JP3321203B2 - Isolated switching circuit, isolated switching circuit with shield function, and isolated switching circuit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The first invention is capable of insulated driving without using insulating means such as a light emitting diode pair, a light receiving diode pair, and a transformer, and furthermore, is continuously turned on with a condition using a DC power supply. = Forward bias driving), and a one-way or two-way insulated switching circuit. Applying this insulated switching circuit makes it possible to form an insulated three-terminal switching circuit or an "ignition power distribution circuit capable of selecting a predetermined ignition coil (ignition step-up transformer), that is, an ignition discharge gap". The insulated switching circuit or the insulated three-terminal switching circuit can be used as an analog switch (= analog gate), an insulated switch, a digital switch (digital gate), or the like. Of course, if the insulated switching circuit and the insulated three-terminal switching circuit are bidirectional, they can be used as an AC switch. And electronic exchanges.

The second invention relates to an insulated switching circuit having a one-way or two-way shield function which can shield between both switch terminals when both switch terminals are off in two directions. . The shielding function is useful for preventing a current such as a leakage current or a displacement current from flowing between the two switch terminals, and is useful for preventing a signal current from leaking. By applying this insulated switching circuit, an insulated three-terminal switching circuit and an ignition power distribution circuit can be configured. In particular, an electronic exchange to which this insulated switching circuit is applied is useful for preventing leakage of wired communication and wired communication.

[0003] The third invention relates to a one-way or two-way insulated switching circuit which can replenish the on-drive voltage any number of times with a condition using a DC power supply. By applying this insulated switching circuit, an ignition power distribution circuit can be configured. In addition, if the two-way insulating switching circuit is used, it is possible to easily change a predetermined inductance or capacitance in the circuit, change a resistance or a load, and the like. Therefore, there are various application fields, for example, a resonance type power conversion circuit, a resonance type switching power supply and an ignition circuit to which the resonance type power conversion circuit is applied. In particular, the third invention is very useful for an ignition circuit with an electronic power distribution function that can select at least one of a plurality of ignition coils.

[0004]

2. Description of the Related Art FIGS. 2 to 7 show six conventional bidirectional insulated switching circuits. In each of the circuits of FIGS. 2, 4 and 6, if one transistor 2 is removed and a diode (not shown) is connected in series to the other transistor 2 as in the embodiment of FIG. The circuit is a one-way isolated switching circuit. Reference: JP-A-55-136720, JP-A-55-136721, JP-A-57-178735, JP-A-59-149421, JP-A-62-195917, and JP-A-1-259620.

In each of the circuits shown in FIGS. 2 and 3, a switch terminal (s
The transformer 12 insulates between the t3 to st6) side and the input terminal (it1 to it4) side, and a gate forward bias voltage (= on drive voltage) is supplied from both input terminals (it1 to it4). Therefore, both switch terminals (st
These circuits and the like have an advantage that even if the potentials of 3 to st6) fluctuate, "the ON drive is not affected and the ON period can be extended". On the other hand, if the supply of the gate forward bias voltage is stopped, there is an advantage in that the off-driving can be performed easily and stably in the circuits shown in FIGS. Although the capacitor 16 is a smoothing capacitor, the capacitor 1 is turned off when the transistor 2 is turned off.
6 must be completely discharged, so that its capacitance cannot be increased so much in terms of energy loss and switching speed.

However, in the isolated switching circuit using the transformer 12, a high frequency AC voltage (periodic voltage) is applied to each of the input terminals (it1 to it4) when the device is turned on due to the demand for downsizing and weight reduction of the device. (Including pulse voltage trains), a dedicated AC power supply is required.
It is convenient if a DC power supply can be turned on. However, both input terminals (it1 to it
4) There is also a method of applying a wide single pulse voltage to perform on-drive. However, in order to prevent the magnetic flux of the transformer 12 from saturating during the on-drive and preventing the back electromotive force from being generated, the following method is used. Since it is necessary to increase the excitation inductance,
The transformer 12 becomes heavier and heavier than in the case of the AC drive described above. In addition, it is necessary to extract and prepare the excitation energy for the next ON drive, and the excitation energy is lost. Therefore, the problem of "desirability of being able to perform insulated driving without using a transformer and using a DC power supply" is a modification of the insulated switching circuits of FIGS. 2 and 3 and the circuit of FIG. 2 described above. One-way insulated switching circuit. (First problem to be solved by the first and third inventions)

In each of the insulating switching circuits shown in FIGS. 4 and 5, the switch terminals (st7 to st10) and the input terminal (i) are connected.
The interval between t5 and it8) is insulated by each of the light emitting diode groups 14 and each of the light receiving diode groups 13, and each of the light emitting diode groups 14 supplies light energy for ON driving and OFF driving. For this reason, "Even if the potential of each of the switch terminals (st7 to st10) fluctuates, the on / off drive is not affected, the on period can be lengthened, and the normally-on type switching means is provided for each transistor 2. There is an advantage of "can be used" in the circuits shown in FIGS.

However, an isolated switching circuit using a pair of a light emitting diode and a light receiving diode has a narrower operating temperature range than a normal circuit, a large change in characteristics due to temperature, and a large energy loss due to low energy conversion efficiency. The output current of the photodiode is small, and the turn-on and turn-off speeds are slow. Therefore, the problem of "desired insulated driving without using a pair of light-emitting and light-receiving diodes" is a problem with the unidirectional switching circuits of FIGS. 4 and 5 and the circuit of FIG. Insulated switching circuit. (Second problem to be solved by the first and third inventions)

In each of the insulation type switching circuits shown in FIGS. 6 and 7, the switch terminals (st11 to st14) and the input terminals (it9 to it12) are insulated DC by capacitors 15 and 17. Then, at the time of the ON drive, a high-frequency AC voltage (including a periodic pulse voltage train and the like) is input to both input terminals (it9 to it12), and the diode 100 rectifies the AC voltage and outputs A gate forward bias voltage is supplied to the transistor 2.
On the other hand, at the time of the off driving, if the input of the AC voltage stops, the resistors 101 and 102 discharge the capacitance between the gate and the source, and each transistor 2 is turned off.

However, when the value of the resistor 101 is set to zero and the drive is on, each input terminal (it9 to it12)
There is also a method of applying a DC voltage to the capacitor 15,
When the battery 17 is charged at that time, the two charging voltages hinder the continuous on-driving of each transistor 2 and the supply of on-driving energy to each transistor 2, so that the on-state is maintained. Becomes unstable. Also,
In order to efficiently supply the gate forward bias voltage, the capacitance of the capacitors 15 and 17 needs to be larger than the capacitance between the gate and the source, and the impedance between each switch terminal and each input terminal is reduced. Become smaller. You need to be aware of these things.

However, when each of the insulation type switching circuits is on, each of the switch terminals (st11 to st14)
And the input terminals (it9 to it12) are in an electrically conducting state by the capacitors 15 and 17 and are not insulated in an alternating manner, so that the circuit on the input terminal side and the circuit on the switch terminal side affect each other. . In addition, when the potential of each switch terminal fluctuates, a displacement current flows between each switch terminal and each input terminal, so that its gate voltage changes and its ON drive is affected.

