler 53 transmits the output signal of the transistor 35 to the transistor 36, and the transistor 36 detects on / off of the thyristors 205 and 216. Then, the photo coupler 54 transmits the output signal of the transistor 37 to the transistor 213, and the transistor 213 detects whether the thyristors 5 and 16 are on or off.

The triggering procedure of this embodiment is almost the same as that of the embodiment of FIG. However, this AC-A
In the case of the C converter, the start and stop are performed at the connection terminal t25.
This is performed by a start / stop signal input to. If this signal falls when switch 55 is on, the converter is activated, and if it rises, the converter stops its operation. Then, when it is desired to directly control the start and stop by opening and closing the switch 55, the voltages of the respective DC constant voltage circuits 52 are detected, and when these voltages exceed the respective set values, the connection terminal t
What is necessary is just to provide the circuit which connects 25 and the connection terminal t24.
Further, when the voltage drops in the opposite direction, the circuit may disconnect these connection terminals. One example is a circuit centered on a Schmitt trigger circuit shown in FIG. In this case, simply, only the voltage of the DC constant voltage circuit 52 on the lower side of FIG. 6 is detected. Connection terminals t23 to t25
Are connected to the same reference numerals. Connection terminal t26
Is connected to the connection terminal t23.

This activation method can be used in other embodiments. According to the number of DC power supplies used in each embodiment, voltage detection means for detecting each supply voltage is provided, and when all supply voltages reach a set value, each power conversion circuit is activated. I just need. FIG.
In each of the embodiments shown in FIGS. 6 to 6 and FIGS. 8 to 14, which will be described later, even if no load is connected to each power conversion circuit, the power conversion circuit oscillates when activated. For example,
In the case of the circuit of FIG. 6, the thyristors 5, 205, 16, 21
When each of the triggers 6 is triggered, it turns on with respect to the respective on / off detection current during the respective trigger period. Therefore, thyristors 5, 16 (or 205,
216) turns off after a trigger period,
A trigger signal for the thyristors 205 and 216 (or 5, 16) is output. Since such a thing is repeated, the power conversion circuit oscillates.

The embodiment of FIG. 8 is a bridge type series inverter, and the way of the resonance current flowing through the load resistor 19 is the same as that of the circuits of FIGS. Connection terminals t32 to t35
Are connected to the same reference numerals. Two pulses
The transformer 50 changes the stored magnetic energy into its primary current and secondary current, and triggers the thyristors 5, 16 or the thyristors 205, 216. This trigger
Two rectifiers 2 to equalize the energy distribution
There are two diodes 75 corresponding to two. Rectifier 2
2, the resistor 23, the transistor 74, and the like detect on / off of the thyristors 5, 16 or the thyristors 205, 216. For this purpose, the respective current paths are configured such that the respective on / off detection currents (the respective currents flowing through four sets of the series circuit of the resistor 2 and the diode 3) flow to the respective rectifiers 22 and the like.

The embodiment of FIG. 9 is also a bridge type series inverter, but the reactor 17 is connected outside the bridge. The same reference numerals are connected to the connection terminals t15 to t22, respectively. For this reason, in the case of the well-known original bridge type series inverter before introducing the technology of the present invention, even if the thyristors 205 and 216 are turned on before the thyristors 5 and 16 are turned off, the inverter is not turned on. Since the voltage of the current capacitor 18 is applied to the thyristors 5 and 16 in the reverse direction, no short circuit occurs in the power supply and the thyristors 5 and 16
16 turns off. However, in order to achieve this, it is necessary for the commutation capacitor 18 to have sufficient charge to apply a reverse voltage to the thyristors 5 and 16 for a period longer than the turn-off time. The same is true when the thyristors 205, 216 turn off.

However, if the accumulation is not sufficient, the thyristor to be turned off does not turn off.
Power supply short circuit occurs. One of the causes is that the timing of resonance and the trigger is shifted due to a change in load characteristics or a connection of a load having a reactance component. Thus, this embodiment solves this problem. In the case of this embodiment, the thyristors 5 and 16 (or 205 and 21)
6) Thyristors 205 and 216 after turning off
(Or 5, 16) turn on, this on,
When switching off, the commutation capacitor 18 is fully charged. Therefore, measures against the short circuit of the power supply are doubled, and the safety is further enhanced. Thyristor 5, 20
Configurations such as on / off detection of 5, 16, and 216 and trigger means are almost the same as those of the circuit of FIG.
In the case of the circuit of FIG. 9, the operation can be performed only by detecting ON / OFF of one of the thyristors 5 and 16 and one of the thyristors 205 and 216.

The embodiment shown in FIG. 10 is an ignition circuit using a series inverter, which is a power conversion circuit for performing an ignition operation. Sparks are generated when the commutation capacitor 18 is charged and discharged. In the figure, reference numeral 76 denotes a DC-D that outputs a negative voltage.
A C converter, 77 is a three-terminal regulator, 81 is an ignition coil, 81a is a primary coil, and 82 is a discharge gap for ignition. An example of the circuit of the DC-DC converter 76 is shown in FIG. This description will be described later. The original main circuit of this embodiment includes a primary coil 81a and a commutation capacitor 18a.
Series resonance circuit, thyristors 5, 205, and DC-
It is a series inverter composed of a DC converter 76 and a DC power supply formed by a power supply capacitor 88.

