CN217363048U

CN217363048U - One-way conduction circuit

Info

Publication number: CN217363048U
Application number: CN202220885943.7U
Authority: CN
Inventors: 金业勇; 包建军; 陈贤; 罗克; 王伟; 张立峰; 王维
Original assignee: Tiandi Changzhou Automation Co Ltd; Changzhou Research Institute of China Coal Technology and Engineering Group Corp
Current assignee: Tiandi Changzhou Automation Co Ltd; Changzhou Research Institute of China Coal Technology and Engineering Group Corp
Priority date: 2022-04-18
Filing date: 2022-04-18
Publication date: 2022-09-02
Anticipated expiration: 2032-04-18

Abstract

The utility model discloses a one-way conduction circuit, one-way conduction circuit includes: the voltage divider comprises an input end Vin, an output end Vout, an MOS (metal oxide semiconductor) tube, a current mutual inductance module, a voltage comparator and a voltage dividing module, wherein the input end Vin is connected with the voltage dividing module, the input end Vin is connected with a drain electrode of the MOS tube, a source electrode of the MOS tube is connected with the current mutual inductance module, the current mutual inductance module is connected with the output end Vout, the voltage comparator is connected with the voltage dividing module, the voltage comparator is connected with the current mutual inductance module, and the voltage comparator is connected with a grid electrode of the MOS tube. Therefore, the current can be conducted in one direction, energy loss can be reduced, and charging efficiency can be improved.

Description

One-way conduction circuit

Technical Field

The utility model relates to the technical field of circuits, especially, relate to a one-way conduction circuit.

Background

In practical applications, there are many low-voltage power input scenarios, such as multiple power input buses, lithium battery charging buses, etc., which all need to prevent the input terminal from being damaged due to reverse current flowing back to the input terminal. Currently, the most common way is to connect the schottky diode in series with the power input bus (as shown in fig. 1) by using the unidirectional conduction characteristic of the schottky diode. However, in this way, after the diode is conducted in the forward direction, there is a forward voltage drop (for example, 0.7V for a silicon tube and 0.3V for a germanium tube), and the larger the current, the larger the voltage drop. On one hand, the voltage drop causes obvious power loss and leads to reduction of charging efficiency, and on the other hand, the voltage drop causes lengthening of charging time and the lithium battery has the problem of insufficient charging.

SUMMERY OF THE UTILITY MODEL

The to-be-solved technical problem of the utility model is: in order to solve the mode that utilizes the diode to realize one-way conduction among the prior art, lead to the technical problem that power loss increases, the effect variation of charging, the utility model provides a one-way conduction circuit can reduce energy loss when realizing one-way conduction.

The utility model provides a technical scheme that its technical problem adopted is: a unidirectional conducting circuit comprising: the voltage divider comprises an input end Vin, an output end Vout, an MOS tube, a current mutual inductance module, a voltage comparator and a voltage dividing module, wherein the input end Vin is connected with the voltage dividing module, the input end Vin is connected with a drain electrode of the MOS tube, a source electrode of the MOS tube is connected with the current mutual inductance module, the current mutual inductance module is connected with the output end Vout, the voltage comparator is connected with the voltage dividing module, the voltage comparator is connected with the current mutual inductance module, and the voltage comparator is connected with a grid electrode of the MOS tube. Therefore, the current can be conducted in one direction, energy loss can be reduced, and charging efficiency can be improved.

Further, the current transformer module includes: current transformer U1, sampling resistor R7 and converting resistor R8, current transformer U1 has first pin, second pin and third pin, sampling resistor R7's one end with the source connection of MOS pipe, sampling resistor R7's the other end with output terminal Vout is connected, second pin and second pin respectively with the both ends of sampling resistor R7 are connected, first pin with converting resistor R8's one end is connected, converting resistor R8's the other end ground connection. Therefore, the current transformer U1 can sense the current flowing through the sampling resistor R7, and the conversion resistor R8 can set the magnitude of the no-load voltage.

