Linear power supply with small size and high conversion rate

Abstract

The utility model relates to the technical field of power supply circuits, in particular to a linear power supply with small volume and high conversion rate, which comprises a rectifying and filtering circuit, a presettable voltage stabilizing circuit, a step-down circuit and an energy storage circuit, alternating current is respectively input into the rectification filter circuit and the step-down circuit; the rectifying and filtering circuit is used for supplying power to the presettable voltage stabilizing circuit after rectifying and filtering the alternating current; the step-down circuit is used for reducing the voltage of the alternating current, transmitting the voltage to the presettable voltage stabilizing circuit through the energy storage circuit, and when the alternating current is in a positive half cycle, providing a conduction voltage for the presettable voltage stabilizing circuit; the energy storage circuit is used for storing electric energy, and when the alternating current is in a negative half cycle, a breakover voltage is provided for the presettable voltage stabilizing circuit; the presettable voltage stabilizing circuit is used for conducting itself when receiving the breakover voltage, stabilizing the breakover voltage to a preset voltage, and outputting a positive direct current and a negative direct current at the preset voltage. The problems that a linear power supply is large in size and low in conversion efficiency are solved.

Description

Technical Field

[0001] The utility model relates to the technical field of power supply circuits, in particular to a linear power supply with small volume and high conversion rate. Background Art

[0002] A linear power supply is an electronic device that converts alternating current (AC) into the required direct current (DC). This conversion is accomplished through a transformer, rectifier, filter, and voltage regulator. The AC power is first stepped down and rectified to produce pulsed DC power. This is then filtered to produce a DC voltage with minimal ripple voltage, which is then stabilized for output. This linear power supply offers exceptionally fast response times to load changes, allows for flexible adjustment of the power supply's output current, and ensures output voltage stability and accuracy.

[0003] However, compared with switching power supplies, linear power supplies have lower conversion efficiency. The reason for this problem is that linear power supplies rely on switching tubes to clamp the voltage, which will result in large losses. Therefore, the efficiency of linear power supplies is much lower than that of switching power supplies. In addition, the common dual-channel output of linear power supplies (i.e., VO+ and GND, VO- and GND) is achieved by connecting a transformer at the output end. Especially for linear power supplies that receive small AC voltages, the transformer will take up a lot of space, which is not conducive to the miniaturization of linear power supplies. Utility Model Content

[0004] In view of the above-mentioned defects, the purpose of the present invention is to provide a small-volume, high-conversion-efficiency linear power supply, which solves the problem of large volume and low conversion efficiency of linear power supplies.

[0005] To achieve this purpose, the present invention adopts the following technical solutions:

[0006] A small-volume, high-conversion-rate linear power supply comprises a rectifier and filter circuit, a preset voltage stabilization circuit, a step-down circuit, and an energy storage circuit; alternating current is input into the rectifier and filter circuit and the step-down circuit respectively;

[0007] The rectification and filtering circuit is used to rectify and filter the AC power and then supply power to the preset voltage stabilization circuit;

[0008] The step-down circuit is used to reduce the voltage of the alternating current and transmit it to the preset voltage stabilizing circuit via the energy storage circuit, and provide a conduction voltage for the preset voltage stabilizing circuit when the alternating current is in a positive half cycle;

[0009] The energy storage circuit is used to store electric energy and provide the turn-on voltage for the preset voltage stabilizing circuit when the alternating current is in the negative half cycle;

[0010] The presettable voltage stabilizing circuit is used to turn itself on when receiving the conduction voltage, stabilize the conduction voltage to a preset voltage, and output positive direct current and negative direct current at the preset voltage.

