CN219351534U - Soft start circuit and single-phase inverter circuit - Google Patents
Soft start circuit and single-phase inverter circuit Download PDFInfo
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- CN219351534U CN219351534U CN202320331963.4U CN202320331963U CN219351534U CN 219351534 U CN219351534 U CN 219351534U CN 202320331963 U CN202320331963 U CN 202320331963U CN 219351534 U CN219351534 U CN 219351534U
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Abstract
The application provides a soft start circuit and a single-phase inverter circuit, wherein the soft start circuit comprises a current-limiting switch circuit, a delay circuit, a driving circuit and a power supply; the current-limiting switch circuit is connected in series between a front-stage circuit and a rear-stage circuit of the single-phase inverter circuit; the input end of the delay circuit is electrically connected with the power supply, the output end of the delay circuit is electrically connected with the input end of the drive circuit, and the output end of the drive circuit is connected with the switch control end of the current-limiting switch circuit, so that the current on the main circuit is restrained from rising rapidly and the current is restrained from being generated when the single-phase inverter circuit is started, and the burning loss phenomenon of devices is reduced.
Description
Technical Field
The application relates to the field of circuits, in particular to a soft start circuit and a single-phase inverter circuit.
Background
In the application of high power occasions, electrical isolation is very critical and necessary, and the isolation type bidirectional DC/DC perfectly realizes the electrical isolation due to the existence of a high-frequency transformer, so that a two-stage inverter circuit structure with high-frequency isolation is mostly used for a single-phase inverter on the market, the circuit structure is divided into a front stage and a rear stage, the front stage DC/DC converter modulates input voltage into ideal voltage meeting the requirement of a rear stage inverter, and then the rear stage DC/AC is used for inversion. The topology of the pre-stage DC/DC converter is more commonly push-pull, half-bridge, full-bridge, etc.
At the turn-off time of the switching tube, a voltage surge with a very high value is generated in the single-phase inverter circuit; at the turn-on time, a current surge with a very high value is generated in the single-phase inverter circuit. And as the switching frequency increases, the voltage or current peaks will be higher, and once the switch endurance limit is reached, permanent damage to the switching tube will occur.
Disclosure of Invention
In view of the foregoing, an object of the present application is to provide a soft start circuit that suppresses a rapid rise in current and a reduction in current generation on a main circuit when a single-phase inverter circuit is started, and reduces a device burn-out phenomenon.
The soft start circuit provided by the embodiment of the application comprises a current limiting switch circuit, a delay circuit, a driving circuit and a power supply;
the current-limiting switch circuit is connected in series between a front-stage circuit and a rear-stage circuit of the single-phase inverter circuit;
the input end of the delay circuit is electrically connected with the power supply, the output end of the delay circuit is electrically connected with the input end of the driving circuit, and the output end of the driving circuit is connected with the switch control end of the current-limiting switch circuit.
In some embodiments, in the soft start circuit, the current limiting switch circuit is configured to be turned on when receiving a driving control signal sent by the driving circuit in a delayed manner, so that a front stage circuit and a rear stage circuit of the single-phase inverter circuit are turned on directly in a delayed manner; and when the current limiting switch circuit is turned off, the front-stage circuit and the rear-stage circuit of the single-phase inverter circuit are conducted through the current limiting switch circuit.
In some embodiments, in the soft start circuit, a voltage output end of the delay circuit is electrically connected with a voltage input end of the driving circuit, so as to delay outputting the driving voltage to the driving circuit when the power supply outputs the auxiliary voltage;
the driving output end of the driving circuit is connected with the switch control end of the current-limiting switch circuit so as to output a delayed driving control signal to the current-limiting switch circuit when receiving the delayed driving voltage.
In some embodiments, in the soft start circuit, the delay circuit includes a first resistor and a delay capacitor module, the first resistor and the delay capacitor module are connected in series, the first resistor is electrically connected with the power supply, and two ends of the delay capacitor module are electrically connected with a voltage input end of the driving circuit as voltage output ends.
In some embodiments, in the soft start circuit, the delay circuit further includes a first diode; the first diode is reversely connected in parallel with the two ends of the first resistor.
In some embodiments, in the soft start circuit, the driving circuit includes a triode;
the base electrode of the triode is connected with the positive electrode of the voltage output end of the delay circuit, the emitter electrode of the triode is connected with the negative electrode of the voltage output end of the delay circuit, and the collector electrode of the triode is used as the driving end to be connected with the switch control end of the current-limiting switch circuit.
