Low-voltage high-current dc power conversion circuit

Abstract

The application discloses a low-voltage large-current direct-current power conversion circuit, further comprising an amplifier circuit and a protection circuit, wherein the current-expanding voltage stabilizer comprises a current-expanding resistor and a voltage stabilizer, the current-expanding resistor is connected in parallel with the voltage stabilizer, the amplifier circuit comprises an amplifier, a fourth resistor, a fifth resistor, a ninth resistor, a third triode, a sixth resistor, a seventh resistor and an eighth resistor, and the protection circuit comprises a fourth triode and a protection circuit control chip. In order to avoid the voltage stabilizer out of control, the ripple voltage of the output end is increased, and the amplifier circuit and a bypass circuit are arranged in the circuit, the bypass circuit is also connected in parallel with the voltage stabilizer, the amplifier circuit is used for controlling the bypass circuit, and thus the ripple voltage of the output end is relieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power conversion circuit, in particular to a low-voltage large-current DC power conversion circuit. BACKGROUND

[0002] At present, with the rapid development of power technology, DC power such as mobile power is more and more in people's life, which brings convenience to people's life and study.

[0003] However, the output of some DC power is small when the voltage is low, which cannot meet the power supply or charging demand of the load. However, the current expansion circuit cannot adapt to variable load, otherwise, the voltage stabilizer is out of control when the load is light, and the ripple voltage of the output end is increased. In addition, the current expansion circuit of other expansion circuits has a complex circuit structure and high cost. SUMMARY

[0004] The purpose of the present application is to provide a low-voltage large-current DC power conversion circuit, which can solve the technical problems of voltage stabilizer out of control and relieve the ripple voltage of the output end, and has a simple circuit structure and low cost.

[0005] To achieve the above purpose, the present application provides a technical scheme: a low-voltage large-current DC power conversion circuit, comprising a current expansion voltage stabilizer, an amplifier circuit and a protection circuit, the current expansion voltage stabilizer comprising a current expansion resistor and a voltage stabilizer, the current expansion resistor being connected in parallel with the voltage stabilizer, the amplifier circuit comprising an amplifier, a fourth resistor, a fifth resistor, a ninth resistor, a third triode, a sixth resistor, a seventh resistor and an eighth resistor, the protection circuit comprising a fourth triode and a protection circuit control chip, the non-inverting input end of the amplifier being connected to one end of the fourth resistor, the other end of the fourth resistor being connected to the positive output end of the current expansion voltage stabilizer, the same-phase input end of the amplifier being connected to one end of the fifth resistor and one end of the ninth resistor, the other end of the fifth resistor being connected to one end of the sixth resistor and the emitter of the third triode, the other end of the ninth resistor being connected to the output end of the amplifier and one end of the eighth resistor, the other end of the eighth resistor being connected to the base of the third triode, the collector of the third triode being connected to one end of the seventh resistor and the negative output end of the current expansion voltage stabilizer, the other end of the seventh resistor being connected to the negative output end of the current expansion voltage stabilizer, the other end of the sixth resistor being connected to the positive input end of the current expansion voltage stabilizer, the emitter of the fourth triode being connected to the positive input end of the current expansion voltage stabilizer, the collector of the fourth triode being connected to the output end of the protection circuit control chip, the positive input end of the protection circuit control chip being connected to the positive output end of the current expansion voltage stabilizer, and the negative input end of the protection circuit control chip being connected to the negative output end of the current expansion voltage stabilizer.

[0006] Preferably, the voltage stabilizer comprises a first triode, a second triode, a first capacitor, a first resistor, a second resistor, a voltage stabilizing tube, the emitter of the second triode is connected to the emitter of the fourth triode, one end of the current spreading resistor, one end of the second resistor, and one end of the first capacitor, the other end of the second resistor is connected to the base of the second triode and the collector of the first triode, the emitter of the first triode is connected to one end of the first resistor and one end of the voltage stabilizing tube, the collector of the second triode is connected to the other end of the current spreading resistor, the base of the first triode is connected to one end of the second capacitor, and the other end of the first resistor and the other end of the second capacitor are connected to the negative output end of the current spreading voltage stabilizer.

