JP3288544B2 - Resonant power conversion circuit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0010]

[Technical field] The present invention provides a method for controlling the operation of one arm of two arms forming an arm pair.
Even if the voltage of the resonance capacitance means is controlled by non-controllable switching means (for example, a diode or the like) and the oscillating voltage is limited to almost zero between the power supply voltage and the power supply voltage, the above-mentioned voltage can be reliably maintained. The present invention relates to a self-oscillation type resonance power conversion circuit capable of oscillating by switching an arm on and off. By using this resonance type power conversion circuit, a resonance type power conversion circuit for ignition, that is, an ignition circuit can be formed.
Used for various ignition devices, discharge lamp lighting devices, induction heating devices, switching power supply devices, etc.

[0020]

[Background technology] Prior art of the present inventor (Japanese Patent Application No. 2-2)
33218) is shown in FIGS. 3 and 4. The conductors with the same reference numerals + V and u3 are in a connected state. In the figure, 1 is a DC-DC converter circuit, 2 to 4 are power supply capacitors, t2 is an input terminal, 42 is a shield case, 43
Is an ignition coil, and 44 is a discharge gap for ignition. The input terminal t2 has a signal "ignition signal for controlling activation and stop of the ignition circuit (corresponding to a start / stop signal in this case)".
Is input from outside. The shield case 42 is provided with an ignition coil 43 and an ignition discharge gap 44 to prevent radio interference.
Is shielded. It is desirable to take out the lead wire of the primary coil 43a to the outside through a feedthrough capacitor. As an example of each power supply voltage, the voltage of the DC power supply 45 is +12 to +16 volts, and the output voltage of the DC-DC converter circuit 1 is on the order of +100 volts.

This ignition circuit utilizes a self-oscillation type resonance type power conversion circuit, and the two leakage inductances of the ignition coil 43, the capacitor 6, and the ignition discharge gap 44 (corresponding to a load) are equivalently provided. They are connected in series. "Series circuit of diode 16 and transistor 7"
Corresponds to one arm described above, and the transistor 10 corresponds to the other arm described above. One arm controls on / off of the other arm. Specifically, the transistor 7 controls the turning on and off of the transistor 10 and, at the same time, constitutes a driving circuit of the transistor 10 together with the power supply capacitor 4 and the like. When the transistor 7 is on, the transistor 10 is kept off, and the power supply capacitor 3 and the like charge the power supply capacitor 4 via the diode 11, the resistor 27, the diode 16 and the like and the transistor 7. When the transistor 7 is off, the power supply capacitor 4 supplies a gate forward bias voltage to the transistor 10 via the resistor 28, so that the transistor 10 is turned on.

When the power switch 46 is on and the ignition signal input to the input terminal t2 is at a high level, "the transistors 7, 8, the diodes 17, 19, the resistor 30,
33 and the power supply capacitor 3 constitute a "switching circuit having a self-holding function and a self-turn-off function". If the main current of the transistor 7 does not cause a sufficient voltage drop (= forward voltage) through the diode 19, the resistance 33
Current does not flow toward the diode 17 and the transistor 8
The transistor 8 keeps the transistor 7 off by flowing to the base of the transistor 8 and keeping the transistor 8 on. But,
If the main current of the transistor 7 flows through the diode 19 and causes a sufficient voltage drop, the current of the resistor 33 becomes
Since the current flows to 7 and does not flow to the base of the transistor 8, the transistor 8 is kept off, and the resistor 30 keeps the transistor 7 on.

That is, while the ignition signal input to the input terminal t2 is at the high level, the transistor 8 controls the turning on and off of the transistor 7 in accordance with the direction of the voltage of the diodes 19 and 24 connected in anti-parallel. Therefore, the transistor 8 eventually turns on and off both the transistors 7 and 10. Moreover, if the clamp diodes 22 and 23 are not connected, the diode 19
The direction of the voltage of 24 always switches according to the direction of the current of the primary coil 43a. As a result, "on / off of the transistors 7 and 10", that is, "on / off of each arm described above" is appropriately controlled according to the direction of the primary current.

