A low-heat voltage stabilizing circuit with wide input voltage range

Abstract

The utility model provides a kind of wide voltage input range low heat generation's voltage stabilizing circuit, including the first voltage divider circuit, voltage reduction circuit and voltage stabilizing circuit connected in turn, voltage reduction circuit includes first switching circuit, second switching circuit, third switching circuit and energy storage circuit, the input end of first switching circuit and second switching circuit is all connected first voltage divider circuit output end, the output end of first switching circuit connects the control end of second switching circuit and ground, the control end of first switching circuit and the input end of third switching circuit are connected, the output end of second switching circuit and the input end of energy storage circuit are connected, the output end of energy storage circuit and the control end of third switching circuit are connected, the output end of third switching circuit is grounded by voltage stabilizing unit, energy storage circuit output end and voltage stabilizing circuit input end are connected, voltage stabilizing circuit output end is used to and load connection.The input voltage range of this circuit is wide, output is stable and the amount of heat is small, cost is lower, practicality is good and applicability is wide.

Description

Technical Field

[0001] This utility model belongs to the field of voltage regulator technology, specifically relating to a voltage regulator circuit with a wide voltage input range and low heat generation. Background Technology

[0002] Many products require compatibility with multiple power supplies. For example, car amplifiers typically need to be compatible with 12V power. These products have small circuit boards and limited space, necessitating a voltage regulator circuit with wide input voltage and low heat generation. Circuits on the market using tri-regulators or DC-DC converters are available to achieve input voltage reduction, such as... Figure 1 As shown, the highest known IC input can only reach 42V and generates significant heat. In addition, there are circuits using transistors for step-down voltage reduction and three-terminal regulator ICs, but these still suffer from significant transistor heat generation; and circuits using transistors for step-down voltage reduction and DC-DC converters are expensive, have many components, and are complex. Summary of the Invention

[0003] In view of the problems existing in the background technology, the purpose of this utility model is to provide a voltage regulator circuit with a wide voltage input range and low heat generation. This circuit has the advantages of low cost, voltage input up to 60V and low heat generation.

[0004] The objective of this utility model can be achieved through the following technical solution: A voltage regulator circuit with a wide voltage input range and low heat generation, comprising a first voltage divider circuit, a step-down circuit, and a voltage regulator circuit connected in sequence. The step-down circuit includes a first switching circuit, a second switching circuit, a third switching circuit, and an energy storage circuit. The input terminals of the first and second switching circuits are both connected to the output terminal of the first voltage divider circuit. The output terminal of the first switching circuit is connected to the control terminal of the second switching circuit and grounded. The control terminal of the first switching circuit is connected to the input terminal of the third switching circuit. The output terminal of the second switching circuit is connected to the input terminal of the energy storage circuit. The output terminal of the energy storage circuit is connected to the control terminal of the third switching circuit. The output terminal of the third switching circuit is grounded through a voltage regulator unit. The output terminal of the energy storage circuit is connected to the input terminal of the voltage regulator circuit. The output terminal of the voltage regulator circuit is used to connect to the load.

[0005] Preferably, the circuit further includes an input voltage protection circuit, which is a first Schottky diode D1. The positive terminal of the first Schottky diode D1 is connected to the output terminal of the first switching circuit, and the negative terminal of the first Schottky diode D1 is connected to the output terminal of the second switch. The output terminal of the first switching circuit and the control terminal of the second switching circuit are both grounded through a second resistor R2.

[0006] Preferably, the first voltage divider circuit is a first resistor R1, and the output terminal of the first resistor R1 is also grounded through a first capacitor C1. The first capacitor C1 is mainly used for input filtering to reduce the impact of input voltage fluctuations on the circuit.

[0007] Preferably, a second capacitor C2 is also connected between the output terminal of the second switching circuit and the control terminal of the first switching circuit.

[0008] Preferably, a second voltage divider circuit is connected between the control terminal of the first switching circuit and the input terminal of the third switching circuit. The second voltage divider circuit is composed of a third resistor R3 and a third capacitor C3 connected in parallel.

