High-precision voltage-limiting and current-stabilizing detection circuit

Abstract

The utility model discloses a high-precision voltage-limiting and current-stabilizing detection circuit, which comprises a voltage detection branch and a current detection branch. The circuit has the functions of voltage detection and current detection, uses universal discrete devices, is common in the market, easy to obtain, low in price, reliable in quality, high in control precision and large in power, and is not limited by special materials. The problem of replacement cycle caused by production halt of a special chip is effectively avoided, and the method is not limited by the delivery period of special materials.

Description

Technical Field

[0001] The utility model relates to the technical field of circuits, in particular to a high-precision voltage-limiting and current-stabilizing detection circuit. Background Art

[0002] When charging a battery, large ripple current can cause harmonic heating or flicker, necessitating voltage and current control within the charging circuit. Existing charging power supplies mostly utilize dedicated, highly integrated chips to achieve this. These chips incorporate peripheral circuitry, such as inductors and capacitors, to form the basic voltage and current stabilization units of a buck or boost topology.

[0003] Existing technologies use dedicated chips, which have limited power and can only be used in small charging devices. At the same time, most of these chips are imported, and delivery and prices are difficult to predict, which will lead to unstable product delivery or cost uncertainty. Products using dedicated chips are usually non-isolated, which brings environmental uncertainty to the product's use, and reliability and anti-interference performance are difficult to grasp. Utility Model Content

[0004] In view of the defects in the prior art, the present invention provides a high-precision voltage-limiting and current-stabilizing detection circuit to solve the technical problems raised in the background technology.

[0005] A high-precision voltage-limiting and current-stabilizing detection circuit includes a voltage detection branch and a current detection branch; wherein,

[0006] The voltage detection branch includes a first voltage dividing unit, a first voltage triggering unit, and a detection feedback unit. The first voltage dividing unit is connected to the charging circuit. The first voltage triggering unit is configured to control the detection feedback unit to output a trigger signal when detecting that the voltage on the first voltage dividing unit is greater than or equal to a set first voltage threshold.

[0007] The current detection branch includes a current acquisition unit, a second voltage divider unit, a second voltage trigger unit and the detection feedback unit; the current acquisition unit is connected to the charging circuit, and the current acquisition unit acquires and amplifies the current signal output by the charging circuit; the second voltage divider unit is connected to the output end of the current acquisition unit to convert the current signal into a voltage signal; the second voltage trigger unit is configured to control the detection feedback unit to output a trigger signal when it detects that the voltage on the second voltage divider unit is greater than or equal to a set second voltage threshold.

[0008] Furthermore, the charging circuit has a positive voltage detection output and a negative voltage detection output, and the negative voltage detection output is grounded;

[0009] The first voltage dividing unit includes a third resistor R3, a fourth resistor R4 and a seventh resistor R7 connected in series between the voltage detection output positive and the ground, and the first voltage triggering unit is configured to collect the voltage value on the seventh resistor R7;

[0010] The detection feedback unit and the first voltage trigger unit are connected in series between the voltage detection output positive and the ground.

[0011] Furthermore, the first voltage trigger unit includes a first voltage regulator, the model of the first voltage regulator is TL431, and the first voltage threshold is 2.5V;

[0012] The reference electrode of the first voltage regulator is connected between the fourth resistor R4 and the seventh resistor R7; the cathode of the first voltage regulator is connected to the detection feedback unit; and the anode of the first voltage regulator is grounded.

[0013] Furthermore, the detection feedback unit includes a first resistor R1, a second resistor R2 and an optocoupler N1, the first resistor R1 and the second resistor R2 are connected in series between the positive voltage detection output and the cathode of the first regulator, the control side of the optocoupler N1 is connected in parallel with the second resistor R2, and the controlled side of the optocoupler N1 outputs a trigger signal.

[0014] Furthermore, a voltage detection threshold adjustment unit is connected between the fourth resistor R4 and the seventh resistor R7. The voltage detection threshold adjustment unit includes a fifth resistor R5 and a sixth resistor R6 connected in parallel. The fifth resistor R5 and the sixth resistor R6 are connected in series with switches and then grounded.

[0015] Furthermore, the charging circuit has a positive current detection output and a negative current detection output, and the negative current detection output is grounded;

[0016] The current acquisition unit includes an operational amplifier and a proportional amplification loop connected between the output terminal and the inverting terminal of the operational amplifier, and the non-inverting terminal of the operational amplifier is positively connected to the current detection output;

[0017] The second voltage dividing unit is connected to the output terminal of the operational amplifier.

