Inverter circuit and signal modulation circuit

Abstract

The utility model belongs to the technical field of inverter circuits, and particularly relates to an inverter circuit and a signal modulation circuit, the signal modulation circuit comprises an operational amplifier, an in-phase voltage distribution module and an amplitude limiting protection circuit module, the in-phase voltage distribution module modulates the amplitude of an alternating current reference signal of a radio frequency power supply and raises the amplitude to a zero level or above, and the amplitude limiting protection circuit module is connected with the operational amplifier. And the operational amplifier modulates the input signal into a control signal with alternately output high and low potentials, so that the high-frequency sine alternating current reference signal is converted into a square wave control signal to provide an effective driving signal for driving the bridge type inverter circuit. Meanwhile, the amplitude limiting protection circuit module is arranged to limit the voltage within a safe range, so that the stability of the inverter circuit is further improved.

Description

TECHNICAL FIELD

[0001] The utility model belongs to inverter circuit technical field, specifically designs a kind of inverter circuit and signal modulation circuit. BACKGROUND

[0002] Bridge inverter circuit is a common inverter circuit, for converting direct current into alternating current. Bridge inverter is generally divided into half-bridge inverter and full-bridge inverter, wherein half-bridge inverter includes two switching elements, and full-bridge inverter includes four switching elements, and the alternate conduction of switching element makes the output voltage switch between direct current power voltage and its negative voltage.

[0003] The controller provides a high-frequency sinusoidal signal as an AC reference signal, in order to effectively drive control the switching element, it is necessary to modulate the modulation signal into a high-low switching square wave control signal, so as to complete the switching element drive of bridge inverter circuit, and output the AC signal that meets the expected AC reference signal control. UTILITY MODEL CONTENTS

[0004] The technical problem to be solved by the utility model is to solve the problem that the existing technology needs to convert high-frequency sinusoidal AC reference signal into square wave control signal to drive bridge inverter circuit, so as to provide an inverter circuit and signal modulation circuit.

[0005] A signal modulation circuit is applied to a radio frequency power supply, and the signal modulation circuit comprises an operational amplifier, a same-phase voltage matching module and an amplitude limiting protection circuit module.

[0006] The same-phase voltage matching module is arranged between a second direct current source and ground, the same-phase voltage matching module modulates the amplitude of the AC reference signal of the radio frequency power supply, and pulls up the amplitude to zero level or above through the second direct current source, to form an input signal.

[0007] The same-phase input end of the operational amplifier obtains the input signal, the opposite-phase input end inputs a limiting signal, and the control signal of high-low electric level alternation is output according to the comparison result.

[0008] The amplitude limiting protection circuit module is arranged between a first direct current source for driving the operational amplifier and ground, and the same-phase input end of the operational amplifier is connected to the potential clamping node of the amplitude limiting protection circuit module.

[0009] Further, the same-phase voltage matching module comprises two resistors connected in series, the two resistors are coupled between the second direct current source and ground, and the series node between the two resistors is electrically connected to the same-phase input end of the operational amplifier.

[0010] Further, one or more direct-current capacitors are arranged between the same-phase input end of the operational amplifier and the line node of the AC reference signal.

[0011] Further, the limiting protection circuit module comprises a first diode and a second diode connected in series in the same conduction direction, the cathode of the first diode is connected to the first DC source, the anode of the second diode is connected to the ground, and the potential clamping node between the first diode and the second diode is connected to the non-inverting input terminal of the operational amplifier.

[0012] Further, the limiting protection circuit module comprises a first diode and a second diode connected in series in the same conduction direction, the cathode of the first diode is connected to the first DC source, the anode of the second diode is connected to the ground, and the potential clamping node between the first diode and the second diode is connected to the non-inverting input terminal of the operational amplifier.

[0013] Further, the limiting protection circuit module comprises a first diode and a second diode connected in series in the same conduction direction, the cathode of the first diode is connected to the first DC source, the anode of the second diode is connected to the ground, and the potential clamping node between the first diode and the second diode is connected to the non-inverting input terminal of the operational amplifier.

