JPH06244703A - Driving circuit for electrostatic inductive thyristor - Google Patents

Abstract

PURPOSE:To prevent an electrostatic inductive thyristor from being turned on due to a noise. CONSTITUTION:The cathode of an electrostatic inductive thyristor SI is connected with the positive electrode of a direct current power source E, and the gate is connected through the correcter-emitter of a transistor Q1 with the negative electrode of the direct current power source E. When the transistor Q1 is turned on, an inverse bias voltage can be impressed to the cathode-gate of the electrostatic inductive thyristor by the direct current power source E, and when the inverse bias voltage is stabilized, the electrostatic inductive thyristor SI can be prevented from being turned on due to the nose.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention According to the present invention, an anode-cathode is forward biased to turn on an electrostatic induction thyristor and an anode-cathode is reverse biased to turn off an electrostatic induction thyristor according to a control signal from the outside. The present invention relates to a drive circuit for an electrostatic induction thyristor.

[0002]

2. Description of the Related Art Generally, in order to turn on an electrostatic induction thyristor, a gate-cathode is forward-biased and a channel for supplying a main current to an anode-cathode is opened. Also,
To turn off the electrostatic induction thyristor, a current in the opposite direction to that at turn-on is applied to the gate to extract charge from the gate and pinch off the channel, as well as displacement current and other currents associated with an increase in the anode-cathode voltage. The gate-cathode is reverse biased to prevent accidental turn-on due to noise.

As a drive circuit for controlling the electrostatic induction thyristor to be turned on / off by switching the gate-cathode of the electrostatic induction thyristor between forward bias and reverse bias according to a control signal from the outside. The configuration shown in FIG. 10 is considered. That is, the collectors and emitters of the transistors Q ₁₁ and Q ₁₂ as switching elements are connected in series, the series circuit is connected between both ends of the DC power source E, and the transistor Q ₁₃ is connected between the bases of the transistors Q ₁₁ and Q _12. Connect the collector-emitter of
Resistors R ₁₁ and R ₁₂ are connected in series to the collector and emitter of the transistor Q ₁₃ , respectively, and this series circuit is connected between both ends of the DC power source E. The gate of the static induction thyristor SI is connected to the connection point of the transistors Q ₁₁ and Q ₁₂ . Further, a series circuit of a resistor R ₁₃ and a Zener diode ZD ₁₁ is connected between both ends of the DC power source E, a capacitor C ₁₁ is connected in parallel to the Zener diode ZD ₁₁ , and this parallel circuit is connected to the electrostatic induction thyristor SI. It is inserted between the cathode and the negative electrode of the DC power source E. Zener diode ZD
₁₁ , the cathode of the electrostatic induction thyristor SI is a DC power source E
Is connected so that the potential is set higher than that of the negative electrode.

In the circuit configuration of FIG. 10, the transistor Q ₁₃
When a control signal for turning on / off the transistor Q ₁₃ is input to the base of the transistor Q ₁₃ , when the transistor Q ₁₃ is on, the transistor Q ₁₁ is off, the transistor Q ₁₂ is on, and when the transistor Q ₁₃ is off, the transistor Q ₁₃ is on. ₁₁ is on and transistor Q ₁₂ is off. When the transistor Q ₁₃ is off, the transistor Q ₁₁ is turned on and a voltage substantially equal to the power supply voltage of the DC power supply E is applied to the gate of the static induction thyristor SI. At this time, the cathode potential of the static induction thyristor SI has its upper limit set by the Zener voltage by the Zener diode ZD ₁₁ , and the Zener voltage is set lower than the power supply voltage. Therefore, the static induction thyristor S
The gate-cathode of I can be forward biased,
The electrostatic induction thyristor SI turns on. The gate current, the transient DC power supply E- transistor Q ₁₁ -
The gate of the static induction thyristor SI - cathode - passing a charging current to the capacitor C ₁₁ and flows through a path of the capacitor C _11, a DC power source E- transistor Q ₁₁ after completion of charging of the capacitor C ₁₁ - gate static induction thyristor SI -Cathode-Zener diode ZD ₁₁ flows through the path.

On the other hand, in order to turn off the electrostatic induction thyristor SI, a control signal for turning on the transistor Q ₁₃ is applied to turn on the transistor Q ₁₂ . At this time, the potential of the gate of the electrostatic induction thyristor SI becomes substantially equal to the potential of the negative electrode of the DC power source E, and the gate-cathode of the electrostatic induction thyristor SI becomes a reverse bias due to the charges accumulated in the capacitor C ₁₁ , and at the time of turn-on. A gate current in the opposite direction to that of the capacitor C _11- cathode of the electrostatic induction thyristor SI-gate-transistor Q _11- negative electrode of the DC power supply E flows through the path.

Here, the charge of the capacitor C ₁₁ is
At the moment when the electrostatic induction thyristor SI is turned off, the electrostatic induction thyristor SI is discharged to supply a reverse bias current to the gate-cathode of the electrostatic induction thyristor SI. - resistance R ₁₁ - is charged in a path of the capacitor C _11. In the circuit configuration described above, a separate DC power supply is not required while switching between the state in which the gate-cathode of the electrostatic induction thyristor SI is forward biased and the state in which it is reverse biased. Since the states can be switched, there is an advantage that the number of DC power supplies is small and the drive circuit can be downsized. Further, since the capacitor C ₁₁ for applying a reverse bias to the gate-cathode is charged during the off period of the static induction thyristor SI,
Since the capacitor C ₁₁ is always maintained in a state of being almost fully charged, it is possible to sufficiently supply the reverse bias gate current due to the charge of the capacitor C ₁₁ to the electrostatic induction thyristor SI even when the on-duty is small. The result is less noise and accidental turn-on.