This will be described in detail. If the drive power supply on the input terminal side and the main power supply on the switch terminal side are insulated both DC and AC except for the insulated switching circuit sections in FIGS. 6 and 7, that is, they are insulated like that. If it is allowed to use the two power supplies provided, there is no need to provide the isolated switching circuit or the like with an insulating function. This is because even if both power supplies are connected in the insulated switching circuit section, there is only one current path between them and no current flows between them. This is because two current paths are necessary for the current to flow. However, in a normal circuit, the driving power supply and the main power supply on the switch terminal side are connected in a DC or AC manner except for the respective switching circuit sections in FIGS. 6 and 7, or both power supplies are common. Therefore, one current path already exists in this part. When another AC current path is formed there through the switching circuit section, a reciprocating current path, that is, a closed circuit is formed in an alternating manner. When the potential of each switch terminal fluctuates, the switch terminal side and the input terminal side are formed. The displacement current flows during the operation.

Moreover, even if the frequency of the potential fluctuation is one-tenth of the frequency of the driving alternating current, if the magnitude of the fluctuating voltage is ten times the magnitude of the driving voltage, both of the fluctuations per hour Since the magnitude of the voltage change is the same, the displacement current flows through the capacitor 15 as much as the drive current. As such an example, there is an example of an ignition circuit with a main power supply voltage of 400 volts using a series inverter circuit as shown in FIG. In this case, the ignition coil (ignition step-up transformer) 43 is switched by a two-way switching circuit for electronic distribution to supply ignition energy by selecting a predetermined ignition discharge gap, but the potential of each switch terminal is commutated. Charge / discharge of the capacitor 44 or switches 41 and 4
It fluctuates with the on / off switching of 2. Further, if the resonance frequency of the series inverter circuit is increased in order to reduce the size and weight of each ignition coil 43 or commutation capacitor 44, the effect is further increased.

[0014] That is why, in the case of circuit conditions in which the potential of each switch terminal fluctuates while the insulated switching circuit is on, it is necessary to insulate especially AC and cut off another current path. is there. If the switch terminal potential does not fluctuate during the on-time, 2
There is no need to use directional insulated switching circuits.
(Refer to the circuit shown in FIG. 32 of JP-A-3-56073) Therefore, the problem of "desired drive insulated from AC is desired" is a problem with each of the insulated switching circuits shown in FIGS. Is a unidirectional insulated switching circuit obtained by modifying the above circuit. (Third problem to be solved by the first and third inventions)

In addition, at the time of the ON driving, each input terminal (i
Since a high-frequency AC voltage (including a periodic pulse voltage train or the like) is applied to t1 to it4), a dedicated AC power supply is required. It is convenient if it can be driven by a DC power supply, but it is also troublesome that continuous ON drive cannot be performed or ON drive energy cannot be supplied as described above. Therefore, there is a problem that "it is desirable to be able to continuously turn on using a DC power supply or to be able to supply on-drive energy using a DC power supply". This is a switching circuit and a unidirectional insulated switching circuit obtained by modifying the above-described circuit of FIG. (Fourth problem to be solved by the first and third inventions)

Then, the two-directionality shown in FIGS.
The conventional insulated switching circuit including each of the directional insulated switching circuits has a problem that “when both switch terminals are off in two directions, the two switch terminals cannot be shielded”. (Problems to be solved by the second invention) As a result, for example, in each of the circuits in FIGS. 2 to 7, leakage occurs via the off-resistance of each transistor 2, the capacitance between drain and source, or the capacitance between drain and gate. Electric current flows. This leads to signal current leakage, but the higher the signal frequency, the greater the amount of leakage current. Particularly in the case of an electronic exchange using an insulated switching circuit, if the carrier frequency or the signal frequency becomes higher with the increase in the information capacity of wired communication or wired communication, the influence of each capacitance becomes large, for example, a certain line There is a high possibility that information leaks from one to another line.

Therefore, the first invention provides a method of "insulating driving without using insulating means such as a pair of light emitting and light receiving diodes and a transformer, and, furthermore, with a condition, a continuous ON driving even with a DC power supply. It is intended to provide a unidirectional or bidirectional isolated switching circuit. (Object of the First Invention) By applying this insulated switching circuit, an insulated three-terminal switching circuit and an ignition power distribution circuit can be configured.

The second invention provides a one-way or two-way insulated switching circuit which "can shield both switch terminals when both switch terminals are off in two directions". It is intended to provide. (Object of the Second Invention) By applying this insulated switching circuit, an insulated three-terminal switching circuit and an ignition power distribution circuit can be configured.

Further, the third aspect of the invention is that "the insulated drive can be performed without using an insulating means such as a light emitting diode pair, a light receiving diode pair, a transformer, and the like. It is an object of the present invention to provide a one-way or two-way insulated switching circuit that can be replenished at any time. (Object of the Third Invention) By applying this insulated switching circuit, an ignition power distribution circuit can be configured.

[0020]

That is, in the first invention, when both switch terminals are off, the switch is off in two directions. At that time, the drive terminal pair and each of the switch terminals are off. A two-terminal switching means that is on in one or two directions when both switch terminals are on, an energy supply means, and conduction and release between the energy supply means and the drive terminal pair. A group of switching means for performing the operation; an on-drive means provided in the drive terminal pair for turning on the two-terminal switching means using an energy storage means incorporated therein when the group of switching means performs the opening; Off-drive means for driving off the two-terminal switching means via the switching means group when the means group conducts the conduction, and the switching means group It is isolated switching circuit with energy supply path means, for supplying energy to said energy storage means through said energy supply means the switching means group when performing the continuity.

However, the drive terminal pair portion is a portion of a control terminal and a main terminal which form a pair for inputting a drive signal, for example, a "gate terminal and source terminal portion", a "gate terminal and emitter terminal portion" or a "base terminal portion". Terminal and emitter terminal '', the energy supply means is, for example, a DC power supply or an AC power supply, and the switching means group is a combination of a plurality of switching means and the like, and the energy storage means Is, for example, capacitance means or inductance means. Further, the off-drive means includes a part or all of the switching means group, and the energy supply path means includes a part or all of the switching means group. Further, the energy supply means and the drive terminal pair are connected so as to sandwich the switching means group, and the switching means group conducts and opens between them.

With this configuration, when the switching means group is on and the energy supply means and the drive terminal pair are electrically connected, the off-driving means drives the two-terminal switching means off. Terminal switching means opens or insulates between the drive terminal pair and each of the switch terminals. For this reason, the energy supply means is insulated from each of the switch terminals.
(Half of the insulating operation) At this time, the energy supply means supplies energy to the energy storage means via the energy supply path means.

