Voltage doubling circuit based on single-phase AC wide voltage input

Abstract

The invention discloses a voltage doubling circuit based on single-phase AC wide voltage input. The input end of a rectification voltage doubling circuit is connected with an AC power supply, and a rectification circuit is connected with the AC power supply; the voltage division trigger circuit is connected with the output end of the rectifying circuit; the switching circuit is connected with the voltage division trigger circuit and the rectifying circuit, and the voltage output by the voltage division trigger circuit is used for controlling the switching-on or switching-off of the switching circuit; the relay control circuit is connected with the switching circuit and the rectification voltage doubling circuit. The voltage division trigger circuit cannot trigger the control switch circuit to be switched on, and the relay control circuit outputs a switch-on signal to the rectification voltage doubling circuit to realize voltage doubling output; when the AC power supply is larger than or equal to the set voltage, the voltage division trigger circuit triggers the control switch circuit to be switched on, and the relay control circuit outputs a disconnection signal to the rectification voltage doubling circuit. The voltage doubling circuit based on single-phase AC wide voltage input not only can give consideration to boosting of various low voltages, but also can reduce the size of the circuit.

Description

Technical Field

[0001] The invention relates to the field of electronic technology, and in particular to a voltage doubling circuit based on a single-phase AC wide voltage input. Background Art

[0002] In the process of power electronics product technology research and development, in the current rapid development of new energy, resource conservation is the problem we need to solve. In addition, the utilization rate and commonality of components and management costs are also problems we need to solve as a factory, because it is also an important indicator of cost control; the current design at the input end is to carry out different R&D design, device selection, verification and other processes according to the input requirements of different countries, so each change will have different design processes, resulting in increased R&D costs, R&D time, and management costs. For this reason, in the field of integrated circuits, it is often necessary to boost the input voltage, for example, output a voltage twice the input voltage after boosting, and various voltage doubling circuits have been developed in the prior art.

[0003] In the existing voltage doubler, thick gate PMOS tubes and thick gate NMOS tubes are used. Among them, the gate oxide layer thickness of the thick gate MOS tube ranges from 6.0nm to 20.0nm. There are some shortcomings in the voltage doubler circuit. For example, due to the use of thick gate transistors, the volume of the circuit is large, which causes a certain degree of difficulty in the integration of the later circuit. In addition, the applicable range of the aforementioned voltage doubler circuit for the input voltage is relatively narrow. Therefore, when the power supply voltage is relatively low, it is an urgent problem to be solved to not only take into account the boosting of multiple low voltages, but also reduce the volume of the circuit. Summary of the invention

[0004] The purpose of the present invention is to provide a voltage doubling circuit based on a single-phase AC wide voltage input in view of the corresponding deficiencies of the prior art. The present invention can not only take into account the boosting of various low voltages, but also reduce the volume of the circuit.

[0005] The technical solutions to the above problems are as follows:

[0006] A voltage doubling circuit based on a single-phase AC wide voltage input includes a main circuit and a control circuit for voltage doubling. The main circuit includes an AC power supply and a rectifier voltage doubling circuit. The input end of the rectifier voltage doubling circuit is connected to the AC power supply. The control circuit includes:

[0007] A rectifier circuit, the rectifier circuit is connected to an AC power source;

[0008] A voltage-dividing trigger circuit connected to an output end of the rectifier circuit;

[0009] A switch circuit connected to the voltage-dividing trigger circuit and the rectifier circuit, wherein the voltage output by the voltage-dividing trigger circuit is used to control the on or off of the switch circuit;

[0010] A relay control circuit, the relay control circuit is connected to the switch circuit and the rectifier voltage doubler circuit respectively;

[0011] When the AC power supply is lower than the set voltage, the voltage-dividing trigger circuit cannot trigger the control switch circuit to conduct, and the relay control circuit outputs a conduction signal to the rectifier voltage-doubling circuit to achieve voltage-doubling output;

[0012] When the AC power supply is greater than or equal to the set voltage, the voltage-dividing trigger circuit triggers the control switch circuit to turn on, and the relay control circuit outputs a disconnect signal to the rectifier voltage-doubling circuit.

