JP2796567B2 - Switching means with self-holding function and self-extinguishing function - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention makes it easy to turn off or to keep it off so that it does not turn on due to malfunction, and to reduce the self-holding current. The present invention relates to a "switching means having a self-holding function and a self-extinguishing function". Therefore, the present invention provides a GTO (gate
Turn-off thyristor), and in addition to power conversion circuits using resonance circuits (eg, series inverters),
The power conversion circuit is applied to a device to which the power conversion circuit is applied, such as an ignition device including an ignition device for an internal combustion engine, a high voltage generator, an ozonizer, a discharge lamp lighting device, and an induction heating device. 2. Description of the Related Art FIG. 2 shows a conventional switching means having a self-holding function and a self-extinguishing function disclosed in Japanese Patent Application Laid-Open No. 57-118438. The operation of this switching means is as follows. Since the transistor 10 connects the collector and the base of the transistor 11 when the transistor 10 is on, a part or all of the main current of the switching means shown in FIG. As long as this main current is larger than the set value of the holding current of the switching means of FIG. 2 (this corresponds to the holding current of the thyristor, hereinafter, referred to as "this"), the base-emitter voltage of the transistor 11 is also a predetermined value. Be larger. Otherwise, the voltage will be less than that predetermined value or go to zero. For this reason, the transistor 9 determines that the base-emitter voltage is higher than the predetermined voltage corresponding to the set value of the holding current.
, The transistor 9 controls the transistor 10 to be on. Otherwise, transistor 9
Turns off the transistor 10. As a result, the operation of the entire switching means of FIG. 2 is positive feedback, and if the positive feedback is prevented, the switching means of FIG. 2 can be turned off. Thus, the switching means of FIG. 2 has a self-holding function and a self-extinguishing function. However, the first problem that "it is desirable to make the turn-off control easy" is shown in FIG.
The conventional switching means shown in FIG. (First Problem) When the switching means of FIG. 2 is turned off, for example, when the base and the emitter of the transistor 9 are short-circuited by a short-circuit switch or the like, a short-circuit current of a certain magnitude flows through the short-circuit switch or the like. That is, unless a certain amount of short-circuit current is passed through the short-circuit switch or the like, the switching means of FIG. 2 cannot be turned off. This is because the turn-off control is not yet easy enough. Incidentally, if the turn-off control is easy, even if the switching means is turned on due to a malfunction, it is easy to return to the off state.
It is also easy to keep the switching means off so as not to turn on. The reason why the turn-off control is not yet easy enough is that the magnitude of the forward voltage of the PN junction between the base and the emitter of both transistors 9 and 11 depends on the magnitude of the main current of the switching means in FIG. Since the switching means shown in FIG. 2 may have a base current sufficient to maintain the self-holding state in a range from the minimum main current (= holding current) for maintaining the self-holding state to the maximum main current. This is because the value of the resistor 13 needs to be set small in order to supply the voltage to the transistor 9. In addition, when the resistor 15 having a small resistance is connected between the base and the emitter of the transistor 11 in order to speed up the turn-off of the transistor 11, the value of the resistor 13 needs to be set smaller. The second problem that the holding current is too large for the magnitude of the maximum main current is present in the conventional switching means shown in FIG. (Second problem) In the switching means of FIG.
Although the transistor 11 also functions as a constant voltage means, when the main current of the switching means of FIG. 2 is reduced, the main current is applied to the base-emitter PN junction of the transistor 11 (and the resistor 15).
Voltage drop in the transistor 11
Chromatography on-off threshold voltage between the scan-emitter intends want smaller than the on-off threshold voltage between the base and emitter of bets <br/> transistor 9 than the original. As a result, the transistor 9 cannot maintain the ON state, and the switching means in FIG. 2 cannot maintain the self-holding state. That is, the switch of FIG.