On the other hand, when the switching means group is off (open), the on-driving means drives the two-terminal switching means on, and the two-terminal switching means switches between the drive terminal pair and each of the switch terminals. , The switching means group opens or insulates between the energy supply means and the drive terminal pair. For this reason, the energy supply means is insulated from each of the switch terminals. (The other half of the insulation operation)

As a result, the energy supply means and each of the switch terminals can be always insulated except at the time of on / off switching.
(Entire Insulation Operation) Therefore, the isolated switching circuit of the first invention is capable of emitting light,
Insulation driving can be performed without using an insulating means such as a pair of light receiving diodes or a transformer. (First effect) Regardless of the type of the energy supply unit, the on-drive unit may perform the two-terminal switching under the condition that “the energy is stored in the energy storage unit” at the time of the on-drive. The means can be continuously driven on.
(Second effect)

The energy storage capacity of the energy storage means may be large, unlike the capacitors 16 in FIGS. 2 and 3, so that the stored energy can be sufficiently increased. Also, by combining two one-way or two-way insulated switching circuits of the first invention, various insulated three-terminal switching circuits can be easily configured. In addition, a discharge circuit for ignition is connected to the secondary coil of the ignition coil (step-up transformer for ignition), and a series circuit in which the primary coil and the bidirectional insulated switching circuit of the first invention are connected in series is specified. By connecting the same number in parallel, an ignition distribution circuit for selecting a predetermined ignition coil, that is, an ignition discharge gap, can be easily configured. When assembling these circuits, the individual insulated switching circuits to be combined need not be of the same type.
Circuits having different configurations may be used.

[0026]

[Disclosure of the Second Invention] The second invention is directed to a 2
Both ends of the two switching means are both switch terminals, and when both switch terminals are off, they are off in two directions, at which time, the connection between the connection part and each of the switch terminals is off, A two-terminal switching means that is on in one or two directions when both switch terminals are on, a potential stabilizing means with a stable potential, and a connection or disconnection between the connection part and the potential stabilizing means; The potential fixing switching means, and the potential fixing switching means is driven off when the two-terminal switching means is driven on, and the potential fixing switching means is driven on when the two-terminal switching means is driven off. An isolated switching circuit having a shielding function and having a switching control means. However, the potential stabilizing means is, for example, a means which is stable in terms of ground or potential.

Thus, when the two-terminal switching means is on, the potential fixing switching means is off, so that the two switch terminals and the connecting portion are electrically connected, but the potential fixing switching means is connected to the connecting portion. Since the potential stabilizing means is opened or insulated, the ON operation between the two switch terminals is not affected by the potential stabilizing means. On the other hand, when the two-terminal switching means is off, the potential fixing switching means is on.
The two switch terminals and the connection are open or insulated, and the potential fixing switching means conducts between the connection and the potential stabilization means, so that the potential of the connection is fixed to the potential of the potential stabilization means. Is done. For this reason,
The two switch terminals are shielded by the connection part. (Effect of the second invention, shielding effect)

This shield function is useful for preventing a leakage current or a displacement current from flowing between the two switch terminals when the switch is off, and thus is useful for preventing leakage of a signal current or the like when the switch is off. Various insulated three-terminal switching circuits can be easily formed by combining the two insulated switching circuits. In particular, an electronic exchange using the insulated switching circuit is useful for preventing leakage of wired communication and wired communication. Further, an ignition discharge gap is connected to the secondary coil of the ignition coil (ignition step-up transformer), and a series circuit in which the primary coil and the bidirectional insulated switching circuit of the second invention are connected in series is provided in a predetermined manner. By connecting a number of parallel connections, it is possible to easily configure an ignition power distribution circuit for selecting a predetermined ignition coil, that is, an ignition discharge gap. When assembling these circuits, the individual insulated switching circuits to be combined need not be of the same type. Circuits having different configurations may be used.

[0029]

Further, the third invention is characterized in that when the connection between the two switch terminals is off, the switch is off in two directions, and the connection between the drive terminal pair and each of the switch terminals is off. An insulated gate type two-terminal switching means that is on in one or two directions when both switch terminals are on, an on-drive voltage supply means, the on-drive voltage supply means, and the drive terminal pair A switching means group that conducts and opens between parts, an external switching means connected between any of the switch terminals and the on-drive voltage supply means, and an external switch when the switching means group performs the opening. If the switching means is on, the release is released and the on-drive voltage supply means is connected to the two-terminal switch via the switching means group and the external switching means. An insulation means comprising an on-drive voltage supply path means for supplying an on-drive voltage to the switching means, and an off-drive means for driving off the two-terminal switching means via the switching means group when the switching means group conducts the conduction. Type switching circuit.

However, the drive terminal pair portion is a portion of a control terminal and a main terminal which form a pair for inputting a drive signal, for example, a "portion of a gate terminal and a source terminal" or a "portion of a gate terminal and an emitter terminal". The on-drive voltage supply means is, for example, a DC power supply, and the switching means group is a combination of a plurality of switching means. Further, the off-drive unit includes a part or all of the switching unit group. Further, the ON drive voltage supply means and the drive terminal pair are connected so as to sandwich the switching means group, and the switching means group conducts and opens between them.

Thus, when the switching means group is turned on and the conduction between the on drive voltage supply means and the drive terminal pair is conducted, the off drive means drives the two-terminal switching means off. If the external switching means is off, the drive terminal pair and each of the switch terminals are open, that is, insulated. For this reason, the ON drive voltage supply means is insulated from each of the switch terminals. (Half of insulation operation)

On the other hand, when the switching means group is off (open), the on-drive charge is charged to the capacitance between the insulated gate drive terminal pairs, and the two-terminal switching means is connected to the drive terminal pairs. Even if the switch is turned on and the switch terminals are turned on, if the external switching means is off, the on-drive voltage supply means and the drive terminal pair are opened or insulated by the switching means group. For this reason, the ON drive voltage supply means is insulated from each of the switch terminals. (The other half of the insulation operation)

As a result, the ON drive voltage supply means and each of the switch terminals can be always insulated except when the external switching means is ON or when ON / OFF switching is performed.
(Entire Insulation Operation) Therefore, the insulation type switching circuit of the third invention is capable of emitting
Insulation driving can be performed without using an insulating means such as a pair of light receiving diodes or a transformer. (First effect)

Then, if the external switching means is on even if the switching means group is off (open), the off operation of the switching means group is released and turned on, so that the on drive voltage supply means Supplies an on-drive voltage to the two-terminal switching means via the on-drive voltage supply path means. Therefore, each time the external switching means is turned on, an on-drive voltage can be supplied to the two-terminal switching means. Therefore, the insulated switching circuit according to the third aspect of the present invention can supply the on-drive voltage any number of times with the condition "every time the external switching means is turned on".
(Second effect)

By the way, a series circuit in which an ignition discharge gap is connected to a secondary coil of an ignition coil (step-up transformer for ignition), and the primary coil and the bidirectional insulated switching circuit of the third invention are connected in series. Are connected in parallel by a predetermined number, and a plurality of the external switching means are shared to be one, so that an ignition distribution circuit capable of selecting a predetermined ignition coil, that is, an ignition discharge gap can be easily configured. When assembling these circuits, the individual insulated switching circuits to be combined need not be of the same type. Circuits having different configurations may be used.

[0036]

BEST MODE FOR CARRYING OUT THE INVENTION In order to describe each invention in more detail, the invention will be described below with reference to the accompanying drawings. The embodiment of FIG. 1 is a common embodiment of the first and second inventions, and is a unidirectional insulated switching circuit according to claim 1 and a unidirectional insulated switching circuit having a shield function according to claim 2. Corresponding to the circuit. If the transistor 26 and the diode 24 are connected, the embodiment of FIG. 1 is a two-way isolated switching circuit.