[0018] Further, the second voltage dividing unit includes an eighth resistor R8, a twelfth resistor R12 and a fifteenth resistor R15 connected in series between the output terminal of the operational amplifier and the ground;

[0019] The second voltage trigger unit is configured to collect the voltage value of the fifteenth resistor R15;

[0020] The detection feedback unit and the second voltage trigger unit are connected in series between the voltage detection output positive and the ground.

[0021] Furthermore, the second voltage trigger unit includes a second voltage regulator, the model of the second voltage regulator is TLV431, and the second voltage threshold is 1.25V;

[0022] The reference electrode of the second voltage stabilizer is connected between the twelfth resistor R12 and the fifteenth resistor R15; the cathode of the second voltage stabilizer is connected to the second resistor R2; and the anode of the second voltage stabilizer is grounded.

[0023] Furthermore, a current detection threshold adjustment unit is connected between the eighth resistor R8 and the twelfth resistor R12. The current detection threshold adjustment unit includes a thirteenth resistor R13 and a fourteenth resistor R14 connected in parallel. The thirteenth resistor R13 and the fourteenth resistor R14 are connected in series with switches and then grounded.

[0024] The beneficial effects of the present invention are as follows:

[0025] This circuit has voltage and current detection functions. It uses commonly available, low-priced, and reliable discrete components. It also offers high control accuracy and high power without the limitations of specialized materials. This effectively avoids the replacement cycle associated with discontinued specialized chips, and is not subject to the delivery constraints of specialized materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly describes the drawings required for the specific embodiments or the description of the prior art. Similar elements or parts are generally identified by similar reference numerals throughout the drawings. Elements or parts in the drawings are not necessarily drawn to scale.

[0027] Figure 1 A structural block diagram of a high-precision voltage-limiting and current-stabilizing detection circuit provided by an embodiment of the utility model;

[0028] Figure 2 A circuit diagram of a high-precision voltage-limiting and current-stabilizing detection circuit provided by an embodiment of the utility model. DETAILED DESCRIPTION

[0029] The following embodiments of the present invention are described in further detail with reference to the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0030] In the description of this utility model, unless otherwise specified, "plurality" means two or more; the terms "upper," "lower," "left," "right," "inner," "outer," "front end," "rear end," "head," "tail," etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings and are intended solely to facilitate the description of this utility model and simplify the description. They do not indicate or imply that the devices or components referred to must have a specific direction, be constructed, or operate in a specific direction, and therefore should not be construed as limiting this utility model. Furthermore, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0031] In the description of this utility model, it should be noted that, unless otherwise specified or limited, the terms "connected" and "connection" should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integral connection; mechanical connection, electrical connection; direct connection, or indirect connection through an intermediary. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on the specific circumstances.

[0032] like Figure 1 As shown, the utility model provides a high-precision voltage-limiting and current-stabilizing detection circuit, comprising a voltage detection branch and a current detection branch. The voltage detection branch comprises a first voltage divider unit, a first voltage trigger unit, and a detection feedback unit. The first voltage divider unit is connected to the charging circuit; the first voltage trigger unit is configured to control the detection feedback unit to output a trigger signal when it detects that the voltage on the first voltage divider unit is greater than or equal to a set first voltage threshold. The current detection branch comprises a current acquisition unit, a second voltage divider unit, a second voltage trigger unit, and the detection feedback unit. The current acquisition unit is connected to the charging circuit and acquires and amplifies the current signal output by the charging circuit. The second voltage divider unit is connected to the output end of the current acquisition unit to convert the current signal into a voltage signal. The second voltage trigger unit is configured to control the detection feedback unit to output a trigger signal when it detects that the voltage on the second voltage divider unit is greater than or equal to a set second voltage threshold.

[0033] Specifically, such as Figure 2 As shown, the charging circuit has a positive voltage detection output P1 and a negative voltage detection output P2, wherein the negative voltage detection output P2 is connected to ground. The first voltage divider unit includes a third resistor R3, a fourth resistor R4, and a seventh resistor R7 connected in series between the positive voltage detection output P1 and ground. The first voltage trigger unit is configured to collect the voltage value across the seventh resistor R7. The detection feedback unit and the first voltage trigger unit are connected in series between the positive voltage detection output P1 and ground.

[0034] Furthermore, the first voltage trigger unit includes a first voltage regulator N2, the model of the first voltage regulator N2 is TL431, and the first voltage threshold is 2.5 V. The reference electrode of the first voltage regulator N2 is connected between the fourth resistor R4 and the seventh resistor R7; the cathode of the first voltage regulator N2 is connected to the detection feedback unit; and the anode of the first voltage regulator N2 is grounded.