[0007]

However, in the drive circuit of the electrostatic induction thyristor described above, as shown in FIG. 11A, at the moment when the electrostatic induction thyristor is _turned off at the time t _OFF , the state shown in FIG. ), The terminal voltage of the capacitor C ₁₁ becomes lower than the Zener voltage V _ZD of the Zener diode ZD ₁₁ , so that the reverse bias voltage of the gate-cathode of the electrostatic induction thyristor SI is as shown in FIG.
Immediately after the turn-off at time t _OFF as shown in 1 (c), it is slightly low, and gradually increases due to the charging of the capacitor C ₁₁ after the turn-off. That is, the electrostatic induction thyristor SI
Immediately after the turn-off, there is a period in which a sufficiently large reverse bias voltage is not applied to the gate-cathode, so there is a problem that the probability of accidentally turning on due to noise increases during this period.

On the other hand, to reduce the variation of the reverse bias voltage due to the discharge of the capacitor C _11, it is conceivable to increase the capacitance of the capacitor C _11, the capacitor C ₁₁ is large, a problem that the cost is high Occurs. Further, the reverse bias voltage is set to a maximum value by the Zener diode ZD, and the Zener voltage is likely to fluctuate depending on the ambient temperature. Therefore, the operating temperature range is limited to a narrow range in order to obtain a desired reverse bias voltage. However, there is a problem that it is difficult to design the Zener voltage especially when integrated into an integrated circuit.

The present invention is intended to solve the above-mentioned problems, and prevents the electrostatic induction thyristor from being accidentally turned on by noise, and can be provided at low cost without the need to use a large-capacity capacitor. In addition, it is an object of the present invention to provide a drive circuit for an electrostatic induction thyristor capable of reliably applying a reverse bias voltage without using a Zener diode which is easily affected by ambient temperature.

[0010]

According to the present invention, in order to achieve the above-mentioned object, the cathode of an electrostatic induction thyristor is connected to the positive electrode of a DC power source, and when the control signal input from the outside is an OFF signal, the static induction is stopped. If the control signal is an ON signal, the OFF control unit that turns off the electrostatic induction thyristor by connecting the gate of the electric induction thyristor to the negative electrode of the DC power supply and applying a reverse bias between the gate and the cathode, A drive circuit comprising: an ON control unit that turns on the electrostatic induction thyristor by applying a voltage higher than a DC power supply voltage to the gate to forward bias between the gate and the cathode, wherein the OFF control unit is Inserted between the gate of the induction thyristor and the negative electrode of the DC power supply, turned on by an off signal and turned off by an on signal
The ON control unit includes a second switch element, one end of which is connected to a negative electrode of a DC power supply and which is turned ON by an OFF signal and turned OFF by an ON signal, and the other end of the second switch element and the DC power supply. A third switch element that is inserted between the positive electrode of the DC power supply and the positive electrode of the DC power source and that is turned OFF by the OFF signal and turned ON by the ON signal; A capacitor inserted between the connection point with the third switch element and the cathode of the diode and charged through the diode when the second switch element is turned on, the connection point between the diode and the capacitor, and the gate of the electrostatic induction thyristor. When the third switch element connected between the two is turned on, it is turned on by the voltage obtained by adding the voltage of the DC power supply and the terminal voltage of the capacitor, and the electrostatic induction It is characterized by comprising a switch circuit for supplying a gate current to turn on the static induction thyristor to the gate of the register.

Claims 2 to 6 are embodiments relating to a specific configuration of the switch circuit. According to a second aspect of the invention, in the switch circuit, a collector and a base are commonly connected, and a collector-emitter is inserted between a connection point of the diode and the capacitor and a positive electrode of the DC power source, and a pnp-type first transistor. , The base is commonly connected to the first transistor, and the collector-emitter is composed of a pnp-type second transistor inserted between the connection point of the diode and the capacitor and the gate of the static induction thyristor.

According to a third aspect of the invention, in the switch circuit, the collector and the base are commonly connected, and the collector-emitter is inserted between the connection point of the diode and the capacitor and the positive electrode of the DC power supply. Second transistor, a base of which is commonly connected to the first transistor and an emitter of which is connected to a connection point of the diode and the capacitor, a connection point of the diode and the capacitor, and a gate of the electrostatic induction thyristor. And a collector-emitter is inserted between the collector and the emitter, and the collector current of the second transistor is input to the base of the npn-type third transistor.

According to a fourth aspect of the invention, in the switch circuit, an auxiliary diode for preventing reverse current, the anode of which is connected to the positive electrode of the DC power supply, the connection point between the second switching element and the third switching element, and the auxiliary diode. Of the auxiliary capacitor which is inserted between the cathode of the second switch element and charged through the auxiliary diode when the second switch element is turned on, the collector and the base are commonly connected, and the collector-emitter is the connection point between the auxiliary diode and the auxiliary capacitor and the DC power source. Pnp type first transistor inserted between the positive electrode and the positive electrode, and a pnp type second transistor having a base commonly connected to the first transistor and an emitter connected to a connection point between the auxiliary diode and the auxiliary capacitor. And the collector-emitter is inserted between the connection point of the diode and the capacitor and the gate of the electrostatic induction thyristor. The collector current of the second transistor is constituted by a third transistor of npn type, which is input to the base is.