In the embodiment shown in FIG. 1, each corresponds to each component of the first invention described above. However, the transistors 25 and 26 are IGBTs. a) The switch terminals st1 and st2 are both switch terminals described above. b) The gate terminal and the emitter terminal of the transistor 25 (26) correspond to the drive terminal pair described above. c1) The series circuit of the transistor 25 and the diode 4 serves as the above-described two-terminal switching means (one-way). However, while the switch 3 is on, the potential of the switch terminal st1 does not become “the potential at which the transistor 25 reversely conducts (= dielectric breakdown or the like)”, and the potential of the switch terminal st2 becomes “the potential at which the diode 4 turns on”. Is limited to the case where the respective potentials of the switch terminals st1 and st2 are controlled so as not to become "." c2) Alternatively, the connection body of the transistors 25 and 26 and the diodes 4 and 24 is the two-terminal switching means (two-way) described above. However, while the switch 3 is on, the switch is set so that the potential of the switch terminal st1 does not become “the potential at which the diode 24 turns on” and the potential of the switch terminal st2 does not become “the potential at which the diode 4 turns on”. Only when each potential of the terminals st1 and st2 is controlled.

D) DC power supply 1 serves as the energy supply means described above. e) The combination of the diode 5 and the switch 3 corresponds to the above-mentioned switching means group. However, while the switch 3 is off, the switch terminals st1 and s2 are set so that the potentials of the switch terminals st1 and st2 do not become “the potential at which the diode 5 turns on”.
Only when each potential of t2 is controlled. f) The capacitor 6 serves as the energy storage means described above. g) A series circuit of the capacitor 6 and the resistor 10 is used as the above-described ON driving means. h) “The DC power supply 1, the diode 5, the resistor 11, the parallel circuit of the capacitor 6 and the resistor 9, the closed circuit formed by the resistor 27 and the switch 3,” is the off-driving means described above. i) The energy supply path means described in "The DC power supply 1, the diode 5, the resistor 11, the capacitor 6, the resistor 27, the parallel circuit such as the gate-emitter capacitance of the transistor 25 and the like, and the closed circuit formed by the switch 3". To.

In the embodiment shown in FIG. 1, each of the components corresponds to each component of the second invention described above. a1) "Series circuit of transistor 25 and diode 4"
To the two switching means (one-way) connected in series as described above. However, while the switch 3 is on, the potential of the switch terminal st1 does not become “the potential at which the transistor 25 reversely conducts (= dielectric breakdown or the like)”, and the potential of the switch terminal st2 becomes “the potential at which the diode 4 turns on”. Is limited to the case where the respective potentials of the switch terminals st1 and st2 are controlled so as not to become "." a2) Or, ““ Transistor 25 and diode 2
4 parallel circuit ”and“ series circuit of transistor 26 and diode 4 parallel circuit ”in the two switching means (bidirectional) connected in series as described above. However, switch 3
While the switch is on, the potential of the switch terminal st1 is “diode 2
And the potential of the switch terminal st2 is set to "the potential at which the diode 4 is turned on".
Only when the respective potentials of the switch terminals st1 and st2 are controlled so as not to be caused.

B) The switch terminals st1 and st2 are the two switch terminals described above. c) The connection point between the emitter terminal of the transistor 25 and the anode terminal of the diode 4 corresponds to the aforementioned connection. d) “Though not shown, one that is maintained at a constant potential to which one power supply terminal of the DC power supply 1 is connected” is the potential stabilizing means described above. e) The combination of the diode 5 and the switch 3 serves as the potential fixing switching means described above. However, while the switch 3 is off, the switch terminals s1 and st2 do not have the potentials at which the diode 5 is turned on.
Only when each potential of t1 and st2 is controlled. f) The “on / off drive circuit formed by the DC power supply 1, the switch 3, the diode 5, the capacitor 6, and the resistors 9 to 11, 27” is the switching control means described above.

The operation of the embodiment of FIG. 1 is as follows when the transistor 26 and the diode 24 are not connected. When the switch 3 is turned on, a current flows from the DC power supply 1 to the switch 3 through the diode 5, the resistor 11, the parallel circuit of the capacitor 6 and the resistor 9, and the parallel circuit of the gate-emitter capacitance of the transistor 25 and the resistor 27. A flowing closed circuit is formed. As a result, the transistor 25 is reverse-biased due to the voltage drop generated in the resistor 27 and is turned off, the connection between the switch terminals st1 and st2 is turned off, and the capacitor 6 is charged. On the other hand, when the switch 3 is turned off, the discharge current of the capacitor 6 flows through a closed circuit including the capacitor 6, the resistor 10, and the capacitance between the gate and the emitter of the transistor 25.
Is turned on to turn on, and both switch terminals st
It is on during 1st2.

By the way, when the switch 3 is on and the transistor 25 is off, "both switch terminals st1, st"
2 Unless both potentials become a potential at which the emitter terminal and one of the switch terminals become conductive, "the two switch terminals st1, st2" and the "gate terminal, emitter terminal, DC power supply 1, switch 3, etc." The drive circuit side is insulated. On the other hand, when the switch 3 is off and the transistor 25 is on, “unless the diode 5 is turned on”, that is, “unless the potentials of both the switch terminals st1 and st2 reach the potential at which a forward voltage is applied to the diode 5”. , And the “direct-current switch side such as both switch terminals st1 and st2, gate terminal and emitter terminal” and “DC power supply 1” are insulated.

However, "conduction between the emitter terminal and the switch terminal st1" means that the connection between the emitter and the collector or between the gate and the collector is broken down toward the collector. Is connected, it means that the diode 24 is turned on. The conduction between the emitter terminal and the switch terminal st2 means, of course, that the diode 4 is turned on. Therefore, "the potential of both switch terminals st1 and st2 is equal to that of either switch terminal and diode 5".
1 is a first and a second embodiment of the present invention, both switch terminals st1 and st2 and DC power supply 1 are insulated, and both switch terminals st1 are turned off when off. , St2 are shielded. Even when the insulation impedance between the switch terminals st1 and st2 cannot be ignored, no current flows directly between the switch terminals st1 and st2.

Nevertheless, it goes without saying that the diode 4, 5 or the like may be temporarily turned on. In this case, the charging current of the capacitor 6 flows from the switch terminal st2 or the like directly to the minus terminal of the DC power supply 1 via a load, a commutation reactor, or the like as in the circuit of FIG. During that time, the insulating action is lost, but the effect is obtained that the DC power supply 1 can supply energy to the capacitor 6. (Additional Effect) By repeating this energy supply, the ON period of the transistor 25 can be extended as much as possible. If the diode 24 is connected, a path for the charging current can be provided on the switch terminal st1 side. More positively, it is conceivable to connect a switching means between the switch terminal st1 or st2 and the minus terminal of the DC power supply 1 like a switch 31 in the circuit of FIG.