[0013] The present invention includes the following benefits: It can be seen from the content of the present invention that the present invention adopts a new type of voltage doubling method based on single-phase AC wide voltage input, which can not only meet the input of AC100-120V, but also meet the input of AC220-AC240V. The present invention cleverly utilizes the voltage stabilization of the three-terminal voltage regulator plus the function of optocoupler isolation, and also utilizes the fact that the AC input end of the product cannot be taken into account at the same time due to different power grids in each country, and also solves the problem of damage caused by different voltages of many current products, so that manufacturers only need one universal product to meet the use of different countries and regions. (Note: the standard voltage in some regions is: AC220V, the standard voltage in some regions is: AC240V, the standard voltage in some regions is: AC120V / AC240V, the standard voltage in some regions is: AC100V, etc.), the circuit of the present invention can set different thresholds according to different input requirements, and is flexible to use and has a wide range of uses. In addition, it can be seen from the circuit schematic diagram of the present invention that the circuit structure of the present invention is simple, compact, and has the advantages of low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a block diagram of a voltage doubling circuit based on single-phase AC wide voltage input.

[0015] Figure 2 It is the schematic diagram of the voltage doubling circuit based on single-phase AC wide voltage input. DETAILED DESCRIPTION

[0016] like Figure 1 and Figure 2As shown, the voltage doubler circuit based on single-phase AC wide voltage input of the present invention includes a main circuit and a control circuit for voltage doubler, the main circuit includes an AC power supply 100, a rectifier voltage doubler circuit 200, the control circuit includes a rectifier circuit 300, a voltage divider trigger circuit 400, a switch circuit 500, and a relay control circuit 600. The basic principle of the present invention is: when the AC power supply 100 is lower than the set voltage, the voltage divider trigger circuit 400 cannot trigger the control switch circuit 500 to turn on, and the relay control circuit 600 outputs a conduction signal to the rectifier voltage doubler circuit 200 to achieve voltage doubler output. When the AC power supply 100 is greater than or equal to the set voltage, the voltage divider trigger circuit 400 triggers the control switch circuit 500 to turn on, and the relay control circuit 600 outputs a disconnection signal to the rectifier voltage doubler circuit 200. Each part is described in detail below.

[0017] The voltage of the AC power supply 100 can be various. For example, the standard voltage in some regions is AC220V, the standard voltage in some regions is AC240V, the standard voltage in some regions is AC120V / AC240V, the standard voltage in some regions is AC100V, and so on.

[0018] The input end of the rectifier and voltage doubler circuit 200 is connected to the AC power supply 100. The rectifier and voltage doubler circuit 200 includes a first full-wave rectifier unit DB1, a first capacitor C1, and a second capacitor C2. The input end of the first full-wave rectifier unit DB1 is connected to the AC power supply 100, one of the output ends of the first full-wave rectifier unit DB1 is connected to the anode of the first capacitor C1, the other output end of the first full-wave rectifier unit DB1 is grounded, the cathode of the first capacitor C1 is connected to the anode of the second capacitor C2, and the cathode of the second capacitor C2 is grounded. The relay control circuit 600 has a controlled normally open contact K1B, one end of the normally open contact K1B is connected to the AC power supply 100, and the other end of the normally open contact K1B is connected to the anode end of the second capacitor C2.

[0019] The rectifier circuit 300 is connected to the AC power supply 100; the rectifier circuit 300 includes a second full-wave rectifier unit DB2 and a third capacitor C3, the input end of the second full-wave rectifier unit DB2 is connected to the AC power supply 100, one of the output ends of the second full-wave rectifier unit DB2 is connected to the anode of the third capacitor C3, and the other output end of the second full-wave rectifier unit DB2 and the cathode of the third capacitor C3 are grounded.

[0020] The voltage-dividing trigger circuit 400 is connected to the output end of the rectifier circuit 300; the voltage-dividing trigger circuit 400 includes a first resistor R1, a second resistor R2, a third resistor R3, and an adjustable voltage regulator Q1, one end of the first resistor R1 is connected to the output end of the rectifier circuit 300, the other end of the first resistor R1 is connected to one end of the second resistor R2, the other end of the second resistor R2 is connected to one end of the third resistor R3, the other end of the third resistor R3 is grounded, one end of the third resistor R3 is also connected to the control electrode of the adjustable voltage regulator Q1, the anode of the adjustable voltage regulator Q1 is grounded, the model of the adjustable voltage regulator Q1 is TL431, and the cathode of the adjustable voltage regulator Q1 is connected to the switch circuit 500.