Further, the current mutual inductance module further comprises a second capacitor C2, one end of the second capacitor C2 is connected to the first pin, and the other end of the second capacitor C2 is grounded. The second capacitor C2 may improve the stability of the voltage at the connection point B.

Further, the voltage dividing module includes: the high-voltage switch comprises a first resistor R1 and a second resistor R2, wherein one end of the first resistor R1 is connected with an input end Vin, the other end of the first resistor R1 is connected with one end of the second resistor R2, and the other end of the second resistor R2 is grounded. The first resistor R1 and the second resistor R2 can set the voltage amplitude at the connection point A.

Further, the voltage comparator includes: the MOS transistor comprises a positive input pin IN +, a negative input pin IN-and an output pin Cvout, wherein the negative input pin IN-is connected with one end of the second resistor R2, the positive input pin IN + is connected with one end of the conversion resistor R8, and the output pin Cvout is connected with the gate of the MOS transistor. Therefore, the voltage comparator can control the turn-off and the turn-on of the MOS tube by comparing the voltage magnitude at the connection points A and B.

Further, the voltage dividing module further comprises: and one end of the first capacitor C1 is connected with one end of the second resistor R2, and the other end of the first capacitor C1 is grounded. The first capacitor C1 can improve the voltage stability at the connection point a.

Further, still include: the anode of the voltage stabilizing diode VD2 is grounded, and the cathode of the voltage stabilizing diode VD2 is connected with the input end Vin.

Further, still include: and one end of the pull-up resistor R6 is connected with the gate of the MOS tube, and the other end of the pull-up resistor R6 is connected with the output end Vout.

Further, still include: and one end of the third capacitor C3 is connected to the output terminal Vout, and the other end of the third capacitor C3 is grounded.

The beneficial effects of the utility model are that, the utility model discloses a mutually supporting of MOS pipe, the mutual inductance module of electric current, voltage comparator and partial pressure module can realize the one-way conduction of electric current to can reduce energy loss, improve charge efficiency. The voltage comparator can control the on and off of the MOS tube by comparing the voltage at the connection points A and B. The utility model discloses simple structure, it is with low costs, the range of application is wide.

Drawings

The present invention will be further explained with reference to the drawings and examples.

Fig. 1 is a schematic diagram of a prior art one-way conduction circuit.

Fig. 2 is a schematic diagram of the unidirectional conducting circuit of the present invention.

Fig. 3 is a schematic diagram of the current transformer module of the present invention.

In the figure: 1. an MOS tube; 2. a current mutual inductance module; 3. a voltage comparator; 4. a voltage division module; 21. a first pin; 22. a second pin; 23. and a third pin.

Detailed Description

The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic drawings and illustrate the basic structure of the present invention only in a schematic manner, and thus show only the components related to the present invention.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", and the like, indicate the orientation or positional relationship indicated based on the drawings, and are only for convenience of description and simplicity of description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore, should not be construed as limiting the present invention. Furthermore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless otherwise specified.

In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood in specific cases to those skilled in the art.