In addition, unlike the capacitors 16 of FIGS. 2 and 3 which must be completely discharged when turned off, there is no need to use them, and a large-capacity capacitor is used for the capacitor 6 which functions as a power supply capacitor. Is possible. Therefore, when the switch 3 is off and the capacitor 6 drives the transistor 25 on, the capacitor 6 can continuously drive the transistor 25 on as long as the capacitor 6 stores energy.

Since the resistor 27 reverse biases the transistor 25, it can be used as a switching means in place of the transistor 25 regardless of the normally-off type or the normally-on type. Switch 3 is also on.
Any switching means having an off function, including a semiconductor switch, can be used. Transistor 2
Since 5 is a normally-off type, it can be kept off without a gate reverse bias, so that the resistor 9 can be removed. When the transistor 25 is turned off, a voltage drop that occurs in the resistor 27 due to the charging current of the capacitor 6 reverse-gate-biases the transistor 25 and helps the transistor 25 to be turned off. Any normally-off type transistor can be used in place of the transistor 25.

Further, when the switch 3 is a bipolar transistor having a small collector saturation current or an M
If it has a current limiting function like an OS-FET and also serves as a current limiting means, the resistor 11 is not required, and the value of the resistor 11 may be zero. Then, the resistor 11 may be connected to the switch 3. That is, both ends of the resistor 11 are short-circuited, the resistor 11 is removed, and a series circuit of the switch 3 and the resistor 11 is used instead of the switch 3. Alternatively, the resistor 11 may be connected to both the diode 5 side and the switch 3 side. Then, if the power supply terminal of the DC power supply 1 is fixed at a constant potential, when the one-way switching circuit is off, the potential of the gate terminal is also fixed at a constant level.
Since the potential of the emitter terminal is also fixed at a substantially constant level, the switch terminals st1 and st2 are shielded.
Therefore, even if the insulation impedance between the switch terminals st1 and st2 at the time of OFF is not negligible, no leakage current flows directly between the switch terminals.

When a bridge-connected rectifier circuit is formed by four diodes (not shown) and four additional diodes 4 in the one-way embodiment shown in FIG. 25 is connected as in the embodiments shown in FIGS. 21 to 23 described later, the bridge connection type rectifier circuit has no shield function. However, this embodiment is a bidirectional first invention. It becomes an Example of. Also, if the two embodiments of FIG. 1 (to which the diode 24 is connected) are connected in anti-parallel at the switch terminals st1 and st2, this circuit becomes a bidirectional insulated switching circuit. In this case, two DC power supplies 1 and the like may be shared to be one as in a circuit of FIG.
The two switches 3 may be shared to be one.

Then, the two unidirectional embodiments shown in FIG. 1 are switched "in the same direction" at the switch terminal st1 or st2.
Or if you connect "inward" or "outward" in series, you can easily create an isolated 3-terminal switching circuit,
The one-way embodiment of FIG. 1 and one of the two-way insulated switching circuits described above are connected to switch terminals st1 or st2.
If a series connection is made at this point, another three-terminal switching circuit can be easily formed. In addition, if two same-type or different kinds of the above-described two-way insulated switching circuits are connected in series at the switch terminal as in each circuit of FIGS. A type 3 terminal switching circuit can be obtained.

In a further development, a discharge gap for ignition is connected to the secondary coil of the ignition coil, and the primary coil and one of the above-described bidirectional insulated switching circuits are connected in series at the switch terminal. By connecting a predetermined number of series circuits in parallel, it is possible to configure an ignition power distribution circuit that can select a predetermined ignition coil, that is, a discharge gap for ignition. As can be seen from the above, the drive circuit units such as the above-described all-insulation type switching circuit are exactly the same. Further, the development from the one-way insulated switching circuit to the two-way insulated switching circuit, the insulated three-terminal switching circuit or the ignition power distribution circuit also applies to each embodiment of the first invention described below. Further, the individual unidirectional isolated switching circuits to be combined need not all be the same. All may be different.

In a common embodiment of the first and second inventions shown in FIG. 9, the capacitor is connected to the gate side. FIG.
0, in each of the common embodiments of the first and second inventions shown in FIG. 11, a capacitor and a coil are used for the energy storage means described above. In the embodiment of FIG. 10, the diode 24 is connected as shown in FIG. 10, and an external switching means is provided between one of the switch terminals and the minus terminal of the DC power supply 1 like a switch 31 of the embodiment of FIG. Once connected,
Even if the transistor 25 is on, the DC power supply 1 can supply energy to the capacitor 6 and the coil 18 when the external switching means is on. In the embodiment of FIG. 11, the diodes 5, 4 can be used as clamp diodes as in the ignition circuits shown in FIGS. In this case, it is temporarily lost in an insulated state, but such a use is also possible.

In a common embodiment of the first and second inventions shown in FIG. 12, a diode 24 is connected as shown in FIG. 12, and one of its switch terminals is connected to a DC terminal as a switch 31 of a circuit shown in FIG. If the external switching means is connected between the minus terminals of the power supply 1, the DC power supply 1 can supply energy to the capacitors 6 even when the transistor 25 is on when the external switching means is on.

In the common embodiment of the first and second inventions shown in FIG. 13, the diode 28 is also included in the switching means group of the first invention and the potential fixing means of the second invention. In the case of the embodiment of FIG. 13, when the transistor 29 is turned on, the series circuit of the transistor 29 and the diode 28 can keep the normally-off type transistor 25 off. Since an AC voltage output means for outputting an AC voltage can be used, it is convenient when the main power supply on the switch terminal side is an AC power supply or the like. Of course, the AC voltage output means may output a voltage in which an AC voltage and a DC voltage are mixed. In this case, the AC power supply 45 or its AC voltage output means corresponds to the above-described energy supply means. However, the switching means that can be used in place of the transistor 25 is limited to a normally-off type. Also, in the embodiment of FIG. 13, the diode 24 is connected as shown in FIG. 13, and an external switching circuit is provided between one of the switch terminals and the minus terminal of the DC power supply 1 like a switch 31 in the circuit of FIG. If the means is connected, the DC power supply 1 can supply energy to the capacitor 6 when the external switching means is on, even if the transistor 25 is on.

In the common embodiment of the first and second inventions shown in FIG. 14, the coil 18 corresponds to the above-mentioned energy storage means. It is to be noted that a voltage drop generated in the resistor 30 or the like when the transistor 25 is turned off causes the gate to be reverse biased.
Instead of the transistor 25, the switching means can be used regardless of the normally-off type or the normally-on type. The switch 3 can use any switch having an on / off function, including a semiconductor switch. If the switch 3 has a current limiting function like a bipolar transistor having a small collector saturation current or a MOS.FET having a large on-resistance, and if the switch 3 also serves as a current limiting means, the resistor 11
Do not need. The resistance 11 may be zero. Further, the resistance 11
May be connected to the switch 3. That is, both ends of the resistor 11 are short-circuited, the resistor 11 is removed, and a series circuit of the switch 3 and the resistor 11 is used instead of the switch 3. Alternatively, the resistor 11 may be connected to both the diode 5 side and the switch 3 side. However, the resistance 1
14 are connected as shown in FIG. 14, when the switch 3 is turned on, the gate potential and the emitter potential are pulled toward the minus potential side of the DC power supply 1 by the voltage drop of the resistor 11, so that both switch terminals can maintain insulation. There is an advantage that the limit on the low potential side of st21 and st22 is reduced. Then, if the diode 19 is provided, even if the coil 18 has completely released its stored energy, the transistor 25 will not be gate-biased due to the reversal of the coil current.

