JPS59159675A - Inverter circuit - Google Patents

Abstract

PURPOSE:To increase the output variable range by connecting a semiconductor switch in series with a resonance capacitor connected in parallel with the primary winding of an oscillation transformer and operating it ON and OFF reversely to the main semiconductor switch. CONSTITUTION:An inverter circuit is formed by connecting the primary winding 4 of an oscillation transformer 3 and a main transistor 2 in series with a DC power source 1, and a series circuit of a resonance capacitor 6 and a transistor 9 in parallel with the primary winding 4, a mian transistor 2 is controlled ON or OFF by a drive circuit, and a transistor 9 is operated ON or OFF reversely thereto. Accordingly, when the transistor 2 is turned ON, the charging current of the capacitor 6 is not flowed thereto, and when the transistor 2 is turned OFF, the output can be produced by the resonance of the primary winding 4 and the capacitor 6, the ON period is shortened to the resonance period, thereby varying the output in a wide range.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to an impark circuit, and aims to improve efficiency and widen the variable range of load power.

Figure 1 shows a conventional impark circuit, where (1) is a DC power supply, f2i is a semiconductor switch consisting of a transistor,
Dry 1 circuit t81 VC is turned off.

(31 is an oscillation transformer with a primary winding (4) and a secondary winding (5)
) has seven. +71 ij There is a negative load - In the above configuration, when the semiconductor switch (2) or the 1441 circuit (8) is turned on, the resonant capacitor (6) is charged in the direction shown by the DC power supply (1), and the oscillation transformer (3101 The voltage E of the DC power supply Ill is applied to the secondary winding (4), a voltage is generated in the secondary winding (5), and load power is supplied to the load (7). The current flowing in the primary winding C41 is determined by the self-inductance L of the primary winding (4) and the voltage E of the DC power supply +11, and the current that increases linearly in the secondary winding (5). The flowing current is converted into a primary value and becomes the sum of the currents. After the semiconductor switch (2) is on for a certain period of time, it is turned off by the dry 1 circuit (8), and the current in the semiconductor switch (2) becomes 0, but due to the inertia current accumulated in the primary winding (4). , the current in this primary winding (4) does not reach VcD immediately, but instead flows into the capacitor (31
The semiconductor switch [21] is turned on, and the capacitor (6) is charged in the opposite direction. Then, as the charging voltage of capacitor C6) increases, the current decreases, and when the voltage of this capacitor (6) reaches its maximum, it becomes 0, and then the accumulated charge li of 5 capacitors + 61 K
A discharge occurs through the primary winding, causing a current to flow through this primary winding in the opposite direction. I received one, the primary winding (41 and the capacitor [
6) resonates. At the same time, the voltage generated in the oscillation transformer [3+ causes the load (7) to
η Supply all power. Thereafter, the semiconductor switch (21) is turned on again, and the same operation as described above is repeated.

This operation will be explained in more detail from the outside with reference to the waveform diagram in FIG. However, in order to make the fxlJ work easier to understand, the negative force (7) will be explained as a connection [7]. In Figure 2, (I2) is the current flowing through the semiconductor switch (2), and (I2) is the current flowing through the semiconductor switch (2).
4) The current flowing in the primary winding (4), C16) is the current flowing in the capacitor (6), (■6) is the current flowing in the capacitor (6)
The charging voltage and (v2) respectively indicate the applied chamber pressure of the semiconductor switch [2I].

When the semiconductor switch (2) is turned on, the capacitor (6) is immediately charged to the voltage E of the DC power supply fi+, and at the same time, the current flowing through the primary winding (4) increases linearly, and at tLK, the semiconductor When the switch (2) is turned off, at this point the capacitor (6) has ',";CE".
(However, CU "-"j'>-9-161) capacity), 1
The energy of the next winding t4'rK j4LI 2 is accumulated, and the current I of the semiconductor switch 2) becomes 0 after t1.
However, the current in the primary winding (4) continues to flow, charging the capacitor (6) in the opposite direction. When the voltage of this capacitor (6) reaches the maximum, the current of the primary winding (4) becomes 0 at t2.
As a result, the energy stored in the primary winding (4) becomes 0, so if the loss in the primary winding (4) and capacitor (6) from t1 to t2 is set to 0, then the following equation can be obtained for C2. holds true.

