CN214674342U - Power protection circuit and electronic equipment - Google Patents
Power protection circuit and electronic equipment Download PDFInfo
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- CN214674342U CN214674342U CN202022805225.8U CN202022805225U CN214674342U CN 214674342 U CN214674342 U CN 214674342U CN 202022805225 U CN202022805225 U CN 202022805225U CN 214674342 U CN214674342 U CN 214674342U
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Abstract
The embodiment of the utility model discloses power protection circuit and electronic equipment, power protection circuit includes first input, the second input, first output, the second output, bleeder circuit, first switch circuit, first signal generation circuit, second switch circuit and prevent flowing backward the circuit, bleeder circuit is used for carrying out the partial pressure to input power, first switch circuit is used for carrying out on-off state's switching based on the voltage that first output was inputed, and export first voltage signal, first signal generation circuit is used for outputting first control signal based on first voltage signal, second switch circuit is used for carrying out on-off state's switching based on first control signal or bleeder circuit's partial pressure, prevent flowing backward the circuit and be used for preventing that the voltage of first output from flowing backward to the voltage of first input. Through the mode, the power supply can be protected from being damaged when abnormal conditions such as reverse connection or short circuit occur on the power supply interface through the pure hardware structure.
Description
Technical Field
The utility model relates to a power electronic technology field especially relates to a power protection circuit and electronic equipment.
Background
The situation of reverse connection or short circuit is inevitable when the power supply is used in daily life, so that the power supply can be damaged by reverse connection or short circuit of the external interface under the condition that the power supply is not provided with related protective measures. For electronic equipment, in order to prevent a user from connecting the positive electrode and the negative electrode reversely, reverse connection protection is usually performed on an interface, for example, the interface is made into a trapezoid or is provided with a notch, and if the power supply is connected reversely, the power supply is not easily inserted into the power supply interface. However, in the above situation, if the user applies too much force during the process of inserting the power into the power interface, the interface may be damaged, thereby directly rendering the electronic device unusable.
Therefore, a reverse connection prevention circuit as shown in fig. 1 appears, however, the circuit needs to adopt a software output signal to the S1 node to control related hardware, that is, the circuit needs software and hardware to cooperate to achieve the purpose of reverse connection prevention, so the method needs to be controlled by software, the control scheme is complex, the implementation difficulty is high, and the cost is high.
SUMMERY OF THE UTILITY MODEL
The embodiment of the utility model provides a aim at providing a power protection circuit and electronic equipment, can realize through pure hardware structure that when abnormal conditions such as reversal or short circuit appear at power source, the protection power is not damaged.
To achieve the above object, in a first aspect, the present invention provides a power protection circuit, including:
the first input end is used for being connected with the positive pole of the input power supply;
a second input terminal for connection with a negative electrode of the input power supply;
the first output end is used for being connected with the anode of the electric equipment;
the second output end is used for being connected with the negative electrode of the electric equipment;
the voltage division circuit is respectively connected with the first input end and the second input end and is used for dividing the voltage of the input power supply;
the first switch circuit is connected with the first output end and used for switching the switch state based on the voltage input by the first output end and outputting a first voltage signal;
a first signal generating circuit connected to an output terminal of the first switching circuit and the first output terminal, the first signal generating circuit being configured to output a first control signal based on the first voltage signal and a voltage input from the first output terminal;
the second switch circuit is connected with the voltage division circuit, the first signal generation circuit, the second input end and the second output end respectively, and is used for switching the switch state based on the first control signal or the voltage division of the voltage division circuit so as to switch the connection state between the second input end and the second output end;
and the backflow prevention circuit is respectively connected with the first input end and the first output end and is used for preventing the voltage of the first output end from flowing backwards into the voltage of the first input end.
In an optional mode, the first switching circuit includes a first capacitor, a first switching tube and a second switching tube;
the two ends of the first capacitor are respectively connected with the control end and the first end of the first switch tube, the control end of the first switch tube is connected with the first output end, the first end of the first switch tube is grounded, the second end of the first switch tube is connected with the control end of the second switch tube, the first end of the second switch tube is connected with the reference power supply, and the second end of the second switch tube is connected with the first signal generating circuit.
In an alternative form, the first signal generating circuit includes a first comparator;
the inverting input end of the first comparator is respectively connected with the output end of the first switch circuit and the ground, and the non-inverting input end of the first comparator is respectively connected with the reference power supply and the first output end.