In some embodiments, in the soft start circuit, the current limiting switch circuit includes a switch circuit and a current limiting circuit connected in parallel;
the switching circuit is connected in series between a front-stage circuit and a rear-stage circuit of the single-phase inverter circuit.
In some embodiments, in the soft start circuit, the switch circuit comprises a relay, the current limiting circuit comprises a second resistor for current limiting, and the second resistor is connected in parallel to two ends of a contact of the relay; the coil of the relay is electrically connected with the driving signal output end of the driving circuit;
or, the switch circuit comprises a MOS tube; the current limiting circuit comprises a third resistor for limiting current, and the third resistor is connected in parallel with two ends of a source electrode and a drain electrode of the MOS tube; and the grid electrode of the MOS tube is electrically connected with the driving signal output end of the driving circuit.
In some embodiments, in the soft start circuit, when the switching circuit includes a relay, two ends of a coil of the relay are connected in anti-parallel to a second diode.
In some embodiments, in the soft start circuit, an anti-interference capacitor is connected in series between the gate of the MOS transistor and the input end of the post-stage circuit.
In some embodiments, in the soft start circuit, a reverse voltage regulator is connected in series between the base of the triode and the positive electrode of the voltage output end of the delay circuit, and a fourth resistor is connected in series between the base of the triode and the negative electrode of the voltage output end of the delay circuit.
In some embodiments, a single-phase inverter circuit is also provided, including a pre-stage circuit, a soft start circuit, and a post-stage circuit; the front-stage circuit is electrically connected with the rear-stage circuit through the soft start circuit; the soft start circuit is the soft start circuit.
The embodiment of the application provides a soft start circuit and a single-phase inverter circuit, wherein the soft start circuit comprises a current-limiting switch circuit, a delay circuit, a driving circuit and a power supply; the current-limiting switch circuit is connected in series between a front-stage circuit and a rear-stage circuit of the single-phase inverter circuit; the input end of the delay circuit is electrically connected with the power supply, the output end of the delay circuit is electrically connected with the input end of the driving circuit, and the output end of the driving circuit is connected with the switch control end of the current-limiting switch circuit, so that when the power supply outputs auxiliary voltage, the delay circuit delays to output driving voltage to the driving circuit; when the driving circuit receives the driving voltage, the driving circuit outputs a driving control signal to the current-limiting switch circuit, and the current-limiting switch circuit is conducted when receiving the driving control signal, so that a front-stage circuit and a rear-stage circuit of the single-phase inverter circuit are directly conducted, the front-stage circuit and the rear-stage circuit are directly conducted in a delayed mode under the control of the delay circuit, voltage and current stress of a starting switch device are reduced, and the burning phenomenon of the device is reduced.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the embodiments will be briefly described below, it being understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered limiting the scope, and that other related drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
FIG. 1 shows a schematic circuit diagram of a soft start circuit according to an embodiment of the present application;
FIG. 2 shows a circuit diagram of a soft start circuit according to an embodiment of the present application;
FIG. 3 shows a circuit diagram of another soft start circuit according to an embodiment of the present application;
fig. 4 shows a schematic circuit diagram of a single-phase inverter circuit according to an embodiment of the present application.
Detailed Description
For the purpose of making the objects, technical solutions and advantages of the embodiments of the present application more clear, the technical solutions of the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application, and it should be understood that the accompanying drawings in the present application are only for the purpose of illustration and description, and are not intended to limit the protection scope of the present application. In addition, it should be understood that the schematic drawings are not drawn to scale. A flowchart, as used in this application, illustrates operations implemented according to some embodiments of the present application. It should be understood that the operations of the flow diagrams may be implemented out of order and that steps without logical context may be performed in reverse order or concurrently. Moreover, one or more other operations may be added to the flow diagrams and one or more operations may be removed from the flow diagrams as directed by those skilled in the art.
In addition, the described embodiments are only some, but not all, of the embodiments of the present application. The components of the embodiments of the present application, which are generally described and illustrated in the figures herein, may be arranged and designed in a wide variety of different configurations. Thus, the following detailed description of the embodiments of the present application, as provided in the accompanying drawings, is not intended to limit the scope of the application, as claimed, but is merely representative of selected embodiments of the application. All other embodiments, which can be made by those skilled in the art based on the embodiments of the present application without making any inventive effort, are intended to be within the scope of the present application.