When the diodes 22 and 23 are not connected, the operation of the circuits shown in FIGS. 3 and 4 is as follows. When the power switch 46 is on and the ignition signal input to the input terminal t2 rises while the DC-DC converter circuit 1 is sufficiently charging the power capacitor 2, the transistor 8 turns off the transistor 7, Power capacitor 4 and resistor 28 turn transistor 10 on. Therefore, the power supply capacitor 2 applies a power supply voltage to the primary coil 43a via the transistor 10, the capacitor 6 (at this time, no voltage) and the diode 24, and a high voltage is induced on the secondary side thereof. Spark discharge occurs in the gap 44, and a resonance current flows. The resonance current flows and reverses during “a half cycle determined by both leakage inductance of the ignition coil 43 and the capacitance of the capacitor 6”, and the resonance current flows from the capacitor 6 to the primary coil 43a, the built-in diode of the transistor 10, the power supply When the current flows through the capacitor 2 and the diode 19, the current of the resistor 33 flows toward the diode 17, so that the transistor 8 is turned off and the transistor 7 is turned on.

Then, the power supply short-circuit current is reduced to the power supply capacitor 2
For example, since the current flows through the transistor 10, the diode 16, and the transistor 7 for a moment and causes a voltage drop in the diode 16 and the like, the forward voltage of the diode 16 causes the gate of the transistor 10 to be reverse biased to turn off the transistor 10. For this reason, the voltage of the capacitor 6 is changed through the primary coil 43 through the transistor 7 and the diode 19 such as the diode 16.
a, and a high voltage is induced on its secondary side, so that a spark discharge or the like occurs in the ignition discharge gap 44 and a resonance current flows. The resonance current flows during the half cycle and reverses, and the capacitor 6 to the diode 24, the built-in diode of the transistor 7, and the “gate of the transistor 10.
When the current flows through the parallel circuit of the source-to-source capacitance and the two Zener diodes 26 and the primary coil 43a, the current of the resistor 33 starts flowing again to the base of the transistor 8, so that the transistor 8 is turned on, and the transistor 7 is turned on.
Turns off. Then, the transistor 10 is turned on.

Then, “the capacitor 6 and the power supply capacitor 2 charged in the same direction as the power supply voltage direction” apply “the sum of the charged voltage and the power supply voltage” to the primary coil 43 a via the transistor 10 and the diode 24. Since a high voltage is induced on the secondary side, spark discharge or the like occurs in the ignition discharge gap 44, and a resonance current flows. Thereafter, the same is repeated in the same manner, and this circuit oscillates, and a power conversion operation involving an ignition operation is performed. The power conversion operation including the oscillation and the ignition operation is performed while the ignition signal is at a high level. When the ignition signal falls, the transistor 8 is kept off as long as the transistor 8 is off at that time. However, if the transistor 8 is on at the time of the fall, the transistor 8 is forcibly turned off. In any case, since the transistor 7 is kept on by leaving the transistor 8 off, the voltage of the capacitor 6 attenuates and oscillates and converges to zero, and the power conversion operation involving its oscillation and ignition operation is stopped. .

The peak value of each oscillating voltage of the capacitor 6 and the primary coil 43a gradually increases and becomes larger than the power supply voltage. However, energy consumption at the ignition discharge gap 44 and the like and energy from the DC-DC converter circuit 1 When the energy supply is balanced, the peak value of each oscillation voltage stops increasing. On the other hand, when the diodes 22 and 23 for clamping are connected as described later, the capacitor 6 and the primary coil 4 are connected.
3a, the peak value of each oscillating voltage is fixed, and becomes almost the same as the magnitude of the power supply voltage. Therefore, if it is attempted to make each peak value the same as before the connection, the magnitude of the power supply voltage is increased by several times as compared with that before the connection. It needs to be raised.

However, when the clamping diodes 22 and 23 (both are non-controllable switching means) are connected to stabilize the peak values of the oscillating voltages of the capacitor 6 and the primary coil 43a, the transistor 10
During the ON period, the current of the primary coil 43a flows from the middle to the diode 22 and no longer flows to the diode 24. As a result, even if the resistor 29 is connected, the above-described on / off control of each arm becomes uncertain.