Ring means can be sufficiently small holding current Do <br/> physician. This leads, for example, to the interruption of the load current or the like before the load current flowing through the switching means of FIG. 2 decreases to zero and does not become zero. Or in the case of an inductive load, a surge voltage is generated. The reason why the holding current cannot be made sufficiently small is considered as follows. a) The base-emitter PN junction of the transistor 11 has a much larger current capacity than the base-emitter PN junction of the transistor 9, and the latter is similar to a power diode from the viewpoint of the former. When a small current of the order of magnitude flows through each PN junction, as can be seen by comparing the forward characteristics of two ordinary diodes having large differences in current capacity, there is a difference in the voltage drop (= forward voltage) generated at each PN junction. That is, the forward voltage of the latter becomes smaller than that of the former. b) When the collector current of the transistor 10 is small, and if both voltage drops (= both forward voltages) are the same, the collector current tends to flow toward the base-emitter PN junction of the transistor 11 without the resistor 13. c) When a resistor 15 having a small resistance value is connected between the base and the emitter of the transistor 11 in order to accelerate the turn-off of the transistor 11, part or most of the collector current of the transistor 10 flows to the resistor 15, and The collector current of the transistor 10 flowing between the base and the emitter of the transistor 9 decreases. Therefore, the present invention provides a "switching means having a self-holding function and a self-arc-extinguishing function" which can easily turn-off control and sufficiently reduce the holding current with respect to the maximum main current. It is aimed at. That is, the present invention does not have a self-holding function but has a self-extinguishing function, and has a normally-off, current-driven first switching means. The control terminal and both main terminals are called a control terminal ct1, a main terminal mt1a, and a main terminal mt1b.
1 and the main terminal mt1a form a pair, and when there is a constant voltage characteristic in the forward bias direction between the control terminal ct1 and the main terminal mt1a, the first resistance means is connected between the control terminal ct1 and the main terminal mt1a. The constant voltage means is arranged in the direction having the constant voltage characteristic and connected in series with the portion between the control terminal ct1 and the main terminal mt1a to form a series circuit .
A voltage detection unit configured to detect whether a voltage input based on an on / off threshold voltage of a current-driven single transistor is greater than the on / off threshold voltage, The voltage of the circuit is input to the voltage detection means via the second resistance means, and the circuit is turned on and off in accordance with the output of the voltage detection means, and the voltage of the series circuit is determined to be larger than a predetermined value. Switching means having a self-holding function and a self-extinguishing function provided with a second switching means having no self-holding function, which connects the main terminal mt1b and the series circuit when the detecting means detects the signal. As a result, the voltage between the control terminal ct1 and the main terminal mt1a corresponds to the voltage of the series circuit on a one-to-one basis. Therefore, the voltage detecting means detects the voltage of the series circuit to control the control terminal ct1. The voltage between the main terminals mt1a can be detected. If a part or all of the main current of the switching means of the present invention flows through the series circuit to cause a voltage drop, and the voltage detection means detects that the magnitude of the voltage drop is larger than a predetermined value, the voltage detection means Controls ON of the first switching means through the second switching means. However, if the voltage detecting means detects that the magnitude of the voltage drop is not larger than a predetermined value, the voltage detecting means controls the first switching means to be turned off through the second switching means. In the self-holding state, the difference between the magnitude of the voltage of the series circuit and the magnitude of the on / off threshold voltage can be increased by the voltage drop of the constant voltage means. Can supply a sufficient forward bias current to the single transistor in order to maintain the ON state even if the resistance value is increased. As a result, when the switching means of the invention is turned off, for example, when the control terminal and the main terminal forming a pair for inputting the drive signal of the single transistor are short-circuited by a short-circuit switch or the like, the resistance value of the second resistance means is reduced. Corresponding to the increase, the short-circuit current flowing through the short-circuit switch and the like becomes smaller than before. In other words, the first effect of the present invention is that the switching means of the present invention can be turned off with a short-circuit current smaller than that of the related art, and "the turn-off control is facilitated".
(First effect) Since the turn-off control is facilitated, it is easy to turn the switching means of the invention back to off even if the switching means of the invention is turned on due to a malfunction. It is easy to keep it off so that it does not turn on. In addition, since the series circuit can generate a sufficient voltage drop for controlling the single transistor to turn on even for a main current smaller than that of the related art,
The holding current of the switching means of the invention is smaller than that of the conventional switching means. Therefore, the switching means of the present invention has a second effect that "the holding current can be sufficiently reduced with respect to the magnitude of the maximum main current". (Second Effect) When the present invention corresponds to the switching means having the self-holding function and the self-extinguishing function according to the eighth aspect, the third switching means described in the same claim as the first switching means described above. Switching means are cascaded. As will be described later with reference to FIGS. 6 and 7, the turn-off control may be further facilitated by the current increasing action of the third switching means. In the case where the present invention corresponds to the switching means having the self-holding function and the self-extinguishing function according to the tenth aspect, the turn-off control is similarly further facilitated by the current increasing action of the first switching means. There is. BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below in more detail with reference to the accompanying drawings. The embodiment of FIG. 1 corresponds to a switching means having a self-holding function and a self-extinguishing function according to claims 1, 2, 3, 5, 6, and 7, respectively. In the embodiment of FIG. 1, each corresponds to each of the above-described components as follows. a) The transistor 11 is the first switching means described above. b) The base terminal, the emitter terminal, and the collector terminal of the transistor 11 are the control terminal ct1 and the main terminal mt described above.