It should be noted that the term "comprising" will be used in the embodiments of the present application to indicate the presence of the features stated hereinafter, but not to exclude the addition of other features.
In the application of high power occasions, electrical isolation is very critical and necessary, and the isolation type bidirectional DC/DC perfectly realizes the electrical isolation due to the existence of a high-frequency transformer, so that a two-stage inverter circuit structure with high-frequency isolation is mostly used for a single-phase inverter on the market, the circuit structure is divided into a front stage and a rear stage, the front stage DC/DC converter modulates input voltage into ideal voltage meeting the requirement of a rear stage inverter, and then the rear stage DC/AC is used for inversion. The topology of the pre-stage DC/DC converter is more commonly push-pull, half-bridge, full-bridge, etc.
At the turn-off time of the switching tube, a voltage surge with a very high value is generated in the single-phase inverter circuit; at the turn-on time, a current surge with a very high value is generated in the single-phase inverter circuit. And as the switching frequency increases, the voltage or current peaks will be higher, and once the switch endurance limit is reached, permanent damage to the switching tube will occur.
Based on the above, the embodiment of the application provides a soft start circuit and a single-phase inverter circuit, wherein the soft start circuit comprises a current-limiting switch circuit, a delay circuit, a driving circuit and a power supply; the current-limiting switch circuit is connected in series between a front-stage circuit and a rear-stage circuit of the single-phase inverter circuit; the input end of the delay circuit is electrically connected with the power supply, the output end of the delay circuit is electrically connected with the input end of the driving circuit, and the output end of the driving circuit is connected with the switch control end of the current-limiting switch circuit; thus, when the power supply outputs auxiliary voltage, the delay circuit delays to output driving voltage to the driving circuit; when the driving circuit receives the driving voltage, the driving circuit outputs a driving control signal to the current-limiting switch circuit, and the current-limiting switch circuit is conducted when receiving the driving control signal, so that a front-stage circuit and a rear-stage circuit of the single-phase inverter circuit are directly conducted, the front-stage circuit and the rear-stage circuit are directly conducted in a delayed mode under the control of the delay circuit, voltage and current stress of a starting switch device are reduced, and the burning phenomenon of the device is reduced.
Referring to fig. 1, fig. 1 shows a schematic circuit diagram of a soft start circuit 100 according to an embodiment of the present application, and specifically, the soft start circuit 100 includes a current-limiting switch circuit 102, a delay circuit 103, a driving circuit 101, and a power supply 104;
the current-limiting switch circuit 102 is connected in series between a front-stage circuit and a rear-stage circuit of the single-phase inverter circuit;
the input end of the delay circuit 103 is electrically connected with the power supply 104, the output end of the delay circuit 103 is electrically connected with the input end of the driving circuit 101, and the output end of the driving circuit 101 is connected with the switch control end of the current-limiting switch circuit 102.
In the soft start circuit 100, the current limiting switch circuit 102 is configured to be turned on when receiving a driving control signal sent by the driving circuit 101 in a delayed manner, so that a front stage circuit and a rear stage circuit of the single-phase inverter circuit are turned on directly in a delayed manner; and conducting between a front stage circuit and a rear stage circuit of the single-phase inverter circuit through the current limiting switch circuit 102 when the single-phase inverter circuit is turned off.
In the soft start circuit 100, the voltage output end of the delay circuit 103 is electrically connected to the voltage input end of the driving circuit 101, so as to delay outputting the driving voltage to the driving circuit 101 when the power supply 104 outputs the auxiliary voltage;
the driving output end of the driving circuit 101 is connected to the switch control end of the current-limiting switch circuit 102, so as to output a delayed driving control signal to the current-limiting switch circuit 102 when receiving the delayed driving voltage.
That is, the delay control of the delay circuit is realized based on the voltage signal.
Specifically, after the single-phase inverter circuit is started, the front-stage circuit and the rear-stage circuit of the single-phase inverter circuit are conducted through the current-limiting switch circuit 102 in a certain delay time period, the current-limiting switch circuit 102 can limit the current magnitude and peak value between the front-stage circuit and the rear-stage circuit, the current is restrained from rising rapidly, the current is restrained from being generated, the voltage and current stress of a starting switch device are reduced, and the burning phenomenon of the device is reduced; after the delay period, the current limiting switch circuit 102 is turned on when receiving the driving control signal, so that the front stage circuit and the rear stage circuit of the single-phase inverter circuit are directly turned on and then run normally, and thus, the electronic device is prevented from being damaged by current surge generated in the single-phase inverter circuit in the starting process.