[0011] Furthermore, the presettable voltage stabilizing circuit includes a linear adjustment module and a voltage follower module; the rectifier and filter circuit supplies power to the presettable voltage stabilizing circuit, and the buck circuit and the energy storage circuit both provide the conduction voltage to the linear adjustment module;

[0012] The linear adjustment module is used for, when receiving the conduction voltage, turning itself on, stabilizing the conduction voltage to a preset voltage, and outputting the preset voltage to the voltage follower module;

[0013] The voltage following module is used to follow the preset voltage and output the positive direct current and the negative direct current at the preset voltage.

[0014] Furthermore, the linear adjustment module includes a switch tube and a voltage clamp submodule; the switch tube is connected in series with the voltage clamp submodule and is electrically connected between the energy storage circuit and the voltage follower module;

[0015] When the switch tube receives the turn-on voltage and turns on, the energy storage circuit is connected to the voltage follower module via the voltage clamping submodule, and the voltage clamping submodule clamps the turn-on voltage to the preset voltage.

[0016] Furthermore, the step-down circuit includes a capacitor C2 and a capacitor C1; the step-down circuit receives the AC power through one end of the capacitor C2 and one end of the capacitor C1, and outputs the conduction voltage through the other end of the capacitor C2;

[0017] The other end of the capacitor C2 is electrically connected to the other end of the capacitor C1.

[0018] Furthermore, the energy storage circuit includes a rectifier tube D1 and a capacitor CE2; the energy storage circuit is electrically connected to the step-down circuit through the anode of the rectifier tube D1, electrically connected to the preset voltage stabilization circuit through the cathode of the rectifier tube D1, and electrically connected to the negative electrode of the output end of the rectifier and filter circuit through the negative electrode of the capacitor CE2;

[0019] The cathode of the rectifier tube D1 is electrically connected to the positive electrode of the capacitor CE2.

[0020] Furthermore, the linear adjustment module includes a resistor R1, a transistor Q1 and a voltage regulator DZ1; the linear adjustment module receives the conduction voltage through the collector of the transistor Q1, outputs the preset voltage through the emitter of the transistor Q1, and is electrically connected to the negative output terminal of the rectifier and filter circuit 1 through the anode of the voltage regulator DZ1;

[0021] One end and the other end of the resistor R1 are electrically connected to the collector and base of the transistor Q1 respectively, and the cathode of the voltage regulator DZ1 is electrically connected to the base of the transistor Q1.

[0022] Furthermore, the voltage follower module includes an operational amplifier U1; the voltage follower module receives the preset voltage through the positive input terminal of the operational amplifier U1, receives power through the positive power supply and negative power supply of the operational amplifier U1, outputs the positive direct current through the positive power supply and output terminal of the operational amplifier U1, and outputs the negative direct current through the negative power supply and output terminal of the operational amplifier U1;

[0023] The positive power supply and the negative power supply of the operational amplifier U1 are electrically connected to the positive output terminal and the negative output terminal of the rectifier and filter circuit 1 respectively. The negative input terminal and the output terminal of the operational amplifier U1 are both grounded.

[0024] Furthermore, the rectifier and filter circuit includes a rectifier bridge B1 and a capacitor CE1; the rectifier and filter circuit receives the alternating current through the positive input terminal and the negative input terminal of the rectifier bridge B1, and supplies power to the preset voltage stabilization circuit through the positive and negative input terminals of the capacitor CE1;

[0025] The positive output terminal and the negative output terminal of the rectifier bridge B1 are electrically connected to the positive electrode and the negative electrode of the capacitor CE1 respectively.

[0026] The technical solution provided by the present invention can include the following beneficial effects: This design first integrates the functions of the switch tube and transformer combination in a traditional linear power supply with a preset voltage-stabilizing circuit. When receiving AC power, it can be divided into two output paths (i.e., VO+ and GND, and VO- and GND) according to preset voltages. This eliminates the space occupied by the transformer and facilitates the miniaturization of the linear power supply. At the same time, the AC power is stepped down by the step-down circuit and then transmitted to the preset voltage-stabilizing circuit via the energy storage circuit. This can effectively reduce the energy consumption of the preset voltage-stabilizing circuit during the positive and negative half-cycles of the AC power, thereby improving the conversion efficiency of the preset voltage-stabilizing circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 The present invention is a circuit diagram of a small-volume, high-conversion-rate linear power supply according to one embodiment of the present invention.