In order to keep the voltage amplitude of the series resonance circuit constant, there are a thyristor 16 and rectifiers 89 and 248. These limit the voltage on commutation capacitor 18 to a range from zero to the voltage on power supply capacitor 88. That is, when the thyristor 5 turns on, the thyristor 1
6 and the rectifier 89 function as a flywheel diode for the primary coil 81a.
The voltage of the commutation capacitor 18 does not become higher than the voltage of the power supply capacitor 88. Therefore, as long as the thyristor 5 is on, the transistor 90 and the like continue to trigger the thyristor 16. On the other hand, during the ON period of the thyristor 205, the voltage of the commutation capacitor 18 does not become lower than zero because the series circuit of the thyristor 205 and the rectifiers 204 and 248 plays a role of a flywheel diode for the primary coil 81a.

The resistors 86 and 286 (each 1 ohm) are protection resistors. The thyristors 5, 205, and 16 are connected to the power supply capacitor 88 by a malfunction caused by ignition noise.
When the commutation capacitor 18 is short-circuited, these resistors protect these thyristors from overcurrent. The two diodes 66 are provided for surge voltage suppression, and almost no current flows through them. As a measure against ignition noise, the ignition coil 81
And the ignition discharge gap 82 are shielded. When the thyristor 5 is turned on, the thyristor 205 must be off, so that the transistor 85 or the like detects the on / off of the thyristor 205. Diode 83 and zener diode 84 prevent transistor 85 from saturating to increase the speed at which transistor 85 turns off. Conversely, when thyristor 205 turns on, thyristors 5, 16
Must be off, the transistor 79 and the like detect on / off of both thyristors 5 and 16.

The operation of this embodiment is as follows. When the ignition signal (start / stop signal in this case) input to the input terminal t36 rises while the switch 87 is on,
Since transistor 47 is turned on, the charging current of capacitor 46 flows to the base of transistor 78.
During a period corresponding to the charging period, the transistor 78 triggers the thyristor 5 and the thyristor 5 turns on, so that the transistor 90 and the like trigger the thyristor 16. At this time, since the voltage of the commutation capacitor 18 is zero, the voltage of the power supply capacitor 88 is first applied to the primary coil 81a, and a high voltage is induced on the secondary side. For this reason, a spark is generated in the ignition discharge gap 82, and this spark substantially continues while the current of the primary coil 81a flows. Power capacitor 8 in the meantime
8 charges commutation capacitor 18 to the same voltage, and transistor 79 charges capacitor 62.

When the current of the primary coil 81a is commutated from the thyristor 5 to the thyristor 16, the thyristor 5 turns off. When the transistor 79 is turned off together with the thyristor 16, the discharge current of the capacitor 62 flows to the base of the transistor 80, and the transistor 80 is turned on. During a period corresponding to the discharge period, the transistor 80 triggers the thyristor 205, so that the thyristor 205 is turned on. At this time, the voltage of the commutation capacitor 18 charged to the voltage of the power supply capacitor 88 is applied to the primary coil 81a in a direction opposite to the previous direction, and a high voltage in the opposite direction is induced on the secondary side. . For this reason, a spark is generated in the ignition discharge gap 82, and this spark continues for a long time while the current of the primary coil 81a flows. Meanwhile, commutation capacitor 18 discharges to zero voltage, and transistor 85 keeps transistor 47 off, causing capacitor 46 to discharge.

The transistor 85 together with the thyristor 205
Is turned off, the transistor 47 is turned on if the ignition signal is high. Hereinafter, the ignition circuit repeats the same operation. However, when the transistor 85 turns off, if the ignition signal is low, the ignition circuit stops the ignition operation. Thus, the ignition circuit continues to generate sparks almost continuously during a period substantially corresponding to the period when the ignition signal is at a high level.

The period during which the current of the primary coil 81a flows through the circuit including the thyristor 16 and the rectifier 89 or the circuit including the thyristor 205 and the rectifiers 204 and 248 is equivalent to the equivalent inductance in each circuit. It changes according to the time constant determined by the resistance. The conditions (for example, the pressure of the gas surrounding the discharge gap 82 for ignition and the length of the gap) when the spark is generated are factors that change the time constant, and the respective periods are affected by the conditions. However, according to the expansion and contraction of the ON periods of the thyristors 5, 16, and 205, the present invention can turn on the power supply capacitor 88 and the commutation capacitor 18 one after another at the optimal timing when the short circuit does not occur. it can.