[0021] The voltage-dividing trigger circuit 400 further includes a fourth capacitor C4 , one end of which is connected to the control electrode of the adjustable voltage regulator Q1 , and the other end of which is connected to the cathode of the adjustable voltage regulator Q1 .

[0022] The switch circuit 500 is respectively connected to the voltage-dividing trigger circuit 400 and the rectifier circuit 300, and the voltage output by the voltage-dividing trigger circuit 400 is used to control the on or off of the switch circuit 500; the switch circuit 500 includes a fourth resistor R4 and a photocoupler U1, one end of the fourth resistor R4 is connected to the output end of the rectifier circuit 300, the other end of the fourth resistor R4 is connected to the first pin of the photocoupler U1, the second pin of the photocoupler U1 is connected to the output end of the voltage-dividing trigger circuit 400, the fourth pin of the photocoupler U1 is connected to the relay control circuit 600, and the third pin of the photocoupler U1 is grounded.

[0023] The relay control circuit 600 is respectively connected to the switch circuit 500 and the rectifier voltage doubler circuit 200; the relay control circuit 600 includes a fifth resistor R5, a fifth capacitor C5, a first voltage regulator diode D1, a second transistor Q2, a relay coil K1A, and a working power supply. One end of the fifth resistor R5 is used to connect the working power supply, and the other end of the fifth resistor R5 is respectively connected to the output end of the switch circuit 500 (the fourth pin of the photocoupler U1), one end of the fifth capacitor C5, and the cathode of the first voltage regulator diode D1. The other end of the fifth capacitor C5 is grounded, the anode of the first voltage regulator diode D1 is connected to the base of the second transistor Q2, the emitter of the second transistor Q2 is grounded, the collector of the second transistor Q2 is connected to one end of the relay coil K1A, and the other end of the relay coil K1A is connected to the working power supply.

[0024] The relay control circuit 600 further includes a seventh capacitor C7 and a second diode D2. One end of the seventh capacitor C7 is connected to the base of the second transistor Q2, and the other end of the seventh capacitor C7 is grounded. The second diode D2 is connected in parallel to both ends of the relay coil K1A. The seventh capacitor C7 serves as a base bypass capacitor of the NPN type second transistor Q2 in the circuit;

[0025] The voltage output by the above working power supply is 24V. The working power supply is a flyback power supply 700. The input end of the flyback power supply 700 is preferentially connected to the rectifier voltage doubler circuit 200. The circuit structure of the flyback power supply belongs to the prior art and is not described here. The second transistor Q2, the second diode D2, and the relay coil K1A form a control circuit for controlling the charging of the second capacitor C2. The second transistor Q2 works in the cut-off region and the saturation region. When the second transistor Q2 works in the saturation region (the second transistor Q2 is turned on), the relay coil K1A is energized, so that the normally open contact K1B is attracted (the normally open contact K1B and the relay coil K1A belong to two related parts of the same relay, which is the conventional structure of the relay), and the AC power supply 100 charges the second capacitor C2. The role of the second transistor D2 in the circuit is that when the second transistor Q2 is turned off, the second transistor D2 and the relay coil K1A form a reverse recovery to absorb the peak voltage.

[0026] The working process of the present invention is as follows:

[0027] The AC power input from the AC power source 100 is rectified by the second full-wave rectifier unit DB2 and filtered by the third capacitor C3 to become a stable DC power source (VDD). Because it is only used for normal signal transmission without energy conversion, the power requirements of the second full-wave rectifier unit DB2 and the third capacitor C3 are relatively low. The DC power source (VDD) is divided by the first resistor R1, the second resistor R2, and the third resistor R3 to obtain a divided voltage, which is provided to the adjustable regulator Q1.