According to a fifth aspect of the invention, in the switch circuit, the collector and the base are commonly connected, and the collector-emitter is inserted between the connection point of the diode and the capacitor and the positive electrode of the DC power supply. , A pnp-type second transistor whose base is commonly connected to the first transistor and whose emitter is connected to a connection point of a diode and a capacitor, and an emitter which is connected to the gate of the static induction thyristor. A series circuit of a collector-emitter and a Zener diode, in which a collector and a base are commonly connected, and a series circuit of a collector-emitter and a Zener diode is connected to a connection point of the diode and the capacitor, and a positive electrode of the DC power source. A pnp-type fourth transistor inserted between and and the base of the fourth transistor. It connected the collector - emitter is constituted by a fifth transistor of the inserted pnp type between the collector of the connection point and the third transistor and a diode and a capacitor.

According to a sixth aspect of the invention, in the switch circuit, the collector and the base are commonly connected, and the collector-emitter is inserted between the connection point of the diode and the capacitor and the positive electrode of the DC power supply. Second transistor, a base of which is commonly connected to the first transistor and an emitter of which is connected to a connection point of the diode and the capacitor, a connection point of the diode and the capacitor, and a gate of the electrostatic induction thyristor. Is inserted between the gate of the electrostatic induction thyristor and the positive electrode of the DC power supply, and the collector-emitter is inserted between the collector and the emitter, and the collector current of the second transistor is input to the base. A fourth switch element is turned on by a signal and turned off by an off signal.

[0016]

According to the structure of the present invention, the cathode of the electrostatic induction thyristor is connected to the positive electrode of the DC power supply, and is inserted between the gate of the electrostatic induction thyristor and the negative electrode of the DC power supply to be turned on by the off signal and turned on. Since the first switch element that is turned off by the signal is provided, when the control signal is the off signal, the cathode of the electrostatic induction thyristor is connected to the positive electrode of the DC power supply, and the gate is connected to the DC power supply through the first switch element. The reverse bias voltage can be applied to the gate-cathode of the static induction thyristor. Since the reverse bias voltage is obtained from the DC power supply, the reverse bias voltage does not fluctuate immediately after the electrostatic induction thyristor turns off, and the electrostatic induction thyristor does not turn on accidentally due to noise. is there. Further, since no capacitor or Zener diode is required to turn off the electrostatic induction thyristor, the size can be reduced and the ambient temperature is unlikely to be affected. This facilitates provision as an integrated circuit.

On the other hand, during the OFF period of the electrostatic induction thyristor, the second switch element whose one end is connected to the negative electrode of the DC power source is turned on, and the capacitor connected in series to the second switch element is turned on. Charging through the diode, turning on the second switch element when the ON signal is input, turning on the third switch element inserted between the positive electrode of the DC power supply and the capacitor, and turning on the voltage of the DC power supply. The voltage added to the terminal voltage of the capacitor is applied to the gate of the electrostatic induction thyristor through the switch circuit, and the potential of the gate is increased with respect to the cathode of the electrostatic induction thyristor connected to the positive pole of the DC power supply, resulting in As a forward bias, the electrostatic induction thyristor is turned on.

[0018]

(Embodiment 1) In this embodiment, as shown in FIG. 1, the cathode of the electrostatic induction thyristor SI is connected to the positive electrode of the DC power supply E, and the gate of the electrostatic induction thyristor SI and the DC power supply E are connected. The collector-emitter of the transistor Q ₁ , which is the first switching element, is inserted between the negative electrode and the negative electrode. The transistor Q ₁ is controlled by an external control signal, and is turned on when the control signal is H level (OFF signal) and turned off when the control signal is L level (ON signal). Further, between the both ends of the DC power source E, a collector-emitter of a pnp type transistor Q ₂ which is a second switch element and a collector-emitter of an npn type transistor Q ₃ which is a third switch element are connected in series. The circuits are connected.
The bases of both transistors Q ₂ and Q ₃ are commonly connected and connected to the connection point of the series circuit of the emitter-collector of the transistor Q ₄ and the resistor R ₁ . Control signal is also input to the base of the transistor Q _4, the transistor Q ₄ are off-on signal, is turned on off signal. Therefore, the transistor Q ₂ is turned off by an on signal and turned on by an off signal, and the transistor Q ₃ is turned on by an on signal and turned off by an off signal. In other words, the transistors Q ₂ and Q ₃ are alternately turned on.

The anode of the diode D ₁ is connected to the positive electrode of the DC power source E via a resistor R _2, and the cathode of the diode D ₁ is connected to the connection point between the emitter of the transistor Q _{2 and} the emitter of the transistor Q ₃ at one end. The other end of the capacitor C ₁ connected to is connected. Furthermore, the diode D
₁ and the connection point between the capacitor C ₁ and the electrostatic induction thyristor S
A switch circuit S is inserted between the gate of I and the gate of I.

The switch circuit S constitutes a current mirror circuit composed of two pnp type transistors Q ₅ and Q ₆ and resistors R _{3 to} R ₅ . The collector and the base of one transistor Q ₅ are commonly connected, and the resistors R ₃ and R ₄ are connected to the collector and the emitter, respectively, and the series circuit of the resistors R ₃ and R ₄ and the transistor Q ₅ is a diode D 5. It is inserted between the connection point between ₁ and the capacitor C ₁ and the positive electrode of the DC power supply E. The base of the transistor Q ₆ is commonly connected to the transistor Q _5, and the emitter of the transistor Q ₆ is connected to the diode D ₁ and the capacitor C via the resistor R _5.
It is connected to the connection point with ₁ . The collector of the transistor Q ₆ is connected to the gate of the static induction thyristor SI.