Since the thyristor 16 is on as long as the thyristor 5 is on, the transistor 79 can detect the on / off of both the thyristors 5 and 16 by detecting the on / off of the thyristor 16. Therefore, the resistor 91 and the diode 92 may be omitted. It is preferable that the excitation inductance of the ignition coil 81 be as large as possible as compared with the primary and secondary leakage inductances. This is because, in the case of this ignition system, it is the current flowing through these leakage inductances that contributes to the spark current, not the current flowing through the exciting inductance. Rather, this latter current is a factor that delays the turn-off of the thyristors 16 and 205, and is a factor that prolongs a wasteful time in which no spark occurs between one spark period and the next spark period. Become. This is the same for the circuits shown in FIGS.

Further, in this embodiment, if there is no ignition discharge gap 82, a high voltage generating circuit for generating a positive or negative high voltage is provided. This circuit becomes a discharge lamp lighting circuit when a discharge lamp is connected instead of the ignition discharge gap 82, and becomes an ozone generation circuit when an ozone generation discharge gap is connected. Further, in this embodiment, if an induction heating coil is connected instead of the primary coil 81a, an induction heating circuit is obtained. These are shown in FIGS.
The same applies to the circuit of FIG. Then, in this embodiment, a spark occurs when the commutation capacitor 18 is charged and discharged. Therefore, in contrast to the capacitor discharge ignition (CDI) method in which spark is generated only at the time of discharge, the capacitor charge and discharge ignition (Condenser Charge an)
d Discharge Ignition) system, or simply referred to as CCDI system or double CDI system.

The embodiment shown in FIG. 11 is a CCDI-type ignition circuit which operates in the same manner as the circuit shown in FIG. 10, but both circuits have a partially different configuration. Although the configuration of the power supply unit on the left side of FIG. 11 is not shown, it is the same as that of FIG. In the case of the circuit of FIG. 10, when the thyristor 205 is turned on, the thyristor 205 and the rectifiers 204 and 248 serve as a flywheel diode for the primary coil 81a. On the other hand, in the circuit of FIG. 11, the thyristor 216 and the rectifier 289 then play such a role. Therefore, as long as thyristor 205 is on,
Transistors 93, 111, etc. continue to trigger thyristor 216. That is, at this time, the thyristor 21
6 continues to flow from transistor 111 toward transistor 85 (or rectifier 289). Then, when thyristor 5 turns on, both thyristors 205 and 216 must be off, so that transistor 85 etc.
Detect both ON and OFF. The subsequent operation is the same as that of the circuit of FIG.

Note that connecting a rectifier to the thyristor 216 in antiparallel improves the triggering of the thyristor 216.
In addition, the transistor 85 turns on and off both the thyristors 205 and 216 by detecting on / off of the thyristor 216.
Since the off state can be detected, the resistor 291 and the diode 292 may be omitted. 10 and FIG.
As can be seen from the first embodiment, the thyristor 205 or 21
By turning off the thyristor 6, the thyristors 5 and 16 receive their trigger signals (corresponding to the turn-on signal), but the current of the primary coil 81a does not always flow through these thyristors at the same time. This is the same for the thyristors 205 and 216 in the circuit of FIG.

The embodiment shown in FIG. 12 has two ignition coils 8.
1. An ignition circuit of the CCDI system having an ignition discharge gap 82 and an electronic power distribution function. Connection terminals t10, t1
1, t37 and t38 are connected with the same reference numerals. Spark is generated in one of the ignition discharge gaps 82 by the changeover switch 95. This circuit configuration is a circuit configuration in which two ignition circuits are integrated and a part thereof is shared. The thyristor 5 is a valve for charging the commutation capacitor 18, and the thyristor 205 is a valve for charging the commutation capacitor 218. The thyristor 16 discharges these. During the ON period of the thyristor 5 (or 205), the voltage of the commutation capacitor 18 (or 218) is changed by the DC power supply 20 because the series circuit of the thyristor 5 (or 205) and the rectifier 48 plays a role of a flywheel diode for the primary coil 81a. Does not exceed the voltage of On the other hand, during the ON period of the thyristor 16, the voltage of the commutation capacitor 18 (or 218) does not become less than zero because the series circuit of the thyristor 16 and the rectifier 248 plays a role of a flywheel diode for the primary coil 81a.

Pulse Transformer 49 and Transistor 1
The operation of 4, 36 is the same as that of the circuit of FIG. The two pulse transformers 49 share a resistance with the Zener diode on their primary side. Which one of them is operated is selected by two transistors 94 and a changeover switch 95. The resistor 65 and the diode 120 are measures against ignition noise and the like. Since it is necessary for the transistor 37 to detect the on / off state of both the thyristors 5 and 205, a current for on / off detection flows to the base of the transistor 37. Thyristor 5 or 205
During the ON period of, the transistor 37 charges the capacitor 62. When the thyristors 5 and 205 are no longer on, the transistor 37 is turned off.
The discharge current of the capacitor 62 is
30 is temporarily turned on. Thereby, the thyristor 1
6 is triggered and turns on. In this embodiment, a circuit using two ignition coils 81 is used, but a circuit using four, six, and eight ignition coils may be used if necessary. Further, one end of the secondary coil may be separated from the primary coil 81a, and another ignition discharge gap 82 may be connected to the one end.