1a and the main terminal mt1b. c) The resistance 15 is the first resistance means described above. d) the rectifier 12 is a constant voltage means as described above or claim 7;
For diodes or non-controllable switches mentioned. e) The series circuit of the base-emitter PN junction of the transistor 11 and the rectifier 12 is the series circuit described above. f) Transistor 9 is a single transistor as described above. g) The connection body of the transistor 9 and the resistor 14 serves as the voltage detecting means described above. h) The resistor 13 serves as the second resistance means described above. i) The connection body of the transistor 10 and the resistors 140 and 142 is the second switching means described above. j) The resistor 16 is a third resistor means according to claim 6. In the embodiment of FIG. 1, the parallel circuit of the rectifier 12 and the resistor 16 helps the transistor 9 and the like to detect the base-emitter voltage of the transistor 11. That is, in the case of the conventional switching means shown in FIG. 2, the set value of the base-emitter voltage of the transistor 11 according to the set value of the holding current is determined by the base-emitter voltage of the transistor 9 when the transistor 9 is turned on. If the voltage is smaller than or equal to the voltage, the transistor 9 and the like cannot detect the base-emitter voltage of the transistor 11. Therefore, the present inventor has proposed a rectifier 12 like the embodiment of FIG.
The voltage of the parallel circuit of the resistor 16 and the resistor 16 is added to the voltage between the base and the emitter of the transistor 11, and the transistor 9 and the like detect the sum of the voltages, but there is no problem in detecting the voltage between the base and the emitter of the transistor 11. . because,
This is because the base-emitter voltage of the transistor 11 corresponds to the sum of the voltages on a one-to-one basis. When the embodiment of FIG. 1 is in the self-holding state,
The sum of the voltages of the resistors 15 and 16 is stabilized at, for example, about 2 volts, and the voltage difference from the on / off threshold voltage of the transistor 9 can be larger than that of the conventional switching means shown in FIG. In the embodiment of FIG. 1, the value of the resistor 13 can be set to be larger than that of the prior art in order to flow the same amount of base current. As a result, the embodiment of FIG.
When the transistor 9 is turned off, for example, if the base and the emitter of the transistor 9 are short-circuited by a short-circuit switch or the like, the short-circuit current flowing through the short-circuit switch or the like becomes smaller than before in response to the increase in the resistance of the resistor 13. In other words, the embodiment of FIG. 1 can be turned off with a short-circuit current smaller than before,
The first effect that "the turn-off control becomes easy" exists in the present invention including the embodiment of FIG. Of course, even with transistors 10, similar to the conventional its turn-off is possible. The resistor 16 may be omitted, but if it is provided, the set value of the holding current can be made accurate. The holding current value of the embodiment shown in FIG. 1 is mainly determined by the values of the resistors 13 to 16 and the value of the on / off threshold voltage between the base and the emitter of the transistor 9 when the transistor 9 is turned on. The size is determined by the "size". However, since a series circuit such as the resistors 15 and 16 can generate a sufficient voltage drop for controlling the transistor 9 even for a main current smaller than that of the related art, FIG. The holding current of the embodiment is smaller than that of the conventional switching means shown in FIG. Therefore, the present invention has the second effect that "the holding current can be sufficiently reduced with respect to the maximum main current", including the embodiment of FIG. The embodiment shown in FIG. 3 corresponds to a switching means having a self-holding function and a self-extinguishing function according to the fourth aspect.
It is connected to the first base side, but its role is the role the same way of the resistor 16 and the rectifier 12 shown in FIG. However, the current capacity of the rectifier 18 is substantially equal to the current capacity of the rectifier 12.
Since it is only necessary to divide by the current amplification factor of the resistor 11,
The embodiment of FIG. 3 has a smaller holding current than the embodiment of FIG.
It has the advantage of being able to. Because, in either embodiment
Even when the main current is small, the transistor 11
The emitter-emitter voltage is higher than the ON / OFF threshold voltage.