The reason for connecting the resistor 29 is as follows. During the ON period of the transistor 10, the primary coil 43a
Current flows toward the diode 22 in the middle, and then the primary side current flows from the primary coil 43a to the diode 2
2, the current flows through the transistor 10 and gradually becomes zero and is cut off, and the primary current does not reverse. As a result, the primary current does not flow through the internal diode of the transistor 10, the power supply capacitor 2, the diode 19, and the capacitor 6, so that the transistor 8 cannot be turned off by the reversal of the primary current. In order to improve this, when the current of the primary coil 43a becomes zero during the ON period of the transistor 10, the capacitor 6
Discharges through the primary coil 43a, the diode 16, etc., the resistor 29 and the diode 19, thereby turning off the transistor 8 and turning on the transistor 7.
The inventor considered turning it on. That is, the resistance 2
The connection 9 is for switching the control for the transistor 7 to the ON control.

Therefore, two non-controllable switching means for clamping (diode 2) are provided in the circuits shown in FIGS.
2, 23) as shown in the figure, the transistor 7 often does not switch from off to on during the power conversion operation even if, for example, the resistor 29 is connected for switching on control. That is, there is a problem that "when two non-controllable switching means for clamping are connected, the circuit often does not oscillate."
(Problem) The same problem occurs even when a bipolar transistor or a gate turn-off thyristor is used instead of the transistor 10. On the other hand, JP-A-2-153618
This is not the case in the circuit of FIG.

Accordingly, an object of the present invention is to provide a resonance type power conversion circuit which can oscillate when two non-controllable switching means for clamping are connected. (The purpose of the invention)

[0140]

That is, the present invention is a resonance type power conversion circuit as described in claim 1. Using the first and second current detecting means and the first and second on / off driving means, the "first self-holding operation based on the magnitude of the main current of the first switching means" Type switching means "
And "the second self-holding switching means that operates based on the current direction of the inductance means". Then, when the second switching means is driven in the OFF direction, the first trigger means guides the charging current of the capacitance means as a trigger current to the detection unit of the first current detection means to cause the first current detection means to detect the first current. While triggering the self-holding switching means of
When the first switching means is driven in the off direction, the second trigger means guides the discharge current of the capacitance means as a trigger current to the detection unit of the second current detection means to cause the second self-switching means to operate. The holding type switching means is triggered.

With this, when the main current becomes smaller than the predetermined value during the ON period of the first switching means, that is, when the main current becomes near zero, it is changed to the first current.
, The first on / off drive means drives the first switching means in the off direction, so that the first switching means does not prevent the discharge of the capacitance means. Therefore, the capacitance means almost charged to the power supply voltage starts discharging through the detection unit of the second current detection means, and triggers the second self-holding type switching means. The off-drive means switches off-drive of the second switching means to on-drive; As a result, even when the first and second non-controllable switching means for clamping are connected, the resonance type power conversion circuit of the present invention can oscillate. (Effect)

Since the second current detecting means detects not the main current of the second switching means but the current direction of the inductance means, the "second current detecting means does not detect the second current during the ON period of the first switching means." Of the first switching means is turned on and the first switching means is turned off. Note that the current of the inductance means flows through the first switching means during the ON period of the first switching means, and flows through the second switching means during the ON period of the second switching means. The “second self-holding type switching means having a self-holding function” can be configured based on the current of the inductance means.

[0170]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings. FIGS. 1 and 2 and FIGS. 5 to 14 show the first to sixth embodiments. The first embodiment shown in FIGS. 1 and 2 is a resonance type power conversion circuit for ignition, that is, an ignition circuit according to the present invention. Conductors with the same reference numerals + V, u1 to u4 and G are in a connected state. In the figure, 1 is a DC-DC converter circuit, 2 to 4 are power supply capacitors, t1 is an input terminal, 42
Is a shield case, 43 is an ignition coil, and 44 is a discharge gap for ignition. An ignition signal for controlling the start and stop of the ignition circuit (start / start in this case) is input to an input terminal t1.
Equivalent to a stop signal. ) Is input from outside. shield·
The case 42 shields the ignition coil 43 and the ignition discharge gap 44 as a measure against radio interference. Primary coil 43
It is desirable that the lead wire a is taken out through a through-type capacitor. Diodes 20, 21 and resistor 3
9 and 40 are also measures against ignition noise. Each value of the resistors 39 and 40 is 0 to several hundred ohms. As an example of each power supply voltage, the voltage of the DC power supply 45 is +12 to +16 volts, DC-DC
The output voltage of converter circuit 1 is a little over +400 volts.