The embodiment of FIG. 13 is also similar to the circuit of FIG.
One ignition coil 81, an ignition discharge gap 82, and a CCDI-type ignition circuit having an electronic power distribution function, wherein two ignition circuits are integrated into one. However, the basic main circuit is that of FIG. Moreover, the circuit in FIG. 13 uses an equivalent circuit of a thyristor including transistors 131 to 134 instead of the thyristor 205 in FIG. Transistors 131 and 132 form a well-known equivalent thyristor, and Darlington-connected transistors 133 and 134 amplify their main current. Therefore, the two ignition circuits share the thyristor 16 with the thyristor equivalent circuit. For this purpose, each of the thyristors 5 and 205 is connected in series to this equivalent circuit via the rectifier 204, and each primary coil 81a is connected in series to the thyristor 16 via the rectifier 89. Spark is generated in one of the ignition discharge gaps 82 by the changeover switch 135. Thyristor 5 or 2
As long as 05 is on, transistor 90 and the like keep thyristor 16 on. During the ON period of the thyristor 16,
At the same time that transistors 79 and 136 charge capacitor 62, transistor 131, together with resistor 138 and diode 139, keeps the base potential of transistor 131 at plus a few volts, forcing transistor 131 off. When the thyristor 16 is turned off, the discharge current of the capacitor 62 flows from the resistor 137 to the emitter and the base of the transistor 131, so that the equivalent circuit of the thyristor is triggered. The whole main operation is the same as that of the circuit of FIG.

The embodiment shown in FIG. 14 is a bridge type inverter. In this circuit, a monostable multivibrator
Driving four sets of Darlington-connected power transistors. For that purpose, the transistor 236 detects ON / OFF of the two sets of transistors 104 to 106, and the transistor 36 detects ON / OFF of the two sets of transistors 140 to 142. A monostable multivibrator centered on transistors 257, 58, 59 drives two sets of transistors 104-106. In this monostable multivibrator, the transistor 58 whose collector is grounded charges the capacitor 60 in order to improve the waveform of the output voltage output from the collector of the transistor 257. The resistor 61 prevents the base current of the transistor 59 from becoming excessive during this charging. Further, since the transistor 257 drives the transistor 104 or the like lower than the ground potential, the transistor 1
There is a diode 107 to prevent extraneous currents from flowing into the base of 04.

A transistor 56 is for triggering the monostable multivibrator. Input terminal t
Transistor 56 is turned off when transistor 36 is turned off when its start / stop signal, which is input to 31, falls, and when transistor 36 is turned off with two sets of transistors 140-142 while this signal is low. Trigger a stable multivibrator. On the other hand, a circuit centered on transistors 236 and 97 to 99 drives two sets of transistors 140 to 142. The operation is as follows. During the on-periods of transistors 104-106, transistor 236 charges capacitor 96. When transistor 236 is turned off along with transistors 104-106, capacitor 96 is discharged. During a period corresponding to the discharge period, the discharge current keeps the transistor 97 that was on until then off. As a result, during this period, transistors 140 along with transistors 98 and 99
142 sets are turned on.

FIG. 15 shows a controllable valve SS having a self-holding function and a self-extinguishing function in order to prevent a short circuit of the power supply.
1 is a bridge type series inverter using SS1 to SS4. Taking the controllable valve SS1 as an example, the transistor 4
Since the base currents of 00 and 403 flow to the other collector, the controllable valve SS1 has a self-holding function. A part of the collector current of the transistor 400 is amplified by the Darlington-connected transistors 401 and 402, and the main current is expanded. Since the emitter junctions of the transistors 401 and 402 serve as a constant voltage means, the magnitude of the base current of the transistor 403 is saturated. It is easy to turn the controllable valve SS1 off or forcibly keep it off. This can be achieved by short-circuiting the base and the emitter of the transistor 400 or 403.

By the way, the original main circuit includes the controllable valves SS1 to SS4, the four rectifiers 48, the reactor 1
7, a commutation capacitor 18 and a load resistor 19.
When the start / stop signal input to the input terminal t50 falls when the inverter is started, the transistor 414
Turns on. Then, since the charging current of the capacitor 417 flows to the base and the emitter of the transistor 415, the transistor 415 triggers the controllable valve SS2. When controllable valve SS2 is on, transistor 412 keeps controllable valve SS4 off, while transistor 409 keeps controllable valve SS3 on.
Therefore, at this time, the transistor 404 keeps the controllable valve SS1 off, and the transistor 408 charges the capacitor 416. That is, the controllable valve SS
As long as transistor 2 is on, transistor 409 keeps controllable valve SS3 on, so transistor 408 detects both on and off from controllable valve SS3 on / off detection.
Off can be detected.