Since the transistor is small and the transistor 11 is off, the main current
Mostly, the collector current of transistor 10
Collector current occurs in each of the diodes 12 and 18
This is because there is a difference in the voltage drop. That is, the current capacity
Comparing the forward characteristics of two diodes with large differences
As can be seen, the same small current is generated at each PN junction.
There is a difference in the pressure drop (= forward voltage), and the embodiment of FIG.
A voltage drop that can turn on transistor 9 with a smaller current
Below is the base-emitter PN junction of transistor 11
Can occur across the series circuit of diodes 18
This is because that. Then, the resistor 17 may be omitted, but if it is present, the set value of the holding current can be made accurate. Since the transistors 10 and 11 are Darlington-connected through a parallel circuit of the resistor 17 and the rectifier 18, when the transistor 10 is on, the collector and the base of the transistor 11 are connected through this parallel circuit . The embodiment shown in FIG. 4 is similar to the embodiment shown in FIG. 1 except that a constant current circuit in which a constant current flows through the collector of the transistor 9 with one less resistor is formed. When the embodiment of FIG. 4 is in the self-holding state, the sum of the voltages of the resistors 15 and 16 is substantially constant, so that the collector current of the transistor 9 is also substantially constant, and the magnitude is determined by the constant voltage and the value of the resistor 19. Decided. The operation is as follows. This increase in the collector current leads to an increase in the voltage of the resistor 19, an increase in the emitter potential of the transistor 9, and a decrease in the base current. Conversely, the decrease in the collector current is caused by the resistance 1
9, the emitter potential of the transistor 9 falls,
This leads to an increase in the base current. Thus, its collector current is kept constant. Turning the embodiment of FIG.
When to be off, for example when short-circuiting the base and emitter of the transistor 9 can Rukoto easily to turn off <br/> the embodiment of FIG. [0200] Although the parallel circuit of the embodiment of FIG. 5 and the resistor 17 a rectifier 18 is connected to the base of the transistor 11, its role is the role and <br/> same as the rectifier 12 and the resistor 16 of FIG. 4 It is. However, the same as described in the description of the embodiment of FIG.
As described above, the embodiment of FIG. 5 has a smaller holding current than the embodiment of FIG.
It has the advantage that it can be cut. In addition, the transistor 1
Since 0 and 11 are Darlington connected via a parallel concave path of the resistor 17 and the rectifier 18, when the transistor 10 is on, the collector and the base of the transistor 11 are connected through this parallel circuit. The embodiment of FIG. 6 corresponds to a switching means having a self-holding function and a self-arc-extinguishing function according to claim 8, wherein transistors 22 and 23 are Darlington-connected, and one base-emitter PN junction is provided. Corresponds to the aforementioned constant voltage means. The transistor 22 is the first transistor described above.
And the transistor 23 may be considered to correspond to the third switching means in claim 8, or may be considered to correspond to the exact opposite. The resistors 26 and 27 are also the first
And the third resistance means in claim 6 may be considered to correspond to each other, or they may be considered to correspond to the exact opposite. The embodiment of FIG. 7 is similar to the embodiment of FIG. 6, but has a resistance smaller by one, and a constant current circuit in which a constant current flows through the collector of the transistor 20 is formed. When the embodiment of FIG. 7 is in the self-holding state, the sum of the voltages of the resistors 26 and 27 is substantially constant, so that the collector current of the transistor 20 is also substantially constant.
Is determined by the value of The operation and effect of the embodiment of FIG.
This is almost the same as the embodiment. Each of the embodiments shown in FIGS. 1 and 3 to 5 constituting a three-stage direct connection type current amplifier circuit and a four-stage direct connection type current amplifier circuit are constituted. Comparing the embodiments of FIGS. 6 and 7, since the latter has a higher total current amplification factor, each transistor 20 has a larger main current than the base current of each transistor 9 for the same main current.
Requires a smaller base current, and each transistor 1
Since the base current of each transistor 21 is smaller than the base current of 0, each transistor 20 and each transistor 21 are easier to turn off than each transistor 9 and each transistor 10.
(Additional Effects) The above-mentioned facts become more remarkable in the embodiments shown in FIGS. 8 and 9 which constitute a kind of current amplifier circuit of a five-stage direct connection type. 8 and 9 correspond to a switching means having a self-holding function and a self-extinguishing function. In each of the embodiments shown in FIGS. 10 to 12, each switching means corresponding to the above-mentioned second switching means includes one DC power supply 143. FIG.