In the common embodiment of the first and second inventions shown in FIG. 15, the diode 28 is also included in the switching means group of the first invention and the potential fixing means of the second invention. In this embodiment, when the transistor 29 is on, a series circuit of the transistor 29 and the diode 28 can keep the normally-off type transistor 25 off. Can be used, so that it is convenient when the main power supply on the switch terminal side is an AC power supply or the like. Of course, the AC voltage output means may output a voltage in which an AC voltage and a DC voltage are mixed. In this case, the AC power supply 45 or its AC voltage output means corresponds to the above-described energy supply means. However, the switching means that can be used in place of the transistor 25 is limited to a normally-off type. In the embodiment of FIG. 15, a diode 24 is connected as shown in FIG. 15, and an external switching means is connected between one of the switch terminals and the minus terminal of the DC power supply 1 like a switch 31 of the circuit of FIG. Is connected, the DC power supply 1 can supply energy to the coil 18 even when the transistor 25 is on, when the external switching means is on.

The common embodiments of the first and second inventions shown in FIGS. 16 to 20 have the above-mentioned shield effect, but the first embodiment shown in FIGS. 21 to 23 has a diode.・ Because of the bridge connection type rectifier circuit, the shield effect described above cannot be obtained. The common embodiment of the first and second inventions shown in FIG. 24 has the above-mentioned shielding effect. It should be noted that the plus power supply line indicated by a dotted line from the middle of FIG. 16 indicates that “if the potentials of the switch terminals st100 and st200 are substantially higher than the potential of the plus power supply line, the switch terminal st
100 and st200 are insulated from the DC power supply 1 ". The same applies to FIGS. 19 to 23. In the circuit of FIG. 16, a series circuit of the built-in diode of one transistor 2 and the diode 5 may be used as a clamp diode or the like like a bidirectional switching circuit in an ignition circuit of FIGS. is there. The same applies to each circuit in FIGS. 19 and 20. In the circuit of FIG. 16, when the resistor 9 is connected, both the transistors 2 can be firmly kept off irrespective of the leakage current between the gate and the source of the two transistors 2.

In the embodiment shown in FIG. 17, two different types of switching means are used. Since both driving bias voltage polarities are the same, but both forward bias voltage values are different, the inventor has added a Zener diode 52 to the base of the transistor 202 in order to match the voltage values.
Connected. In this case, the transistor 202 and the Zener
It can be considered that the diode 52 is one switching means and its cathode is its control terminal.

In the embodiment of FIG. 18, two bipolar transistors 202 are used, and each base forward bias current is evenly distributed. If both characteristics are equal, both emitter junctions (PN junction between base and emitter) may be directly connected in parallel. Each transistor 202
This circuit is convenient when a switching means such as a thyristor, a junction type FET, a normally-on type SIT, an SI thyristor, or the like, in which a drive current constantly flows at the time of forward bias is used.

In the circuit shown in FIG. 20, when the diode 20 is provided, the capacitor 6 completely releases its stored energy, and when the coil 18 still drives both transistors 2, the energy of the coil 18 is not absorbed by the capacitor 6. And the ON driving operation is not hindered. Therefore, there is an effect that the period during which the ON drive can be performed can be lengthened. The same applies to each of the circuits shown in FIGS. 10, 11, and 23.

A common embodiment of the first and second inventions shown in FIG. 25 and an embodiment of the first invention shown in FIG. 26 are two-way insulated three terminals in which two-way insulated switching circuits are connected in series. It is a switching circuit. In the embodiment of FIG.
An insulated three-terminal switching circuit in which one of the two transistors 2 is removed and a normal diode is directly connected to a place where the built-in diode is connected and replaced is also possible. Also, in the embodiment of FIG. 25, one of the two transistors 2 on the right side of the figure is similarly replaced with a normal diode, and one of the two transistors 2 on the left side of the figure is similarly replaced with a normal diode. A unidirectional isolated three-terminal switching circuit is also possible.

As a matter of course, FIGS.
, A two-way isolated switching circuit as shown in FIGS. 21 to 23 and a two-way isolated switching circuit as shown in FIG. 24 are connected in series. The insulated three-terminal switching circuit described above is also possible, and the two-way insulated switching circuit as shown in FIGS. 21 to 23 or the two-way insulated switching circuit as shown in FIG. An insulated three-terminal switching circuit in which directional insulated switching circuits are connected in series is also possible.

A common embodiment of the first and second aspects of the present invention shown in FIGS. 27 to 30 is an ignition circuit with an electronic power distribution function. In the figure, V, G, M, a and b are connected with the same reference numerals. Further, 21 is a constant voltage means such as a three-terminal regulator, 22 is a DC-DC converter circuit for outputting a negative voltage, and 23 is an input terminal for inputting an ignition signal from outside. This ignition circuit uses a series inverter circuit. The circuit part in FIG. 29 is an ignition power distribution circuit, and the circuit part in FIG. 30 is a circuit for switching the capacity of the commutation capacitor 44. Alternatively, Japanese Patent Application Laid-Open No. 2-146265 discloses an ignition circuit.
The circuit shown in FIG. 20 can be used in combination with the ignition distribution circuit shown in FIG. Reference: JP-A-3-56073
FIG. 14 of JP-A-3-96660 and JP-A-2-2-1.
FIG. 21 of No. 46265, Japanese Utility Model Laid-Open No. 3-80691.

The circuit shown in FIG. 31 is a DC-DC converter circuit, which is used in the ignition circuits shown in FIGS.
This is an example of the converter circuit 22. In addition, JP-A-2-
FIG. 7 of Japanese Patent Application Publication No. 119575/1990
There are also the circuits shown in FIGS. 17 to 19 of No. 5.

The common embodiment of the first and second inventions shown in FIG. 32 having the diode 5 has almost the same configuration as the embodiment of FIG. 1, and becomes bidirectional when the transistor 26 is connected. In addition, in the embodiment of FIG.
This embodiment is bidirectional even if a transistor 25 is connected between both DC terminals when forming a bridge connection type rectifier circuit with four diodes (not shown). In this case, the diode 24 may or may not be provided. Further, as in the circuit of FIG. 24, the two circuits of FIG. 32 are connected in anti-parallel at the switch terminals st23 and st24, and the two switches 31 are shared to form a single two-way insulated switching circuit. is there. In this case, the two DC power supplies 1 may be shared and used as one as in the circuit of FIG. 24, or the two switches 3 may be shared and used as one. Then, when the switch 31 is on, the charging current of the capacitor 6 flows from the DC power supply 1 to the switch 31 via the resistor 11, the capacitor 6, and the diode 24 regardless of whether the transistor 25 is on or off, and the DC power supply 1 Can supply energy. Therefore, if the switch 31 is turned on many times and this energy replenishment is repeated, the ON period of the transistor 25 can be extended as much as possible.