[0028] Among them: rectifier filter circuit 1, preset voltage stabilization circuit 2, step-down circuit 3, energy storage circuit 4, linear adjustment module 21, voltage follower module 22, capacitor C2, capacitor C1, rectifier tube D1, capacitor CE2, resistor R1, transistor Q1, voltage regulator tube DZ1, operational amplifier U1, rectifier bridge B1, capacitor CE1. DETAILED DESCRIPTION

[0029] The following describes embodiments of the present invention in detail. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended only to explain the present invention and are not to be construed as limiting the present invention.

[0030] In the description of the embodiments of the present invention, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include one or more of the described features. In the description of the embodiments of the present invention, "plurality" means two or more, unless otherwise specifically specified.

[0031] In the description of the embodiments of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to direct connections or indirect connections through an intermediate medium; they may refer to internal communication between two components or an interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the embodiments of the present invention based on specific circumstances.

[0032] The following combination Figure 1 , describing a small-volume, high-conversion-rate linear power supply according to an embodiment of the present utility model.

[0033] A small-volume, high-conversion-rate linear power supply includes a rectifier and filter circuit 1, a preset voltage stabilization circuit 2, a step-down circuit 3, and an energy storage circuit 4. AC power is input to the rectifier and filter circuit 1 and the step-down circuit 3 respectively.

[0034] The rectifier and filter circuit 1 is used to rectify and filter the AC power and then supply power to the preset voltage stabilizing circuit 2;

[0035] The step-down circuit 3 is used to reduce the voltage of the AC power and transmit it to the preset voltage stabilizing circuit 2 through the energy storage circuit 4. When the AC power is in the positive half cycle, it provides a conduction voltage for the preset voltage stabilizing circuit 2.

[0036] The energy storage circuit 4 is used to store electrical energy and provide a conduction voltage for the preset voltage stabilizing circuit 2 when the AC power is in the negative half cycle;

[0037] The preset voltage stabilizing circuit 2 is used to turn itself on when receiving a conduction voltage, stabilize the conduction voltage to a preset voltage, and output positive direct current and negative direct current at the preset voltage.

[0038] The present invention proposes a preferred embodiment of a small-volume, high-conversion-rate linear power supply, such as Figure 1 As shown, this design first integrates the functions of the switch tube and transformer combination in a traditional linear power supply with a preset voltage-stabilizing circuit 2. When receiving AC power, it can be divided into two output paths of positive DC power and negative DC power (i.e., VO+ and GND, and VO- and GND) according to a preset voltage. This eliminates the space occupied by the transformer and is conducive to the miniaturization of the linear power supply. At the same time, the AC power is stepped down by the step-down circuit 3 and then transmitted to the preset voltage-stabilizing circuit 2 via the energy storage circuit 4. This can effectively reduce the energy consumption of the preset voltage-stabilizing circuit 2 during the positive and negative half-cycles of the AC power, thereby improving the conversion efficiency of the preset voltage-stabilizing circuit 2.

[0039] Furthermore, the preset voltage stabilizing circuit 2 includes a linear adjustment module 21 and a voltage follower module 22; the rectifier and filter circuit 1 supplies power to the preset voltage stabilizing circuit 2, and the buck circuit 3 and the energy storage circuit 4 both provide a conduction voltage for the linear adjustment module 21;

[0040] The linear adjustment module 21 is used to turn itself on when receiving the conduction voltage, stabilize the conduction voltage to a preset voltage, and output the preset voltage to the voltage follower module 22;

[0041] The voltage follower module 22 is used to follow a preset voltage and output positive direct current and negative direct current at the preset voltage.