0, the DC power supply 143 and the transistors 30, 3
1 and the like corresponds to the above-mentioned second switching means, and in the embodiment of FIG.
43 and the switching means formed by the transistors 82 and 83 correspond to the above-mentioned second switching means. In the embodiment of FIG.
The switching means formed by 65 and the like corresponds to the above-mentioned second switching means. In the embodiment shown in FIG. 12, the transistor 64 and the like correspond to the above-described voltage detecting means. Means can be configured. [Related Patents] a) JP-B-55-37178 b) JP-B-56-
5098 c) JP-B-56-26216 d) JP-A-62-206
5019e) PCT / JP87 / 00053 (Japanese Patent Application No. 62-5)
00831) f) Japanese Patent Application No. 62-086800 g) Japanese Patent Application No. 62-8686
120234

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 an example of a conventional switching means. 3 to 12 are circuit diagrams showing one embodiment of the present invention.

Claims (1)

(57) [Claims] It does not have a self-holding function but has a self-extinguishing function, has a normally-off, current-driven type first switching means, and has its control terminal and both main terminals connected to a control terminal ct.
1, called a main terminal mt1a and a main terminal mt1b, a control terminal ct1 and a main terminal mt1a form a pair for driving signal input, and there is a constant voltage characteristic in a forward bias direction between the control terminal ct1 and the main terminal mt1a. Then, the first resistance means is connected between the control terminal ct1 and the main terminal mt1a, and the constant voltage means is aligned in the direction having the constant voltage characteristic and connected in series with the portion between the control terminal ct1 and the main terminal mt1a. A series circuit is configured to determine whether a voltage input based on an on / off threshold voltage of a normally-off , current-driven single transistor is larger than the on / off threshold voltage. A voltage detecting means for detecting, a voltage of the series circuit is input to the voltage detecting means via a second resistance means, and an on / off operation is performed according to an output of the voltage detecting means; When the voltage detecting means detects that the magnitude of the voltage of the circuit is larger than a predetermined value, a second switching means having no self-holding function, which connects the main terminal mt1b and the series circuit, is provided. Switching means that has a self-holding function and a self-extinguishing function. 2. The first switching means is in a bipolar mode
2. A switching means having a self-holding function and a self-extinguishing function according to claim 1, wherein the switching means is a transistor. 3. The single transistor is in bipolar mode
3. The transistor according to claim 1, wherein
Switching means having the self-holding function and the self-extinguishing function described. 4. 4. The switching means having a self-holding function and a self-extinguishing function according to claim 1, wherein the constant voltage means is connected to the control terminal ct1. 5. 4. The switching means having a self-holding function and a self-extinguishing function according to claim 1, wherein the constant voltage means is connected to the main terminal mt1a. 6. The switching means having a self-holding function and a self-extinguishing function according to any one of claims 1 to 5, wherein a third resistance means is connected in parallel to the constant voltage means. 7. 7. A method according to claim 1, wherein said constant voltage means is a diode or a non-controllable switch.
Switching means having a self-holding function and a self-extinguishing function described in the paragraph. 8. It does not have a self-holding function but has a self-extinguishing function, has normally-off, current-driven third switching means, and has its control terminal and both main terminals connected to a control terminal ct.
3, called a main terminal mt3a and a main terminal mt3b, a control terminal ct3 and a main terminal mt3a form a pair for driving signal input, and there is a constant voltage characteristic in a forward bias direction between the control terminal ct3 and the main terminal mt3a; Control terminal ct1, main terminal mt
1a and the control terminal ct3 when the forward bias voltage polarity is the same between the control terminal ct3 and the main terminal mt3a.
7. The switching means having a self-holding function and a self-extinguishing function according to claim 6, wherein a portion between the main terminals mt3a is used as the constant voltage means, and the main terminals mt1b and mt3b are connected. 9. The third switching means is in a bipolar mode;
Switching means having a self-holding function and a self-extinguishing feature of claim 8, wherein it is a transistor. 10. The first switching means is provided with a polarity of a drive signal.
10. A switching device having a self-holding function and a self-extinguishing function according to claim 1, wherein the switching device is a cascade-connected transistor in which a plurality of bipolar mode transistors having the same function are connected in cascade. means.