'/2 CVc2=,'72 CE2+ '/2 Ll
"■ is the on-period 1jlTon of the semiconductor switch (2),
'ff1BEEK is proportional, so f = a TonE
(Ton=t+-to). Therefore, in C2, Vc E It +")'-'a"7Fon-)'--
------Kl. Thereafter, the charge in the capacitor (6) causes a current in the reverse direction to flow through the primary winding C41, causing txVcl
=" then, the voltage of the capacitor (6) becomes HE, the current of the primary winding (4) at this time becomes 1 VC, the listener conductor switch 121 of C3-14 turns on in the opposite direction, and DC A linear regenerative current flows to the power supply H1, and then the same operation occurs.Since the voltage of the secondary winding width 1 is proportional to the voltage of the primary winding C41 [capacitor f+61], the load power changes. It is necessary to change the current of the primary I☆ wire (41 [capacitor (6)]).When the semiconductor switch (2) is turned on, the voltage of the primary winding (4) is equal to that of the DC power supply (1).
However, the voltage when the semiconductor switch (2) is off is determined by the formula +i H'l' Therefore, the on-period Ton of the semiconductor switch (2) is changed +i: From the center and the center, the primary winding (
41 [capacitor (6)] can be changed.

However, as can be seen from the equation, even if the on-period T○n of the semiconductor switch ('l) is 1=D, the capacitor (
6) is charged and the voltage VC is charged to E, so the output voltage cannot be reduced to 0 even if the ON period is set to +O.

Period when semiconductor switch (2j is off) - E+VC is applied to this semiconductor switch (2) - The output voltage is widened to 1/
To vary over one range, the voltage at rated load Vc
If the voltage E is not made large, the secondary winding (5
) cannot be made sufficiently small for the full rated voltage. As a result, in order to obtain a wide variation range of the load power, the withstand voltage of the semiconductor switch (2) needs to be higher than the voltage E of 11. , when the semiconductor switch (2') is turned on, a charging current flows into the capacitor (6), but at this time, since there is nothing to limit the current, the peak value of the current becomes high, and the semiconductor switch (2') ) requires a large current that can flow,
Power loss in the semiconductor switch (2) increases and efficiency deteriorates. That is, the semiconductor switch (2) must have a high withstand voltage when off and a high withstand peak current when on, which is inconvenient.

In view of these conventional problems, the present invention achieves good efficiency by connecting in series to a resonant capacitor another semiconductor switch that operates on and off in the opposite direction to the semiconductor switch connected in series with the primary winding. The present invention provides an impark circuit that is capable of widening the variable range of load power.

Hereinafter, the illustrated embodiments will be sequentially described from the first invention to the fifth invention.

FIG. 6 shows the basic circuit of the first invention, and FIGS. 4 and 5 show waveforms at various parts thereof. Resonant capacitor telid forming a resonant circuit with the primary winding (4), primary winding 14
) is connected in parallel with the capacitor (6), and another semiconductor switch (91) is connected in series with the semiconductor switch (2). ) is designed so that it operates on and off in reverse.

In the case of stiffness J, the semiconductor switch f2i (91 turns on and off in reverse to each other, so when the semiconductor switch (2) is on, the semiconductor switch (9)
is turned off, the capacitor (6) is not charged by the DC power supply (1), and the voltage across the capacitor (6) is equal to O. Therefore, since the charging current of the capacitor (6) flows at a rate f′L in the semiconductor switch +21, only a current that increases linearly due to the self-increasing force of the primary winding (4) flows as shown in Fig. 4. It is. Semiconductor switch 4-
12) is turned off, the voltage Vc at tda is +CV
c2=+L l2 VC"" r I-r a"l"onCL. Period t+ during which the semiconductor switch (2) is off
' ~t mouth is resonating with the primary @ @ (411 capacitor (6), its resonance period (is determined by LC, and by shortening the on period 'ron with respect to the resonance period) The output voltage can be varied over a wide range.

For example, when the on-period Ton of the semiconductor switch +21 is set to % of the total, the waveform shown in FIG. 5 becomes f as shown in the waveform shown in FIG.

FIG. 6 shows the basic circuit of the second invention, and the waveforms of each part are shown in FIG. In this, the resonant capacitor (6) is connected in parallel with the semiconductor switch (2) and the capacitor (
61K, semiconductor switch (2) is turned on in the opposite direction.

Semiconductor switches (9) that are turned off are connected in series.

FIG. 7 shows waveforms when the semiconductor switch 12) is turned on when the capacitor (6) is charged to the voltage E. In this case, when the capacitor (6) is charged with the polarity shown in Figure 6, the semiconductor switch (2) is turned to
Even if it is turned on by I+, the semiconductor switch (9) is off during the on period Ton, so the capacitors (61, 61,
Current with a high peak value does not flow through the loops of the semiconductor switch (2) and the semiconductor switch (9).