In an alternative mode, the second switching circuit includes a third switching tube;
the control end of the third switching tube is connected with the output end of the first signal generating circuit, the first end of the third switching tube is connected with the second input end, and the second end of the third switching tube is connected with the second output end.
In an alternative mode, the backflow prevention circuit comprises a first diode;
the anode of the first diode is connected with the first input end and the second switch circuit respectively, and the cathode of the first diode is connected with the first output end.
In an optional manner, the backflow prevention circuit includes a differential amplification circuit, a second signal generation circuit, and a third switch circuit;
the differential amplification circuit is respectively connected with the first input end and the first output end, and is used for outputting a differential amplification signal based on the difference value between the voltage of the first input end and the voltage of the first output end;
the second signal generating circuit is connected with the differential amplifying circuit and is used for outputting a second control signal based on the differential amplifying signal;
the third switch circuit is connected to the second signal generating circuit, and the third switch circuit is configured to switch a switching state based on the second control signal.
In an alternative mode, the differential amplifying circuit includes a first operational amplifier;
the non-inverting input end of the first operational amplifier is connected with the first output end, the inverting input end of the first operational amplifier is connected with the first input end, and the output end of the first operational amplifier is connected with the input end of the second signal generating circuit.
In an alternative form, the second signal generating circuit includes a second comparator;
and the non-inverting input end of the second comparator is respectively connected with the reference power supply and the ground, and the inverting input end of the second comparator is connected with the output end of the differential amplification circuit.
In an optional mode, the third switching circuit comprises a fourth switching tube and a fifth switching tube;
the control end of the fourth switch tube is connected with the output end of the second signal generating circuit, the first end of the fourth switch tube is respectively connected with the second input end and the second switch circuit, the second end of the fourth switch tube is connected with the control end of the fifth switch tube, the first end of the fifth switch tube is connected with the first output end, and the second end of the fifth switch tube is connected with the first input end.
In a second aspect, the embodiments of the present invention further provide an electronic device, where the electronic device includes the power protection circuit as described above.
The embodiment of the utility model provides a beneficial effect is: the utility model provides a power protection circuit includes first input, the second input, first output, the second output, bleeder circuit, first switch circuit, first signal generation circuit, second switch circuit and prevent flowing backward the circuit, wherein, first input is used for being connected with input power's positive pole, the second input is used for being connected with input power's negative pole, first output is used for being connected with consumer's positive pole, the second output is used for being connected with consumer's negative pole, bleeder circuit is used for carrying out the partial pressure to input power, first switch circuit is connected with first output, first switch circuit is used for carrying out on-off state's switching based on the voltage that first output was inputed, and export first voltage signal, first signal generation circuit is connected with first switch circuit's output and first output, first signal generation circuit is used for exporting first control signal based on first voltage signal and the voltage that first output was inputed The second switch circuit is respectively connected with the voltage division circuit, the first signal generation circuit, the second input end and the second output end, the second switch circuit is used for switching the switch state based on the first control signal or the voltage division of the voltage division circuit, so as to switch the connection state between the second input terminal and the second output terminal, the backflow prevention circuit is respectively connected with the first input terminal and the first output terminal, and the backflow prevention circuit is used for preventing the voltage of the first output terminal from flowing backwards to the voltage of the first input terminal, therefore, when the power interface is reversely connected, i.e. the voltage at the second output terminal is equal to the voltage at the second input terminal and is greater than the voltages at the first output terminal and the first input terminal, the second switch circuit is switched to be in a turn-off state through the voltage division of the voltage division circuit, and then the connection state between the second input end and the second output end is in a disconnection state, so that the connection between the second input end and the second output end is disconnected to protect the input power supply; when the power interface is short-circuited, the first control signal output by the first signal generating circuit can control the second switch circuit to be switched to a disconnected state, so that the connection between the second input end and the second output end is disconnected to protect the input power supply; when the positive pole of the electric equipment is higher than the voltage of the positive pole of the input power supply, the backflow prevention circuit can also prevent the voltage of the first output end from flowing backwards into the voltage of the first input end to protect the input power supply, and therefore when the power interface is reversely connected or short-circuited or the positive pole of the electric equipment is higher than the voltage of the positive pole of the input power supply, the input power supply can be protected from being damaged.
Drawings
One or more embodiments are illustrated by way of example in the accompanying drawings, which correspond to the figures in which like reference numerals refer to similar elements and which are not to scale unless otherwise specified.
