JPS6356173A - Invertor device - Google Patents

Abstract

PURPOSE:To simplify the constitution of a circuit, miniaturize and reduce the cost of the title device, by a method wherein a regenerative current, conducted through a resonance circuit and a diode, is rectified and smoothed to make an auxiliary D.C. power source circuit while an electricity is supplied to a current detecting circuit and a drive circuit from the power source circuit. CONSTITUTION:An invertor device is constituted of a D.C. power source 1, a resonance circuit 13, consisting of an inductance element 7 such as a transistor or the like and a capacitor 6, a reverse parallel connecting body of a transistor (hereinafter referred to Tr) 9 and a diode 10, interposed between both of the power source 1 and the resonance circuit 13, an auxiliary D.C. power source circuit 3, a current detecting circuit 4, a drive circuit 5 for the Tr 9 and the like to supply an electricity to a load 8. This auxiliary D.C. power source circuit 3 conducts only a regenerative current conducted through the resonance circuit 13 and the diode 10 to rectify and smooth the current and supply it to the operating power source of the detecting circuit 4 and the drive circuit 5. The regenerative current, conducted into the power source circuit 3, is detected by the detecting circuit 4 and the output thereof is given to the drive circuit 5.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to an LC resonance type one-system inverter H.

[Background technology]

Conventionally, in order to reduce switching loss associated with higher frequencies in inverter devices that use transistors as switching elements, class D, class E, or Y$ using LC resonance has been developed.
E class inverter equipment is used. In such an inverter device, oscillation can be controlled by detecting conduction of a diode connected in anti-parallel to a unidirectional switching element such as a transistor that can control turn-off, or by detecting conduction of a transistor that is a unidirectional switching element. There is a method of controlling the conduction timing of a transistor by detecting the voltage zero crossing of the collector-emitter voltage.

FIG. 14 shows a circuit diagram of an example of a conventional inverter device of this type. This inverter device includes a DC power source 10
1. Power switch 102. A DC power supply circuit consisting of a smoothing capacitor 103 and the like, and an oscillation transformer 108. Resonant capacitor 110.1 - Unidirectional switching element 112. such as a transistor. An inverter main circuit consisting of a diode 111, a load 109 connected to the secondary winding of the oscillation transformer 108, and a detection coil 116 that detects the current flowing through the diode 112. Resistance 117. Amplifier 118° Differential capacitor 119. A current detection circuit 131 consisting of a diode 120 and the like, gate elements 121, 124, and a capacitor 122. Variable resistance 123. A monostable multivibrator 132 consisting of a resistor 129 and the like and triggered by a signal from a current detection circuit 131, transistors 1, 27, 128, resistors 125, 126, and resistor 114 that are turned on and off alternately by the output of this monostable multipipe rake 132. .115. A drive circuit 134 consisting of a capacitor 113, etc., and a resistor 104. Capacitor 106, two-terminal switch element 107. It is composed of a starting circuit 133 consisting of a diode 105 and the like.

Next, the operation of this inverter device will be explained with reference to FIG. 15. When the power switch 102 is turned on, the resistor 104
When the potential of the capacitor 106 reaches the breakover voltage of the two-terminal switch element 107, the charge of the capacitor 106 passes through the two-terminal switch element 107 to the trigger terminal of the monostable multi-bi break 132, that is, the gate. It is input to one input terminal of element 121. This trigger signal causes the capacitor 122 . An output with a pulse width determined by the time constant of the variable resistor 123 is generated, which makes the transistor 127 conductive via the resistor 125, and the resistor 114. The unidirectional switching element 112 is made conductive for a certain period of time via the capacitor 113. Therefore, a collector current I flows from the DC power supply 101 to the unidirectional switching element 112 through the primary winding of the oscillation transformer 108 . (FIG. 15(B)) flows, magnetic energy is accumulated in the primary winding of the oscillation transformer 108, and power is supplied from the secondary winding of the oscillation transformer 108 to the load 109.