[0009] Preferably, the energy storage circuit includes a freewheeling diode D2, an inductor L1, and a fourth capacitor C4. The negative terminal of the freewheeling diode D2 and the first terminal of the inductor L1 are both connected to the output terminal of the second switching circuit. The second terminal of the inductor L1 is connected to the positive terminal of the fourth capacitor C4 and the control terminal of the third switching circuit via a third voltage divider circuit. The positive terminal of the freewheeling diode D2 and the negative terminal of the fourth capacitor C4 are both grounded. The third voltage divider circuit includes a fifth resistor R5 and a sixth resistor R6. The first terminal of the fifth resistor R5 is connected to the second terminal of the inductor L1, and the second terminal of the fifth resistor R5 is connected to the control terminal of the third switching circuit. The first terminal of the sixth resistor R6 is connected to the second terminal of the fifth resistor R5, and the second terminal of the sixth resistor R6 is grounded.

[0010] Preferably, the first switching circuit is a transistor Q1, which is a PNP transistor; the second switching circuit is a switching transistor Q2, which is a PNP transistor or a P-type MOSFET; and the third switching circuit is a transistor Q3, which is an NPN transistor.

[0011] Preferably, the output terminal of the transistor Q3 is also connected to the second terminal of the inductor L1 through the fourth resistor R4, and the voltage regulator unit is the second Schottky diode D2. The positive terminal of the second Schottky diode D2 is grounded, and the negative terminal is connected to the output terminal of the transistor Q3.

[0012] Preferably, the voltage regulator circuit includes a fifth capacitor C5, a three-terminal voltage regulator chip U1, a sixth capacitor C6, and a seventh capacitor C7; the first terminal of the fifth capacitor C5 is connected to the output terminal of the energy storage circuit, and the second terminal is grounded; the input of the three-terminal voltage regulator chip U1 is connected to the first terminal of the fifth capacitor C5, and the output terminal is connected to the first terminals of the sixth capacitor C6 and the seventh capacitor C7 respectively, and the ground terminal is grounded; the second terminals of the sixth capacitor C6 and the seventh capacitor C7 are both grounded.

[0013] Compared with the prior art, the present invention has the following advantages: 1. It only uses transistors and switching transistors to form the front-end step-down circuit, and can be directly modified on the existing solution, so the cost is low; 2. It has a wide input voltage range, with a maximum input voltage of 60V, which meets the needs of most occasions and has wide applicability; 3. The heat generation is half that of the original circuit that directly uses a three-terminal voltage regulator chip. Attached Figure Description

[0014] Figure 1 This is a voltage regulator circuit used in existing technology.

[0015] Figure 2 This is a diagram of the voltage regulator circuit with a wide input voltage range and low heat generation according to this utility model. Detailed Implementation

[0016] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this utility model, and should not be construed as limiting this utility model.

[0017] like Figure 2 As shown, this embodiment provides a voltage regulator circuit with a wide input voltage range and low heat generation, including a first voltage divider circuit, a step-down circuit, and a voltage regulator circuit connected in sequence. The first voltage divider circuit uses a first resistor R1, and the output terminal of the first resistor R1 is also grounded through a first capacitor C1. The first capacitor C1 is preferably a 100uF electrolytic capacitor, mainly used for input filtering and stabilizing the input voltage.

[0018] The step-down circuit comprises four parts: an input voltage protection circuit, a first switching circuit, a second switching circuit, a third switching circuit, and an energy storage circuit. The inputs of both the first and second switching circuits are connected to the output of the first voltage divider circuit. The output of the first switching circuit is connected to the control terminal of the second switching circuit and grounded. The control terminal of the first switching circuit is connected to the input of the third switching circuit. The output of the second switching circuit is connected to the input of the energy storage circuit. The output of the energy storage circuit is connected to the control terminal of the third switching circuit. The output of the third switching circuit is grounded through a voltage regulator unit. The output of the energy storage circuit is connected to the input of the voltage regulator circuit. The output of the voltage regulator circuit is used to connect to the load.