[0042] In this embodiment, although the on-state voltage transmitted through the energy storage circuit 4 is stepped down by the step-down circuit 3 to a voltage close to the preset voltage to reduce losses, it is still not equal to the preset voltage and cannot be directly output. Therefore, it is possible to preset the voltage stabilizing circuit 2 so that the linear adjustment module 21 receives the on-state voltage from the AC power in the positive and negative half-cycles to achieve linear conversion and adjustment of the on-state voltage, and then the voltage follower module 22 outputs the positive DC power and the negative DC power according to the adjusted preset voltage.

[0043] Furthermore, the linear adjustment module 21 includes a switch tube and a voltage clamp submodule; the switch tube is connected in series with the voltage clamp submodule, and is electrically connected between the energy storage circuit 4 and the voltage follower module 22;

[0044] When the switch tube receives the conduction voltage and is turned on, the energy storage circuit 4 is connected to the voltage following module 22 via the voltage clamping submodule, and the voltage clamping submodule clamps the conduction voltage to a preset voltage.

[0045] In this embodiment, the linear adjustment module 21 functions by adding a voltage clamping submodule to the switching transistor. The switching transistor performs the linear conversion function. Due to the voltage reduction provided by the step-down circuit 3, the switching transistor experiences a small voltage difference, resulting in minimal losses and improved conversion efficiency when operating in the linear region. Furthermore, the voltage clamping submodule performs the clamping function. During conduction, the voltage clamping submodule clamps the conduction voltage and transmits it to the voltage follower module 22, ensuring the stability of both positive and negative DC power. More importantly, by adjusting the parameters of the voltage clamping submodule, the preset voltage value can be easily changed to suit different application requirements, demonstrating the preset functionality of the preset voltage stabilization circuit 2.

[0046] Furthermore, the step-down circuit 3 includes a capacitor C2 and a capacitor C1; the step-down circuit 3 receives AC power through one end of the capacitor C2 and one end of the capacitor C1, and outputs a conduction voltage through the other end of the capacitor C2;

[0047] The other end of the capacitor C2 is electrically connected to the other end of the capacitor C1 .

[0048] In this embodiment, the step-down circuit 3 is to step down the voltage of the alternating current. Based on the characteristic that the capacitor allows the alternating current to pass, a two-capacitor voltage-dividing structure is preferably used. The voltage of the alternating current is shared by the two capacitors to step down the voltage, and the degree of voltage reduction can be adjusted by adjusting the capacitance values of the two capacitors.

[0049] Furthermore, the energy storage circuit 4 includes a rectifier tube D1 and a capacitor CE2; the energy storage circuit 4 is electrically connected to the step-down circuit 3 through the anode of the rectifier tube D1, is electrically connected to the preset voltage stabilizing circuit 2 through the cathode of the rectifier tube D1, and is electrically connected to the negative electrode of the output terminal of the rectifier and filter circuit 1 through the negative electrode of the capacitor CE2;

[0050] The cathode of the rectifier tube D1 is electrically connected to the positive electrode of the capacitor CE2.

[0051] In this embodiment, the power transmitted by the step-down circuit 3 is still alternating current, so the rectifier tube D1 is used for rectification, and after filtering by the capacitor CE2, it is transmitted to the switch tube of the linear adjustment module 21 for conduction, that is, the alternating current provides a conduction voltage for the preset voltage-stabilizing circuit 2 in the positive half cycle; and when the alternating current is in the negative half cycle, the electric energy stored in the capacitor CE2 in the positive half cycle will be released, so as to provide a conduction voltage for the preset voltage-stabilizing circuit 2 in the negative half cycle.

[0052] Furthermore, the linear adjustment module 21 includes a resistor R1, a transistor Q1, and a voltage regulator DZ1; the linear adjustment module 21 receives a conduction voltage through the collector of the transistor Q1, outputs a preset voltage through the emitter of the transistor Q1, and is electrically connected to the negative output terminal of the rectifier and filter circuit 1 through the anode of the voltage regulator DZ1;

[0053] One end and the other end of the resistor R1 are electrically connected to the collector and base of the transistor Q1 respectively, and the cathode of the voltage regulator tube DZ1 is electrically connected to the base of the transistor Q1.