FIG. 1 is a schematic diagram of a reverse connection prevention circuit provided in the prior art;
fig. 2 is a schematic structural diagram of a power protection circuit according to an embodiment of the present invention;
fig. 3 is a schematic circuit diagram of a power protection circuit according to an embodiment of the present invention;
fig. 4 is a schematic circuit diagram of a power protection circuit according to another embodiment of the present invention;
fig. 5 is a schematic circuit diagram of a power protection circuit according to another embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some embodiments of the present invention, but not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the present invention.
Referring to fig. 2, fig. 2 is a schematic structural diagram of a power protection circuit according to an embodiment of the present invention, as shown in fig. 2, the power protection circuit includes a first input terminal 10, a second input terminal 20, a first output terminal 30, a second output terminal 40, a voltage dividing circuit 50, a first switch circuit 60, a first signal generating circuit 70, a second switch circuit 80, and a backflow preventing circuit 90.
The voltage dividing circuit 50 is connected to the first input terminal 10 and the second input terminal 20, the first switch circuit 60 is connected to the first output terminal 30, the first signal generating circuit 70 is connected to the output terminal of the first switch circuit 60 and the first output terminal 30, the second switch circuit 80 is connected to the voltage dividing circuit 50, the first signal generating circuit 70, the second input terminal 20 and the second output terminal 40, and the backflow preventing circuit 90 is connected to the first input terminal 20 and the first output terminal 40.
Specifically, the voltage dividing circuit 50 is used for dividing the input power; the first switching circuit 60 is capable of switching a switching state between an off state and an on state based on the voltage input from the first output terminal 30, and outputting a first voltage signal to the first signal generating circuit 70; the first signal generating circuit 70 can output a first control signal according to the received first voltage signal and the voltage input by the first output terminal 30, that is, the first voltage signal and the voltage output by the first output terminal 30 are both input signals of the first signal generating circuit 70, and the change conditions of the first voltage signal and the voltage output by the first output terminal 30 are combined to output a corresponding first control signal; the second switch circuit 80 is configured to switch a switch state based on a first control signal or a voltage division of the voltage division circuit 50 to switch a connection state between the second input terminal 20 and the second output terminal 40, where the switch state refers to a switch between an off state and an on state, and the connection state between the second input terminal 20 and the second output terminal 40 refers to a connection state or an off state between the second input terminal 20 and the second output terminal 40, and the first control signal or the voltage division of the voltage division circuit 50 can control the second switch circuit 80.
In practical applications, in normal connection, the first input terminal 10 is connected to the positive pole of the input power source, the second input terminal 20 is connected to the negative pole of the input power source, the first output terminal 30 is connected to the positive pole of the electric device, and the second output terminal is connected to the negative pole of the electric device. At this time, the voltage dividing circuit 50 can divide the input power to control the second switch circuit 80 to be in a conducting state, so that the second input terminal 20 and the second output terminal 40 are in a connected state, and the input power can be used for normally providing the power supply voltage for the electric device.
The interface directly connected to the electric device is referred to as a power interface, that is, in the present embodiment, the first output terminal 30 and the second output terminal 40 are power interfaces.
When the power source interface is reversely connected, that is, the first output terminal 30 is connected to the negative pole of the electric device, the second output terminal 40 is connected to the positive pole of the electric device, and at this time, the first input terminal 10 is connected to the positive pole of the input power source, and the second input terminal 20 is connected to the negative pole of the input power source. If the consumer is also an active load, such as a battery, the input power may be damaged if no measures are taken. Therefore, the voltage division of the input power by the divided voltage 50 can switch the second switch circuit 80 to the off state, so as to disconnect the second input terminal 20 and the second output terminal 40, thereby well protecting the input power from being damaged.
In an embodiment, a power protection circuit shown in fig. 3 is taken as an example to illustrate how to protect an input power when a reverse connection occurs in a power interface.
Referring to fig. 3 IN conjunction with fig. 2, the first input terminal 10 is an IN1 terminal, the second input terminal 20 is an IN2 terminal, the first output terminal 30 is an OUT1 terminal, the second output terminal 40 is an OUT2 terminal, the voltage divider circuit 50 includes a resistor R9 and a resistor R10, and the second switch circuit 80 includes a third switch Q3. The resistor R9 is connected IN series with the resistor R10, one end of the resistor R9 is connected with the IN1 end, the connection point between the resistor R9 and the resistor R10 is connected with the control end of the third switching tube Q3, the first end of the third switching tube Q3 is connected with the IN2 end and one end of the resistor R10 respectively, the second end of the third switching tube Q3 is connected with the OUT2 end, the IN2 end is communicated with the OUT2 end when the third switching tube Q3 is turned on, and the connection between the IN2 end and the OUT2 end is broken when the third switching tube Q3 is turned off.