When the output of the monostable multivibrator 132 disappears,
At the same time as transistor 127 turns off, transistor 1
28 is turned on, the charge in the capacitor 113 is discharged, and the unidirectional switching element 112 is reverse biased, so the unidirectional switching element 112 is suddenly turned off, and from this point on, the oscillation transformer 108 and the capacitor 11
0 resonance begins, and the collector-emitter voltage VOY of the transistor, which is the unidirectional switching element 112, changes sinusoidally as shown in FIG. 15(A). When sufficient resonance occurs, the collector-emitter voltage VCE
returns to zero volts again, and from this point on the resonant energy is transferred to smoothing capacitor 103. A regenerative current ID is caused to flow through the diode 111 as shown in FIG. 15 CB). This regenerative current■. is detected by the detection coil 116 and amplified by the amplifier 118 as shown in FIG. 15(C).
9 to the trigger input terminal of the monostable multipipe rake 1320 as shown in FIG. 15(D).

Thereafter, by repeating the above-described operations, the unidirectional switching element 112 is turned on and off to continue the oscillation operation and supply power to the load 109.

15(E) shows the output signal of the monostable multivibrator 132, and FIG. 15(F) shows the base current 8 of the transistor which is the unidirectional switching element 112.

Such conventional examples are widely known as synchronous single-stone resonant inverters or E-class switching inverters, and have features such as high efficiency and easy output control, and are suitable for driving various loads. is used as.

However, in such a conventional inverter device, due to the circuit configuration, in addition to the DC type a1, the drive circuit 134, which includes a current detection circuit 131, a monostable multi-vibration break 132, etc., has a voltage ■. A separate auxiliary DC power supply circuit for adding 0 is required, and there are problems in that the configuration is complicated, large-sized, and expensive. Furthermore, in order to obtain a synchronizing signal for turning on and off the unidirectional switching element 112, a complicated current detection circuit 131 including a detection coil 116 is required, which also increases the size and cost. There's a problem.

[Purpose of the invention]

An object of the present invention is to provide an inverter device that can be simplified in configuration, reduced in size, and reduced in cost.

[Disclosure of the invention]

The inverter device of the present invention includes a DC power source, a resonant circuit including an inductance element and a capacitor, a unidirectional switching element inserted between the DC power source and the resonant circuit, and an inverter connected to the unidirectional switching element. diodes connected in parallel, an auxiliary DC power supply circuit that is connected in parallel with the DC power supply and that rectifies and smoothes only the regenerative current flowing through the resonant circuit and the diode to generate a DC voltage; a current detection circuit that operates to detect the regenerative current flowing into the auxiliary DC power supply circuit; and a current detection circuit that is operated by being supplied with power from the auxiliary DC power supply circuit and operates the unidirectional switching element in synchronization with the output of the current detection circuit. It includes a drive circuit that conducts for a certain period of time, and a load that is supplied with power from the resonant circuit.

According to the configuration of the present invention, an auxiliary DC power supply circuit is created by rectifying and smoothing the regenerative current flowing through the resonant circuit and the diode, and power is supplied from this auxiliary DC power supply circuit to the current detection circuit and the drive circuit. Power supplies for driving the detection circuit and drive circuit can be easily obtained. In addition, since the configuration uses a current detection circuit to detect the regenerative current flowing into the auxiliary DC power supply circuit, the synchronization signal for drive circuit operation can be obtained with a simple configuration without the need for a detection coil as in conventional examples. .

Therefore, the circuit configuration can be simplified and downsized.

Cost reduction can be achieved.

Embodiment An embodiment of the present invention will be explained based on FIGS. 1 to 13. This inverter device, as shown in Figure 1,
A resonant circuit 13 consisting of a DC power supply 1, an inductance element 7 such as a transformer, and a capacitor 6, a unidirectional switching element 9 such as a transistor inserted between the DC power supply 1 and the resonant circuit 13, and this unidirectional A diode 10 connected in antiparallel to the switching element 9, and an auxiliary DC power supply circuit 3 connected in parallel with the DC power supply 1 and rectifying and smoothing only the regenerative current flowing through the resonance circuit 13 and the diode 10 to generate a DC voltage. a current detection circuit 4 that is powered by the auxiliary DC power supply circuit 3 and operates to detect the regenerative current flowing into the auxiliary DC power supply circuit 3; and a current detection circuit 4 that is powered by the auxiliary DC power supply circuit 3 and operates to detect the current. It includes a drive circuit 5 that makes the unidirectional switching element 9 conductive for a certain period of time in synchronization with the output of the circuit 4, and a load 8 that is supplied with power from a resonance circuit 13.

Note that 2 is an impedance element that prevents or limits the regenerative current from flowing into the DC power supply l.