[0014] Further, the limiting protection circuit module comprises a first diode and a second diode connected in series in the same conduction direction, the cathode of the first diode is connected to the first DC source, the anode of the second diode is connected to the ground, and the potential clamping node between the first diode and the second diode is connected to the non-inverting input terminal of the operational amplifier.

[0015] Further, the limiting protection circuit module comprises a first diode and a second diode connected in series in the same conduction direction, the cathode of the first diode is connected to the first DC source, the anode of the second diode is connected to the ground, and the potential clamping node between the first diode and the second diode is connected to the non-inverting input terminal of the operational amplifier.

[0016] Further, the limiting protection circuit module comprises a first diode and a second diode connected in series in the same conduction direction, the cathode of the first diode is connected to the first DC source, the anode of the second diode is connected to the ground, and the potential clamping node between the first diode and the second diode is connected to the non-inverting input terminal of the operational amplifier.

[0017] Further, the limiting protection circuit module comprises a first diode and a second diode connected in series in the same conduction direction, the cathode of the first diode is connected to the first DC source, the anode of the second diode is connected to the ground, and the potential clamping node between the first diode and the second diode is connected to the non-inverting input terminal of the operational amplifier.

[0018] Further, the limiting protection circuit module comprises a first diode and a second diode connected in series in the same conduction direction, the cathode of the first diode is connected to the first DC source, the anode of the second diode is connected to the ground, and the potential clamping node between the first diode and the second diode is connected to the non-inverting input terminal of the operational amplifier.

[0019] Further, the limiting protection circuit module comprises a first diode and a second diode connected in series in the same conduction direction, the cathode of the first diode is connected to the first DC source, the anode of the second diode is connected to the ground, and the potential clamping node between the first diode and the second diode is connected to the non-inverting input terminal of the operational amplifier.

[0020] Further, the limiting protection circuit module comprises a first diode and a second diode connected in series in the same conduction direction, the cathode of the first diode is connected to the first DC source, the anode of the second diode is connected to the ground, and the potential clamping node between the first diode and the second diode is connected to the non-inverting input terminal of the operational amplifier.

[0021] Further, the limiting protection circuit module comprises a first diode and a second diode connected in series in the same conduction direction, the cathode of the first diode is connected to the first DC source, the anode of the second diode is connected to the ground, and the potential clamping node between the first diode and the second diode is connected to the non-inverting input terminal of the operational amplifier.

[0022] Further, the limiting protection circuit module comprises a first diode and a second diode connected in series in the same conduction direction, the cathode of the first diode is connected to the first DC source, the anode of the second diode is connected to the ground, and the potential clamping node between the first diode and the second diode is connected to the non-inverting input terminal of the operational amplifier.

[0023] The drain electrode of the first switch tube is connected with a direct current source; the source electrode of the first switch tube is connected with the drain electrode of the second switch tube to form an output terminal of the half-bridge switching circuit; and the source electrode of the second switch tube is connected with the ground.

[0024] The output terminal of the signal modulation circuit is electrically connected with the gate electrodes of the first switch tube and the second switch tube, and a NAND gate or an inverter is arranged between the gate electrode of the first switch tube or the second switch tube and the output terminal of the signal modulation circuit.

[0025] An inverter circuit comprises a half-bridge switching circuit, a delay control module and a signal modulation circuit as described above.

[0026] The half-bridge switching circuit comprises a first switch tube and a second switch tube.

[0027] The drain electrode of the first switch tube is connected with a direct current source; the source electrode of the first switch tube is connected with the drain electrode of the second switch tube to form an output terminal of the half-bridge switching circuit; and the source electrode of the second switch tube is connected with the ground.