If the third transistor Q3 is an NMOS transistor, the gate of the NMOS transistor is the control end of the third transistor Q3, the source of the NMOS transistor is the first end of the third transistor Q3, and the drain of the NMOS transistor is the second end of the third transistor Q3.
Under normal operation, the terminal IN1 is connected to the positive pole of the input power, the terminal IN2 is connected to the negative pole of the input power, the terminal OUT1 is connected to the positive pole of the electric device, and the terminal OUT2 is connected to the negative pole of the electric device. At this time, the source of the third switching tube Q3 is connected to the negative electrode of the input power source, that is, the voltage of the source of the third switching tube Q3 is 0, the voltage on the gate of the third switching tube Q3 is the divided voltage of the input power source on the resistor R10, then there is a voltage difference between the gate and the source of the third switching tube Q3, and the voltage of the gate of the third switching tube Q3 is greater than the voltage of the source, and the third switching tube Q3 is an NMOS tube, at this time, the third switching tube Q3 is turned on, the IN2 end is communicated with the OUT2 end, and the input power source and the electric device both work normally.
When the power interface is reversely connected, namely the OUT1 terminal is connected to the negative pole of the electric equipment, and the OUT2 terminal is connected to the electric equipmentThe positive electrode of (1). Since the third transistor Q3 is still turned on at the beginning, when the reverse connection occurs, the drain and gate of the terminal OUT2 through the third transistor Q3 are connected to the terminal OUT1, and at this time, the voltage V at the terminal OUT2OUT2Equal to the voltage V at the IN2 terminalIN2And is greater than voltage V at IN1 terminalIN1Is also greater than the voltage V at the terminal OUT1OUT1I.e. VOUT2＝VIN2>VIN1>VOUT1That is, the voltage at the source of the third switch tube Q3 is VIN2And the voltage of the grid of the third switching tube Q3 is V at mostIN2The voltage is divided by the resistor R9, therefore, the voltage of the gate of the third switching tube Q3 is less than the voltage of the source, the third switching tube Q3 is an NMOS tube, the third switching tube Q3 is turned off, and the connection between the IN2 terminal and the OUT2 terminal is broken, so that the protection of the input power supply is realized when the reverse connection occurs to the power interface.
When the power interface is short-circuited, that is, the first output terminal 30 and the second output terminal 40 are short-circuited, the voltage of the first output terminal 30 is pulled low, so that the first switch circuit 60 can output a corresponding first voltage signal to the first signal generating circuit 70, and meanwhile, the other input terminal of the first signal generating circuit 70 and the first output terminal 30, that is, the input voltage of the other input terminal of the first signal generating circuit 70 also changes, and the first signal generating circuit 70 can output a first control signal to the second switch circuit 80 by combining the two changing processes, so that the second switch circuit 80 is in an off state, thereby disconnecting the second input terminal 20 from the second output terminal 40, and protecting the input power supply from being damaged.
In an embodiment, a power protection circuit shown in fig. 3 is taken as an example to illustrate how to protect an input power when a short circuit occurs in a power interface.
Specifically, the first switch circuit 60 includes a first capacitor C1, a first switch transistor Q1 and a first switch transistor Q2, and the first switch circuit includes a first capacitor C1, a first switch transistor Q1 and a second switch transistor Q2. Assuming that the first switch tube Q1 and the first switch tube Q2 are both triodes, the base of the triode is the control end of the first switch tube Q1 and the first switch tube Q2, the emitter of the triode is the first end of the first switch tube Q1 and the first switch tube Q2, and the collector of the triode is the second end of the first switch tube Q1 and the first switch tube Q2.
The two ends of the first capacitor C1 are connected to the base and emitter of the first switch tube Q1, the base of the first switch tube Q1 is connected to the OUT1, the emitter of the first switch tube Q1 is grounded, the collector of the first switch tube Q1 is connected to the base of the second switch tube Q2, the emitter of the second switch tube Q2 is connected to the reference power supply V1, and the collector of the second switch tube Q2 is connected to the first signal generating circuit 70. The first capacitor C1 can control the on-time of the first switch Q1, and the first switch Q1 is turned on and off based on the voltage across the first capacitor C1, i.e., the input voltage at the OUT1 terminal, and simultaneously controls the on and off of the second switch Q2.