In the first embodiment shown in FIGS. 1 and 2, each corresponds to each component described in claim 1 as follows. a) The transistor 10 is the first switching means according to claim 1. b) The gate terminal, the source terminal, and the drain terminal of the transistor 10 are the control terminal ct, the main terminal mta, and the main terminal mtb according to claim 1, respectively. c) The "parallel circuit of the diode 16 and the resistor 36" corresponds to the voltage drop means according to claim 1. d) The transistor 7 is the second switching means according to claim 1. e) "Transistor 10," diode 16 and resistor 36 "
And a series circuit of the transistor 7 ”in the arm pair according to claim 1. f) The drain terminal of the transistor 10 and the transistor 7
2. The portion between the source terminals of claim 1 is the portion between both outer terminals according to claim 1. g) "DC-DC converter circuit 1 and power supply capacitor 2"
A parallel circuit of the DC power supply means according to claim 1. h) The "connection body between the ignition discharge gap 44 and the ignition coil 43" is the load inductance means according to claim 1. i) The capacitor 6 is a capacitance means according to claim 1. j) The diode 22 is the first non-controllable switching means according to claim 1. k) The diode 23 is the second non-controllable switching means according to claim 1. l) "Transistor 9, two or four diodes 1
8, the diode 15 and the resistors 34 and 35 (the resistor 38
The first current detecting means according to claim 1, wherein "the current detecting means formed by both of them). m) "Transistor 9, diode 13, both Zeners
The first on / off driving means according to claim 1, wherein "the on / off driving means formed by the diode 26 and the resistors 28, 36". n) “Power supply capacitor 3, etc., diode 11, resistor 2
7. The on-drive power supply means according to claim 1, wherein "the DC power supply means formed by the power supply capacitor 4, the diodes 12, 16 and the transistor 7". o) Claiming "self-holding switching means formed by transistors 10, 9, two or four diodes 18, diodes 13, 15, two Zener diodes 26 and resistors 28, 34-36 (both resistors 38)". Item 1. The first self-holding type switching means according to Item 1. p) The first trigger means according to claim 1, wherein a series circuit of the diode 11 and the resistors 27 and 28 (the resistor 37) is used. q) "" Transistor 9, two or four diodes 1
8, diode 15 and resistors 34 and 35 (both resistors 38) "," transistor 8, diode 14, 17, 1
9, 24 and resistors 32, 33 (, 41) "and resistor 3
2. The second means according to claim 1, wherein:
For current detection means. r) The "on / off driving means formed by the transistor 8, the zener diode 25 and the resistor 30" is the second on / off driving means according to claim 1. s) The second transistor according to claim 1, wherein “transistor 7, a self-holding switching device formed by the current detecting device described in the above q) and the on / off driving device described in the above r)” is used. Self-holding type switching means.

As can be seen from the circuits shown in FIGS. 1 and 2, the current of the primary coil 43 a flows through the transistor 10 during the ON period of the transistor 10.
The current a is almost the same as the main current of the transistor 10. The current of the primary coil 43a flows through the transistor 7 during the ON period of the transistor 7, so that the current of the primary coil 43a is almost the same as the main current of the transistor 7. Therefore, the input of the transistor 8 is an OR circuit to detect the current of the primary coil 43a, and the transistor 8 is connected to the "anti-parallel connected diode 1".
9 and 24 etc. ”and“ 2
Operation based on the current detection results of one (or four) diodes 18 and the like, so that even if the current of the primary coil 43a is commutated from the capacitor 6 to the diode 22 during the ON period of the transistor 10, the current detection is hindered. There is no. Moreover, while the primary current is flowing through the transistor 10, the transistors 9 and 8 drive the transistor 7 off, so that the transistor 10 never turns off when the transistor 7 turns on. The capacitor 5 reduces the charge / discharge speed of the capacitance between the gate and the source of the transistor 10 so that “on / off of the transistors 7 and 10 that occurs when the transistor 10 is switched on / off is performed at a higher frequency than usual. Abnormal oscillation switching ”is suppressed. It is more effective to connect one end of the capacitor 5 connected to the drain side of the transistor 7 as close to the drain of the transistor 7 as possible.