[0028] The input terminal of the delay control module is connected with the signal modulation circuit, the gate electrodes of the first switch tube and the second switch tube are electrically connected with two output terminals of the delay control module, and the control signals output by the two output terminals of the delay control module are in opposite phase or staggered phase.

[0029] Beneficial effects: The inverter circuit and the signal modulation circuit provided by the utility model, the signal modulation circuit comprises an operational amplifier, a same-phase voltage matching module and a limiting amplitude protection circuit module, the same-phase voltage matching module modulates the amplitude of an alternating reference signal of a radio frequency power supply, and pulls up the amplitude to a zero level or above, to form an input signal, the operational amplifier modulates the input signal into a control signal with high and low potentials outputting alternately, so as to convert a high-frequency sinusoidal alternating reference signal into a square wave control signal, to provide an effective driving signal for the driving of the bridge type inverter circuit. Meanwhile, the utility model limits the voltage within a safe range through the setting of the limiting amplitude protection circuit module, and further improves the stability of the inverter circuit. BRIEF DESCRIPTION OF DRAWINGS

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative effort.

[0031] Figure 1 It is a schematic block diagram of the overall structure of the utility model;

[0032] Figure 2The signal modulation circuit principle diagram of the utility model;

[0033] Figure 3 The utility model relates to a kind of half-bridge switching circuit principle diagram;

[0034] Figure 4 The utility model relates to another kind of half-bridge switching circuit principle diagram;

[0035] Figure 5 The utility model relates to another kind of half-bridge switching circuit principle diagram;

[0036] Figure 6 The utility model relates to another kind of half-bridge switching circuit principle diagram.

[0037] Mark explanation:

[0038] ①, in-phase voltage matching module;②, opposite-phase voltage matching module;③, limiting amplitude protection circuit module;IV, half-bridge switching circuit;

[0039] R, drive resistance piece;R1, first resistance;R2, second resistance;R3, third resistance;R4, fourth resistance;R5, fifth resistance;R6, sixth resistance;R7, seventh resistance;C, direct current separation capacitor;C1, first capacitor;C2, second capacitor;C3, third capacitor;D1, first diode;D2, second diode;U1, operational amplifier;U2, gate buffer;U3, inverter;U4, non gate;VCC1, first direct current source;VCC2, second direct current source;VCC3, third direct current source;VCC4, fourth direct current source;VCC5, fifth direct current source;VCC6, sixth direct current source;Q1, first switch tube;Q2, second switch tube. Specific embodiments

[0040] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific embodiments of the present application will be described in detail below. In the following description, a lot of specific details are set forth in order to fully understand the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the spirit of the present application, therefore the present application is not limited by the specific embodiments disclosed below.

[0041] In the description of the present application, it should be understood that the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Therefore, the features limited by "first", "second" can be explicitly or implicitly included at least one feature. In the description of the present application, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise specifically limited.

[0042] In this application, unless otherwise expressly specified and limited, the terms "mounting", "connecting", "connecting", "fixing" and other terms should be understood broadly, for example, it can be fixed connection, or detachable connection, or integrated; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through intermediate medium, it can be the internal communication of two elements or the interaction relationship of two elements, unless otherwise expressly limited. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0043] Embodiment one:

[0044] Referring to Figure 1 and Figure 2 The embodiment provides a signal modulation circuit applied to a radio frequency power supply. The signal modulation circuit comprises an operational amplifier U1, a same-phase voltage matching module ① and an amplitude limiting protection circuit module ③. The same-phase voltage matching module ① is arranged between a second direct current source VCC2 and the ground. The same-phase voltage matching module ① modulates the amplitude of an alternating current reference signal of the radio frequency power supply and pulls up the amplitude to a zero level or above by the second direct current source VCC2, so as to form an input signal.

[0045] The same-phase input end of the operational amplifier U1 obtains the input signal, the opposite-phase input end inputs a limiting signal, and the control signal with high and low potentials alternately is output according to the comparison result. The amplitude limiting protection circuit module ③ is arranged between a first direct current source VCC1 and the ground for driving the operational amplifier U1. The potential clamping node of the amplitude limiting protection circuit module ③ is connected to the same-phase input end of the operational amplifier U1.