Each of the common embodiments of the first and second inventions shown in FIGS. 33 to 37 having the diode 5 is similar to the embodiment of FIG. 32 when the switch 31 is turned on many times. The energy supply to the driving capacitor and the driving coil can be repeated. FIG. 3 with diode 5
5. In each of the embodiments shown in FIGS. 37 and 37, when the switch 3 is turned on, the series circuit of the switch 3 and the diode 28 can keep the normally-off type transistor 25 off. Since an AC voltage output means for outputting an AC voltage as described above can be used, it is convenient when the main power supply on the switch terminal side is an AC power supply or the like. Of course, the AC voltage output means may output a voltage in which an AC voltage and a DC voltage are mixed. However, the switching means that can be used in place of the transistor 25 is limited to a normally-off type.

In each of the common embodiments of the first and second inventions shown in FIGS. 38 to 39 and the embodiment of the first invention shown in FIG. 40, if the switch 31 is connected, the embodiment of FIG. As in the example, if the switch 31 is turned on many times,
Energy supply to the driving capacitor and the driving coil can be repeated. 38 to 40, if the diode 28 is connected, the discharge of the gate-source capacitance of the transistor 2 can be accelerated, and the turn-off can be accelerated. In addition, FIG.
In each of the embodiments shown in FIG. 40, the inventor introduced a three-terminal switch into the charge / discharge circuit section to increase the discharge current of the capacitor 6 and to speed up the turn-on of the transistor 2. (Reference: JP-A-2-153
No. 618)

An embodiment in which two diodes are connected to a positive power supply terminal as shown in FIG. 41 is a common embodiment of the second and third inventions, and is a unidirectional insulating type having a shield function according to claim 2. It corresponds to a switching circuit and a unidirectional isolated switching circuit according to claim 3. If the transistor 26 is connected, the embodiment of FIG. 41 is a bidirectional isolated switching circuit. When a bridge connection type rectifier circuit is formed by four of the diode 4 and three additional diodes (not shown) in the one-way embodiment of FIG. 41, the transistor 25 is connected between both DC terminals. As shown in FIG. 21 to FIG. 23, the bridge connection type rectifier circuit has no shield function, but this embodiment is a two-way embodiment of the third invention. . In this case, the diode 24 may or may not be provided.

Also, the two embodiments of FIG. 41 are connected in anti-parallel at both switch terminals as in the embodiment of FIG.
If the two switches 31 are made common to one, this circuit becomes a bidirectional insulated switching circuit. In this case, the two DC power supplies 1 may be shared and used as one as in the embodiment of FIG. 24, or the two switches 3 may be shared and used as one. Further, an ignition discharge gap is connected to the secondary coil of the ignition coil, and a predetermined number of series circuits in which the primary coil and one of the above-described bidirectional insulated switching circuits are connected in series are connected in parallel by a predetermined number. If a plurality of switches 31 are used in common, a single ignition coil, that is, an ignition power distribution circuit that can select a predetermined ignition discharge gap can be configured. As can be understood from the above, the drive circuit units such as the above-described all-insulated switching circuit are exactly the same. The development from the one-way insulated switching circuit to the two-way insulated switching circuit and the ignition distribution circuit described above also applies to the other embodiments of the third invention. At this time, it is not necessary that all the one-way insulated switching circuits to be used have the same configuration, and they may be different.

In the common embodiment of the second and third inventions shown in FIG. 42 in which the diode 5 is present, each corresponds to each component of the third invention as described below. a) The switch terminals st25 and st26 are both switch terminals described above. b) The gate terminal and the emitter terminal of the transistor 25 (26) correspond to the drive terminal pair described above. c1) The series circuit of the transistor 25 and the diode 4 serves as the above-described two-terminal switching means (one-way). c2) Alternatively, the connection body of the transistors 25 and 26 and the diodes 4 and 24 is the two-terminal switching means (two-way) described above. However, in both the one-way and two-way directions, the switch 31 is off and the switch 3 is on so that the potential of the switch terminal st25 does not become “the potential at which the diode 24 turns on” and the switch terminal st2
Only when each potential of the switch terminals st25 and st26 is controlled so that the potential of No. 6 does not become “the potential at which the diode 4 is turned on”.

D) The DC power supply 1 serves as the ON drive voltage supply means described above. e) The combination of the diode 5 and the switch 3 corresponds to the above-mentioned switching means group. However, while the switch 3 is off, each potential of the switch terminals st25 and st26 is “diode 5”.
Switch terminal st2 so that the potential does not become "on".
5. Only when each potential of st26 is controlled. f) The switch 31 serves as the external switching means described above. g) The “closed circuit formed by the DC power supply 1, the diode 5, the resistors 11, 10, the gate-emitter capacitance 32, the diode 24, and the switch 31” is the ON drive voltage supply path means described above. h) "DC power supply 1, diode 5, resistors 11, 9, 27"
And the closed circuit formed by the switch 3 ”is the off-driving means described above.

The operation of the embodiment shown in FIG. 42 having the diode 5 is as follows. When switch 3 turns on,
A closed circuit in which a current flows from the DC power supply 1 to the switch 3 via the resistors 11, 9, 27 is formed. Therefore, the gate of the transistor 25 is reverse-biased by the voltage drop generated in the resistor 27, and the transistor 25 is turned off.
It is off between 5 and st26. When the switch 3 is off and the switch 31 is on, the DC power supply 1
10, gate-emitter capacitance 32, diode 2
A closed circuit in which a current flows to the switch 31 via 4 is formed, the transistor 25 is turned on and turned on, and the switch terminals st25 and st26 are turned on. When the switches 3 and 31 are both turned on, the current of the resistor 9 flows not only to the resistor 27 but also from the diode 24 to the switch 31, so that the voltage drop of the resistor 27 is almost equal to the forward voltage of the diode 24. .

As described above, when the switch 3 is off and the switch 31 is on, the gate-emitter capacitance 3
2 is the diode 24 and the switch terminal st25.
Then, the current flows through the switch 31 to the minus terminal of the DC power supply 1, and the DC power supply 1 supplies an ON drive voltage to the gate-emitter capacitance 32. Such an effect exists in the embodiment of FIG. 42, and a similar effect exists in the entire third invention.
(Effect) Therefore, if the switch 31 is repeatedly turned on during the OFF period of the switch 3 and the supply of the ON drive voltage is repeated, the ON period of the transistor 25 can be extended as much as possible. When the switch 31 is turned off, the DC power supply 1 is switched off as in the first and second embodiments.
And the switch terminals st25 and st26 are insulated. Such an effect exists in the embodiment of FIG. 42, and a similar effect exists in the entire third invention.
(Effect) For this reason, the third invention including this embodiment can perform the insulated driving without using an insulating means such as a light emitting / receiving diode pair or a transformer. Can be used to replenish the ON drive voltage any number of times.

Since the resistance 27 reversely gates the transistor 25 when the transistor 25 is turned off, the transistor 2
Instead of 5, switching means can be used regardless of the normally-off type and the normally-on type. Any of the switches 3 and 31 can be used as long as they have an on / off function, including a semiconductor switch. Further, a new capacitor is additionally connected between the gate and the emitter of the transistor 25 to prolong the ON state,
It may be stabilized.