Next, the operation will be described with reference to FIG. The left half of FIG. 2 shows a period during which the electrostatic induction thyristor SI is off. As shown in FIG. 2A, when the control signal is at H level and is off signal, the transistors Q ₁ and Q ₄ are turned on. When turned on, the transistor Q ₂ is turned on and the transistor Q ₃ is turned off. As a result, as shown in FIG. 2B, the potential at the connection point of the transistors Q ₂ and Q ₃ becomes the potential of the negative electrode of the DC power source E, which is called resistor R ₂ -diode D ₁ -capacitor C ₁ -transistor Q _2. A charging path is formed by the path, and the capacitor C ₁ is charged. That is, FIG.
As shown in (c), diode D ₁ and capacitor C ₁
The potential at the connection point with changes only for a short time, and the capacitor C ₁
A charging current i ₁ as shown in FIG. At this time, since the transistor Q ₁ is on,
As shown in (f), the power supply voltage Vcc of the DC power supply E is applied in the reverse direction to the cathode-gate of the static induction thyristor SI, and the reverse bias keeps the static induction thyristor SI off. . Power supply voltage V of DC power supply E
If cc does not change, the reverse bias voltage does not change, and it is possible to prevent the electrostatic induction thyristor SI from being accidentally turned on by noise from the outside. Further, since the emitter potential of the transistor Q ₅ of the switching circuit S is lower than the potential of the collector, the transistor Q _5, Q ₆ is a off, as shown in FIG. 2 (e), the transistors Q ₅ and electrostatic The currents i ₂ and i ₃ do not flow through the gate of the induction thyristor SI.

On the other hand, the right half of FIG. 2 shows the period when the electrostatic induction thyristor SI is on. That is, when the control signal is at the L level and becomes the ON signal as shown in FIG.
Since the transistor Q ₂ is off and the transistor Q ₃ is on, the potential at the connection point of the transistors Q ₂ and Q ₃ is as shown in FIG.
As shown in (b), the power source voltage Vcc of the DC power source E is reached. At this time, the potential at the connection point between the diode D ₁ and the capacitor C ₁ is changed to the power source voltage Vcc of the capacitor C ₁ as shown in FIG. 2C. The value is the sum of the terminal voltages. At this time,
The potential of the emitter of the transistor Q ₅ of the switch circuit S becomes higher than the potential of the collector, and the transistors Q ₅ , Q
_{When 6} is turned on, the discharge currents i ₂ and i ₃ of the capacitor C ₁ flow through the transistors Q ₅ and Q ₆ as shown in FIG. 2 (e). At this time, since the transistor Q ₁ is off, the cathode-gate of the static induction thyristor SI is forward biased, and as a result, the static induction thyristor SI is turned on, as shown in FIG. Since the electrostatic induction thyristor SI has a very high gate sensitivity, it is turned on with a gate current i ₃ of several mA, and when turned on, positive feedback is caused by the main current flowing through the anode-cathode and the on state is maintained even if there is no gate current. It Therefore, as the capacitor C _1, it is possible to use a capacitor having a small enough capacity to turn on the electrostatic induction thyristor SI. Here, the current i ₂ can be adjusted mainly by the resistor R ₃ , and the current i ₃ can be adjusted by the resistors R ₄ and R ₅ .

As mentioned above, the electrostatic induction thyristor SI
Is off, the voltage across the DC power supply E is applied to the cathode-gate of the electrostatic induction thyristor SI for reverse bias, so there is no fluctuation in the reverse bias voltage and it is less susceptible to noise. It is possible to prevent the thyristor SI from being accidentally turned on. Moreover, unlike the conventional configuration, a large-capacity capacitor for applying a reverse bias and a Zener diode for stabilizing the reverse bias voltage are not required, which enables downsizing as a whole and easy integration into an integrated circuit. It will be. In FIG. 1, the portion surrounded by the alternate long and short dash line is a portion to be integrated into a circuit, and in the following embodiments, the portion enclosed by the alternate long and short dash line is the object when integrated into a circuit.

(Embodiment 2) In Embodiment 1, the gate current when turning on the electrostatic induction thyristor SI was passed through the emitter-collector of the pnp type transistor Q ₆ which constitutes the switch circuit S. A current of about 100 mA will flow through the transistor Q ₆ . In general, an integrated circuit is mainly composed of npn type transistors, and when a pnp type transistor is formed, the occupied area is n.
100m because it is larger than pn type transistor
A pnp transistor Q ₆ capable of flowing about A
If it is provided, it becomes large in size when integrated into a circuit, which causes inconvenience.

Therefore, in the present embodiment, an npn type transistor Q _{7 for} supplying a gate current to the electrostatic induction thyristor SI.
Is added to the switch circuit S. That is, the collector of the transistor Q ₇ is connected to the diode D ₁ via the resistor R _6.
And the capacitor C _1
By connecting the emitter of _{7 to} the gate of the static induction thyristor SI, a gate current is given through the collector-emitter of the transistor Q ₇ . The base of the transistor Q ₇ is connected to the collector of the transistor Q ₆ , and when the transistor Q ₆ is turned on and a current flows between the collector and the emitter, the transistor Q ₇ is turned on.

As is apparent from the above structure, the on / off state of the transistor Q ₇ corresponds to the on / off state of the transistor Q ₆ , and therefore the operation is the same as that of the first embodiment shown in FIG. . In addition, electrostatic induction thyristor SI
Since the gate current to the transistor flows through the npn-type transistor Q _7, it is not necessary to use a pnp-type transistor having a large current capacity, and it is possible to reduce the size of the integrated circuit as compared with the configuration of the first embodiment. Other configurations and operations are the same as those in the first embodiment, and thus the description thereof is omitted.