In the embodiment of the application, the front-stage circuit of the single-phase inverter circuit is a DC/DC converter, and the rear-stage circuit is a DC/AC inverter circuit. The DC/DC converter is more commonly a push-pull circuit, a half-bridge circuit, a full-bridge circuit, etc.
The power supply 104 outputs a dc voltage for assisting the soft start circuit 100 to start; the power supply 104 may be a dc power supply 104, an output end of an external dc circuit, etc.; the external direct current circuit may be a DC/DC circuit or the like.
Referring to fig. 2, the delay circuit 103 includes a first resistor R1 and a delay capacitor module, where the first resistor R1 and the delay capacitor module are connected in series, the first resistor R1 is electrically connected to the power source 104, and two ends of the delay capacitor module are electrically connected to a voltage input end of the driving circuit 101 as voltage output ends.
When the power supply 104 has voltage output, the delay capacitor module is charged through the first resistor R1, and the voltage at two ends of the delay capacitor module is increased until the voltage at two ends of the delay capacitor module meets the requirement of the driving circuit 101, and the driving circuit 101 outputs a driving voltage signal to the current-limiting switch module, so that the current-limiting switch module is turned on.
In this embodiment of the present application, the delay capacitor module specifically includes a first capacitor C1 and a second capacitor C2 connected in parallel.
Referring to fig. 2, the delay circuit 103 in the soft start circuit 100 according to the embodiment of the present application further includes a first diode D1; the first diode D1 is reversely connected in parallel to two ends of the first resistor R1.
Here, the first diode D1 is used to accelerate the discharge speed of the first capacitor C1 and the second capacitor C2.
Referring to fig. 2, in the soft start circuit 100 according to the embodiment of the present application, the driving circuit 101 includes a transistor Q1;
the base electrode of the triode Q1 is connected with the positive electrode of the voltage output end of the delay circuit 103, the emitter electrode is connected with the negative electrode of the voltage output end of the delay circuit 103, and the collector electrode of the triode Q1 is used as a driving end to be connected with the switch control end of the current-limiting switch circuit 102.
When the voltage output end of the delay circuit 103 rises to the voltage of the base electrode of the triode Q1 to meet the opening condition, when the triode Q1 is conducted, a driving signal is output to the current-limiting switch circuit 102 by the collector electrode of the triode Q1, so that the current-limiting switch circuit 102 is conducted, the current-limiting state of the current-limiting switch circuit 102 is switched to a conducting state, and the front-stage circuit and the rear-stage circuit of the single-phase inverter circuit are switched from the state of current-limiting conduction through the current-limiting switch circuit 102 to a direct conduction state.
Specifically, referring to fig. 2, the current-limiting switch circuit 102 includes a switch circuit and a current-limiting circuit connected in parallel;
the switching circuit is connected in series between a front-stage circuit and a rear-stage circuit of the single-phase inverter circuit.
That is, the front stage circuit and the rear stage circuit of the single-phase inverter circuit are turned on through the current limiting circuit during the delay period to suppress the current in the main circuit and prevent the current from being excessively large; and after the delay is finished, the current limiting circuit is directly conducted through the conducted switching circuit, and the conducted switching circuit is used for shorting the current limiting circuit.
In this embodiment of the present application, the switching circuit includes a relay K1, the current limiting circuit includes a second resistor R2 for limiting current, and the second resistor R2 is connected in parallel to two ends of a contact of the relay K1; the coil of the relay K1 is electrically connected with the driving signal output end of the driving circuit 101;
or, the switch circuit comprises a MOS tube Q2; the current limiting circuit comprises a third resistor R3 for limiting current, and the third resistor R3 is connected in parallel with two ends of a source electrode and a drain electrode of the MOS tube Q2; the gate of the MOS transistor Q2 is electrically connected to the driving signal output end of the driving circuit 101.
Specifically, when the switching circuit comprises a relay K1 and the current limiting circuit comprises a second resistor R2 for current limiting, the second resistor R2 is connected in parallel with two ends of a contact of the relay K1;
the contact of the relay K1 is connected in series between a front-stage circuit and a rear-stage circuit of the single-phase inverter circuit;
the first end of the coil of the relay K1 is electrically connected to the power source 104, and the second end of the coil is electrically connected to the collector of the triode Q1, so that the relay K1 is turned on when the triode Q1 receives the driving voltage output by the delay circuit 103 in a delay mode.