[0007] Preferably, the voltage stabilizer further comprises a tenth resistor and an eleventh resistor, one end of the tenth resistor is connected to the positive output end of the current spreading voltage stabilizer, the other end of the tenth resistor is connected to one end of the eleventh resistor and the base of the first triode, and the other end of the eleventh resistor is connected to the negative output end of the current spreading voltage stabilizer.

[0008] Preferably, the voltage stabilizer further comprises a third capacitor, one end of the third capacitor is connected to the positive output end of the current spreading voltage stabilizer, and the other end of the third capacitor is connected to the negative output end of the current spreading voltage stabilizer.

[0009] Preferably, the power supply end of the protection circuit control chip is connected in parallel with a capacitor.

[0010] Preferably, the power supply end of the protection circuit control chip is connected with a backup battery.

[0011] Preferably, the protection circuit control chip is selected from NUP4201MR6T1G.

[0012] Compared with the prior art, the present application has the following beneficial effects:

[0013] 1. In order to avoid the loss of control of the voltage stabilizer, the ripple voltage of the output end is increased, and the present application further provides an amplifier circuit and a bypass circuit in the circuit, the bypass circuit is also in parallel with the voltage stabilizer, and the amplifier circuit is used to control the bypass circuit, thereby relieving the ripple voltage of the output end. When the current spreading voltage stabilizer is working normally, the third triode is in a conducting state, and the resistors in the bypass circuit are the sixth resistor and the seventh resistor. Since the seventh resistor is large, it is equivalent to an infinite resistor connected in parallel with the current spreading resistor, and the current flows through the current spreading resistor branch, thereby outputting a large current. When the current spreading voltage stabilizer loses control, the current output by the current spreading voltage stabilizer is compared by the amplifier, and the third triode is controlled to be disconnected by the amplifier output end, so that the resistor in the bypass circuit is the sixth resistor, and the sixth resistor is used to realize the shunt effect, thereby relieving the ripple voltage of the output end.

[0014] 2. When the current is abnormal, the fourth triode is controlled to be disconnected by the protection circuit control chip, so that the entire current spreading voltage stabilizer is disconnected, thereby avoiding the damage of components, and realizing the circuit protection.

[0015] 3、The application is to protect the power supply of the protection circuit control chip, and the power supply end of the protection circuit control chip is connected with a capacitor C31 in parallel.

[0016] 4、The power supply end of the protection circuit control chip of the application is connected with a standby battery, and the protection circuit control chip is separated from the circuit, and the protection circuit control chip can still work normally when the circuit is abnormal.

[0017] 5、The circuit of the application has simple structure, low cost, safety and reliability, and can be widely used.

[0018] The additional aspects and advantages of the present application will be in part apparent and in part pointed out hereinafter in the description. BRIEF DESCRIPTION OF DRAWINGS

[0019] Fig. 1 It is the circuit schematic diagram of the application;

[0020] Fig. 2 It is the circuit schematic diagram of the protection circuit of the application.

[0021] In the figure: R1, first resistor; R2, second resistor; R3, current expansion resistor; R4, fourth resistor; R5, fifth resistor; R6, sixth resistor; R7, seventh resistor; R8, eighth resistor; R9, ninth resistor; R10, tenth resistor; R11, eleventh resistor; C1, first capacitor; C2, second capacitor; C31, capacitor; Q1, first triode; Q2, second triode; Q3, third triode; U1A, amplifier; U6, protection circuit chip; DETAILED DESCRIPTION

[0022] The technical solutions in the embodiments of the application will be clearly and completely described below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the application.

[0023] In the application, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connecting", "fixing" and the like should be understood in a broad sense, for example, can be fixed connection, can be detachable connection, or integral connection; can be mechanical connection, or electrical connection; can be direct connection, or indirect connection through an intermediate medium, or internal communication of two elements. Those skilled in the art can understand the specific meanings of the above terms in the application according to the specific circumstances.