(Embodiment 3) In Embodiments 1 and 2, in order to turn on the static induction thyristor SI, the charge charged in the capacitor C ₁ while the static induction thyristor SI is off is used. A gate current is supplied to the electrostatic induction thyristor SI, and the charge of the capacitor C ₁ is used for controlling the switch circuit S. Therefore, the gate current cannot flow through the electrostatic induction thyristor SI for a long time. In this case, no problem occurs when the electrostatic induction thyristor SI is used in a resistive load circuit and the main current has no phase shift delay, but when used in an inductive load circuit such as a motor, Since there is a time lag between when the gate current is first applied and before the main current starts flowing, the electrostatic induction thyristor SI must be kept on unless the gate current is maintained until the main current starts flowing. However, there is a problem that it cannot operate normally.

The present embodiment can be used even in the case where there is a relatively long time delay from the application of the gate current to the flow of the main current.
That is, as shown in FIG. 4, in the switch circuit S, an auxiliary capacitor C ₂ is provided in addition to the capacitor C ₁ which gives a gate current, and the charge of the auxiliary capacitor C ₂ causes the capacitor C ₁ and the gate of the electrostatic induction thyristor SI to operate. It controls ON / OFF of the transistor Q ₇ inserted between and, and maintains the gate current to the static induction thyristor SI. In short, with respect to a current mirror circuit consisting of transistors Q _5, Q ₆ and the resistor R ₄ to R ₆ Metropolitan in the configuration of Example 2, the resistance R _2, a diode D _1, resistors R ₇ instead of the capacitor C _1, the auxiliary It has a configuration in which a diode D ₂ and an auxiliary capacitor C ₂ are newly provided. The series circuit of the resistor R ₇ , the auxiliary diode D ₂ and the auxiliary capacitor C ₂ is connected in parallel to the collector-emitter of the transistor Q ₃ , and the resistors R ₅ , R ₆ are connected at the connection point of the auxiliary diode D ₂ and the auxiliary capacitor C _2. Is connected to each end.

Next, the operation of the above configuration will be described with reference to FIG. The left half of FIG. 5 is the operation when the electrostatic induction thyristor SI is off, and at this time, the operation is similar to that of the first embodiment. That is, when a control signal which is an off signal is given as shown in FIG. 5A, the potential at the connection point of the transistors Q ₂ and Q ₃ becomes the potential of the negative electrode of the DC power source E, so that FIG.
Such the charging current i ₁ capacitor C _1, C ₂ is charged respectively as the potential at the connection point between the capacitor C ₁ and diode D ₁ is changed as shown in FIG. 5 (d), the auxiliary and the auxiliary capacitor C ₂ The potential at the connection point with the diode D ₂ changes as shown in FIG. In this state, the transistors Q ₅ and Q ₆ are off, and the current i ₂ does not flow in the collector-emitter of the transistor Q ₆ as shown in FIG.
Therefore, the transistor Q _{7 is} also off, and FIG.
As described above, the current i ₃ does not flow through the collector-emitter of the transistor Q ₇ . That is, as shown in FIG. 5H, a reverse bias voltage is applied to the gate-cathode of the static induction thyristor SI, and the static induction thyristor SI is kept off.

On the other hand, when the control signal becomes an ON signal as shown in the right half of FIG. 5A, the transistors Q ₅ and Q ₆ are turned ON and the auxiliary capacitor C ₂ is discharged as shown in FIG. 5C. , the base current i ₂ to the transistor Q ₇ flows as in FIG. 5 (f), the transistor Q ₇ is turned on. Therefore, as shown in FIG. 5D, the capacitor C ₁ also starts discharging and gives a gate current to the electrostatic induction thyristor SI. Here, the electrostatic induction thyristor SI has a capacitance component in the cathode-gate, charges this capacitance component when a gate current is passed from the off state, and turns on when the potential difference between the cathode and gate reaches a predetermined value. ing. That is,
When turning on the electrostatic induction thyristor SI, a large gate current is required at the initial stage, and thereafter, the gate current can be maintained with a minute current. However, when the transistor Q ₇ is turned on, a large gate current i ₃ flows as shown in FIG. 5 (g) due to the electric charge of the capacitor C ₁ , and the cathode − of the electrostatic induction thyristor SI as shown in FIG. 5 (h). A forward bias voltage is applied to the gate. Thereafter, as shown in FIG. 5D, the charge of the capacitor C ₁ is rapidly discharged, so that the gate current i ₃ due to the charge of the capacitor C ₁ becomes smaller, but the current passing through the collector-emitter of the transistor Q ₆ is reduced. It is possible for i ₂ to continue flowing a minute gate current to the static induction thyristor SI through the base-emitter of the transistor Q ₇ . Since the current i ₂ is very small, the auxiliary capacitor C ₂ continues to flow for a relatively long time, and there is a time delay from the start of energization of the gate current to the electrostatic induction thyristor SI to the start of the main current. Even if there is, it will be possible to reliably turn it on. Other configurations are similar to those of the first embodiment.

(Embodiment 4) In the present embodiment, as in the case of Embodiment 3, even if there is a time delay from the application of the gate current to the electrostatic induction thyristor SI to the flow of the main current, it can be turned on. This is another example of the configuration, in which a current mirror circuit is inserted between the connection point of the diode D ₁ and the capacitor C ₁ and the transistor Q ₇ with respect to the circuit configuration of the second embodiment. This current mirror circuit has a pnp in which a collector and a base are commonly connected.
Provided in the form of transistors Q _8, a transistor Q ₉ of the pnp type transistor Q ₈ and bases commonly connected, a Zener diode ZD connected to the collector of the transistor Q _8, and a resistor R ₈ to R _10. Each transistor Q
_One ends of resistors R ₈ and R ₉ are connected to the emitters of ₈ and Q ₉ , respectively, and the other ends of the resistors R ₈ and R ₉ are commonly connected and connected to the connection point of the diode D ₁ and the capacitor C _1. . The resistor R ₁₀ is inserted between the Zener diode ZD and the positive electrode of the DC power source E. The collector of the transistor Q ₉ is connected to the collector of the transistor Q _7, the collector of the transistor Q ₉ - so that the flow gate current static induction thyristor SI through the emitter - collector of the emitter and the transistor Q _7.