When both the controllable valves SS2 and SS3 are turned off, the discharge current of the capacitor 416 flows to the base and the emitter of the transistor 407, so that the transistor 406 triggers the controllable valve SS1. When controllable valve SS1 is on, transistor 410 keeps controllable valve SS3 off while transistor 4
11 keeps controllable valve SS4 on. Therefore, at this time, the transistor 405 keeps the controllable valve SS2 off, and the transistor 413
14 is kept off, and the capacitor 417 is discharged.
That is, as long as the controllable valve SS1 is on, the transistor 411 keeps the controllable valve SS4 on.
The transistor 413 can detect both ON and OFF from the ON / OFF detection of the controllable valve SS4. When the transistor 413 is turned off together with the controllable valves SS1 and SS4, if the start / stop signal is low, the transistor 414 is turned on, and so on. This repetition continues as long as the start / stop signal is at a low level. However, when the turn off,
If the stop signal is at a high level, the operation of the inverter is stopped while the transistor 414 remains off.

The embodiments shown in FIGS. 16 and 17 are also bridge type series inverters having a function of preventing short-circuit of the power supply. The same symbols are connected to the connection terminals t51 to t611, respectively. In this main circuit, the controllable valves SS5, SS7, S
S8 and SS10 are bridge-connected, and the commutation capacitor 18, the reactor 17, and the load resistor 19 form a series resonance circuit. The controllable valves SS6 and SS9 are connected to the DC power supply 20 in the opposite direction to make the peak voltage applied to the load resistor 19 constant. However, the controllable valve SS5, SS6 or the controllable valve SS8,
It should be noted that when SS9 turns on at the same time, they short circuit commutation capacitor 18.
In conjunction with the controllable valve SS10, the controllable valve SS5,
SS9 turns on. To that end, transistor 423 detects the voltage between the base of transistor 427 and the emitter of transistor 428 and controls controllable valve SS5. Similarly, the transistor 422 detects this voltage and controls the controllable valve SS9.

When the voltage of the commutation capacitor 18 becomes the same as the voltage of the DC power supply 20 during the on-period of the controllable valves SS5 and SS10, the rectifier 438 which has been off because of the reverse voltage is turned on. Load current is rectifier 4
44, the controllable valve SS10, the rectifier 440, the controllable valve SS9 and the rectifier 438. This is because they play a role as a flywheel diode for the reactor 17. Therefore, after that, during a period determined by the time constant of the reactor 17 and the load resistor 19, the load current flows, attenuates to zero. As a result, no current flows through the rectifier 48.
The four rectifiers 48 are provided for surge voltage suppression, but need not be provided. Further, the ON period of the controllable valve SS10 changes depending on the magnitude of the load resistance 19.

On the other hand, the controllable valves SS8 and SS6 are turned on in cooperation with the controllable valve SS7. To this end, the transistor 426 controls the controllable valve SS8 via the transistor 421 and the controllable valve SS6 via the transistor 420. Controllable valve S
When the voltage of the commutation capacitor 18 becomes the same as the voltage of the DC power supply 20 during the ON periods of S7 and SS8, the rectifier 437 which was off because of the reverse voltage is turned on, so that the load current is reduced. It passes through the controllable valve SS6, the rectifier 436, the controllable valve SS7, and the rectifier 443. This is because they play a role as a flywheel diode for the reactor 17. Therefore, after that, during the period determined by the time constants of the reactor 17 and the load resistor 19, the load current flows, and is reduced to zero. Therefore, the rectifier 48
No current flows through. Further, the ON period of the controllable valve SS7 changes depending on the magnitude of the load resistance 19.

The trigger operation of this embodiment is almost the same as that of the embodiment shown in FIG. In addition, transistor 4
13, the controllable valves SS7, SS
8, when either SS6 is on, transistor 412
Changes the controllable valve SS10 (therefore, the controllable valve S
(S5, SS9 also), forcibly keep off. During the ON period of the transistor 37, that is, SS10, SS5, SS9
Is on, transistor 405 turns controllable valve SS7 (and thus controllable valves SS8, SS6
Well), keep it off. Furthermore, the controllable valve SS
As a method for keeping the controllable valves SS5 and SS9 on in cooperation with the controllable valve S10, the on / off of the controllable valve SS10 is detected as in the embodiment of FIGS.
A method of keeping the controllable valves SS5 and SS9 on when S10 is on is of course also possible. Controllable valve SS6
The same applies to SS8. Then load resistance 1
If the primary coil 81a of the ignition coil 81 is connected instead of the inverter 9, the inverter becomes the above-mentioned CCDI-type ignition circuit. In this case, since the leakage inductance of the ignition coil 81 plays the role of the reactor 17, the reactor 17 is not required.

Finally, the following six points will be supplemented. (1) The turn-on signal described in the claims may be a trigger signal or an on-off signal (see FIG.
4 circuit). Therefore, the turn-on signal generation means TS1 to TS4 correspond to a trigger circuit or an on-off signal generation circuit (such as a monostable multivibrator) in some embodiments. (2) It is desirable that all diodes and rectifiers used in each embodiment of the power conversion circuit are of a fast recovery type.