Optionally, the first switch circuit 60 further includes a resistor R1, a resistor R2, and a resistor R3, and the specific connection relationship is shown in fig. 3 and is not described herein again.
In another embodiment, the first signal generating circuit 70 includes a first comparator U1, the inverting input terminal of the first comparator U1 is connected to the output terminal of the first switch circuit 60 and to ground, respectively, and the non-inverting input terminal of the first comparator U1 is connected to the reference power supply V1 and the OUT1, respectively. The first comparator U1 outputs a corresponding control signal to the gate of the third switching transistor Q3 based on the variation of the input voltage at the OUT1 terminal to control the on/off of the third switching transistor Q3.
Optionally, the first signal generating circuit 70 further includes a resistor R4, a resistor R5, a resistor R6, a resistor R7, a resistor R8, a second capacitor C2, and a third capacitor C3, and the specific connection relationship is as shown in fig. 3, which is not described herein again.
In practical applications, in a normal condition, the voltage at the OUT1 end is at a high level, and then the voltage at the OUT1 end is divided by the resistors R1 and R2 and is used as the base input voltage of the first switch tube Q1, that is, the voltage at the base of the first switch tube Q1 is the divided voltage of the voltage at the OUT1 end at the resistor R2, while the emitter of the first switch tube Q1 is grounded, the first switch tube Q1 is turned on, the base of the second switch tube Q2 is connected to the ground through the collector and the emitter of the first switch tube Q1, the emitter of the second switch tube Q2 is connected to the reference power supply V1, the second switch tube Q2 is also turned on, the reference power supply V1 is divided by the resistors R4 and R5, and the divided voltage of the reference power supply V1 at the resistor R5 is the voltage at the inverting input end of the first comparator U1; meanwhile, the voltage difference between the voltage at the OUT1 terminal and the reference power supply V1 (the voltage at the OUT1 terminal is set to be much larger than the reference power supply V1) is divided into a voltage at the non-inverting input terminal of the first comparator U1, and the voltage is larger than the voltage at the inverting input terminal of the first comparator U1, and the first comparator U1 outputs a high-level signal. That is, the first control signal is a high level signal, the third switching tube Q3 is turned on, the IN2 terminal and the OUT2 terminal are connected, and the input power source and the electric device are both IN a normal working state.
When the power interface is short-circuited, the voltage at the OUT1 end is pulled low, the first capacitor C1 is charged instantly, at this time, due to the existence of the first capacitor C1, the first switching tube Q1 is still in a conducting state, the inverting input end of the first comparator U1 is not changed, and the voltage at the inverting input end of the first comparator U1 is still the voltage division of the reference power supply V1 on the resistor R5; on the non-inverting input terminal of the first comparator U1, the voltage at the terminal OUT1 is 0, and the voltage at the non-inverting input terminal of the first comparator U1 is the voltage division of the reference power supply V1 across the resistor R8. Therefore, as long as the resistance value of the selection resistor R8 is smaller than that of the resistor R5, at this time, the voltage of the non-inverting input terminal of the first comparator U1 is smaller than that of the inverting input terminal of the first comparator U1, the first comparator U1 outputs a low-level signal, that is, the first control signal is a low-level signal, the third switch tube Q3 is turned off, and the connection between the IN2 terminal and the OUT2 terminal is disconnected, so that the input power supply is protected when a short-circuit condition occurs IN the power supply interface.
Meanwhile, the first capacitor C1 can discharge through the resistor R2, when the voltage of the first capacitor C1 discharged to the two ends of the first capacitor C1 is not enough to turn on the first switch Q1, the first switch Q1 is turned off, then the second switch Q2 is turned off, the voltage of the inverting input terminal of the first comparator U1 is 0, at this time, the voltage of the non-inverting input terminal of the first comparator U1 is greater than the voltage of the inverting input terminal of the first comparator U1, the first comparator U1 outputs a high level signal, that is, the first control signal is a high level signal, and the third switch Q3 is turned on again to return to the normal condition. However, if the power interface still has a short circuit condition, the protection process for the power supply is executed again.
When the voltage of the first output terminal 30 is higher than the voltage of the first input terminal 10, the backflow prevention circuit 90 can prevent the voltage of the first output terminal 30 from flowing backward into the voltage of the first input terminal 10, thereby protecting the input power.