Thus, when the triode Q1 is conducted after receiving the driving voltage output by the delay circuit 103 in a delay way, the coil of the relay K1 is electrified, and the contact of the relay K1 is conducted, so that the front-stage circuit and the rear-stage circuit of the single-phase inverter circuit are directly conducted; and before the triode Q1 is not conducted, the front-stage circuit and the rear-stage circuit of the single-phase inverter circuit are conducted through a current-limiting second resistor R2.
Referring to fig. 2, when the switching circuit includes a relay K1, two ends of a coil of the relay K1 are connected in anti-parallel to a second diode D2. The second diode D2 in anti-parallel connection is a reverse freewheeling diode.
When the triode Q1 is turned off, the coil self-inductance of the relay K1 generates very high reverse electromotive force, and reverse freewheeling diodes connected in parallel to two ends of the pin 1 and the pin 2 of the relay K1 provide freewheeling paths, and clamp the reverse electromotive force to prevent breakdown of the triode Q1.
In some embodiments, a bus filter capacitor is connected in parallel between the 5 th pin (i.e., the X2 terminal) of the relay K1 and the input terminal of the post-stage circuit.
In this embodiment, in the soft start circuit 100, a reverse voltage regulator D3 is connected in series between the base of the triode Q1 and the positive electrode of the voltage output end of the delay circuit 103, so as to improve the on threshold voltage of the triode Q1.
In the soft start circuit 100 of the embodiment of the present application, a fourth resistor R4 is connected in series between the base of the triode Q1 and the negative of the voltage output end of the delay circuit 103.
And a pull-down resistor is added to the base electrode of the triode Q1, so that the inter-electrode capacitance between the base electrode and the emitter electrode is ensured to accelerate the discharge, the cut-off of the triode Q1 is accelerated, and meanwhile, the working state of the triode Q1 cannot be determined when the input end is suspended or in a high-resistance state is prevented.
The operation of the soft start circuit 100 shown in fig. 2 is described below with reference to fig. 2.
In fig. 2, an anti-surge current circuit composed of a relay K1 and a second resistor R2 (cement resistor) is employed as the current-limiting switch circuit 102. After isolation and boosting of a front-stage circuit of the single-phase inverter circuit, a direct-current high voltage is output through circuits such as a rectifier bridge, and then the second resistor R2 plays a role in limiting current through X1, so that instant surge current is prevented from being switched on. When the auxiliary power supply outputs 12V voltage, the 12V voltage passes through the second resistor R2 and charges the first capacitor C1 and the second capacitor C2, when the base potential of the triode Q1 meets the opening condition, the triode Q1 is conducted, the relay K1 acts, the coil is electrified, the pin 5 and the pin 8 of the relay K1 are closed, the main branch X1X2 is conducted, the second resistor R2 is bypassed, and the single-phase inverter circuit enters a normal running state. The delay time of the current limit depends on a time constant, which is determined by the first resistor R1, the second capacitor C2 and the second capacitor C2. When the triode Q1 is turned off, the coil self-inductance of the relay K1 generates very high reverse electromotive force, and reverse freewheeling diodes (second diodes D2) connected in parallel to two ends of the pin 1 and the pin 2 of the relay K1 provide freewheeling paths, and clamp the reverse electromotive force at the same time to prevent breakdown of the triode Q1. And a pull-down resistor (a fourth resistor R4) is added to the base electrode of the triode Q1, so that the inter-electrode capacitance between the base electrode and the emitter electrode is ensured to accelerate the discharge, the cut-off of the triode Q1 is accelerated, and meanwhile, the working state of the triode Q1 cannot be determined when the input end is suspended or in a high-resistance state is prevented. The base of the triode Q1 is added with a reverse voltage stabilizing tube D3 to improve the conduction threshold voltage of the triode Q1.
In some embodiments, referring to fig. 3, when the switching circuit includes a MOS transistor Q2, the switching circuit includes a MOS transistor Q2; the current limiting circuit comprises a third resistor R3 for limiting current; the third resistor R3 is connected in parallel with two ends of a source electrode and a drain electrode of the MOS tube Q2;
the driving circuit 101 further includes an optocoupler U1, where a collector of the triode Q1 is electrically connected to the power supply 104 through the optocoupler U1, and is electrically connected to a gate of the MOS transistor Q2 through the optocoupler U1, so that the MOS transistor Q2 is turned on when the triode Q1 receives the driving voltage delayed and output by the delay circuit 103.