The operation of the first embodiment shown in FIGS. 1 and 2 is as follows. When the power switch 46 is on, the DC-D
When the ignition signal input to the input terminal t1 rises while the C converter circuit 1 is sufficiently charging the power supply capacitor 2, the transistor 8 turns the transistor 7 on.
Turn off. Subsequently, first, from the power supply capacitor 3, the diode 11, the resistors 27 and 28, the gate of the transistor 10
The source-to-source capacitance, etc.
Since a current flows through the primary coil 43a, the capacitor 6, and the diode 24, the transistor 9 is turned on, and then the power supply capacitor 4 and the resistor 28 are connected to the transistor 9 The transistor 10 is turned on by forward biasing the gate of the transistor 10 via the diode 13.

Therefore, the power supply capacitor 2 and the like are connected to the primary coil 43a via the transistor 10, the diode 18, the capacitor 6 (at this time, no voltage) and the diode 24.
Since a high voltage is induced on the secondary side of the power supply, a spark discharge or the like occurs in the ignition discharge gap 44, and a primary side current flows. When the voltage of the capacitor 6 becomes substantially equal to its power supply voltage, the diode 22 which has been turned off because of the reverse voltage turns on, so that its primary current is diverted from the capacitor 6 to the diode 22. . Even if the commutation occurs, the transistor 9 controls the transistor 7 to be turned off through the transistor 8, so that the transistor 7 does not turn on erroneously. Then, part 1
When the secondary current attenuates to almost zero, the transistor 9
Is turned off, the gate forward bias voltage is prevented from being supplied to the transistor 10, and the resistor 36 controls the transistor 10 in the off direction.

Then, the capacitor 6 is connected to the primary coil 43
a, the diode 18, the “capacitance between the gate and the source of the transistor 10, the parallel circuit of the diode 16 and the resistor 36”, the discharge through the resistor 29 and the diode 19, and the current of the resistor 33 As it flows to 17, transistor 8 turns off and transistor 7 turns on. As a result, a power supply short-circuit current flows from the power supply capacitor 2 and the like through the transistor 10, the “gate-source capacitance of the transistor 10, the parallel circuit of the diode 16 and the resistor 36” and the transistor 7, and the voltage drops to the diode 16 and the like. Therefore, the forward voltage of the diode 16 and the like causes the gate of the transistor 10 to be reverse-biased and turned off.

Therefore, the voltage of the capacitor 6 almost charged to the power supply voltage is
Etc., via the transistor 7 etc. and the diode 19
Since a high voltage is applied to the secondary coil 43a in the opposite direction as before and a high voltage is induced on the secondary side thereof, a spark discharge or the like is generated in the ignition discharge gap 44, and a primary current flows. When the voltage of the capacitor 6 becomes almost zero, the diode 23, which has been off because of the reverse voltage, turns on and short-circuits the both ends of the capacitor 6. Thereafter, when the primary side current attenuates to almost zero, the current of the resistor 33 starts flowing again to the base of the transistor 8, so that the transistor 8 is turned on and the transistor 7 is turned off.

Then, the power supply capacitor 3 and the like turn on the transistor 9 again, and then the power supply capacitor 4 and the like turn on the transistor 10 again. Thereafter, the same is repeated in the same manner, and this circuit oscillates, and a power conversion operation involving an ignition operation is performed. The power conversion operation involving the oscillation and the ignition operation is performed while the ignition signal is at a high level. However, if the transistor 8 is off when the ignition signal falls, the primary current flows through the transistor 7 and the like and attenuates to zero, the transistor 8 remains off and the circuit stops operating. . On the other hand, if transistor 8 is on when the ignition signal falls, transistor 9 keeps transistor 8 on while the main current of transistor 10 is greater than a predetermined value.
Thereafter, the main current becomes smaller than a predetermined value, and the transistor 7 is turned on. Similarly, the primary side current flows through the transistor 7 and the like to be reduced to zero, and this circuit stops operating. In any case, the voltage of the capacitor 6 is reset to almost zero, and the operation stops while the transistor 7 remains on.

When the transistor 7 is turned off, the current of the resistors 27 and 28 triggers the transistor 9, but when the resistor 37 is connected, the current of the resistor 37 also triggers the transistor 9, so that the transistor 10 is turned on. The switching speed is faster. If the value of the resistor 30 is increased to reduce the turn-on speed of the transistor 7, the power supply short-circuit current passing through the transistors 10 and 7 at the time of the turn-on can be reduced.