[0024] Referring to Figs. 1-2 The low-voltage large-current DC power conversion circuit provided by the embodiment of the present disclosure comprises a current-expanding voltage stabilizer, an amplifier circuit and a protection circuit. The current-expanding voltage stabilizer comprises a current-expanding resistor R3 and a voltage stabilizer. The current-expanding resistor R3 is connected in parallel with the voltage stabilizer. The amplifier circuit comprises an amplifier U1A, a fourth resistor R4, a fifth resistor R5, a ninth resistor R9, a third transistor Q3, a sixth resistor R6, a seventh resistor R7 and an eighth resistor R8. The protection circuit comprises a fourth transistor and a protection circuit control chip. One end of the fourth resistor R4 is connected to the inverting input terminal of the amplifier U1A. The other end of the fourth resistor R4 is connected to the positive output terminal of the current-expanding voltage stabilizer. One end of the fifth resistor R5 and one end of the ninth resistor R9 are connected to the non-inverting input terminal of the amplifier U1A. The other end of the fifth resistor R5 is connected to one end of the sixth resistor R6 and the emitter of the third transistor Q3. The other end of the ninth resistor R9 is connected to the output terminal of the amplifier U1A and one end of the eighth resistor R8. The other end of the eighth resistor R8 is connected to the base of the third transistor Q3. The collector of the third transistor Q3 is connected to one end of the seventh resistor R7 and the negative output terminal of the current-expanding voltage stabilizer. The other end of the seventh resistor R7 is connected to the negative output terminal of the current-expanding voltage stabilizer. The other end of the sixth resistor R6 is connected to the positive input terminal of the current-expanding voltage stabilizer. The positive input terminal of the current-expanding voltage stabilizer is connected to the emitter of the fourth transistor. The collector of the fourth transistor is connected to the output terminal of the protection circuit control chip. The positive input terminal of the protection circuit control chip is connected to the positive output terminal of the current-expanding voltage stabilizer. The negative input terminal of the protection circuit control chip is connected to the negative output terminal of the current-expanding voltage stabilizer.

[0025] The voltage stabilizer comprises a first transistor Q1, a second transistor Q2, a first capacitor C1, a first resistor R1, a second resistor R2 and a voltage stabilizing tube. The emitter of the second transistor is connected to the emitter of the fourth transistor, one end of the current-expanding resistor R3, one end of the second resistor R2 and one end of the first capacitor C1. The other end of the second resistor R2 is connected to the base of the second transistor Q2 and the collector of the first transistor Q1. The emitter of the first transistor Q1 is connected to one end of the first resistor R1 and one end of the voltage stabilizing tube. The collector of the second transistor Q2 is connected to the other end of the current-expanding resistor R3. The base of the first transistor Q1 is connected to one end of the second capacitor C2. The other end of the first resistor R1 and the other end of the second capacitor C2 are connected to the negative output terminal of the current-expanding voltage stabilizer. One end of the tenth resistor R10 is connected to the positive output terminal of the current-expanding voltage stabilizer,

[0026] In order to further improve the voltage stabilizing function of the circuit, the present application further comprises a tenth resistor R10, an eleventh resistor R11 and a third capacitor C3. The other end of the tenth resistor R10 is connected to one end of the eleventh resistor R11 and the base of the first transistor Q1. The other end of the eleventh resistor R11 is connected to the negative output terminal of the current-expanding voltage stabilizer. One end of the third capacitor C3 is connected to the positive output terminal of the current-expanding voltage stabilizer. The other end of the third capacitor C3 is connected to the negative output terminal of the current-expanding voltage stabilizer.

[0027] The application is to protect the power supply of the protection circuit control chip, and the power supply end of the protection circuit control chip is connected with a capacitor C31 in parallel.

[0028] The power supply end of the protection circuit control chip is connected with a backup battery, and the protection circuit control chip is separated from the circuit, and the protection circuit control chip can still work normally when the circuit is abnormal, and the protection circuit control chip is selected from NUP4201MR6T1G.

[0029] Working principle: in principle, all devices that can increase the output current in parallel with the voltage stabilizer can be used to expand the current, so that the current expansion resistor R3 can expand the output current of the voltage stabilizer after being connected in parallel with the voltage stabilizer, and the voltage stabilizer includes a first transistor Q1, a second transistor Q2, a first capacitor C1, a first resistor R1, a second resistor R2, a voltage stabilizing tube, a tenth resistor R10, an eleventh resistor R11 and a third capacitor C3, and the voltage stabilizing tube and the tenth resistor R10 and the eleventh resistor R11 can play a voltage stabilizing effect.