Figure 8 is wood gX! The basic circuit of the J3 invention is shown, with the primary winding 14)<, a reverse diode (10
) and a resonant capacitor (6) are connected in parallel, and the diode (tlD) K semiconductor switch (9) is connected in parallel. In this case as well, the semiconductor switches +21 and i91 are configured to turn on and off in opposite directions. Therefore, even if the semiconductor switch (21) is on, the semiconductor switch (9) is off, and since the diode (10) is in the opposite direction to the power supply i11, the semiconductor switch (21) is connected to the semiconductor switch (21) through the capacitor (6). )
No current flows through. In this case, the semiconductor switch (9) has the advantage of being a unidirectional semiconductor switch that can turn on and off only one side.

Figure 9.9 illustrates the basic circuit of the fourth invention, in which the semiconductor switch (9) is turned on by the charging voltage of the capacitor (6) in an inverse relationship to the semiconductor switch (2).

Configured to turn off. That is, tI' in Figure 4
- [3°, since the capacitor (6) is charged with the polarity shown in Figure 9, the base current flows through the resistor (il) ra = to the transistor (+21) that constitutes the semiconductor switch (9). , this transistor (121dK is turned on. Then, when the transistor (12) is turned on by the storage gear 11a, the capacitor (6)
The polarity of is reversed and the voltage at point A becomes lower than that of the emitter, and a reverse base current flows through the diode θ, turning it off. In this case, the semiconductor switch (9)
The drive circuit becomes simple. Note that the semiconductor switch (2
)(9) and 1. In this case, transistors, FETs, GTOs, etc. can be used, and the load is not limited to resistive loads, but also inductances, rectifiers and smoothing capacitors used for DC power supplies, etc. can be used.

Figure 10 shows the basic circuit of the fifth invention, in which the voltage difference between the voltage of the capacitor (6) and the voltage of the DC power supply fi+ causes the transistor (14) constituting the semiconductor switch (9) to
) is what makes it work on and off, and the capacitor! The transistor (!4
I turns on. In other words, during this period t1゛°~t3゛,
The base current flows into the transistor (14j) through the resistor (I5), turning on the transistor (14). Only current flows through the transistor (+4!+d), and no current flows through the transistor (+4!+d), which turns it off.

The 11th hook utilizes the present invention in a lighting circuit for a fluorescent lamp.
ballast choke (+81 S7 through 7 fluorescent lights (ILR)
) are connected. In Figure 11, a DC power supply (1
1, the resistor (base current k flows through transistor 12+1 through 201, conotransistor I21) is turned on. Then, when the transistor 1) is turned on, the voltage generated in the feedback winding 1221 causes the transistor i2+! Turn on completely.

At this time, transistor +25i 1d remains off. When the collector current of the transistor (211) reaches a certain value or more, the transistor f2G turns on and the entire base current of the transistor 1211 is diverted to the transistor I211.
Boohoo. In other words, the collect current is converted into a current transformer! 27
After detecting with 1 and 7, and rectifying with the rectifier circuit cost, 1. ii';
? .

It is compared with the reference voltage from the voltage circuit 29) by a voltage comparator '30+, and based on the comparison output, a base current is passed through the transistor to turn it on. Then, the base current of the transistor (211) is shunted, and the transistor (211 is turned off.
) and the resistor, and is turned on by the base current supplied from the capacitor (61 and -transistor 1251 via the feedback winding 131) through the resistor +321.

Then, when the transistor (251) is turned on, the charge in the capacitor (6) is discharged via the transistor (251).

Note that at this time, the primary winding (4) and the capacitor (6) are in a resonant state. When the voltage across the capacitor 16) becomes 0, the transistor 125) turns off. At that time, the primary winding 14
At 1vC, a current flows in the opposite direction to that described above, and the transistor () turns on in the opposite direction, causing a reverse current to flow. and,
After this sending current finishes flowing, the transistor 311 is turned on in the positive direction, and the process is repeated thereafter.

As described in detail in the embodiments above, according to the first invention, the primary winding of a DC power source oscillation transformer and a semiconductor switch are connected in series, and the resonant capacitor constitutes a resonant circuit with the primary winding. In the impark circuit, the primary winding and the resonant capacitor are connected in parallel, and the resonant capacitor is connected in series with another semi-integrated switch that operates on and off in the opposite way to the previous two semiconductor switches. , there is no large current flowing through the curved semiconductor switch, and the efficiency is good.'-1
: The variable range of load power can be widened by controlling the on-period of the semiconductor switch.

Direct current again? In an impark circuit including an R source, a primary winding of an oscillation transformer, and a semiconductor switch connected in series, and a resonant capacitor forming a resonant circuit with the primary @ line, a resonant capacitor is connected in parallel to the semiconductor switch, According to the second invention, in which another semiconductor switch, which operates on and off in the opposite manner to the semiconductor switch, is connected in full series to this resonant capacitor, the first [! It has the same effect as No. 11.