[0028] When the AC power supply 100 is greater than or equal to the set voltage, the DC voltage rises so that the voltage of the divided voltage reaches the voltage that can turn on the adjustable voltage regulator Q1, and the adjustable voltage regulator Q1 stabilizes the voltage at both ends of the anode and cathode at 2.5V. When the adjustable voltage regulator Q1 is turned on, the current of the second full-wave rectifier unit DB2 flows through the fourth resistor R4, the photocoupler U1, the adjustable voltage regulator Q1 to the ground loop in sequence, the photocoupler U1 is turned on, and the fourth pin of the photocoupler U1 outputs a signal. Since most of the power in the loop of the fourth resistor R4, the photocoupler U1, and the adjustable voltage regulator Q1 is shared by the fourth resistor R4, the light intensity inside the photocoupler U1 can be adjusted by adjusting the resistance value of the fourth resistor R4 to adjust the sensitivity of the photocoupler U1. After the photocoupler U1 is turned on, for the relay control circuit 600, at this time, the 24V working voltage passes through the fifth resistor to form a loop to the ground, so the base of the second transistor Q2 is directly pulled to the ground, the second transistor Q2 is in the cut-off state, the relay coil K1A is in the power-off state, and at this time, the normally open contact K1B is in the disconnected state. At this time, the output voltage of the main circuit is the voltage across the first capacitor C1. The output circuit of the main circuit can be used by the inverter circuit 800.

[0029] When the AC power supply 100 is lower than the set voltage, the DC voltage rises and the voltage of the voltage divider reaches a level that makes it impossible to turn on the adjustable voltage regulator Q1, and the adjustable voltage regulator Q1 is in a cut-off or disconnected state. The current of the second full-wave rectifier unit DB2 cannot flow through the fourth resistor R4, the photocoupler U1, the adjustable voltage regulator Q1 to the ground loop, the input end of the photocoupler U1 is in a disconnected state, and the fourth pin and the third pin of the photocoupler U1 have no output signal. For the relay control circuit 600, at this time, the 24V power supply charges the fifth capacitor C5 through the fifth resistor R5, and after a time delay and charging to a certain value, the first voltage regulator diode D1 is reversely broken down, and the model of the second transistor Q2 is NPN. type, the driving current is small, the second transistor Q2 is turned on, and the 24V working voltage forms a current through the relay coil K1A, the collector of the second transistor Q2, the emitter of the second transistor and the ground. The relay coil K1A works to control the normally open contact K1B to be attracted. At this time, the AC power supply 100 directly charges the second capacitor C2. At this time, the voltage output by the main circuit is the sum of the voltage across the first capacitor C1 and the voltage across the second capacitor C2, so it is equivalent to twice the voltage across the first capacitor C1, thereby realizing the voltage doubling function.

[0030] In different countries, the single-phase voltage of the mains electricity is different. In order to meet the different mains power ranges and ensure the consistency of our product research and development design to meet the different customer needs, we need such a design with wide voltage input.

[0031] For the single-phase AC wide voltage input voltage doubling circuit described in the above embodiment, the circuit parameter design steps are as follows (the components involved are abbreviated, for example, R1 represents the first resistor R1 in the above embodiment, Q1 represents the adjustable stabilizer Q1 in the above embodiment, and U1 represents the photoelectric coupler U1 in the above embodiment. Based on the above examples, the abbreviations of the components involved are not described one by one below):

[0032] Step 1: Establish a single-phase AC wide voltage doubler circuit. The first full-wave rectifier unit DB1 and the second full-wave rectifier unit DB2 use 3A signal full-bridge rectifier modules. The input AC frequency is 50Hz mains power, which has a low frequency. After rectification, it is filtered by the third capacitor C3.

[0033] Step 2: Set the threshold. The low voltage input includes AC100-130V and AC200-240V, with a fluctuation of ±15%. Therefore, according to the AC130V input +15% fluctuation, take AC150V; and AC220V input -15% fluctuation, take AC180V; so the threshold voltage Udc can be set to, that is, between: 212-254V.

[0034] Step 3: After determining the threshold voltage Udc, The voltage divider resistor value is determined by the calculation formula. In addition, when Q1 is turned on, the second pin of U1 will be pulled to 2.5V, so the value of R4 is more critical, because once U1 is turned on, all the power will be loaded to both ends of R4, and the current Power R4 =I R4 2 *R4.