[0054] In this embodiment, the specific circuit structure of the linear adjustment module 21 is preferably based on the above structure, wherein the switching tube is the transistor Q1, and the voltage clamping submodule is the voltage regulator DZ1. Under the premise that the step-down circuit 3 steps down the AC power, the switching tube does not need to withstand a large voltage difference, energy consumption is reduced, and service life is extended. Therefore, the lower-cost transistor Q1 can be selected as the switching tube. In order to facilitate the voltage clamping submodule to adjust the preset voltage parameters, the voltage regulator DZ1 is preferably used, which can be achieved by replacing a single component.

[0055] Furthermore, the voltage follower module 22 includes an operational amplifier U1; the voltage follower module 22 receives a preset voltage through the positive input terminal of the operational amplifier U1, receives power through the positive power supply and the negative power supply of the operational amplifier U1, outputs positive direct current through the positive power supply and the output terminal of the operational amplifier U1, and outputs negative direct current through the negative power supply and the output terminal of the operational amplifier U1;

[0056] The positive and negative power supply electrodes of the operational amplifier U1 are electrically connected to the positive and negative output terminals of the rectifier and filter circuit 1 respectively. The negative input terminal and output terminal of the operational amplifier U1 are both grounded.

[0057] In this embodiment, the voltage follower module 22 is composed of an operational amplifier U1 to form a voltage follower to realize the voltage following function, and uses the combination of its positive power supply and output end, as well as the negative power supply and output end, to divide the output into positive DC and negative DC, replacing the role of the transformer.

[0058] Furthermore, the rectifier and filter circuit 1 includes a rectifier bridge B1 and a capacitor CE1; the rectifier and filter circuit 1 receives AC power through the positive input terminal and the negative input terminal of the rectifier bridge B1, and supplies power to the preset voltage stabilizing circuit 2 through the positive and negative terminals of the capacitor CE1;

[0059] The positive output terminal and the negative output terminal of the rectifier bridge B1 are electrically connected to the positive electrode and the negative electrode of the capacitor CE1 respectively.

[0060] In this embodiment, the rectifier and filter circuit 1 is composed of a rectifier bridge B1 and a capacitor CE1 , wherein the rectifier bridge B1 is responsible for converting AC power into DC power, and the capacitor CE1 is responsible for filtering the DC power, ultimately supplying power to the presettable voltage stabilizing circuit 2 .

[0061] Other structures and operations of a small-volume, high-conversion-rate linear power supply according to an embodiment of the present invention are known to those skilled in the art and will not be described in detail here.

[0062] Throughout this specification, references to terms such as "embodiment" and "example" indicate that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0063] Although the embodiments of the present invention have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and purpose of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A small-volume, high-conversion-rate linear power supply, characterized by: It includes a rectifier and filter circuit, a preset voltage stabilization circuit, a step-down circuit and an energy storage circuit; AC power is input into the rectifier and filter circuit and the step-down circuit respectively; The rectification and filtering circuit is used to rectify and filter the AC power and then supply power to the preset voltage stabilization circuit; The step-down circuit is used to reduce the voltage of the alternating current and transmit it to the preset voltage stabilizing circuit via the energy storage circuit, and provide a conduction voltage for the preset voltage stabilizing circuit when the alternating current is in a positive half cycle; The energy storage circuit is used to store electric energy and provide the turn-on voltage for the preset voltage stabilizing circuit when the alternating current is in the negative half cycle; The presettable voltage stabilizing circuit is used to turn itself on when receiving the conduction voltage, stabilize the conduction voltage to a preset voltage, and output positive direct current and negative direct current at the preset voltage.