[0019] Specifically, the input voltage protection circuit is a first Schottky diode D1; the first switching circuit is a transistor Q1, which is a PNP transistor; the second switching circuit is a switching transistor Q2, which is either a PNP transistor or a P-type MOSFET; and the third switching circuit is a transistor Q3, which is an NPN transistor. In this embodiment, the switching transistor Q2 is preferably a P-type MOSFET. The anode of the first Schottky diode D1 is connected to the collector of the PNP transistor, and the cathode of the first Schottky diode D1 is connected to the drain of the P-type MOSFET. The collector of the PNP transistor and the gate of the P-type MOSFET are both grounded through a second resistor R2. A second capacitor C2 is also connected between the drain of the P-type MOSFET and the base of the NPN transistor. A second voltage divider circuit is connected between the base of the NPN transistor and the collector of the PNP transistor, and the second voltage divider circuit is composed of a third resistor R3 and a third capacitor C3 connected in parallel. The energy storage circuit includes a freewheeling diode D2, an inductor L1, and a fourth capacitor C4. The cathode of the freewheeling diode D2 and the first terminal of the inductor L1 are both connected to the output of the second switching circuit. The second terminal of the inductor L1 is connected to the anode of the fourth capacitor C4 and, through a third voltage divider circuit, to the base of the NPN transistor. The third voltage divider circuit includes a fifth resistor R5 and a sixth resistor R6. The first terminal of the fifth resistor R5 is connected to the second terminal of the inductor L1, and the second terminal of the fifth resistor R5 is connected to the base of the NPN transistor. The first terminal of the sixth resistor R6 is connected to the second terminal of the fifth resistor R5, and the second terminal of the sixth resistor R6 is grounded. The anode of the freewheeling diode D2 and the cathode of the fourth capacitor C4 are both grounded. The emitter of the NPN transistor is also connected to the second terminal of the inductor L1 through the fourth resistor R4. The voltage regulator is a second Schottky diode D2. The anode of the second Schottky diode D2 is grounded, and the cathode is connected to the output of the transistor Q3.

[0020] The voltage regulator circuit includes a fifth capacitor C5, a three-terminal voltage regulator chip U1, a sixth capacitor C6, and a seventh capacitor C7. The first terminal of the fifth capacitor C5 is connected to the second terminal of the inductor L1, and the second terminal of the fifth capacitor C5 is grounded. The input of the three-terminal voltage regulator chip U1 is connected to the first terminal of the fifth capacitor C5, and the output terminal is connected to the first terminals of the sixth capacitor C6 and the seventh capacitor C7, respectively. The ground terminal is grounded. The second terminals of the sixth capacitor C6 and the seventh capacitor C7 are both grounded.

[0021] The working principle of this utility model is as follows: At the moment the circuit starts, the power supply is first input after being divided by the first resistor R1, and then the second resistor R2 provides a sufficiently large gate current to the P-type MOSFET. The P-type MOSFET is saturated and turned on, and part of its drain current charges the fourth capacitor C4 through the inductor L1 to supply the load, while part of it is stored in the inductor L1. When the voltage across the fourth capacitor C4 rises above 15V, the base potential of the NPN transistor increases, increasing its conduction. This increases the collector current of the NPN transistor, causing the base potential of the PNP transistor to decrease. The PNP transistor's conduction is enhanced, which in turn raises the gate potential of the P-type MOSFET and reduces its current. The potential at the upper end of the second capacitor C2 decreases. Since the voltage across the second capacitor C2 cannot change abruptly, the base potential of the PNP transistor continues to decrease rapidly, causing the gate potential of the P-type MOSFET to rise rapidly until it is quickly turned off. After the P-type MOSFET is turned off, the energy stored in inductor L1 is released to the fourth capacitor C4 and the load through the freewheeling diode D2, reducing the output voltage of inductor L1. When the output voltage of inductor L1 decreases, the base potential of the NPN transistor decreases, weakening its conduction. The base potential of the PNP transistor increases, extending the conduction time of the P-type MOSFET, and the output voltage recovers, thus achieving voltage reduction and regulation. This allows for the output of a lower and more stable voltage to the subsequent voltage regulator circuit, reducing the heat generated during the voltage regulation process. Ultimately, the voltage regulator circuit outputs a stable +12V DC voltage.

[0022] The specific embodiments described herein are merely illustrative examples illustrating the spirit of this utility model. Those skilled in the art to which this utility model pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of this utility model or exceeding the scope defined by the appended claims.