Next, the operation will be described with reference to FIG. The operation of the electrostatic induction thyristor SI when it is off is the same as that of the first embodiment, so a description thereof will be omitted, and only the operation when turning on will be described. That is, FIG. 7 (a)
When the control signal becomes an ON signal as shown in the right half of FIG. 7, the potential at the connection point of the transistors Q ₂ and Q ₃ becomes substantially equal to the power source voltage Vcc of the DC power source E, and the diode is turned on, as shown in FIG. 7B. The potential at the connection point between D ₁ and the capacitor C ₁ rises above the power supply voltage Vcc as shown in FIG. 7 (c).
Therefore, the transistors Q ₅ and Q ₆ are turned on, the current i ₂ flows through the collector-emitter of the transistor Q ₆ and the base current flows through the transistor Q ₇ , as shown in FIG. On the other hand, at the time when the ON signal is input, the potential at the connection point between the diode D ₁ and the capacitor C ₁ is the Zener voltage V _ZD of the Zener diode _ZD and the power supply voltage Vc.
It is set to be higher than the added value with c, the transistors Q ₈ and Q ₉ are turned on at the start of discharging the capacitor C ₁ , and as shown in FIG. 7 (f), the transistor Q ₉ and
A current i _{3 is} passed through Q ₇ . Then the diode D ₁
Since the potential at the connection point between the capacitor C ₁ and the capacitor C ₁ becomes lower than the sum of the power supply voltage Vcc and the Zener voltage V _{ZD in} a relatively short time, the transistors Q ₈ and Q ₉ are turned off, and the current i ₃ is Stop. Here, the current i ₂ is the transistor Q
Electrostatic induction thyristor SI through base-emitter ₇
Since a small gate current is applied to the electrostatic induction thyristor S during the current i ₂ is flowing, as shown in FIG.
The forward bias voltage can be reliably applied to the cathode-gate of I. That is, even if there is a time delay from the start of the energization of the gate current to the start of the energization of the main current, the turn-on can be reliably performed. Other configurations are similar to those of the first embodiment.

(Embodiment 5) In this embodiment, as in Embodiments 3 and 4, the electrostatic induction thyristor SI is turned on even if there is a time delay from the time when the gate current is applied until the main current starts flowing. It is another example of the configuration that enables the. In order to achieve this object, the auxiliary capacitor C ₂ is added in the third embodiment, and the current mirror circuit having the Zener diode ZD is added in the fourth embodiment, which results in a slightly high cost. In view of this, the present embodiment shows an example in which the transistor Q ₁₀ is added to the structure of the second embodiment as shown in FIG. 8 to achieve the above object while suppressing an increase in cost.

That is, as shown in FIG. 8, the collector-emitter of the transistor Q ₁₀ as a switch element which operates so as to be turned on / off in reverse to the transistor Q ₁ is connected to the positive electrode of the DC power source E and the electrostatic induction thyristor. a than is connected between the gate of the SI, the transistor Q ₁₀ is coupled to the collector of the transistor Q _4. In this configuration, when the electrostatic induction thyristor SI is turned off, the transistor Q ₁ is turned on and the transistor Q ₁₀ is turned off. Conversely, when the electrostatic induction thyristor SI is turned on, the transistor Q ₁ is turned off and the transistor Q ₁₀ is turned on. It will be.

Next, the operation will be described with reference to FIG. Here, the operation when the electrostatic induction thyristor SI, which is the left half of FIG. 9, is off is the same as that of the first embodiment, so a description thereof is omitted. When the electrostatic induction thyristor SI, which is the right half of FIG. 9, is turned on. Only the operation of will be described. That is, FIG.
When the control signal is the ON signal as shown in (a), the transistor Q ₁₀ is turned on. At this time, the gate potential of the electrostatic induction thyristor SI is substantially equal to the potential of the negative electrode of the DC power supply, and therefore FIG. As shown in (f), a relatively large gate current i ₃ instantaneously flows through the transistor Q ₁₀ .
The gate current i ₃ stops when the gate potential becomes substantially equal to the power supply voltage Vcc.

On the other hand, when the control signal is an ON signal,
As shown in FIG. 9B, the potential at the connection point between the transistors Q ₂ and Q ₃ becomes the power supply voltage Vcc, and the potential at the connection point between the diode D ₁ and the capacitor C ₁ becomes the power supply voltage Vcc as shown in FIG. 9C.
It will be higher than cc. Therefore, the transistor Q ₅ ,
Q ₆ is turned on, the transistor Q ₇ is turned on by the base current flows through the transistor Q _7. As a result,
As shown in (e), the gate current i is applied to the electrostatic induction thyristor SI.
₂ will flow. Here, if the resistance R ₆ is set relatively large so that the gate current i ₂ becomes a minute current,
Since the current i ₂ can be flowed for a relatively long time, the electrostatic induction thyristor SI can be reliably turned on even if there is a time delay from the start of energization of the gate current to the start of energization of the main current. is there. Other configurations and operations are similar to those of the second embodiment.