Also f! ;5 According to 1, in the in-hark circuit, the DC power supply, the primary winding of the oscillation transformer, and the semi-integrated switch are all connected in series, and the primary spring ridge and a resonant capacitor forming a resonant circuit are provided. The next winding is connected in parallel with a series circuit of diodes and resonant capacitors in the opposite direction to the DC power supply.
Since this diode is connected in parallel with another semiconductor switch that operates on and off in the opposite direction to the semiconductor switch, in addition to increasing the efficiency and variable range described above, a unidirectional type semiconductor switch can be used as another semiconductor switch. It has the advantage of being able to use

Furthermore, according to the fourth invention, in an impark circuit in which a DC power source, a primary winding of an oscillation transformer, and a semiconductor switch are connected in series, and a resonant capacitor that constitutes a resonant circuit with the primary winding is provided, the primary A series circuit consisting of a diode and a resonant capacitor in the opposite direction to the DC power supply is connected in parallel to the winding, and another semiconductor switch is connected in parallel to the diode, which turns on and off in the opposite direction to the semiconductor switch based on the charging voltage of the resonant capacitor. Because they are connected, the configuration of a drive circuit for another semiconductor switch is simple.

Further, a DC power source, a primary winding of an oscillation transformer, and a semiconductor switch are connected in series, and an inverter circuit is provided with a resonant capacitor that constitutes a resonant circuit with the primary winding. A series circuit of a forward diode and a resonant capacitor is connected in parallel, and another semiconductor switch is connected in parallel to this diode, which turns on and off in the opposite direction to the semiconductor switch due to the voltage difference between the DC power supply and the charging voltage of the resonant capacitor. As soon as it is connected, the 5th invention also makes the 4th
The same effect as the invention can be obtained.

[Brief explanation of drawings]

Fig. 1 is a circuit diagram showing a conventional example, Fig. 2 is an alternative waveform diagram,
6 is a circuit diagram showing the basic circuit of the first invention, FIGS. 4 and 5 are waveform diagrams thereof, FIG. 6 is a circuit diagram showing the basic circuit of the second invention, and FIG. 7 is a waveform diagram thereof, 8 to 10 are circuit diagrams showing basic circuits of the sixth to fifth inventions, and FIG. 11 is a circuit diagram showing a specific example. 11)...DC power supply, (2)...semiconductor switch, (
3)...Oscillation transformer, (4)...Primary winding, (6
)...resonant capacitor, (91...another semiconductor switch.

Claims (1)

[Scope of Claims] 1. In an impark circuit in which a DC power source, a primary @ line of an oscillation transformer, and a semiconductor switch are connected in series, and a primary winding and a resonant capacitor forming a resonant circuit are provided, the primary winding 1. An impark circuit characterized in that a line and a resonant capacitor are connected in parallel, and another semiconductor switch that operates on and off in reverse to the semiconductor switch is connected in series with the resonant capacitor. 2. A direct current power source, a primary winding of an oscillation transformer, and a semiconductor switch are connected in series, and the primary winding is connected to the semiconductor switch in an impark circuit equipped with a resonant capacitor that constitutes a seven-resonance circuit. An impark circuit characterized in that a resonant capacitor is connected in parallel, and another semiconductor switch that operates on and off in the opposite direction to the semiconductor switch is connected in series with the resonant capacitor. & The DC power supply, the primary winding of the oscillation transformer, and the semiconductor switch are connected in series, and the primary winding is divided into an inverter circuit equipped with a resonant capacitor that forms a resonant circuit, and the primary winding is connected to the DC power supply. 1. An impark circuit characterized in that a series circuit (reverse direction gouoto and resonant capacitor) is connected in parallel, and this diode is connected in parallel with another semiconductor switch that operates on and off in the opposite direction to the semiconductor switch. 4 In an example of an inverter circuit in which a DC power supply, the primary winding of an oscillation transformer, and a semiconductor switch 7 are connected in series, and a resonant capacitor that constitutes a resonant circuit with the primary winding is provided, the primary winding is connected to the DC power supply. A series circuit consisting of a reverse diode and a resonant capacitor is all connected in parallel, and this diode is connected in parallel with another semiconductor switch that operates on and off in the opposite direction to the semiconductor switch according to the charging voltage of the resonant capacitor. impark circuit. 5. A four-band circuit "vc'j, -" which connects a DC power supply and a semiconductor switch on the primary winding of an oscillation transformer in series, and is equipped with a resonant capacitor that constitutes a resonant circuit with the primary winding, and the semiconductor switch A series circuit of a forward Gouio F and a resonant capacitor is connected in parallel to a DC power source, and the Gouiode is turned on and off in the opposite manner to the semiconductor switch due to the voltage difference between the DC power source and the charging voltage of the resonant capacitor. An inverter circuit in which 41& is another semiconductor switch connected in parallel.