2. The small-volume, high-conversion-rate linear power supply according to claim 1, characterized in that: The presettable voltage stabilizing circuit includes a linear adjustment module and a voltage follower module; the rectifier and filter circuit supplies power to the presettable voltage stabilizing circuit, and the buck circuit and the energy storage circuit both provide the conduction voltage to the linear adjustment module; The linear adjustment module is used for, when receiving the conduction voltage, turning itself on, stabilizing the conduction voltage to a preset voltage, and outputting the preset voltage to the voltage follower module; The voltage following module is used to follow the preset voltage and output the positive direct current and the negative direct current at the preset voltage.

3. The small-volume, high-conversion-rate linear power supply according to claim 2, characterized in that: The linear adjustment module includes a switch tube and a voltage clamp submodule; the switch tube is connected in series with the voltage clamp submodule and is electrically connected between the energy storage circuit and the voltage follower module; When the switch tube receives the turn-on voltage and turns on, the energy storage circuit is connected to the voltage follower module via the voltage clamping submodule, and the voltage clamping submodule clamps the turn-on voltage to the preset voltage.

4. The small-volume, high-conversion-rate linear power supply according to claim 1, characterized in that: The step-down circuit includes a capacitor C2 and a capacitor C1; the step-down circuit receives the AC power through one end of the capacitor C2 and one end of the capacitor C1, and outputs the conduction voltage through the other end of the capacitor C2; The other end of the capacitor C2 is electrically connected to the other end of the capacitor C1.

5. The small-volume, high-conversion-rate linear power supply according to claim 1, characterized in that: The energy storage circuit includes a rectifier tube D1 and a capacitor CE2; the energy storage circuit is electrically connected to the step-down circuit through the anode of the rectifier tube D1, electrically connected to the preset voltage stabilization circuit through the cathode of the rectifier tube D1, and electrically connected to the negative electrode of the output end of the rectifier and filter circuit through the negative electrode of the capacitor CE2; The cathode of the rectifier tube D1 is electrically connected to the positive electrode of the capacitor CE2.

6. The small-volume, high-conversion-rate linear power supply according to claim 3, characterized in that: The linear adjustment module includes a resistor R1, a transistor Q1 and a voltage regulator DZ1; the linear adjustment module receives the conduction voltage through the collector of the transistor Q1, outputs the preset voltage through the emitter of the transistor Q1, and is electrically connected to the negative output terminal of the rectifier and filter circuit 1 through the anode of the voltage regulator DZ1; One end and the other end of the resistor R1 are electrically connected to the collector and base of the transistor Q1 respectively, and the cathode of the voltage regulator DZ1 is electrically connected to the base of the transistor Q1.

7. The small-volume, high-conversion-rate linear power supply according to claim 2, characterized in that: The voltage follower module includes an operational amplifier U1; the voltage follower module receives the preset voltage through the positive input terminal of the operational amplifier U1, receives power through the positive power supply and negative power supply of the operational amplifier U1, outputs the positive direct current through the positive power supply and output terminal of the operational amplifier U1, and outputs the negative direct current through the negative power supply and output terminal of the operational amplifier U1; The positive power supply and the negative power supply of the operational amplifier U1 are electrically connected to the positive output terminal and the negative output terminal of the rectifier and filter circuit 1 respectively. The negative input terminal and the output terminal of the operational amplifier U1 are both grounded.

8. The small-volume, high-conversion-rate linear power supply according to claim 1, characterized in that: The rectifier and filter circuit includes a rectifier bridge B1 and a capacitor CE1; the rectifier and filter circuit receives the AC power through the positive input terminal and the negative input terminal of the rectifier bridge B1, and supplies power to the preset voltage stabilization circuit through the positive and negative input terminals of the capacitor CE1; The positive output terminal and the negative output terminal of the rectifier bridge B1 are electrically connected to the positive electrode and the negative electrode of the capacitor CE1 respectively.

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