In the common embodiment of the second and third inventions shown in FIG. 43 having the diode 5, when the switch 3 is on, a series circuit of the switch 3 and the diode 28 keeps the normally-off transistor 25 off. Since an AC voltage output means (not shown) for outputting an AC voltage such as an AC power supply can be used instead of the DC power supply 1, the main power supply on the switch terminal side can be used as an AC power supply. It is convenient when. Of course, the AC voltage output means may output a voltage in which an AC voltage and a DC voltage are mixed. In this case, the AC power supply or the AC voltage output means corresponds to the above-described ON drive voltage supply means of the third invention. However, the switching means that can be used in place of the transistor 25 is limited to a normally-off type.

A common embodiment of the first and second embodiments of the present invention shown in FIG. 44 uses a unidirectional insulated switching circuit formed by a transistor 2 and a diode 4 on the high potential side.
In the terminal switching circuit, the unidirectional isolated switching circuit of FIG. 9 is applied. Although the drain of the transistor 2 on the high potential side is not insulated from the DC power supply 1 or the like, when both transistors 2 are off, "if the potential of the switch terminal st27 does not reach the potential at which the diodes 5 and 4 are simultaneously turned on, or The switch terminal st27 is insulated from the DC power supply 1 and the like unless the internal diode of the transistor 2 on the low potential side is turned on or the diode 46 is turned on unless the diode 46 is turned on.

A common embodiment of the first and second embodiments of the present invention shown in FIG. 45 also uses a one-way insulating switching circuit formed by a transistor 2 and a diode 4 on the high potential side.
In the terminal switching circuit, the unidirectional isolated switching circuit of FIG. 1 is applied. This three-terminal switching circuit also has the same insulating function as the circuit of FIG. Transistor 47, Zener diode 49 and resistor 50
Constitutes a known constant voltage circuit, and performs high-speed charging of capacitor 6 and prevention of overcharging when transistor 33 is on.
Diode 48 protects transistor 47 from reverse overvoltage.

In the common embodiment of the second and third aspects of the present invention shown in FIG. 46, as shown in FIG.
When there is a pair of 3, the on-drive voltage can be supplied to both transistors 2 by this photoelectric conversion means even when the switch 31 is off. In this case, the original operation of the second and third inventions is not affected even if the output current of these photoelectric conversion units becomes small depending on the temperature or the like. Even if the output current of the light-emitting / light-receiving diode pair drops, it is just as if it had not existed from the beginning.

In the common embodiment of the first and second aspects of the present invention shown in FIG. 47, even when the off period of the switch 3 becomes long, the light emitting and light receiving diode pairs supply the driving energy to the transistor 2 via the capacitor 6. Can be. Also in this case, even if the output current of these photoelectric conversion units becomes small due to temperature or the like, the original operation of the present invention is not affected. It's just as if it hadn't been there since the beginning.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing an embodiment common to the first and second inventions.

FIGS. 2 to 7 are circuit diagrams showing one example of a conventional two-way insulated switching circuit.

FIG. 8 is a circuit diagram showing an example of an ignition circuit having an electronic power distribution function using a plurality of conventional two-way insulating switching circuits.

9 to 20 are circuit diagrams each showing one embodiment common to the first and second inventions.

FIGS. 21 to 23 are circuit diagrams each showing one embodiment of the first invention.

FIGS. 24 and 25 are circuit diagrams each showing one embodiment common to the first and second inventions.

FIG. 26 is a circuit diagram showing one embodiment of the first invention.

27 to 30 are circuit diagrams showing one embodiment common to the first and second inventions in four figures arranged in numerical order.

FIG. 31 shows a DC-D used in the embodiment shown in FIGS.
FIG. 3 is a circuit diagram illustrating an example of a C converter circuit.

FIGS. 32 to 39 are circuit diagrams each showing one embodiment common to the first and second inventions.

FIG. 40 is a circuit diagram showing one embodiment of the first invention.

FIGS. 41 to 43 are circuit diagrams each showing one embodiment common to the second and third inventions.

FIGS. 44 to 47 are circuit diagrams each showing one embodiment common to the first and second inventions.

[Explanation of symbols]

 st1 to st27 switch terminal st100, st200 switch terminal it1 to it12 input terminal 13 light receiving diode group 14 light emitting diode group 21 constant voltage means 22 DC-DC converter circuit 23 input terminal 25, 26 transistor (IGBT) 43 ignition coil 51 drive pulse output Means V, G, M, a, b Codes indicating connections between the same codes

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI H03K 17/56 F 17/687 D (56) References JP-A-2-119416 (JP, A) JP-A-4-296116 ( JP, A) JP-A-4-170813 (JP, A) JP-A-4-117025 (JP, A) JP-A-63-302217 (JP, A) JP-A-3-56073 (JP, A) JP Hei 3-179815 (JP, A) Japanese Utility Model Showa 64-47593 (JP, U) Japanese Utility Model Hei 3-80691 (JP, U) Japanese Utility Model 3-69936 (JP, U) Japanese Utility Model 3-82931 (JP) , U) (58) Fields investigated (Int. Cl. ⁷ , DB name) H03K 17/687 H03K 17/567 H03K 17/78

Claims (3)

(57) [Claims] 1. When the voltage between both switch terminals is off, 2
Two-terminal switching, which is off in one direction and then off between the drive terminal pair and each of the switch terminals, and is on in one or two directions when both switch terminals are on Means, an energy supply means, a switching means group for conducting and opening between the energy supply means and the drive terminal pair, and a switching means group for performing the release in the drive terminal pair. On-drive means for turning on the two-terminal switching means using built-in energy storage means, and off for driving off the two-terminal switching means via the switching means group when the switching means group conducts the conduction. A driving unit, wherein the energy supply unit switches the switching unit group when the switching unit group conducts the conduction. Isolated switching circuit, characterized in that it comprises an energy supply path means, for supplying energy to said energy storage means and. 2. Both ends of two switching means connected in series are both switch terminals, and when both switch terminals are off, they are off in two directions, and then the connection part and each of said switches A two-terminal switching unit that is off between terminals and is on in one or two directions when both of the switch terminals are on; a potential stabilizing unit with a stable potential; the connection unit and the potential stabilization A potential fixing switching means for conducting or opening between the means, and the two-terminal switching means for driving the potential fixing switching means off and the two-terminal switching means for off driving the two-terminal switching means. Switching control means for turning on the potential fixing switching means, and an insulation type switch having a shield function. Grayed circuit. 3. When two switch terminals are off, 2
An insulated gate type that is off in one direction, and then off between the drive terminal pair and each of the switch terminals, and on in one or two directions when both switch terminals are on. A two-terminal switching means, an on-drive voltage supply means, a switching means group for conducting and releasing between the on-drive voltage supply means and the drive terminal pair, a switch terminal and the on-drive voltage An external switching means connected between supply means, and if the external switching means is on when the switching means group performs the opening, the opening is released and the on-drive voltage supply means is switched by the switching means group. An on-drive voltage supply path means for supplying an on-drive voltage to the two-terminal switching means via the external switching means; Isolated switching circuit etching means group is characterized by having an off drive means, for turning off driving the two-terminal switching means via said switching means group when performing the continuity.