[0046] In the embodiment, the amplitude of the alternating current reference signal of the radio frequency power supply is modulated by the same-phase voltage matching module ①, and the amplitude is pulled up to the zero level or above, so as to form the input signal. The input signal is modulated into the control signal with high and low potentials alternately by the operational amplifier U1, so that the high-frequency sine alternating current reference signal is converted into the square wave control signal, and an effective driving signal is provided for the driving of the bridge inverter circuit. Meanwhile, the voltage is limited in the safe range by the arrangement of the amplitude limiting protection circuit module ③, and the voltage is limited in 0~VCC1 in the embodiment, so that the stability of the inverter circuit is further improved.

[0047] Specifically, the same-phase voltage matching module ① comprises two resistors connected in series, the two resistors are coupled between the second direct current source VCC2 and the ground, and the series node between the two resistors is electrically connected to the same-phase input end of the operational amplifier U1. In the embodiment, the two resistors are a first resistor R1 and a second resistor R2, the first resistor R1 is connected to the second direct current source VCC2, and the second resistor R2 is grounded. As a further improvement of the embodiment, a third resistor R3 is further included, one end of the third resistor R3 is connected to the alternating current reference signal, and the other end is grounded.

[0048] As a further improvement of the embodiment, one or more DC blocking capacitors C are arranged between the non-inverting input of the operational amplifier U1 and the line node of the AC reference signal. In the embodiment, the DC blocking capacitors C comprise a first capacitor C1 connected between the AC reference signal and the third resistor R3 and a second capacitor C2 connected between the second resistor R2 and the third resistor R3.

[0049] In the embodiment, the positive supply of the operational amplifier U1 is connected to the first DC source VCC1 and grounded via a third capacitor C3, and the negative supply of the operational amplifier U1 is grounded.

[0050] Specifically, the amplitude limiting protection circuit module ③ comprises a first diode D1 and a second diode D2 connected in series in the same conduction direction, the cathode of the first diode D1 is connected to the first DC source VCC1, the anode of the second diode D2 is grounded, and the potential clamping node between the first diode D1 and the second diode D2 is connected to the non-inverting input of the operational amplifier U1.

[0051] The inverting voltage dividing module ② further comprises two resistors connected in series and coupled between the third DC source VCC3 and the ground, and the series node between the two resistors is electrically coupled to the inverting input of the operational amplifier U1. In the embodiment, the two resistors are a fourth resistor R4 and a fifth resistor R5, one end of the fourth resistor R4 is connected to the third DC source VCC3, the other end is connected to the inverting input of the operational amplifier U1, one end of the fifth resistor R5 is connected to the inverting input of the operational amplifier U1, and the other end is grounded.

[0052] The driving resistor R further comprises a first end connected to the fourth DC source VCC4, and the output of the operational amplifier U1 is connected to a second end of the driving resistor R and electrically coupled to the gate of one or more switching tubes of the bridge-type switching circuit. In the embodiment, the driving resistor R is a sixth resistor R6.

[0053] Specifically, the gate buffer U2 is further arranged between the switching tube and the output of the operational amplifier U1. The gate buffer U2 is a combination of one or more of inverters, AND gates, or OR gates. In the embodiment, the gate buffer U2 is an AND gate, and the two input ends of the AND gate are connected to the output of the operational amplifier U1. In the embodiment, an output resistor is further connected between the input end of the gate buffer U2 and the output of the operational amplifier U1, and is denoted as a seventh resistor R7.

[0054] In this embodiment, the first DC source VCC1, the second DC source VCC2, the third DC source VCC3, and the fourth DC source VCC4 are the same, partially the same, or different DC sources. In some implementations of this embodiment, the first DC source VCC1, the second DC source VCC2, the third DC source VCC3, and the fourth DC source VCC4 are the same 5V power supply.