[0035] Furthermore, the detection feedback unit includes a first resistor R1, a second resistor R2 and an optocoupler N1, the first resistor R1 and the second resistor R2 are connected in series between the voltage detection output positive P1 and the cathode of the first regulator N2, the control side of the optocoupler N1 is connected in parallel with the second resistor R2, and the controlled side of the optocoupler N1 outputs a trigger signal.

[0036] Furthermore, a voltage detection threshold adjustment unit is connected between the fourth resistor R4 and the seventh resistor R7. The voltage detection threshold adjustment unit includes a fifth resistor R5 and a sixth resistor R6 connected in parallel. The fifth resistor R5 and the sixth resistor R6 are respectively connected in series with a switch K1 and then grounded. The switch K1 is a dip switch.

[0037] Furthermore, the charging circuit has a positive current detection output P5 and a negative current detection output P6. The negative current detection output P6 is grounded and has the same potential as the negative voltage detection output P2. The current acquisition unit includes an operational amplifier N3B and a proportional amplification circuit connected between the output and inverting terminals of the operational amplifier N3B. The amplification factor of the operational amplifier N3B on the non-inverting terminal input is adjusted by setting the resistance value of the proportional amplification circuit. The non-inverting terminal of the operational amplifier N3B is connected to the positive current detection output P5.

[0038] The second voltage divider unit is connected to the output terminal of the operational amplifier N3B. The second voltage divider unit includes an eighth resistor R8, a twelfth resistor R12, and a fifteenth resistor R15 connected in series between the output terminal of the operational amplifier N3B and ground. The second voltage trigger unit is configured to collect the voltage value across the fifteenth resistor R15. The detection feedback unit and the second voltage trigger unit are connected in series between the voltage detection output positive terminal P1 and ground.

[0039] Furthermore, the second voltage trigger unit includes a second voltage regulator N4, the model of the second voltage regulator N4 is TLV431, and the second voltage threshold is 1.25 V. The reference electrode of the second voltage regulator N4 is connected between the twelfth resistor R12 and the fifteenth resistor R15; the cathode of the second voltage regulator N4 is connected to the second resistor R2; and the anode of the second voltage regulator N4 is grounded.

[0040] Furthermore, a current detection threshold adjustment unit is connected between the eighth resistor R8 and the twelfth resistor R12. The current detection threshold adjustment unit includes a thirteenth resistor R13 and a fourteenth resistor R14 connected in parallel. The thirteenth resistor R13 and the fourteenth resistor R14 are respectively connected in series with a switch K2 and then grounded. The switch K2 is a dip switch.

[0041] Working principle:

[0042] The core component of the voltage detection branch is N2. The control voltage signal across P1 and P2 is obtained through voltage division by R3, R4, and R7. When the control voltage signal reaches N2's reference voltage (2.5V), N2 outputs a low resistance, allowing a larger current to flow through N1's control side. This reduces the resistance between P3 and P4 on N1's controlled side, thus achieving voltage detection.

[0043] The core component of the current detection circuit is N4. The operational amplifier N3B amplifies the tiny current signal between P5 and P6 into a current signal with a larger amplitude. Then, when the signal divided by R8, R12 and R15 reaches the reference voltage value of N4 (1.25V), N2 will output low resistance, allowing a larger current to flow through the control side of N1, reducing the resistance between P3 and P4 on the controlled side of N1, thereby realizing current detection.

[0044] By adjusting the resistance value of the voltage detection threshold adjustment unit connected in parallel to the voltage detection branch through switch K1, the voltage detection threshold of the entire high-precision voltage-limiting and current-stabilizing detection circuit is adjusted; by adjusting the resistance value of the current detection threshold adjustment unit connected in parallel to the current detection branch through switch K2, the current detection threshold of the entire high-precision voltage-limiting and current-stabilizing detection circuit is adjusted.

[0045] In summary, this circuit has both voltage and current detection functions. It uses commonly available, low-priced, and reliable discrete components. It also offers high control precision and high power without the limitations of specialized materials. This effectively avoids the replacement cycle associated with discontinued specialized chips, and eliminates the lead time constraints of specialized materials.

[0046] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and description of the present invention.