[0030] In order to avoid the output end of the voltage stabilizer from losing control, an amplifier circuit and a bypass circuit are arranged in the circuit, the bypass circuit is also in parallel with the voltage stabilizer, the amplifier circuit is used to control the bypass circuit, so as to relieve the ripple voltage of the output end. When the current expansion voltage stabilizer works normally, the third electrode tube is in a conductive state, and the resistors in the bypass circuit are the sixth resistor and the seventh resistor. Since the seventh resistor is large, it is equivalent to an infinite resistor connected in parallel with the current expansion resistor, and the current flows through the current expansion resistor branch, and a large current is output. When the current expansion voltage stabilizer loses control, the current output by the current expansion voltage stabilizer is compared by the amplifier, and the third electrode tube is controlled by the amplifier output end to be disconnected, so that the resistor in the bypass circuit is the sixth resistor, and the sixth resistor is used to realize the shunt effect, so as to relieve the ripple voltage of the output end.

[0031] In addition, the current output by the current expansion voltage stabilizer enters the protection circuit control chip, and when the current is abnormal, the fourth transistor is controlled to be disconnected by the protection circuit control chip, so that the entire current expansion voltage stabilizer is disconnected, and damage to components is avoided, thereby realizing circuit protection.

[0032] In the description of the application, it should be understood that the indicated orientation or positional relationship is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the application and simplifying the description, and does not indicate or imply that the indicated device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the application.

[0033] In the description of the specification, reference to "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" means that a particular feature, structure, material, or characteristic being described is included in at least one embodiment or example of the application. The appearances of the above expressions in various places in the specification are not necessarily referring to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics can be combined in any suitable manner in one or more embodiments or examples.

[0034] While embodiments of the application have been shown and described, it is to be understood that the application is not limited to these embodiments. Rather, it is the intention that modifications, changes, substitutions, and variations be made in the embodiments without departing from the spirit and scope of the application, which is defined solely by the claims and their equivalents.

Claims

1. A low voltage, high current, DC power conversion circuit comprising a current-boosting regulator, characterized in that, The amplifier circuit, the protection circuit, the current expansion stabilizer, the current expansion resistor, the stabilizer, the amplifier, the fourth resistor, the fifth resistor, the ninth resistor, the third triode, the sixth resistor, the seventh resistor, the eighth resistor, the fourth triode, the protection circuit control chip, the fourth resistor, the positive output end of the current expansion stabilizer, the fifth resistor, the ninth resistor, the sixth resistor, the emitter of the third triode, the output end of the amplifier, the eighth resistor, the base of the third triode, the seventh resistor, the negative output end of the current expansion stabilizer, the other end of the sixth resistor, the positive input end of the current expansion stabilizer, the emitter of the fourth triode, the collector of the fourth triode, the output end of the protection circuit control chip, the positive output end of the current expansion stabilizer, the negative output end of the current expansion stabilizer, the power supply end of the protection circuit control chip, the capacitor, the backup battery are arranged.

2. The low-voltage high-current DC power conversion circuit of claim 1, wherein The stabilizer, the first triode, the second triode, the first capacitor, the first resistor, the second resistor, the stabilizing tube, the emitter of the fourth triode, the one end of the current expansion resistor, the one end of the second resistor, the one end of the first capacitor, the other end of the second resistor, the base of the second triode, the collector of the first triode, the one end of the first resistor, the one end of the stabilizing tube, the other end of the current expansion resistor, the collector of the second triode, the base of the first triode, the other end of the first resistor, the other end of the second capacitor, the negative output end of the current expansion stabilizer are arranged.

3. The low-voltage high-current DC power conversion circuit of claim 2, wherein, The tenth resistor, the eleventh resistor, the one end of the tenth resistor, the positive output end of the current expansion stabilizer, the other end of the tenth resistor, the one end of the eleventh resistor, the base of the first triode, the other end of the eleventh resistor, the negative output end of the current expansion stabilizer are arranged.

4. The low-voltage high-current DC power conversion circuit of claim 2, wherein, The third capacitor, the one end of the third capacitor, the positive output end of the current expansion stabilizer, the other end of the third capacitor, the negative output end of the current expansion stabilizer are arranged.

5. The low-voltage high-current DC power conversion circuit of claim 1, wherein, The protection circuit control chip is selected from NUP4201MR6T1G.

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