[0055] Example 2:

[0056] Reference Figure 3 As shown, this embodiment provides an inverter circuit, including a half-bridge switching circuit ④ and two signal modulation circuits. The architecture of the two signal modulation circuits is the same as that of the signal modulation circuit in Embodiment 1. The half-bridge switching circuit ④ includes a first switching transistor Q1 and a second switching transistor Q2. The drain of the first switching transistor Q1 is connected to the fifth DC source VCC5. The source of the first switching transistor Q1 and the drain of the second switching transistor Q2 are connected to form the output terminal of the half-bridge switching circuit ④. The source of the second switching transistor Q2 is grounded. The output terminals of the two signal modulation circuits are electrically connected to the gates of the first switching transistor Q1 and the second switching transistor Q2, respectively, and the phases of the control signals output by the two signal modulation circuits are out of phase or interleaved.

[0057] Example 3:

[0058] Reference Figure 4 and Figure 5 As shown, this embodiment provides an inverter circuit, characterized in that it includes a half-bridge switching circuit ④ and a signal modulation circuit as described in Embodiment 1; the half-bridge switching circuit ④ includes Q1 and a second switching transistor Q2; the drain of the first switching transistor Q1 is connected to a sixth DC source VCC6; the source of the first switching transistor Q1 and the drain of the second switching transistor Q2 are connected to form the output terminal of the half-bridge switching circuit ④; the source of the second switching transistor Q2 is grounded; the output terminal of the signal modulation circuit is electrically connected to the gates of the first switching transistor Q1 and the second switching transistor Q2, and an inverting device is disposed between the gate of the first switching transistor Q1 or the second switching transistor Q2 and the output terminal of the signal modulation circuit.

[0059] In this embodiment, the inverting device can be a NOT gate U4 or an inverter U3. Preferably, the inverting device is an inverter U3, which is disposed between the gate of the first switch Q1 and the output terminal of the signal modulation circuit.

[0060] Example 4

[0061] Reference Figure 6As shown, the embodiment provides an inverter circuit, which comprises a half-bridge switching circuit 4, a delay control module and a signal modulation circuit as in the first embodiment; the half-bridge switching circuit 4 comprises a first switch tube Q1 and a second switch tube Q2; the drain electrode of the first switch tube Q1 is connected with a fifth direct current source VCC5; the source electrode of the first switch tube Q1 and the drain electrode of the second switch tube Q2 are connected to form an output end of the half-bridge switching circuit 4; the source electrode of the second switch tube Q2 is grounded; the input end of the delay control module is connected with the signal modulation circuit, the two output ends of the delay control module are electrically connected with the gate electrodes of the first switch tube Q1 and the second switch tube Q2 respectively, and the control signals outputted by the two output ends of the delay control module are in opposite phase or staggered.

[0062] The technical features of the above embodiments can be combined in any manner. In order to make the description simple, all possible combinations of the technical features in the above embodiments are not described, however, as long as the combinations of the technical features do not contradict, they should be considered as the scope of the present application.

[0063] The above embodiments only express several implementation manners of the present application, the description is relatively specific and detailed, however, it should not be understood as the limitation of the patent application scope. It should be pointed out that, for the ordinary skilled in the art, several modifications and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the patent protection scope of the present application should be subject to the appended claims.

Claims

1. A signal modulation circuit, applied to an radio frequency power supply, characterized in that, The signal modulation circuit includes an operational amplifier, a non-inverting voltage matching module, and a limiting protection circuit module; The in-phase voltage matching module is configured between the second DC source and ground. The in-phase voltage matching module modulates the amplitude of the AC reference signal of the radio frequency power supply and pulls the amplitude to zero level or above through the second DC source to form an input signal. The operational amplifier acquires the input signal at its non-inverting input terminal, receives a limit signal at its inverting input terminal, and outputs a control signal that alternates between high and low potentials based on the comparison result. The limiting protection circuit module is configured between the first DC source driving the operational amplifier and ground, and the potential clamping node of the limiting protection circuit module is connected to the non-inverting input terminal of the operational amplifier.