As shown in fig. 2, the utility model discloses a unidirectional circuit, include: the voltage source driving circuit comprises an input end Vin, an output end Vout, an MOS tube 1, a current mutual inductance module 2, a voltage comparator 3 and a voltage dividing module 4, wherein the input end Vin is connected with the voltage dividing module 4, the input end Vin is connected with a drain electrode of the MOS tube 1, a source electrode of the MOS tube 1 is connected with the current mutual inductance module 2, the current mutual inductance module 2 is connected with the output end Vout, the voltage comparator 3 is connected with the voltage dividing module 4, the voltage comparator 3 is connected with the current mutual inductance module 2, and the voltage comparator 3 is connected with the voltage dividing module 4The gate of the MOS transistor 1 is connected. In this embodiment, the MOS transistor 1 is a P-type MOS transistor, and the MOS transistor 1 has three legs, generally G (gate), D (drain) and S (source), when V is a characteristic of PMOS _GS When the voltage is smaller than Vt (threshold voltage), MOS tube 1 is turned on, otherwise MOS tube 1 is turned off. When the input end Vin is suspended and the output end Vout is connected with a power supply (namely, reverse current exists), the current transformer module 2 can generate no-load voltage VB1, the voltage divider module 4 can generate voltage VA1, the voltages VB1 and VA1 are loaded into the voltage comparator 3, and the voltage comparator 3 can output high level to the gate of the MOS transistor 1, so that the MOS transistor 1 is cut off, and the reverse current cannot be reversely output from the input end Vin. When the input end Vin is connected with a power supply and the output end Vout is suspended, the current mutual inductance module 2 can generate a voltage VB2, the voltage division module 4 can generate a voltage VA2, the voltages VB2 and VA2 are loaded into the voltage comparator 3, and the voltage comparator 3 can output a low level to the grid electrode of the MOS tube 1, so that the MOS tube 1 is conducted, and the forward current can be ensured to supply power to a load. In other words, the utility model discloses a mutually supporting of MOS pipe 1, the mutual inductance module of electric current 2, voltage comparator 3 and partial pressure module 4 can realize the one-way conduction of circuit to can reduce the energy loss of circuit.

The current transformer module 2 includes: the current transformer U1, the sampling resistor R7 and the conversion resistor R8, the current transformer U1 is provided with a first pin 21, a second pin 22 and a third pin 23, one end of the sampling resistor R7 is connected with the source electrode of the MOS transistor 1, the other end of the sampling resistor R7 is connected with the output end Vout, the second pin 22 and the third pin 23 are respectively connected with two ends of the sampling resistor R7, the first pin 21 is connected with one end of the conversion resistor R8, and the other end of the conversion resistor R8 is grounded. Specifically, the second pin 22 and the third pin 23 are input terminals, the first pin 21 is an output terminal, the current transformer U1 can sense a current flowing through the sampling resistor R7, so as to generate a sense current, the sense current is output from the first pin 21, when the sense current flows through the converting resistor R8, a voltage VB can be generated at the connection point B, the voltage VB is a product of a resistance value of the R8 and the sense current, and a resistance value of the converting resistor R8 is 10K Ω. The current transformer module 2 further includes a second capacitor C2, one end of the second capacitor C2 is connected to the first pin 21, and the other end of the second capacitor C2 is grounded. The second capacitor C2 is a bypass capacitor, which can ensure the stability of the voltage at the connection point B. In this embodiment, the resistance of the sampling resistor R7 is preferably 33m Ω, and the internal resistance of the MOS transistor 1 is also small, so that the voltage drop generated when the current flows through is almost zero, and the energy loss of the whole circuit can be reduced.

The voltage dividing module 4 includes: the switch circuit comprises a first resistor R1 and a second resistor R2, wherein one end of the first resistor R1 is connected with an input end Vin, the other end of the first resistor R1 is connected with one end of the second resistor R2, and the other end of the second resistor R2 is grounded. When a forward current is input to the input terminal Vin, the forward current flows through the first resistor R1 and the second resistor R2 to generate a divided voltage VA at the connection point a, where VA is Vin × R2/(R1+ R2), the resistance of the first resistor R1 is 1M Ω, and the resistance of the second resistor R2 is 150K Ω. The voltage dividing module 4 further includes: one end of the first capacitor C1 and one end of the first capacitor C1 are connected to one end of the second resistor R2, and the other end of the first capacitor C1 is grounded. The first capacitor C1 is a bypass capacitor, which can ensure the stability of the voltage at the connection point a.