[0035] P R4 Indicates the power consumed by R4, I R4 represents the current flowing through R4, and Ufrd represents the voltage drop between Q1 and U1.

[0036] Step 4: The signal is converted by the U1 optocoupler isolation to control the low-voltage side signal. When the low-voltage end of U1 is disconnected, the 24V power supply starts to charge C5 through R5 until it can break through the reverse voltage of D1.

[0037] Charging voltage U C5 =U D1 +0.7.

[0038] In the above formula, U D1 represents the voltage across the first stabilizing diode D1.

[0039] Charging time constant, the normally open contact K1B is in the normally open state by default.

[0040] Step 5: After D1 breaks down, it drives Q2 to work. After Q2 is turned on, 24V passes through relay K1A, the collector and emitter of Q2 to the ground, forming a loop. After the relay coil K1A is energized, the normally open contact K1B is closed, and finally a voltage doubling function is generated in the main circuit.

[0041] It can be seen from the content of the present invention that the present invention adopts a new type of voltage doubling method based on single-phase AC wide voltage input, which can not only meet the input of AC100-120V, but also meet the input of AC220-AC240V. The present invention cleverly utilizes the voltage stabilization of the three-terminal voltage regulator plus the function of optocoupler isolation, and also utilizes the fact that the AC input end of the product cannot be taken into account at the same time due to different power grids in each country, and also solves the problem of damage caused by different voltages of many current products, so that manufacturers only need one universal product to meet the use of different countries and regions. (Note: the standard voltage in some regions is: AC220V, the standard voltage in some regions is: AC240V, the standard voltage in some regions is: AC120V / AC240V, the standard voltage in some regions is: AC100V, etc.), the circuit of the present invention can set different thresholds according to different input requirements, and is flexible to use and has a wide range of uses. In addition, it can be seen from the circuit schematic diagram of the present invention that the circuit structure of the present invention is simple and has the advantage of low cost.

[0042] According to the above formula, different input voltage ranges are different, and only the threshold voltage Udc needs to be determined.

[0043] In a specific implementation case, the parameters of components can be reasonably selected according to circuit requirements, and those skilled in the art can obtain them through calculation or debugging based on the structure and operating principle of the circuit diagram and actual time requirements, which will not be introduced in detail here.

[0044] The examples described above are only some embodiments of the present invention, rather than all of them. Based on the examples in the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative work are within the scope of protection of the present invention.

Claims

1. A voltage doubling circuit based on a single-phase AC wide voltage input, comprising a main circuit and a control circuit for voltage doubling, wherein the main circuit comprises an AC power supply (100) and a rectifier voltage doubling circuit (200), wherein the input end of the rectifier voltage doubling circuit (200) is connected to the AC power supply (100), and wherein: The control circuit comprises: A rectifier circuit (300), the rectifier circuit (300) is connected to the AC power source (100); A voltage-dividing trigger circuit (400), the voltage-dividing trigger circuit (400) being connected to an output end of the rectifying circuit (300); A switch circuit (500) connected to the voltage-dividing trigger circuit (400) and the rectifier circuit (300), wherein the voltage output by the voltage-dividing trigger circuit (400) is used to control the on or off of the switch circuit (500); A relay control circuit (600), the relay control circuit (600) is connected to the switch circuit (500) and the rectifier voltage doubler circuit (200) respectively; When the AC power source (100) is lower than the set voltage, the voltage-dividing trigger circuit (400) cannot trigger the control switch circuit (500) to turn on, and the relay control circuit (600) outputs a conduction signal to the rectifier voltage-doubling circuit (200) to achieve voltage-doubling output; When the AC power source (100) is greater than or equal to a set voltage, the voltage-dividing trigger circuit (400) triggers the control switch circuit (500) to turn on, and the relay control circuit (600) outputs a disconnection signal to the rectifier voltage doubler circuit (200).