2. The signal modulation circuit according to claim 1, characterized in that, The in-phase voltage distribution module includes two resistors connected in series. The two resistors are coupled between the second DC source and ground, and the series node between the two resistors is electrically coupled to the in-phase input terminal of the operational amplifier.

3. The signal modulation circuit according to claim 1, characterized in that, One or more DC blocking capacitors are configured between the non-inverting input of the operational amplifier and the line node of the AC reference signal.

4. The signal modulation circuit according to claim 1, characterized in that, The limiting protection circuit module includes a first diode and a second diode connected in series in the same conduction direction. The cathode of the first diode is connected to the first DC source, and the anode of the second diode is connected to the ground. The potential clamping node between the first diode and the second diode is connected to the non-inverting input terminal of the operational amplifier.

5. A signal modulation circuit according to claim 1, characterized in that, It also includes an inverting voltage distribution module, comprising two resistors connected in series, the two resistors being coupled between a third DC source and ground, and the series node between the two resistors being electrically coupled to the inverting input terminal of the operational amplifier.

6. A signal modulation circuit according to claim 5, characterized in that, It also includes a driving resistor, the first end of which is connected to a fourth DC source, and the output end of the operational amplifier is connected to the second end of the driving resistor and the gate of one or more switching transistors electrically coupled to a bridge switching circuit.

7. A signal modulation circuit according to claim 6, characterized in that, It also includes a gate buffer, which is configured between the switching transistor and the output of the operational amplifier.

8. A signal modulation circuit according to claim 7, characterized in that, The gate buffer is a combination of one or more of an inverter, an AND gate, or an OR gate.

9. A signal modulation circuit according to claim 6, characterized in that, The first DC source, the second DC source, the third DC source, and the fourth DC source are the same, partially the same, or different DC sources.

10. An inverter circuit, characterized in that, It includes a half-bridge switching circuit and two signal modulation circuits, the architecture of which is the same as that of any of the signal modulation circuits described in claims 1 to 9; The half-bridge switching circuit includes a first switching transistor and a second switching transistor; The drain of the first switching transistor is connected to a DC source; the source of the first switching transistor is connected to the drain of the second switching transistor to form the output terminal of the half-bridge switching circuit; the source of the second switching transistor is grounded. The output terminals of the two signal modulation circuits are electrically connected to the gates of the first switch and the second switch, respectively, and the phases of the control signals output by the two signal modulation circuits are out of phase or interleaved.

11. An inverter circuit, characterized in that, Includes a half-bridge switching circuit and a signal modulation circuit as described in any one of claims 1 to 9; The half-bridge switching circuit includes a first switching transistor and a second switching transistor; The drain of the first switching transistor is connected to a DC source; the source of the first switching transistor is connected to the drain of the second switching transistor to form the output terminal of the half-bridge switching circuit; the source of the second switching transistor is grounded. The output terminal of the signal modulation circuit is electrically connected to the gates of the first switch and the second switch, and a NOT gate or inverter is configured between the gate of the first switch or the second switch and the output terminal of the signal modulation circuit.

12. An inverter circuit, characterized in that, Includes a half-bridge switching circuit, a delay control module, and a signal modulation circuit as described in any one of claims 1 to 9; The half-bridge switching circuit includes a first switching transistor and a second switching transistor; The drain of the first switching transistor is connected to a DC source; the source of the first switching transistor is connected to the drain of the second switching transistor to form the output terminal of the half-bridge switching circuit; the source of the second switching transistor is grounded. The input terminal of the delay control module is connected to the signal modulation circuit, and the two output terminals of the delay control module are electrically connected to the gates of the first switch and the second switch, respectively. The control signals output by the two output terminals of the delay control module are out of phase or interleaved.

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