The difference between this inverter device and the conventional example is that the regenerative current is rectified and smoothed by the auxiliary DC power supply circuit 3, and the operating power is supplied from the auxiliary DC power supply circuit 3 to the current detection circuit 4 and the drive circuit 5. The regenerative current flowing into the power supply circuit 3 is detected by the current detection circuit 4, and this output is given to the drive circuit 5.The other points are almost the same as the conventional example, and the oscillation starts. 1! The subsequent operations are almost the same as in the conventional example.

Examples will be described in detail below. As described above, this inverter device includes a DC power source 1. Resonant circuit 13. Unidirectional switching element9. Diode 10. Auxiliary DC power supply circuit 3. The current detection circuit is composed of a 5° impedance element 2 and the like.

As shown in FIG. 3, the DC power supply 1 has an AC power supply 21,
It is composed of a diode bridge 22 that rectifies this AC power supply 21 and a smoothing capacitor 23 that smoothes its output, but some models do not have the smoothing capacitor 23.

As the impedance element 2 that prevents or limits the flow of regenerative current into the DC power source 1, a diode 31. Inductor 32. resistance 33
．． A parallel circuit of a capacitor 34 and a diode 35 is conceivable, both of which have the effect of preferentially allowing the regenerative current to flow toward the auxiliary DC power supply circuit 3. Note that this impedance element 2 is connected to the smoothing capacitor 2 in the DC power supply 1 described above.
It is not necessary if there is no 3.

The auxiliary DC power supply circuit 3 is connected in parallel to the DC power supply 1 via an impedance element 2, and as shown in FIG. capacitor 44
Charging is not performed by the DC power supply 1, but only by regenerative current, and the current detection circuit 4 and the drive circuit 5 are operated by the charging voltage of the capacitor 44. As shown in FIG. 5, the bypass filter 45 includes a capacitor 41. Diode 42.
A capacitor 44 is charged through a capacitor 41 and a diode 42 which have low impedance to high frequencies. The diode 43 is the capacitor 44
The electric charge is transferred to the resonant circuit 13. A discharge is caused through the unidirectional switching element 2.

6 shows a configuration in which a starting circuit 11 is added to the one shown in FIG. 5, and the starting circuit 11 includes a resistor 71. Capacitor 72. It is composed of a diode 73. This starting circuit 11 connects the capacitor 72 through the diode 73 at the same time as the power is turned on.
A charging current flows and charges the smoothing capacitor 44. As a result, the current detection circuit 4. Starting power is supplied to the drive circuit 5, and the current detection circuit 4. The unidirectional switching element 9 is turned on via the drive circuit 5, and the oscillation operation is started. After startup, the capacitor 44 is charged by the above-mentioned regenerative current, and the auxiliary power supply circuit 3° current detection circuit 4. Oscillation continues with the drive circuit 5.

The current detection circuit 4 detects the charging current flowing through the capacitor 44 and generates a pulse, and as shown in FIG. ) Langimeta 52. resistance 53
,55.57. It is composed of a capacitor 54. Then, when the capacitor 44 is charged, the transistor 52 is turned on, and the coupling capacitor 54 is turned on.
Due to this action, the potential at the terminal f momentarily drops, and this is input to the drive circuit 5 as a trigger signal.

FIG. 8 shows a circuit diagram of another current detection circuit 4', in which the resistor 55 is removed from the circuit diagram of FIG.

In this circuit, when capacitor 44 is charged, transistor 52 conducts and the charge on capacitor 54 is transferred to transistor 52. When the voltage is discharged through the diode 56 and the transistor 52 is cut off, a positive pulse voltage for triggering is generated by the capacitor 54 from the terminal f.

As shown in FIG. 9, the drive circuit 5' includes gate elements 71, 72 . Capacitor 73. A monostable multivibrator circuit 82 consisting of a resistor 74 and a transistor 77
．． 78. Resistor 75, 76° Capacitor 80. Resistance 79.
81, in response to the output of the current detection circuit 4, the unidirectional switching element 9 is turned on for a certain period of time, and then turned off.

FIG. 10 shows a circuit diagram of another drive circuit 5. In FIG.

This drive circuit includes a resistor 61. A monostable multi-by-break 68 consisting of a timer integrated circuit (for example, NE555 manufactured by Signetain Inc.) 63 and capacitors 62 and 64.
, a capacitor 66, and resistors 65 and 67, and operates in the same way as the one shown in FIG.