Claims

1. A voltage regulator circuit with a wide input voltage range and low heat generation, characterized in that, The device includes a first voltage divider circuit, a step-down circuit, and a voltage regulator circuit connected in sequence. The step-down circuit includes a first switching circuit, a second switching circuit, a third switching circuit, and an energy storage circuit. The input terminals of the first and second switching circuits are both connected to the output terminal of the first voltage divider circuit. The output terminal of the first switching circuit is connected to the control terminal of the second switching circuit and grounded. The control terminal of the first switching circuit is connected to the input terminal of the third switching circuit. The output terminal of the second switching circuit is connected to the input terminal of the energy storage circuit. The output terminal of the energy storage circuit is connected to the control terminal of the third switching circuit. The output terminal of the third switching circuit is grounded through a voltage regulator unit. The output terminal of the energy storage circuit is connected to the input terminal of the voltage regulator circuit. The output terminal of the voltage regulator circuit is used to connect to the load.

2. The low heat generation voltage regulator circuit with wide input voltage range according to claim 1, characterized in that, It also includes an input voltage protection circuit, which is a first Schottky diode D1. The positive terminal of the first Schottky diode D1 is connected to the output terminal of the first switching circuit, and the negative terminal of the first Schottky diode D1 is connected to the output terminal of the second switch. The output terminal of the first switching circuit and the control terminal of the second switching circuit are both grounded through the second resistor R2.

3. The low heat generation voltage regulator circuit with wide input voltage range according to claim 1 or 2, characterized in that, The first voltage divider circuit is a first resistor R1, and the output terminal of the first resistor R1 is also grounded through a first capacitor C1.

4. The low heat generation voltage regulator circuit with wide input voltage range according to claim 1 or 2, characterized in that, A second capacitor C2 is also connected between the output terminal of the second switching circuit and the control terminal of the first switching circuit.

5. The low heat generation voltage regulator circuit with wide input voltage range according to claim 1 or 2, characterized in that, A second voltage divider circuit is connected between the control terminal of the first switching circuit and the input terminal of the third switching circuit. The second voltage divider circuit is composed of a third resistor R3 and a third capacitor C3 connected in parallel.

6. The low heat generation voltage regulator circuit with wide input voltage range according to claim 1 or 2, characterized in that, The energy storage circuit includes a freewheeling diode D2, an inductor L1, and a fourth capacitor C4. The negative terminal of the freewheeling diode D2 and the first terminal of the inductor L1 are both connected to the output terminal of the second switching circuit. The second terminal of the inductor L1 is connected to the positive terminal of the fourth capacitor C4 and the control terminal of the third switching circuit via a third voltage divider circuit. The positive terminal of the freewheeling diode D2 and the negative terminal of the fourth capacitor C4 are both grounded. The third voltage divider circuit includes a fifth resistor R5 and a sixth resistor R6. The first terminal of the fifth resistor R5 is connected to the second terminal of the inductor L1, and the second terminal of the fifth resistor R5 is connected to the control terminal of the third switching circuit. The first terminal of the sixth resistor R6 is connected to the second terminal of the fifth resistor R5, and the second terminal of the sixth resistor R6 is grounded.

7. The low heat generation voltage regulator circuit with wide input voltage range according to claim 1 or 2, characterized in that, The first switching circuit is transistor Q1, which is a PNP transistor; the second switching circuit is switching transistor Q2, which is a PNP transistor or a P-type MOSFET; the third switching circuit is transistor Q3, which is an NPN transistor.

8. The low heat generation voltage regulator circuit with wide input voltage range according to claim 1 or 2, characterized in that, The output terminal of the third switching circuit is also connected to the second terminal of the fourth resistor R4 and the inductor L1. The voltage regulator unit is the second Schottky diode D2. The positive terminal of the second Schottky diode D2 is grounded, and the negative terminal is connected to the output terminal of the third switching circuit.

9. The low heat generation voltage regulator circuit with wide input voltage range according to claim 1 or 2, characterized in that, The voltage regulator circuit includes a fifth capacitor C5, a three-terminal voltage regulator chip U1, a sixth capacitor C6, and a seventh capacitor C7. The first terminal of the fifth capacitor C5 is connected to the output terminal of the energy storage circuit, and the second terminal is grounded. The input of the three-terminal voltage regulator chip U1 is connected to the first terminal of the fifth capacitor C5, and the output terminal is connected to the first terminals of the sixth capacitor C6 and the seventh capacitor C7, respectively. The ground terminal is grounded. The second terminals of the sixth capacitor C6 and the seventh capacitor C7 are both grounded.

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