Here, the MOS transistor Q2 plays a role of a switch, and an anti-interference capacitor C3 is connected in series between the gate of the MOS transistor Q2 and the input end of the post-stage circuit, so as to improve the anti-interference capability of the MOS transistor Q2, and further improve the stability of the system.
Specifically, the anti-interference capacitor C3 is a patch capacitor made of NPO material.
The soft start circuit 100 shown in fig. 3 is an anti-surge current circuit composed of a MOS transistor Q2 and a cement resistor (a third resistor R3), that is, a current limiting switch circuit 102. After the isolation and the boost of the front-stage circuit, the direct-current high voltage is output through circuits such as a rectifier bridge, and then the surge current at the moment of switching on is prevented through the third resistor R3 and the X1. When the auxiliary power supply outputs 12V voltage, the 12V passes through the first resistor R1 and charges the first capacitor C1 and the second capacitor C2, when the base potential of the triode Q1 meets the opening condition, the triode Q1 is conducted, the light emitting diode in the optocoupler U1 emits light, the resistance between the pin 3 and the pin 4 of the optocoupler U1 is reduced and is equivalent to the switch on, the driving circuits 101T1 and T2 are connected, the grid electrode of the MOS tube Q2 is powered on, when the potential of the MOS tube Q2 meets the opening condition, the MOS tube Q2 is conducted, the main branch X1X2 between the front-stage circuit and the rear-stage circuit is conducted, the third resistor R3 is bypassed, and the single-phase inverter circuit enters a normal running state. The delay time of the current limit depends on a time constant, which is determined by the first resistor R1, the second capacitor C2 and the second capacitor C2. Similarly, a pull-down resistor (a fourth resistor R4) is added to the base electrode of the triode Q1, so that the inter-electrode capacitance between the base electrode and the emitter electrode is ensured to accelerate the discharge, the cut-off of the triode Q1 is accelerated, and meanwhile, the working state of the triode Q1 cannot be determined when the input end is prevented from being suspended or in a high-resistance state. The base of the triode Q1 is added with a reverse voltage stabilizing tube D3 to improve the conduction threshold voltage of the triode Q1.
Meanwhile, referring to fig. 3, an anti-interference capacitor C3 is connected in series between the gate of the MOS transistor Q2 and the input end of the post-stage circuit, and when the delay circuit 103 operates, after the branch of X1X2 is turned on, the current output by X2 is filtered by the anti-interference capacitor C3 and then connected to the post-stage circuit.
Based on the same inventive concept, the embodiment of the present application further provides a single-phase inverter circuit corresponding to the soft start circuit 100, and since the principle of solving the problem of the single-phase inverter circuit in the embodiment of the present application is similar to that of the soft start circuit 100 described in the embodiment of the present application, the implementation of the single-phase inverter circuit can refer to the implementation of the soft start circuit 100, and the repetition is omitted.
Referring to fig. 4, in the embodiment of the present application, a single-phase inverter circuit is further provided, where the single-phase inverter circuit includes a front stage circuit, a soft start circuit 100, and a rear stage circuit; the front-stage circuit is electrically connected with the back-stage circuit through the soft start circuit 100; the soft start circuit 100 is the soft start circuit 100 described in the embodiments of the present application.
It will be clearly understood by those skilled in the art that, for convenience and brevity of description, specific working procedures of the above-described system and apparatus may refer to corresponding procedures in the method embodiments, which are not described in detail in this application. In several embodiments provided in the present application, it should be understood that the disclosed MOS drive circuit 101 may be implemented in other manners. The circuit embodiments described above are merely illustrative, for example, the division is merely a logical function division, and there may be other manners of dividing the actual implementation, and for example, multiple or circuits may be combined or integrated into another circuit or module, or some features may be omitted, or not performed.
The descriptions of separate components may or may not be physically separate, and may be located on one circuit board, or may be distributed over multiple circuit boards. Some or all of the circuits may be selected according to actual needs to achieve the purpose of the embodiment.
The foregoing is merely a specific embodiment of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art can easily think about changes or substitutions within the technical scope of the present application, and the changes or substitutions are covered in the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.