FIG. 11 shows a specific configuration of an inverter device constructed by combining the above-mentioned circuits. Since the operation has been described previously, the explanation will be omitted.

FIG. 12 is a waveform diagram of each part in FIG. 11, where (A> is the trigger signal given from the current detection circuit 4 to the monostable multi-bi break 68, (B) is the output of the monostable multi-bi break 68, and ( C) is a unidirectional switching element 9
(D) is the collector current 1c and regenerative current iD of the transistor, and (E) is the collector voltage V. (F) shows the regenerative current iD flowing through the capacitor 44 and the output voltage of the auxiliary DC power supply circuit 2, that is, the voltage of the capacitor 44, respectively.

FIG. 13 shows a circuit diagram of another specific example of the inverter device. This inverter device has an inductance element 7
' is a single-turn transformer, load 8' is a discharge lamp such as a fluorescent lamp, current detection circuit 4# is used, and resistors 74, 75 . This circuit uses a starting circuit 11' consisting of a two-terminal switch element 76 and a diode 77, and is otherwise the same as the circuit shown in FIG. Note that 12 is a capacitor for starting the lamp.

The operation of this inverter device is the same as that of FIG. 11 except that the discharge lamp, which is the load 8', is started and lit by the oscillation output, so detailed explanation will be omitted.

Note that in the above embodiment, the inductance element 7.
Although an insulated transformer or a single-turn transformer is used as 7', a choke coil may also be used.Also, the positions of capacitors 6 and 6' are not limited to the illustrated positions, and can be placed between inductance elements 7 and 7'. It can be placed anywhere as long as it forms a resonant circuit.

Further, the load 8,8' is not limited to a discharge lamp or the like, and the present invention is also effective in a circuit that rectifies the output of the resonant circuit 13 and 13' and then supplies power to the load.

〔Effect of the invention〕

According to the inverter device of the present invention, an auxiliary DC power supply circuit is created by rectifying and smoothing the regenerative current flowing through the resonant circuit and the diode, and power is supplied from the auxiliary DC power supply circuit to the current detection circuit and the drive circuit. Power supplies for driving the current detection circuit and drive circuit can be easily obtained. In addition, since the configuration uses a current detection circuit to detect the regenerative current flowing into the auxiliary DC power supply circuit, the synchronization signal for drive circuit operation can be obtained with a simple configuration without the need for a detection coil as in conventional examples. .

Therefore, the circuit configuration can be simplified and downsized.

Cost reduction can be achieved.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIGS. 2 to 10 are specific circuit diagrams of each block in FIG. 1,
Fig. 11 is a circuit diagram of an example of an inverter device, Fig. 12 is a waveform diagram of each part thereof, Fig. 13 is a circuit diagram of another example of an inverter device, Fig. 14 is a circuit diagram of a conventional example, and Fig. 15 is a circuit diagram of an example of an inverter device. It is a waveform diagram of each part. 1... DC power supply, 3... Auxiliary DC power supply circuit, 4...
・Current detection circuit, 5... Drive circuit, 6... Capacitor, 7... Inductance element, 8... Load,
9... Unidirectional switching element, 10... Diode, 13... Resonant circuit 1.-1 current power source 3-11. - Whisper 9-1 - On the other hand, 11λ I...I> 7 elements 10-9 Iode 13 - Vibration circuit Fig. 1 Fig. 2 Z3 Blade No. 47 Fig. 5 Fig. 6 Fig. 12

Claims (1)

[Claims] a DC power supply, a resonant circuit comprising an inductance element and a capacitor, a unidirectional switching element interposed between the DC power supply and the resonant circuit, a diode connected in antiparallel to the unidirectional switching element, and the DC power supply; an auxiliary DC power supply circuit that is connected in parallel with the power supply and that rectifies and smoothes only the regenerative current that flows through the resonant circuit and the diode to generate a DC voltage; and the auxiliary DC power supply circuit that operates by being supplied with power from the auxiliary DC power supply circuit. a current detection circuit that detects the regenerative current flowing into the auxiliary DC power supply circuit; a drive circuit that is operated by being supplied with power from the auxiliary DC power supply circuit and makes the unidirectional switching element conductive for a certain period of time in synchronization with the output of the current detection circuit; and a load supplied with power from the resonant circuit.