[0037]

As described above, according to the present invention, the cathode of the electrostatic induction thyristor is connected to the positive electrode of the DC power supply, and it is inserted between the gate of the electrostatic induction thyristor and the negative electrode of the DC power supply and turned on by the OFF signal. First turned off by a turn-on signal
When the control signal is an OFF signal, the cathode of the electrostatic induction thyristor is connected to the positive electrode of the DC power supply, and the gate is connected to the negative electrode of the DC power supply through the first switching element. Therefore, the reverse bias voltage can be applied to the gate-cathode of the static induction thyristor, and the reverse bias voltage does not fluctuate immediately after the turn off of the static induction thyristor. This has the advantage that the thyristor can be prevented from being accidentally turned on. Also,
Since no capacitor or Zener diode is required to turn off the electrostatic induction thyristor, there are advantages that it can be downsized and that it is not easily affected by ambient temperature.

According to a second aspect of the present invention, in order to turn on the electrostatic induction thyristor, the electric charge charged in the capacitor is used when the electrostatic induction thyristor is turned off. The electrostatic induction thyristor can be easily turned on with a simple structure. Can be made. According to the invention of claim 3, the gate current for turning on the electrostatic induction thyristor is supplied through the npn-type transistor, so that an occupied area can be reduced when integrated into an integrated circuit, which leads to a reduction in size. is there.

In order to turn on the electrostatic induction thyristor, a relatively large current is first applied as a gate current, and then a small current is applied to the gate current for a relatively long time. It is possible to keep the current flowing, and even when using a load circuit such as an inductive load in which there is a time lag between when the gate current is applied to the electrostatic induction thyristor and when the main current begins to flow, the main current is There is an advantage that the gate current can be held and turned on reliably until the current flows.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing a first embodiment.

FIG. 2 is an operation explanatory diagram of the first and second embodiments.

FIG. 3 is a circuit diagram showing a second embodiment.

FIG. 4 is a circuit diagram showing a third embodiment.

FIG. 5 is an operation explanatory diagram of the third embodiment.

FIG. 6 is a circuit diagram showing a fourth embodiment.

FIG. 7 is an operation explanatory diagram of the fourth embodiment.

FIG. 8 is a circuit diagram showing a fifth embodiment.

FIG. 9 is an operation explanatory diagram of the fifth embodiment.

FIG. 10 is a circuit diagram showing a conventional example.

FIG. 11 is an operation explanatory diagram of a conventional example.

[Explanation of symbols]

C ₁ capacitor C ₂ capacitor D ₁ diode D ₂ diode E DC power supply Q ₁ transistor Q ₂ transistor Q ₃ transistor Q ₄ transistor Q ₅ transistor Q ₆ transistor Q ₇ transistor Q ₈ transistor Q ₉ transistor Q ₁₀ transistor S switch circuit SI static Electric induction thyristor ZD Zener diode

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[Procedure amendment]

[Submission date] June 7, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0008

[Correction method] Change

[Correction content]

On the other hand, to reduce the variation of the reverse bias voltage due to the discharge of the capacitor C _11, it is conceivable to increase the capacitance of the capacitor C _11, the capacitor C ₁₁ is large, a problem that the cost is high Occurs. Further, the reverse bias voltage is set to a maximum value by the Zener diode ZD, and the Zener voltage is likely to fluctuate depending on the ambient temperature. Therefore, the operating temperature range is limited to a narrow range in order to obtain a desired reverse bias voltage. There is a problem that, there is a problem that will have to be difficult design of the Zener voltage in the case of particular integrated circuit.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] 0023

[Correction method] Change

[Correction content]

As mentioned above, the electrostatic induction thyristor SI
Is off, the voltage across the DC power supply E is applied to the cathode-gate of the electrostatic induction thyristor SI for reverse bias, so there is no fluctuation in the reverse bias voltage and it is less susceptible to noise. It is possible to prevent the thyristor SI from being accidentally turned on. Moreover, unlike the conventional configuration, it does not require a large-capacity capacitor for applying a reverse bias or a Zener diode for stabilizing the reverse bias voltage, which enables downsizing as a whole and facilitates integration into an integrated circuit. It will be. A portion surrounded by a chain line in FIG. 1, co
It can be chipped with the exception of the capacitor C _1.
It is possible to form an integrated circuit as a hybrid integrated circuit by using the capacitor and the capacitor C ₁ . Also in the following examples
It is the same. In addition, a transistor Q ₁ is attached to the chip.
May be built-in.

[Procedure 3]

[Document name to be amended] Statement

[Name of item to be corrected] 0030

[Correction method] Change

[Correction content]

On the other hand, when the control signal becomes an ON signal as shown in the right half of FIG. 5A, the transistors Q ₅ and Q ₆ are turned ON and the auxiliary capacitor C ₂ is discharged as shown in FIG. 5C. , the base current i ₂ to the transistor Q ₇ flows as in FIG. 5 (f), the transistor Q ₇ is turned on. Therefore, as shown in FIG. 5D, the capacitor C ₁ also starts discharging and gives a gate current to the electrostatic induction thyristor SI. Here, the electrostatic induction thyristor SI has a capacitance component in the cathode-gate, charges this capacitance component when a gate current is passed from the off state, and turns on when the potential difference between the cathode and gate reaches a predetermined value. ing. That is,
When turning on the static induction thyristor SI requires a large gate currents initially, thereafter Au with small gate current
It is possible to maintain a good state . When preparative transistor <br/> Q ₇ is turned on, and a large gate current i ₃ as shown in FIG. 5 (g) stream by the charge of the capacitor C _1,
A forward bias voltage is applied to the cathode-gate of the electrostatic induction thyristor SI as shown in FIG. After that, FIG.
As shown in (d), since the charge of the capacitor C ₁ is rapidly discharged, the gate current i ₃ due to the charge of the capacitor C ₁ is small, but the current i ₂ passing through the collector-emitter of the transistor Q ₆ is It is possible to keep a minute gate current flowing through the static induction thyristor SI through the base-emitter of Q ₇ . Since the current i ₂ is minute, the auxiliary capacitor C ₂ continues to flow for a relatively long time, and the electrostatic induction thyristor SI
Even if there is a time delay from the start of the energization of the gate current to the main current to the start of the main current, it is possible to reliably turn it on. Other configurations are similar to those of the first embodiment.