IN one embodiment, referring to fig. 3 again, the anti-backflow circuit 90 includes a first diode D1, an anode of the first diode D1 is connected to the second switch circuit 50 and the IN1 terminal, and a cathode of the first diode D1 is connected to the OUT1 terminal. By using the unidirectional conductivity of the first diode D1, the voltage of the first output terminal 30 can be prevented from flowing back into the voltage of the first input terminal 10, so as to protect the input power from being damaged.
Further, in other embodiments, the first diode D1 may be referred to as a switch-transistor design related circuit, since the first diode D1 has voltage drop loss and generates heat more seriously when the operating current is larger.
For example, as shown in fig. 4 or fig. 5, the backflow prevention circuit 90 includes a differential amplification circuit 91, a second signal generation circuit 92, and a third switch circuit 93. The differential amplifier circuit 91 is connected to the terminals IN1 and OUT1, respectively, the second signal generator circuit 92 is connected to the differential amplifier circuit 91, and the third switch circuit 93 is connected to the second signal generator circuit 92.
The differential amplification circuit 91 is configured to output a differential amplification signal based on a difference between a voltage at the IN1 terminal and a voltage at the OUT1 terminal, the second signal generation circuit 92 is configured to output a second control signal based on the differential amplification signal, and the third switch circuit 93 is configured to perform switching of a switch state based on the second control signal.
Optionally, the differential amplifying circuit 91 includes a first operational amplifier U2, wherein a non-inverting input terminal of the first operational amplifier U2 is connected to the OUT1 terminal, an inverting input terminal of the first operational amplifier U2 is connected to the IN1 terminal, and an output terminal of the first operational amplifier U2 is connected to an input terminal of the second signal generating circuit 92. The first operational amplifier U2 can amplify and output the difference between the voltages at the IN1 terminal and the OUT1 terminal. Optionally, the second signal generating circuit 92 includes a second comparator U3, wherein the non-inverting input terminal of the second comparator U3 is connected to the reference power supply V1 and the ground AGND, respectively, and the inverting input terminal of the second comparator U3 is connected to the output terminal of the differential amplifying circuit 91, i.e., the inverting input terminal of the second comparator U3 is connected to the output terminal of the first operational amplifier U2.
Optionally, the third switching circuit 93 includes a fourth switching tube Q4 and a fifth switching tube Q5. If the fourth switching tube Q4 is a PMOS tube and the fifth switching tube Q5 is a triode, the corresponding relationship between each pin of the PMOS tube and each port of the fourth switching tube Q4 and the corresponding relationship between each pin of the triode and each port of the fifth switching tube Q5 are similar to those described above, which is within the scope easily understood by those skilled in the art and will not be described herein again.
The base of the fourth switching tube Q4 is connected with the output end of the second signal generating circuit 92, the emitter of the fourth switching tube Q4 is connected with the INT2 end and the second switching circuit 80 respectively, the collector of the fourth switching tube Q4 is connected with the gate of the fifth switching tube Q5, the source of the fifth switching tube Q5 is connected with the OUT1 end, and the drain of the fifth switching tube Q5 is connected with the INT1 end.
Under normal conditions, the voltage of the INT1 terminal is equal to that of the OUT1 terminal, so that the differential amplification signal of the output of the first operational amplifier U2 is 0 or close to 0, and the voltage of the inverting input terminal of the second comparator U3 is 0; the voltage of the non-inverting input end of the second comparator U3 is the divided voltage of the reference power supply V1 on the resistor R17, the voltage of the non-inverting input end of the second comparator U3 is greater than the voltage of the inverting input end of the second comparator U3, the second comparator U3 outputs a high level signal, the fourth switching tube Q4 is turned on, the gate of the fifth switching tube Q5 is connected to the negative electrode of the input power supply through the collector and the emitter of the fourth switching tube Q4, the fifth switching tube Q5 is turned on, the INT1 end is communicated with the OUT1 end, and the input power supply and the electric load are both in a normal working state.
When the voltage at the end OUT1 is greater than the voltage at the end INT1, the voltage value of the differential amplification signal output by the first operational amplifier U2 is greater than the divided voltage of the reference power source V1 on the resistor R17, that is, the voltage at the non-inverting input terminal of the second comparator U3 is less than the voltage at the inverting input terminal of the second comparator U3, the second comparator U3 outputs a low-level signal, the fourth switching tube Q4 is turned off, the fifth switching tube Q5 is also turned off, and the connection between the end INT1 and the end OUT1 is broken, so that the voltage at the end OUT1 is prevented from flowing backwards into the voltage at the end INT 1.