The second embodiment shown in FIGS.
2 in the first embodiment shown in FIGS.
A resonance-type power conversion circuit for ignition, that is, an ignition circuit, which is improved to "eliminate the energy loss due to 9, 24" or "to completely ground one end of the capacitor 6". Conductors with the same sign for + V, u3, u5 to u8, and G are in a connected state. t3 is an input terminal for inputting an ignition signal (corresponding to a start / stop signal in this case) from the outside. For the improvement, the present inventor takes out a control signal for turning off the transistor 8 from the four diodes 18 through the transistor 50 and the like, and supplies the control signal to the transistor 8 through the transistor 49 and the like. The maximum output current of the base-grounded transistor 50 is limited to some extent by the diodes 18 and the resistor 55 on the left side of FIG.
2 prevents oversaturation of transistor 49. Diode 51 helps transistor 49 keep transistor 8 off. Capacitors 53 and 54 are provided to prevent malfunction due to ignition noise or the like. Note that the ignition coil 48 is replaced by the first embodiment shown in FIGS.
It is of course possible to use a four-terminal ignition coil as in the fifth embodiment shown in FIGS. Also, one end of the resistor 31 is not connected to the collector of the transistor 9 but to the transistor 1.
It may be connected to the source or gate of 0.

The third embodiment shown in FIGS. 7 and 8 is also a resonance type power conversion circuit for ignition, that is, an ignition circuit. Sign +
Conductors with the same reference numerals for V, u3, s1 to s4, and G are in a connected state. In the third embodiment, "the transistor 57, the diodes 17, 59, the zener diode 26, the two diodes 18, the resistors 60, 28, 3
The current detecting means and the on / off driving means formed by 6 "correspond to the first current detecting means and the first on / off driving means described in claim 1. That is, the main current of the transistor 10 is a predetermined value (corresponding to the predetermined value described in claim 1).
If it is smaller, the transistor 57 and the like prevent the resistor 28 from supplying the gate forward bias voltage from the power supply capacitor 4 to the transistor 10, and the transistor is turned off. However, when the main current is larger than the predetermined value, the sum of the forward voltages generated in the two diodes 18 on the right side of the figure is equal to the value of the diode 1.
Since the base of the transistor 57 is reverse-biased via the transistor 7, the transistor 57 is turned off, and the transistor 10 is gate-biased and turned on.
(Reference: Japanese Patent Application No. 2-233218) Other configurations are almost the same as those of the second embodiment shown in FIGS. Note that the resistor 29 may serve as the second trigger means in place of the resistor 29 as described in claim 1, and thus the resistor 29 may not be provided. Also, see FIG.
8 to 8 in the third embodiment shown in FIGS.
7, diode 17, four diodes 18 and resistor 6
0, 28, etc. formed by the self-holding switching means "and" the transistor 7 in the first embodiment shown in FIGS.
8, self-holding switching means formed by diodes 17, 18, 24 and resistors 30, 33, etc. "
Except for the point 1, the configuration is almost the same.

In the fourth embodiment shown in FIGS. 9 and 10, the number is two in order to reduce the energy loss due to the four diodes 18 and the like in the third embodiment shown in FIGS. The ignition-type resonance power conversion circuit, that is, the ignition circuit is reduced. Conductors with the same sign for + V, u3, s5 to s9, and G are in a connected state. In order to reduce the loss, the present inventor also utilizes the forward voltage of the diode 16 and creates the base current of the transistor 50 from the sum of the forward voltages of the diode 18 and the diode 16 on the left side of the drawing. The diode 61 is provided to cause the transistor 50 to perform non-saturated switching. The capacitor 64 is a speed-up capacitor.

In the fifth embodiment shown in FIGS. 11 to 12, the detection of the current flowing through the diode 18 on the right side of FIG.
8 to 8 and the fourth embodiment shown in FIGS. 9 to 10 and the transistor 57 and the diode 17 as in the fourth embodiment.
The detection of the current flowing through the diode 18 on the left side of the figure is performed in the same manner by the transistor 67 and the diode 68. As a result, as in the fourth embodiment shown in FIGS. 9 and 10, the number of diodes 18 can be reduced to two, and energy loss can be reduced. Transistor 67
Controls the transistor 49 via the transistor 50. Transistor 50 is driven with a common base and its maximum output current is limited.