(3) In each embodiment of the ignition circuit, the ignition signal corresponds to the start / stop signal. As a method for obtaining the ignition signal, there is a method in which a computer or the like for controlling the engine generates the signal. There is also a method of using a signal AC generator that rotates in synchronization with the crankshaft as follows. In a well-known current cutoff type ignition device using a transistor, for example, an ignition signal is generated from a signal generated by a signal alternator built in a distributor, and this ignition signal is determined by the ignition start timing and the ignition start timing. It contains information on the current application period of the primary current of the ignition coil. The end of the current supply period is the ignition start timing. On the other hand, in the CCDI system of the present invention, the ignition signal includes information on the ignition period in which spark is repeated after the start of ignition and the ignition start timing. Therefore, if the output signal of the signal alternator is input to the comparator with the plus and minus of the signal inverted, and the output signal of the comparator is used as the ignition signal, the ignition start timing and the ignition period are controlled in the CCDI system. be able to.

(4) A starting method and an operation stopping method will be described. When the present invention is the power conversion circuit described in any one of claims 2 to 9, the present invention forms an oscillation circuit. Looking back on this situation in the embodiment of FIG. 3, when the switch 38 is turned on and the transistor 1 is turned on.
Turn on 3,14, turn on thyristors 5,16 and transistors 37,213,214, turn on thyristors 205,216 and transistors 35,36, and turn on transistors 13,14. Return to Similarly, the turn-on continues as long as the switch 38 is on. This looks like a domino defeat, or a relay competition baton, with "turn on" propagating through these valves one after the other. Therefore, in a state where the switch 38 is short-circuited by the inverter and the switch 38 is removed, to start the inverter, one of these valves may be turned on once. As one of the methods, there is a method in which one of them is turned on and then turned off by an output signal of a monostable multivibrator (not shown). However,
The ON period must be such that the pulse transformer 39 or 40 can perform a sufficient trigger operation.

On the other hand, in order to stop the operation of the inverter, the above-mentioned "turn on" should not be transmitted from one valve to the next. To do so, one of the valves may be forcibly kept off or on. However, when it is kept on, care should be taken that the thyristors 5, 216 or 205, 16 are not turned on at the same time. For example, the thyristor 5, 16 or 205, 216 is turned off by the transistor 2
Since it can be detected by 13 or 36 or the like, after the other set of thyristors is turned on during the off period of one set of thyristors, an operation stop operation such as keeping the thyristors on all the time may be performed. In this regard, the transistor 35
This problem does not exist when .about.37, 213, 214 are kept on all the time. The same applies to the other embodiments. However, in the case of the embodiment of FIG. 14, the method of stopping the operation in which the primary side current of the transformer shown in FIG.

(5) Example of DC-DC converter 76: FIG. 18 shows an example of a circuit of the DC-DC converter 76 used in each circuit of FIGS. In the figure, t40 is an input terminal, and t41 is an output terminal. First, the basic configuration will be described. "Flip-flops centered on transistors 160 and 167, and power MOS field-effect transistors 151 and 175 each having a positive output voltage and a complementary output voltage as input signals. Similarly, each output voltage is used as an input signal. , Transistors 151 and 175
Transistors 153, 1 for hastening turn-off of
73 and the respective primary windings 187 that generate oppositely directed magnetic fluxes in the transformer 187 when the respective drain currents of the transistors 151 and 175 flow in the respective windings.
a, 187b, and the respective current detection resistors 158, 166 through which the respective drain currents flow (0.075 ohm each)
When the respective drain currents flowing through the respective resistors 158 and 166 reach their predetermined values, the transistors 159, 168, etc. for switching the state of the flip-flop constitute an inverter circuit. Then, a "Schmitt trigger circuit or the like centered on transistors 178 and 179 for monitoring the magnitude of the DC output voltage obtained by rectifying and smoothing the AC output voltage, and the DC output according to the output signal of the Schmitt trigger circuit. There is a transistor 177 that controls the start and stop of the inverter circuit through the transistors 153 and 173 so that the voltage maintains a predetermined value.

Now, detailed points will be described. Diodes 150 and 176 are transistors 151 and 175
The primary windings 187a, 18
When the current of 7b is cut off, generation of a surge voltage is suppressed.
Zener diodes 152 and 174 are transistors 1
The gates 51 and 1753 are protected from overvoltage. The diode 155 prevents the base current of the transistor 167 from flowing toward the resistor 154 through the resistors 164 and 172. The same applies to the diode 169. Resistor 164 (100 ohms) and diode 162 are provided to turn off transistor 167 when capacitor 156 discharges through these, transistor 160 and diode 155. The same applies to the resistor 163 (100 ohms) and the diode 161. Diode 184
Of the resistor 183, the diode 184,
85 and the capacitor 186 provide a constant potential of about 1.2 to 1.4 volts.