The first switch tube Q1, the second switch tube Q2, the third switch tube Q3, the fourth switch tube Q4 and the fifth switch tube Q5 may be transistors, IGBT switch tubes or MOS transistors, and the first switch tube Q1, the second switch tube Q2, the third switch tube Q3, the fourth switch tube Q4 and the fifth switch tube Q5 may be the same or different, for example, the first switch tube Q1, the second switch tube Q2, the third switch tube Q3, the fourth switch tube Q4 and the fifth switch tube Q5 are all transistors.
The utility model provides a power protection circuit includes first input 10, second input 20, first output 30, second output 40, bleeder circuit 50, first switch circuit 60, first signal generation circuit 70, second switch circuit 80 and prevent flowing backward circuit 90, wherein, first input 10 is used for being connected with the positive pole of input power, second input 20 is used for being connected with the negative pole of input power, first output 30 is used for being connected with the positive pole of consumer, second output 40 is used for being connected with the negative pole of consumer, bleeder circuit 50 is used for carrying out the bleeder circuit to the input power, first switch circuit 60 is connected with first output 30, first switch circuit 60 is used for carrying out switching state based on the voltage that first output 60 inputted, and output first voltage signal, first signal generation circuit 70 is connected with the output of first switch circuit 60 and first output 10, the first signal generating circuit 70 is configured to output a first control signal based on a first voltage signal and a voltage input by the first output terminal 40, the second switch circuit 80 is respectively connected to the voltage dividing circuit 50, the first signal generating circuit 70, the second input terminal 20 and the second output terminal 40, the second switch circuit 80 is configured to switch a switching state based on the first control signal or a voltage division of the voltage dividing circuit 50 to switch a connection state between the second input terminal 20 and the second output terminal 40, the backflow prevention circuit 90 is respectively connected to the first input terminal 10 and the first output terminal 30, the backflow prevention circuit 90 is configured to prevent a voltage of the first output terminal 40 from flowing backward into a voltage of the first input terminal 20, and therefore, when the power interface is connected in a reverse direction, that is, a voltage of the second output terminal 40 is equal to a voltage of the second input terminal 20 and is greater than voltages of the first output terminal 30 and the first input terminal 10, thereby switching the second switch circuit 80 to an off state by the voltage division of the voltage division circuit 50, and then making the connection state between the second input terminal 20 and the second output terminal 40 to an off state, thereby disconnecting the connection between the second input terminal 20 and the second output terminal 40 to protect the input power; when the power interface is short-circuited, the first control signal output by the first signal generating circuit 70 can control the second switching circuit 80 to switch to the off state, so as to disconnect the second input terminal 20 and the second output terminal 40 to protect the input power; when the voltage of the positive electrode of the electric equipment is higher than the voltage of the positive electrode of the input power supply, the backflow prevention circuit 90 can also prevent the voltage of the first output end 30 from flowing backwards into the voltage of the first input end 10 to protect the input power supply, and therefore when the power interface is in a reversed connection or a short circuit or the voltage of the positive electrode of the electric equipment is higher than the voltage of the positive electrode of the input power supply, the input power supply can be protected from being damaged.
Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit it; within the idea of the invention, also technical features in the above embodiments or in different embodiments can be combined, steps can be implemented in any order, and there are many other variations of the different aspects of the invention as described above, which are not provided in detail for the sake of brevity; although the present invention has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present application.
Claims (10)
1. A power protection circuit, comprising:
the first input end is used for being connected with the positive pole of the input power supply;
a second input terminal for connection with a negative electrode of the input power supply;
the first output end is used for being connected with the anode of the electric equipment;
the second output end is used for being connected with the negative electrode of the electric equipment;
the voltage division circuit is respectively connected with the first input end and the second input end and is used for dividing the voltage of the input power supply;
the first switch circuit is connected with the first output end and used for switching the switch state based on the voltage input by the first output end and outputting a first voltage signal;
a first signal generating circuit connected to an output terminal of the first switching circuit and the first output terminal, the first signal generating circuit being configured to output a first control signal based on the first voltage signal and a voltage input from the first output terminal;
the second switch circuit is connected with the voltage division circuit, the first signal generation circuit, the second input end and the second output end respectively, and is used for switching the switch state based on the first control signal or the voltage division of the voltage division circuit so as to switch the connection state between the second input end and the second output end;
and the backflow prevention circuit is respectively connected with the first input end and the first output end and is used for preventing the voltage of the first output end from flowing backwards into the voltage of the first input end.