Incidentally, each of the insulated DC power supplies 65 and 66 may be a circuit for rectifying and smoothing the AC output of the insulating transformer, a combination of a light emitting diode and a light receiving diode, or a device utilizing piezoelectric means. Or,
The DC power supply 65 may of course be constituted by the diode 11, the power supply capacitor 4 and the resistor 27 as in the fourth embodiment shown in FIGS. In addition, 2 of the ignition coil 43
The secondary side may have a well-known configuration of electronic power distribution using a high withstand voltage diode.

In the sixth embodiment shown in FIGS. 13 and 14, the detection of the current flowing through the diode 18 on the left side of FIG.
Unlike the DC power supply 66 of the fifth embodiment shown in FIGS. 1 to 12, a negative power supply is used. The negative power supply is formed by “the power supply capacitor 2, etc., the transistor 10, the power supply capacitor 69, the transistor 70, the diode 74, the zener diode 75, and the resistor 76”.
While the transistor 10 is on, the power supply capacitor 2 and the like charge the power supply capacitor 69 to a predetermined voltage. The current of the diode 18 on the left side of the figure is detected by the minus power supply, the transistor 73, the diode 68, and the like. Then, the transistor 73 controls the transistor 49 through the transistors 72 and 50. The maximum output current of transistor 50 is limited by resistor 77 and transistor 71. Incidentally, even if the power supply capacitor 69 is not charged before the start of the sixth embodiment shown in FIGS. Because, even if the charging voltage of the power supply capacitor 69 is zero, the transistors 73 and 72
This is because both are off and the transistor 72 is turned on after the power supply capacitor 69 is charged.

Finally, the fourth embodiment shown in FIGS. 9 and 10, the fifth embodiment shown in FIGS. 11 and 12, and the sixth embodiment shown in FIGS. There is an advantage that the energy loss due to 18 or the like is small as compared with the other embodiments.

The circuit constants of the second embodiment shown in FIGS. 5 and 6, the third embodiment shown in FIGS. 7 and 8, and the fourth embodiment shown in FIGS. 9 and 10 are respectively shown. An example of the components used is shown below. Voltage of DC power supply 45... +/- 15 volts DC-DC converter circuit 1 Circuit of FIG. 31 of Japanese Patent Application No. 2-09579, or circuit of FIG. 10 of Japanese Patent Application Laid-Open No. 2-119575. . Output voltage is over +400 volts. Transistors 7, 10 ... 4 2SK1358 connected in parallel. If possible, connect 4 pieces of 2SK1489 in parallel. Drains, sources, and gates are directly connected. Toshiba Corporation 8, 49, 57 2SC2002 9, 50 2SA1413 NEC Corporation

Diodes 11, 12, 16, 18, 22, 23 ... 12JG11 or 12JH11 Toshiba Corporation 13, 20, 21, 58 ... V09G or V19G Hitachi, Ltd. 15, 17, 51, 52, 59: 1S1588 Toshiba Corporation 61: V19G Hitachi, Ltd. Zener diode 25, 26: 26 RD11F manufactured by NEC Corporation

Power Supply Capacitor 2 Five 2.2 μFarads are connected in parallel. Withstand voltage of 630 volts or more. Metallized film type. 3 ……………… 100 micro farads 4 ……………… 10 micro farads 47 ……………… 470 micro farads Capacitors 5, 53, 54 0.01 microfarad 6 0.33 microfarad Withstand voltage. Three 1 microfarads with 500 VDC withstand voltage are connected in series. Metallized film type. 64 .................. 0.001 microfarad

Resistance 27 20 ohms 28 ohms 250 ohms 29 ohms 30 ohms 30 ohms ………… 200 ohms to 1 kilo ohm 31 …………… 100 kilo ohms 32,34,56… 510 ohms 33,36,60 ……… 4.7 km ohm 38 ……………… 1 km ohm 55 ………………………………… 51 ohm 62 …………………… ………………………………………… ………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………… CM61-20 Hitachi, Ltd. Capacitor removed.) Toyo Denso Co., Ltd. Closed magnetic circuit type, ignition coil with as low magnetic resistance as possible He is good. that's all

[0370]

[Related technologies]

(1) Three-terminal switch using a MOS-FET or the like: a) JP-A-55-3259 b) JP-A-55-136727 (Japanese Patent Publication No. 2-3324)
C) JP-A-58-21920 d) JP-A-61-21
E) Japanese Patent Application No. 63-43334 (Spontaneous withdrawal) f) JP-A-2-153618 g) Japanese Patent Application No. 2-
230724