Claims (6)

[Claims] 1. A gate of an electrostatic induction thyristor is connected to a positive electrode of a DC power supply, and a gate of the electrostatic induction thyristor is connected to a negative electrode of a DC power supply when a control signal input from the outside is an OFF signal. An OFF control unit that turns off the electrostatic induction thyristor by applying a reverse bias between the cathodes and a gate-cathode by applying a voltage higher than the DC power supply voltage to the gate of the electrostatic induction thyristor when the control signal is an ON signal. A drive circuit comprising an ON control unit for turning on the electrostatic induction thyristor by applying a forward bias between the OFF control unit and the OFF control unit, which is inserted between the gate of the electrostatic induction thyristor and the negative electrode of the DC power supply. A first switch element that is turned on by a signal and turned off by an on signal is provided, and the on control unit has one end connected to the negative electrode of the direct current power source and turned off. A second switch element which is turned on by a signal and turned off by the on signal; and a second switch element which is inserted between the other end of the second switch element and the positive electrode of the DC power source and turned off by the off signal and turned on by the on signal. A switch element of No. 3, a diode for blocking a reverse current, the anode of which is connected to the positive electrode of the DC power supply, and a second node which is inserted between the connection point of the second switch element and the third switch element and the cathode of the diode. Of the DC power supply and the terminal of the capacitor connected between the connection point between the diode and the capacitor and the gate of the electrostatic induction thyristor, which is charged through the diode when the switching element of ON is turned on The gate current that turns on by the voltage that adds the voltage and turns on the electrostatic induction thyristor is applied to the gate of the electrostatic induction thyristor. Driving circuit of an electrostatic induction thyristor, characterized in that it consists of a latch circuit. 2. A switch circuit, in which a collector and a base are commonly connected, and a collector-emitter is inserted between a connection point of a diode and a capacitor and a positive electrode of a DC power supply.
An np-type first transistor and a pnp-type second transistor in which the base is commonly connected to the first transistor and the collector-emitter is inserted between the connection point between the diode and the capacitor and the gate of the static induction thyristor. The drive circuit for an electrostatic induction thyristor according to claim 1, comprising a transistor. 3. A switch circuit, wherein a collector and a base are commonly connected and a collector-emitter is inserted between a connection point of a diode and a capacitor and a positive electrode of a DC power supply.
An np-type first transistor, a pnp-type second transistor having a base commonly connected to the first transistor and an emitter connected to a connection point between the diode and the capacitor, and a connection point between the diode and the capacitor 2. An electrostatic capacitor according to claim 1, further comprising an npn-type third transistor having a collector-emitter inserted between the gate of the electric induction thyristor and the collector current of the second transistor being input to the base. Induction thyristor drive circuit. 4. The switch circuit includes an auxiliary diode for blocking reverse current, the anode of which is connected to the positive electrode of the DC power source, and the second diode.
The auxiliary capacitor inserted between the connection point of the switch element and the third switch element and the cathode of the auxiliary diode and charged through the auxiliary diode when the second switch element is turned on is commonly connected to the collector and the base. A pnp-type first transistor having a collector-emitter inserted between the connection point of the auxiliary diode and the auxiliary capacitor and the positive electrode of the DC power supply, and a base commonly connected to the first transistor and an emitter having the auxiliary diode and the auxiliary. The collector-emitter is inserted between the connection point of the diode and the capacitor and the gate of the electrostatic induction thyristor, and the collector current of the second transistor is connected to the connection point of the capacitor and the pnp type second transistor. 2. An npn-type third transistor input to the base. Driving circuit of the electrostatic induction thyristor of the mounting. 5. A switch circuit, in which a collector and a base are commonly connected, and a collector-emitter is inserted between a connection point of a diode and a capacitor and a positive electrode of a DC power supply.
An np-type first transistor, a pnp-type second transistor whose base is commonly connected to the first transistor and whose emitter is connected to a connection point between a diode and a capacitor, and an emitter at the gate of the static induction thyristor. An npn-type third transistor connected to the base of the collector current of the second transistor and a series circuit of a collector-emitter and a Zener diode connected to the collector and the base are connected to form a connection point between the diode and the capacitor. And a pnp-type fourth inserted between the positive electrode of the DC power supply
And a pnp-type fifth transistor whose base is commonly connected to the fourth transistor and whose collector-emitter is inserted between the connection point of the diode and the capacitor and the collector of the third transistor. The drive circuit for the electrostatic induction thyristor according to claim 1. 6. A switch circuit, wherein a collector and a base are commonly connected, and a collector-emitter is inserted between a connection point of a diode and a capacitor and a positive electrode of a DC power supply.
An np-type first transistor, a pnp-type second transistor having a base commonly connected to the first transistor and an emitter connected to a connection point between the diode and the capacitor, and a connection point between the diode and the capacitor A collector-emitter is inserted between the gate of the electric induction thyristor and the collector current of the second transistor is input to the base, and an npn type third transistor, and the gate of the electrostatic induction thyristor and the positive electrode of the DC power supply. 2. A drive circuit for an electrostatic induction thyristor according to claim 1, further comprising a fourth switch element which is inserted between them and which is turned on by an on signal and turned off by an off signal.