Claims (12)
1. The soft start circuit is characterized by comprising a current-limiting switch circuit, a delay circuit, a driving circuit and a power supply;
the current-limiting switch circuit is connected in series between a front-stage circuit and a rear-stage circuit of the single-phase inverter circuit;
the input end of the delay circuit is electrically connected with the power supply, the output end of the delay circuit is electrically connected with the input end of the driving circuit, and the output end of the driving circuit is connected with the switch control end of the current-limiting switch circuit.
2. The soft start circuit of claim 1, wherein,
the current-limiting switch circuit is used for being conducted when receiving a drive control signal sent by the drive circuit in a delayed manner, so that a front-stage circuit and a rear-stage circuit of the single-phase inverter circuit are directly conducted in a delayed manner; and when the current limiting switch circuit is turned off, the front-stage circuit and the rear-stage circuit of the single-phase inverter circuit are conducted through the current limiting switch circuit.
3. A soft start circuit according to claim 1 or 2, wherein,
the voltage output end of the delay circuit is electrically connected with the voltage input end of the driving circuit, so that when the power supply outputs auxiliary voltage, the driving voltage is delayed to be output to the driving circuit;
the driving output end of the driving circuit is connected with the switch control end of the current-limiting switch circuit so as to output a delayed driving control signal to the current-limiting switch circuit when receiving the delayed driving voltage.
4. The soft start circuit of claim 1, wherein the delay circuit comprises a first resistor and a delay capacitor module, the first resistor and the delay capacitor module are connected in series, the first resistor is electrically connected with a power supply, and two ends of the delay capacitor module are electrically connected with a voltage input end of the driving circuit as voltage output ends.
5. The soft start circuit of claim 4, wherein the delay circuit further comprises a first diode; the first diode is reversely connected in parallel with the two ends of the first resistor.
6. The soft start circuit of claim 1, wherein the drive circuit comprises a transistor;
the base electrode of the triode is connected with the positive electrode of the voltage output end of the delay circuit, the emitter electrode of the triode is connected with the negative electrode of the voltage output end of the delay circuit, and the collector electrode of the triode is used as the driving end to be connected with the switch control end of the current-limiting switch circuit.
7. A soft start circuit according to claim 1 or 6, wherein the current limiting switching circuit comprises a switching circuit and a current limiting circuit in parallel;
the switching circuit is connected in series between a front-stage circuit and a rear-stage circuit of the single-phase inverter circuit.
8. The soft start circuit of claim 7, wherein the switching circuit comprises a relay, the current limiting circuit comprises a second resistor for limiting current, the second resistor is connected in parallel across contacts of the relay; the coil of the relay is electrically connected with the driving signal output end of the driving circuit;
or, the switch circuit comprises a MOS tube; the current limiting circuit comprises a third resistor for limiting current, and the third resistor is connected in parallel with two ends of a source electrode and a drain electrode of the MOS tube; and the grid electrode of the MOS tube is electrically connected with the driving signal output end of the driving circuit.
9. The soft start circuit of claim 8, wherein when the switching circuit comprises a relay, the two ends of the coil of the relay are antiparallel with a second diode.
10. The soft start circuit of claim 9, wherein an anti-interference capacitor is connected in series between the gate of the MOS transistor and the input terminal of the post-stage circuit.
11. The soft start circuit of claim 6, wherein a reverse voltage regulator is connected in series between the base of the triode and the positive electrode of the voltage output terminal of the delay circuit, and a fourth resistor is connected in series between the base of the triode and the negative electrode of the voltage output terminal of the delay circuit.
12. The single-phase inverter circuit is characterized by comprising a front-stage circuit, a soft start circuit and a rear-stage circuit; the front-stage circuit is electrically connected with the rear-stage circuit through the soft start circuit; the soft start circuit is the soft start circuit of any one of claims 1-11.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202320331963.4U CN219351534U (en) | 2023-02-27 | 2023-02-27 | Soft start circuit and single-phase inverter circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202320331963.4U CN219351534U (en) | 2023-02-27 | 2023-02-27 | Soft start circuit and single-phase inverter circuit |
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| Publication Number | Publication Date |
|---|---|
| CN219351534U true CN219351534U (en) | 2023-07-14 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202320331963.4U Active CN219351534U (en) | 2023-02-27 | 2023-02-27 | Soft start circuit and single-phase inverter circuit |
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| Country | Link |
|---|---|
| CN (1) | CN219351534U (en) |
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2023
- 2023-02-27 CN CN202320331963.4U patent/CN219351534U/en active Active
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