(2) Driving Circuit for Switching Means: a) US Pat. No. 4,125,814 b) JP-A-54-132727 c) JP-A-62-147953 d) JP-A-63-299768 e) Japanese Patent Application No. 2-230724

(3) Switching circuit having self-holding function and self-turn-off function: a) Japanese Utility Model Application Laid-Open No. 54-163859 b) Japanese Utility Model Application Laid-Open No. 55-44690 c) Japanese Patent Application Laid-Open No. Sho 57-118438 d) PCT / JP87 / 00612 (WO88 / 01805) (JP-A-62-504785) e) JP-A-2-2-1609 f) Japanese Patent Application No. 2-29662 g) Japanese Patent Application No. 2-233218

[Brief description of the drawings]

1 and 2 are circuit diagrams showing a first embodiment of the present invention.

FIGS. 3 and 4 are circuit diagrams showing a prior art resonant power conversion circuit (ignition circuit) for ignition of the inventor of the present invention.

FIGS. 5 and 6 are circuit diagrams showing a second embodiment of the present invention.

FIGS. 7 and 8 are circuit diagrams showing a third embodiment of the present invention.

9 and 10 are circuit diagrams showing a fourth embodiment of the present invention in both figures.

FIGS. 11 to 12 are circuit diagrams showing a fifth embodiment of the present invention.

13 and 14 are circuit diagrams showing a sixth embodiment of the present invention in both figures.

[Explanation of code]

 1 DC-DC converter circuit 2-3, 69 Power supply capacitor 42 Shield case 43, 48 Ignition coil 43a Primary coil 44 Ignition discharge gap t1-t7 Input terminal

Claims (1)

(57) [Claims] A first switching means having a normally-off function and a self-turn-off function, but not having a self-holding function, has a control terminal and both main terminals connected to a control terminal ct and a main terminal mta. When the control terminal ct and the main terminal mta form a pair for driving signal input, the reverse bias voltage direction between the main terminal mta and the control terminal ct and the "voltage drop due to the flowing current" , The voltage drop direction of the reverse bias voltage drop means ”and the main terminal mta ·
A portion between the control terminals ct is connected between both ends of the voltage drop means, and a portion between the main terminal mtb and the main terminal mta is provided such that the "second switching means having a self-turn-off function" is provided on the voltage drop means side. The voltage drop means and the second switching means are connected in series to form an arm pair, and a portion between both outer terminals of the arm pair is connected between both power terminals of a "DC power supply means for supplying a DC voltage". Then, the load and the inductance means are connected directly or equivalently in series to form a load inductance means, and the load inductance means comes to the main terminal mta side and via a portion between the main terminal mtb and the main terminal mta. The load inductance means and the capacitance means are connected in series between the two power supply terminals, and a first non-controllable switch is connected to the power supply voltage of the DC power supply means. The main terminal mtb · main terminals m and a quenching means in the opposite direction
The first non-controllable switching means is connected in parallel to the series circuit between the ta section and the load inductance means, and the second non-controllable switching means is turned in the opposite direction with respect to the power supply voltage to the capacitance means. A second non-controllable switching means is connected in parallel, and a first current detection for detecting whether the magnitude of the main current is larger than a predetermined value is provided in a current path through which the main current of the first switching means flows. Means for operating on the basis of the output signal of the first current detecting means, and when the first current detecting means detects that the magnitude of the main current is greater than the predetermined value, an on-drive power supply Means for driving the first switching means on, and turning off the first switching means when the first current detection means detects that the current is not large. Off driving means "and is provided, the first switching means,
The first current detecting means and the first on / off driving means constitute a "first self-holding type switching means having a self-holding function", wherein "the second switching means is driven in the off direction. Then, a first trigger means for guiding the charging current of the capacitance means as a trigger current to the detection unit of the first current detection means to trigger the first self-holding switching means "is provided, and the inductance means is provided. "A second current detecting means for detecting the direction of the current" is provided in a current path through which the current flows, and "operates based on an output signal of the second current detecting means, and A second on / off driving means for driving the second switching means on / off so as to assist the resonance operation. " A second self-holding switching means having a self-holding function, comprising: a first self-holding switching means having a self-holding function; A second trigger means for guiding the discharge current of the capacitance means as a trigger current to the detection unit of the second current detection means to trigger the second self-holding switching means " A resonance type power conversion circuit characterized by the above-mentioned.