The relationship between the anode potential, the base potential of transistor 179 (around 0.7 volts), and the potential of output terminal t41 is similar to the relationship between the fulcrum, action point, and power point in the "Leverage Principle". It is almost determined by the resistance ratio of 181 and 180. The size of the resistor 182 (47 kilo ohms) is negligible. When the potential of the output terminal t41 has not dropped to the predetermined value, the base potential of the transistor 179 is high enough to keep the transistor 179 on, so that the transistors 177 and 178 are off and the inverter circuit is operating. On the other hand, when the potential of the output terminal t41 is lower than the predetermined value, the base potential of the transistor 179 is also low, so that the transistor 179 is off, the transistors 177 and 178 are on, and the operation of the inverter circuit stops. In this way, the Schmitt trigger circuit and the like control the start and stop of the inverter circuit section and work to keep the DC output voltage constant.
The current value of each of the resistors 158 and 166 when the flip-flop switches is the current value when the transistor 159 or the transistor 168 is turned on by the voltage of each of the resistors 158 and 166. Therefore, each current value can be adjusted by the size of the resistors 158, 166, 157, and 165.

(6) An example of a controllable valve having a self-holding function and a self-extinguishing function: FIG. 19 shows a circuit diagram of the controllable valve. The controllable valve SS1 in FIG. 15 has an advantage that its on-voltage can be reduced as compared with the controllable valve formed by the transistors 131 to 134 in FIG. 13, but has a longer turn-off time. It has the disadvantage that. Here's why. The magnitude of the base current of the transistor 403 in FIG.
Since it does not increase according to the magnitude of the main current of S1,
Unless the base current is set large in accordance with the large main current from the beginning, the on-voltage cannot be kept low even for the large main current. However, when its main current is small, its large base current causes transistor 403 to be overdriven. This slows down the turn-off. Therefore, the ON voltage is lower than that of the controllable valve of FIG.
The controllable valve whose turn-off is earlier than that of the controllable valve SS1 is the controllable valve shown in FIG. The controllable valve in FIG. 19 may be replaced with the controllable valve in FIG.

(7) Two Examples of Prior Art Series Inverter Circuit and Ignition Circuit of the Inventor: In the series inverter circuit of FIG. 20, the transistors 63, 57, 12 and the rectifier 22 etc. have a controllable valve having a self-holding function. Constitute. And
An embodiment of the present invention comprising thyristor 5, diodes 3, 68, 72, transistor 57, resistors 67, 69, 71 and capacitor 70 triggers the controllable valve. This main circuit is basically the same as that of the circuit of FIG. 12, but has two commutation capacitors 18, 218. The transistor 12 detects the magnitude of the load current flowing through the rectifiers 22 and the resistors 73 together therewith. If this magnitude is equal to or greater than a set value (corresponding to the holding current of the thyristor; determined by the magnitude of the two resistors 73 and the like), the transistor 12 keeps the transistor 63 on just like the thyristor through the transistor 57 and the like. In other words, this is the same as a thyristor that depends on the magnitude of its main current to maintain its on state. The operations of the transistors 14, 36 and the pulse transformer 49 are the same as those of the circuit of FIG.
DC power supply 20, thyristor 5, diode 3, resistor 6
7, diode 68, capacitor 70 and diode 7
2 corresponds to the above-described second circuit, and the circuit including the capacitor 70, the resistor 71, and the emitter junction of the transistor 57 corresponds to the above-described first circuit. Then, the DC power supply 20, thyristor 5, diode 3, resistors 67 and 6
The circuit including the diode 9 and the diode 72 corresponds to the third circuit described above. If an induction heating coil is connected instead of the series circuit of the reactor 17 and the load resistor 19, this inverter circuit becomes an optimal induction heating circuit. Then, a trigger circuit similar to the trigger circuit of this circuit is shown in FIG.
Circuit. Transistors 79 and 136, resistor 13
7, 138, a capacitor 62, a transistor 131, a diode 139, and the like.

The circuit of FIG. 21 is an ignition circuit using a series inverter similarly to the circuit of FIG. 12, and uses a trigger circuit similar to the embodiment of FIG. Transistors 79, 10
1, diodes 320, 72, resistors 109, 321, 3
This is a trigger circuit composed of the capacitor 22, the capacitor 62, and the like. In this ignition circuit, the transistors 99 to 103 and the transistors 78, 104 to 106, 108 and the like each form a controllable valve having a self-holding function. The transistor 99 detects a voltage between the base of the transistor 102 and the emitter of the transistor 103, and controls the transistors 101 to 103 via the transistor 100 if the voltage is equal to or higher than a set value. This effect is illustrated in FIG.
Is the same as that of the controllable valves SS1 to SS4. The transistor 108 also detects a voltage between the base of the transistor 105 and the emitter of the transistor 106, and controls the transistors 104 to 106 via the transistor 78 if this voltage is equal to or higher than a set value. Transistor 4
The trigger circuit constituted by 7, 78, the capacitor 46 and the like is the same as that of FIG. However, the transistor 10
Transistor 85 forces transistors 104-106 off during the on-periods 1-103. Of course, during the ON period of the transistors 104 to 106, the transistor 7
9 forces transistors 99-103 off.
Note that the controllable valve SS1 shown in FIG. 15 may be used instead of the controllable valve formed by the transistors 99 to 103 and the like.