2. The voltage doubling circuit based on single-phase AC wide voltage input according to claim 1, characterized in that: The rectifier and voltage doubler circuit (200) comprises a first full-wave rectifier unit (DB1), a first capacitor (C1), and a second capacitor (C2); an input end of the first full-wave rectifier unit (DB1) is connected to an AC power source (100); one of the output ends of the first full-wave rectifier unit (DB1) is connected to an anode of the first capacitor (C1); another output end of the first full-wave rectifier unit (DB1) is grounded; a cathode of the first capacitor (C1) is connected to an anode of the second capacitor (C2); and a cathode of the second capacitor (C2) is grounded; The relay control circuit (600) has a normally open contact (K1B), one end of the normally open contact (K1B) is connected to the AC power source (100), and the other end of the normally open contact (K1B) is connected to the anode end of the second capacitor (C2).

3. The voltage doubling circuit based on single-phase AC wide voltage input according to claim 1, characterized in that: The rectifier circuit (300) comprises a second full-wave rectifier unit (DB2) and a third capacitor (C3); an input end of the second full-wave rectifier unit (DB2) is connected to an AC power source (100); one of the output ends of the second full-wave rectifier unit (DB2) is connected to an anode of the third capacitor (C3); and the other output end of the second full-wave rectifier unit (DB2) and a cathode of the third capacitor (C3) are grounded.

4. The voltage doubling circuit based on single-phase AC wide voltage input according to claim 1, characterized in that: The voltage-dividing trigger circuit (400) comprises a first resistor (R1), a second resistor (R2), a third resistor (R3), and an adjustable voltage regulator (Q1); one end of the first resistor (R1) is connected to the output end of the rectifier circuit (300); the other end of the first resistor (R1) is connected to one end of the second resistor (R2); the other end of the second resistor (R2) is connected to one end of the third resistor (R3); the other end of the third resistor (R3) is grounded; one end of the third resistor (R3) is also connected to the control electrode of the adjustable voltage regulator (Q1); the anode of the adjustable voltage regulator (Q1) is grounded; and the cathode of the adjustable voltage regulator (Q1) is connected to the switch circuit (500).

5. The voltage doubling circuit based on single-phase AC wide voltage input according to claim 4, characterized in that: The voltage-dividing trigger circuit (400) further comprises a fourth capacitor (C4), one end of which is connected to the control electrode of the adjustable voltage regulator (Q1), and the other end of which is connected to the cathode of the adjustable voltage regulator (Q1).

6. The voltage doubling circuit based on single-phase AC wide voltage input according to claim 1, characterized in that: The switch circuit (500) comprises a fourth resistor (R4) and a photoelectric coupler (U1); one end of the fourth resistor (R4) is connected to the output end of the rectifier circuit (300); the other end of the fourth resistor (R4) is connected to the first pin of the photoelectric coupler (U1); the second pin of the photoelectric coupler (U1) is connected to the output end of the voltage-dividing trigger circuit (400); the fourth pin of the photoelectric coupler (U1) is connected to the relay control circuit (600); and the third pin of the photoelectric coupler (U1) is grounded.

7. The voltage doubling circuit based on single-phase AC wide voltage input according to claim 1, characterized in that: The relay control circuit (600) comprises a fifth resistor (R5), a fifth capacitor (C5), a first voltage-stabilizing diode (D1), a second transistor (Q2), a relay coil (K1A), and a working power supply, wherein one end of the fifth resistor (R5) is used to connect to the working power supply, the other end of the fifth resistor (R5) is respectively connected to the output end of the switch circuit (500), one end of the fifth capacitor (C5), and the cathode of the first voltage-stabilizing diode (D1), the other end of the fifth capacitor (C5) is grounded, the anode of the first voltage-stabilizing diode (D1) is connected to the base of the second transistor (Q2), the emitter of the second transistor (Q2) is grounded, the collector of the second transistor (Q2) is connected to one end of the relay coil (K1A), and the other end of the relay coil (K1A) is connected to the working power supply.

8. The voltage doubling circuit based on single-phase AC wide voltage input according to claim 7, characterized in that: The relay control circuit (600) further comprises a seventh capacitor (C7), one end of the seventh capacitor (C7) is connected to the base of the second transistor (Q2), and the other end of the seventh capacitor (C7) is grounded.

9. The voltage doubling circuit based on single-phase AC wide voltage input according to claim 7, characterized in that: The relay control circuit (600) further comprises a second diode (D2), which is connected in parallel between two ends of the relay coil (K1A).

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