Claims

1. A high-precision voltage-limiting and current-stabilizing detection circuit, characterized in that: It includes a voltage detection branch and a current detection branch; wherein, The voltage detection branch includes a first voltage dividing unit, a first voltage triggering unit and a detection feedback unit, wherein the first voltage dividing unit is connected to the charging circuit; the first voltage triggering unit is configured to control the detection feedback unit to output a trigger signal when it is detected that the voltage on the first voltage dividing unit is greater than or equal to a set first voltage threshold; The current detection branch includes a current acquisition unit, a second voltage divider unit, a second voltage trigger unit and the detection feedback unit; the current acquisition unit is connected to the charging circuit, and the current acquisition unit acquires and amplifies the current signal output by the charging circuit; the second voltage divider unit is connected to the output end of the current acquisition unit to convert the current signal into a voltage signal; the second voltage trigger unit is configured to control the detection feedback unit to output a trigger signal when it is detected that the voltage on the second voltage divider unit is greater than or equal to a set second voltage threshold.

2. A high-precision voltage-limiting and current-stabilizing detection circuit as claimed in claim 1, characterized in that: The charging circuit has a positive voltage detection output and a negative voltage detection output, and the negative voltage detection output is grounded; The first voltage dividing unit includes a third resistor R3, a fourth resistor R4 and a seventh resistor R7 which are sequentially connected in series between the voltage detection output positive and the ground, and the first voltage triggering unit is configured to collect the voltage value on the seventh resistor R7; The detection feedback unit and the first voltage trigger unit are connected in series between the voltage detection output positive and the ground.

3. A high-precision voltage-limiting and current-stabilizing detection circuit as claimed in claim 2, characterized in that: The first voltage trigger unit includes a first voltage regulator, the model of the first voltage regulator is TL431, and the first voltage threshold is 2.5V; The reference electrode of the first voltage stabilizer is connected between the fourth resistor R4 and the seventh resistor R7; the cathode of the first voltage stabilizer is connected to the detection feedback unit; and the anode of the first voltage stabilizer is grounded.

4. A high-precision voltage-limiting and current-stabilizing detection circuit as claimed in claim 3, characterized in that: The detection feedback unit includes a first resistor R1, a second resistor R2 and an optocoupler N1. The first resistor R1 and the second resistor R2 are connected in series between the positive voltage detection output and the cathode of the first regulator. The control side of the optocoupler N1 is connected in parallel with the second resistor R2. The controlled side of the optocoupler N1 outputs a trigger signal.

5. A high-precision voltage-limiting and current-stabilizing detection circuit as claimed in claim 4, characterized in that: A voltage detection threshold adjustment unit is also connected between the fourth resistor R4 and the seventh resistor R7. The voltage detection threshold adjustment unit includes a fifth resistor R5 and a sixth resistor R6 connected in parallel. The fifth resistor R5 and the sixth resistor R6 are connected in series with switches and then grounded.

6. A high-precision voltage-limiting and current-stabilizing detection circuit as claimed in claim 4, characterized in that: The charging circuit has a positive current detection output and a negative current detection output, and the negative current detection output is grounded; The current acquisition unit comprises an operational amplifier and a proportional amplification loop connected between the output terminal and the inverting terminal of the operational amplifier, and the inverting terminal of the operational amplifier is positively connected to the current detection output; The second voltage dividing unit is connected to the output end of the operational amplifier.

7. A high-precision voltage-limiting and current-stabilizing detection circuit as claimed in claim 6, characterized in that: The second voltage dividing unit comprises an eighth resistor R8, a twelfth resistor R12 and a fifteenth resistor R15 which are connected in series in sequence between the output terminal of the operational amplifier and the ground; The second voltage trigger unit is configured to collect the voltage value on the fifteenth resistor R15; The detection feedback unit and the second voltage trigger unit are connected in series between the voltage detection output positive and the ground.

8. A high-precision voltage-limiting and current-stabilizing detection circuit as claimed in claim 7, characterized in that: The second voltage trigger unit includes a second voltage regulator, the model of the second voltage regulator is TLV431, and the second voltage threshold is 1.25V; The reference electrode of the second voltage stabilizer is connected between the twelfth resistor R12 and the fifteenth resistor R15; the cathode of the second voltage stabilizer is connected to the second resistor R2; and the anode of the second voltage stabilizer is grounded.

9. A high-precision voltage-limiting and current-stabilizing detection circuit as claimed in claim 8, characterized in that: A current detection threshold adjustment unit is also connected between the eighth resistor R8 and the twelfth resistor R12. The current detection threshold adjustment unit includes a thirteenth resistor R13 and a fourteenth resistor R14 connected in parallel. The thirteenth resistor R13 and the fourteenth resistor R14 are connected in series with switches and then grounded.

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