[0068]

[Related Patents] Japanese Patent Application Laid-Open No. 62-5019, Japanese Patent Application No. 61-013938, Japanese Patent Application No. 61-1986
197349, Japanese Patent Application No. 62-005027
No., PCT / JP87 / 00053, Japanese Patent Application No. 62-120234, Japanese Patent Application No. 62-1708.
No. 98, PCT / JP87 / 00575, PCT /
JP 87/00612.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing one embodiment of the present invention.

FIG. 2 is a circuit diagram showing seven embodiments of components of the present invention.

FIGS. 3 to 6 are circuit diagrams showing one embodiment of the present invention.

FIG. 7 is a circuit diagram showing one embodiment of components of a start / stop unit which can be used in the embodiment of FIG. 6 and the like;

8 to 15 are circuit diagrams each showing one embodiment of the present invention.

16 and 17 are left and right sides of a circuit diagram showing one embodiment of the present invention.

FIG. 18 shows a DC-DC used in the embodiments shown in FIGS.
FIG. 3 is a circuit diagram illustrating an example of a converter 76.

FIG. 19 is a circuit diagram showing an example of a controllable valve having a self-holding function and a self-extinguishing function.

FIG. 20 is a circuit diagram showing an example of a series inverter circuit of the inventor's prior art.

FIG. 21 is a circuit diagram showing an example of a prior art ignition circuit of the inventor.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI H02M 7/5383 H02M 7/5383 7/5387 7/5387 Z

Claims (6)

(57) [Claims] 1. A controllable valve S2 and a one-way valve S3.
Are connected in series, a plurality of arms each having a one-way controllable valve S1 as a component, one or more arms each having a controllable valve S4 as a component, and when each of the controllable valves S2 is on. Each of the controllable valves S2 is supplied with a current that is set so as not to hinder the turn-off of the controllable valve S2 without passing through the one-way valve S3.
2, a current path flowing in the same direction as the forward direction of each of the controllable valves S1, a current detecting means CS1 for detecting all the currents, and an operation according to the current detecting means CS1; Has turn-on signal generating means TS1 for generating one or more turn-on signals for turning on all the controllable valves S4 when detecting that no current flows. A power conversion recess. 2. When each of the controllable valves S4 is a one-way controllable valve in which a controllable valve S5 and a one-way valve S6 are connected in series, and when each of the controllable valves S5 is on, Each of the currents set to a size that does not prevent the turn-off of each of the controllable valves S5 is performed without passing through each of the one-way valves S6.
5 operates in accordance with the respective current paths flowing in the same direction as the forward direction of the respective controllable valves S4, current detection means CS2 for detecting the currents of all the controllable valves S5, and the current detection means CS2. , When the current detecting means CS2 detects that no current of the controllable valve S5 stops flowing, one or more turn-on switches for turning on all the controllable valves S1.
2. The power conversion circuit according to claim 1, further comprising: turn-on signal generation means for generating an on-signal. 3. One of the plurality of controllable valves S2.
A current detecting means CS3 for detecting the current of the controllable valve S2a, which operates according to the current detecting means CS3, and when the current detecting means CS3 detects that the current of the controllable valve S2a flows, Turn-on signal generating means TS3 for generating one or more turn-on signals for turning on all of the controllable valves S1 that do not include the controllable valve S2a; The power conversion circuit according to claim 2, wherein the signal generation means (TS2) generates only a turn-on signal of the controllable valve (S1) including the controllable valve (S2a). 4. As long as the current detecting means CS3 detects that the current of the controllable valve S2a is flowing,
4. The turn-on signal generating means TS3 continues to generate one or more turn-on signals according to claim 3, and the current detecting means CS1 detects the current of the controllable valve S2a. The power conversion circuit according to claim 3, wherein the detection is performed via another controllable valve (S2). 5. One of the plurality of controllable valves S5.
A current detecting means CS4 for detecting the current of the controllable valve S5a, which operates according to the current detecting means CS4, and when the current detecting means CS4 detects that the current of the controllable valve S5a flows, Turn-on signal generating means TS4 for generating one or more turn-on signals for turning on all of the controllable valves S4 not including the controllable valve S5a; The power conversion circuit according to claim 2, wherein the signal generation means (TS1) generates only a turn-on signal of the controllable valve (S4) including the controllable valve (S5a). 6. As long as said current detecting means CS4 detects that said current of said controllable valve S5a is flowing,
The turn-on signal generating means TS4 continues to generate one or more turn-on signals according to claim 5, and the current detecting means CS2 detects the current of the controllable valve S5a. The power conversion circuit according to claim 5, wherein the detection is performed via another controllable valve (S5).