2. The power protection circuit of claim 1,
the first switch circuit comprises a first capacitor, a first switch tube and a second switch tube;
the two ends of the first capacitor are respectively connected with the control end and the first end of the first switch tube, the control end of the first switch tube is connected with the first output end, the first end of the first switch tube is grounded, the second end of the first switch tube is connected with the control end of the second switch tube, the first end of the second switch tube is connected with the reference power supply, and the second end of the second switch tube is connected with the first signal generating circuit.
3. The power protection circuit of claim 1,
the first signal generating circuit comprises a first comparator;
and the non-inverting input end of the first comparator is respectively connected with the reference power supply and the first output end.
4. The power protection circuit of claim 1,
the second switching circuit comprises a third switching tube;
the control end of the third switching tube is connected with the output end of the first signal generating circuit, the first end of the third switching tube is connected with the second input end, and the second end of the third switching tube is connected with the second output end.
5. The power protection circuit according to any one of claims 1 to 4,
the backflow prevention circuit comprises a first diode;
the anode of the first diode is connected with the first input end and the second switch circuit respectively, and the cathode of the first diode is connected with the first output end.
6. The power protection circuit according to any one of claims 1 to 4,
the backflow prevention circuit comprises a differential amplification circuit, a second signal generation circuit and a third switch circuit;
the differential amplification circuit is respectively connected with the first input end and the first output end, and is used for outputting a differential amplification signal based on the difference value between the voltage of the first input end and the voltage of the first output end;
the second signal generating circuit is connected with the differential amplifying circuit and is used for outputting a second control signal based on the differential amplifying signal;
the third switch circuit is connected to the second signal generating circuit, and the third switch circuit is configured to switch a switching state based on the second control signal.
7. The power protection circuit of claim 6,
the differential amplifying circuit comprises a first operational amplifier;
the non-inverting input end of the first operational amplifier is connected with the first output end, the inverting input end of the first operational amplifier is connected with the first input end, and the output end of the first operational amplifier is connected with the input end of the second signal generating circuit.
8. The power protection circuit of claim 6,
the second signal generating circuit comprises a second comparator;
and the non-inverting input end of the second comparator is respectively connected with the reference power supply and the ground, and the inverting input end of the second comparator is connected with the output end of the differential amplification circuit.
9. The power protection circuit of claim 6,
the third switching circuit comprises a fourth switching tube and a fifth switching tube;
the control end of the fourth switch tube is connected with the output end of the second signal generating circuit, the first end of the fourth switch tube is respectively connected with the second input end and the second switch circuit, the second end of the fourth switch tube is connected with the control end of the fifth switch tube, the first end of the fifth switch tube is connected with the first output end, and the second end of the fifth switch tube is connected with the first input end.
10. An electronic device, characterized in that the electronic device comprises a power protection circuit according to any one of claims 1-9.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202022805225.8U CN214674342U (en) | 2020-11-26 | 2020-11-26 | Power protection circuit and electronic equipment |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202022805225.8U CN214674342U (en) | 2020-11-26 | 2020-11-26 | Power protection circuit and electronic equipment |
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| CN214674342U true CN214674342U (en) | 2021-11-09 |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116505645A (en) * | 2023-06-21 | 2023-07-28 | 灿芯半导体(成都)有限公司 | Escape circuit for coping with built-in power failure |
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2020
- 2020-11-26 CN CN202022805225.8U patent/CN214674342U/en active Active
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116505645A (en) * | 2023-06-21 | 2023-07-28 | 灿芯半导体(成都)有限公司 | Escape circuit for coping with built-in power failure |
| CN116505645B (en) * | 2023-06-21 | 2023-09-12 | 灿芯半导体(成都)有限公司 | Escape circuit for coping with built-in power failure |
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Address after: 518000 19th floor, building 1, kaidar group center building, No. 168, Tongsha Road, Xinwei community, Xili street, Nanshan District, Shenzhen, Guangdong Patentee after: Shenzhen Delian Minghai New Energy Co.,Ltd. Address before: 701-3, building 2, kaidar group center building, 168 Tongsha Road, Xili street, Nanshan District, Shenzhen City, Guangdong Province Patentee before: Shenzhen Poweroak Newener Co.,Ltd. |
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