The voltage comparator 3 includes: the positive input pin IN +, the negative input pin IN-and the output pin Cvout, the negative input pin IN-is connected with one end of the second resistor R2, the positive input pin IN + is connected with one end of the conversion resistor R8, and the output pin Cvout is connected with the grid of the MOS tube 1. The voltage comparator 3 further has a positive electrode pin and a negative electrode pin, the positive electrode pin is used for connecting a power supply to supply power to the voltage comparator 3, and the negative electrode pin is used for grounding. According to the characteristics of the voltage comparator 3, when V _IN+ Greater than V _IN- When the output pin Cvout can output high level, when V _IN+ Less than V _IN- The output pin Cvout may output a low level. Specifically, the positive input pin IN + is connected with the connection point B, the negative input pin IN-is connected with the connection point a, the connection point a is a reference point for dividing voltage by resistors and can be used as a reference point, the voltage at the connection point B is related to induced current and can be used as a detection and judgment point, when the MOS transistor 1 is turned off, the first resistor R1 and the second resistor R2 do not generate power consumption, namely, the voltage at the connection point a is zero, when the MOS transistor 1 is turned on, the connection point a can generate divided voltage, the voltage VA is greater than the voltage VB, and the voltages VB and VA can be compared by the voltage comparator 3And comparing to output corresponding level signals. The level signal is input to the grid of the MOS tube 1, and the on and off of the MOS tube 1 can be controlled.

The unidirectional conduction circuit may further include: a voltage stabilizing diode VD2, a pull-up resistor R6 and a third capacitor C3. The anode of the voltage stabilizing diode VD2 is grounded, the cathode of the voltage stabilizing diode VD2 is connected with the input end Vin, and when the input voltage of the input end Vin is too high, the voltage stabilizing diode VD2 can stabilize the input voltage below 6V, so that all components in the circuit can work within a safety range. One end of the pull-up resistor R6 is connected with the grid of the MOS transistor 1, the other end of the pull-up resistor R6 is connected with the output end Vout, and the response speed of the on and off of the MOS transistor 1 can be adjusted by setting the resistance value of the pull-up resistor R6. One end of the third capacitor C3 is connected to the output terminal Vout, the other end of the third capacitor C3 is grounded, and the third capacitor C3 is a filter capacitor, so that the stability of the output voltage of the circuit can be ensured, and unnecessary alternating current components can be filtered out.

The utility model discloses a theory of operation is:

when the input end Vin is suspended and the output end Vout is connected with a power supply, the unidirectional conducting circuit does not generate current, at this time, the current transformer U1 does not collect current and generates no-load current (i.e., the current transformer U1 can output a current of 1 to 20 microamperes), the no-load current flows through the conversion resistor R8, a no-load voltage VB1 is generated at the connection point B, and the no-load voltage VB1 is loaded to the positive input end IN + of the voltage comparator 3; since the input terminal Vin is floating, the voltage VA1 generated by the first resistor R1 and the second resistor R2 at the connection point a is equal to 0, the voltage VA1 is applied to the negative input pin IN — of the voltage comparator 3, at this time, VB1> VA1, the voltage comparator 3 outputs a high level, and the high level is applied to the gate of the MOS transistor 1, so that the MOS transistor 1 is turned off.

When the input end Vin is connected with a power supply and the output end Vout is suspended, the unidirectional conduction circuit generates charging current because Vin > Vout, at the moment, the current transformer U1 collects reverse current to generate monk induced current, the induced current flows through the transfer resistor R8, voltage VB2 is generated at the connection point B, voltage VB2 is loaded to the positive input end IN + of the voltage comparator 3, because the input end Vin is connected with the power supply, voltage VA2 is generated at the connection point A, voltage VA2 is loaded to the negative input pin IN-of the voltage comparator 3, at the moment, VA2> VB2, the voltage comparator 3 outputs low level, and the low level is loaded to the grid electrode of the MOS tube 1, so that the MOS tube 1 is conducted.

In other words, when the input terminal Vin and the output terminal Vout are in a normal operating state, the MOS transistor 1 can be normally turned on, and the circuit can operate normally. When the input end Vin and the output end Vout are connected reversely, the MOS tube 1 is cut off, and the circuit is prevented from being damaged.

The utility model discloses utilize the size that reverse current can be responded to the mutual module 2 of electric current, produce different induced voltage, can distinguish the back discharge condition through voltage comparator 3 to control the shutoff of MOS pipe 1. Adopt the technical scheme of the utility model, under the condition that does not influence the normal work of circuit, quiescent current is under 200 μ A (show the utility model discloses a circuit static power dissipation is low), and can discern reverse current, improves the security.

In light of the foregoing, it will be apparent to those skilled in the art from this disclosure that various changes and modifications can be made without departing from the spirit and scope of the invention. The technical scope of the present invention is not limited to the content of the specification, and must be determined by the scope of the claims.

Claims

1. A unidirectional turn-on circuit, comprising: the voltage divider comprises an input end Vin, an output end Vout, an MOS (metal oxide semiconductor) tube (1), a current mutual inductance module (2), a voltage comparator (3) and a voltage dividing module (4), wherein the input end Vin is connected with the voltage dividing module (4), the input end Vin is connected with the drain electrode of the MOS tube (1), the source electrode of the MOS tube (1) is connected with the current mutual inductance module (2), the current mutual inductance module (2) is connected with the output end Vout, the voltage comparator (3) is connected with the voltage dividing module (4), the voltage comparator (3) is connected with the current mutual inductance module (2), and the voltage comparator (3) is connected with the grid electrode of the MOS tube (1).

2. A unidirectional turn-on circuit according to claim 1, characterized in that said current transformer module (2) comprises: current transformer U1, sampling resistor R7 and converting resistor R8, current transformer U1 has first pin (21), second pin (22) and third pin (23), sampling resistor R7's one end with the source of MOS pipe (1) is connected, sampling resistor R7's the other end with output Vout is connected, second pin (22) and third pin (23) respectively with sampling resistor R7's both ends are connected, first pin (21) with converting resistor R8's one end is connected, converting resistor R8's the other end ground connection.

3. A unidirectional turn-on circuit according to claim 2, characterized in that the current transformer module (2) further comprises a second capacitor C2, one end of the second capacitor C2 is connected to the first pin (21), and the other end of the second capacitor C2 is connected to ground.

4. A unidirectional turn-on circuit according to claim 2, characterized in that said voltage dividing module (4) comprises: the circuit comprises a first resistor R1 and a second resistor R2, wherein one end of the first resistor R1 is connected with an input end Vin, the other end of the first resistor R1 is connected with one end of the second resistor R2, and the other end of the second resistor R2 is grounded.

5. A unidirectional turn-on circuit according to claim 4, characterized in that the voltage comparator (3) comprises: the MOS transistor comprises a positive input pin IN +, a negative input pin IN-and an output pin Cvout, wherein the negative input pin IN-is connected with one end of the second resistor R2, the positive input pin IN + is connected with one end of the conversion resistor R8, and the output pin Cvout is connected with the grid electrode of the MOS transistor (1).

6. A unidirectional conduction circuit according to claim 4, characterized in that said voltage dividing module (4) further comprises: and one end of the first capacitor C1 is connected with one end of the second resistor R2, and the other end of the first capacitor C1 is grounded.

7. The unidirectional turn-on circuit of claim 1, further comprising: the anode of the voltage stabilizing diode VD2 is grounded, and the cathode of the voltage stabilizing diode VD2 is connected with the input end Vin.

8. The unidirectional turn-on circuit of claim 1, further comprising: one end of the pull-up resistor R6 is connected with the grid of the MOS tube (1), and the other end of the pull-up resistor R6 is connected with the output end Vout.

9. A unidirectional conduction circuit as claimed in claim 1, further comprising: and one end of the third capacitor C3 is connected to the output terminal Vout, and the other end of the third capacitor C3 is grounded.