CN113820619A - Short circuit detection circuit, electronic device and short circuit detection method - Google Patents
Short circuit detection circuit, electronic device and short circuit detection method Download PDFInfo
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- CN113820619A CN113820619A CN202110826079.3A CN202110826079A CN113820619A CN 113820619 A CN113820619 A CN 113820619A CN 202110826079 A CN202110826079 A CN 202110826079A CN 113820619 A CN113820619 A CN 113820619A
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/50—Testing of electric apparatus, lines, cables or components for short-circuits, continuity, leakage current or incorrect line connections
- G01R31/52—Testing for short-circuits, leakage current or ground faults
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R1/00—Details of instruments or arrangements of the types included in groups G01R5/00 - G01R13/00 and G01R31/00
- G01R1/36—Overload-protection arrangements or circuits for electric measuring instruments
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/40—Testing power supplies
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Abstract
The invention relates to a short circuit detection circuit, an electronic device and a short circuit detection method, wherein the short circuit detection circuit is used for connecting a power supply circuit and a load circuit, and comprises the following steps: the voltage divider comprises a first connecting end, a second connecting end, a voltage dividing circuit, a voltage sampling circuit, a first switch circuit, a second switch circuit, a first switch driving circuit and a second switch driving circuit; the first connecting end is connected with the second connecting end through a voltage division circuit and a first switch circuit which are connected in series; the first switch driving circuit is connected with the first switch circuit; the first connecting end is also connected with the second connecting end through a second switch circuit and is conducted with the second connecting end when the second switch circuit is conducted; the second switch driving circuit is connected with the second switch circuit; the voltage sampling circuit is connected with the voltage division circuit and used for obtaining the voltage division of the voltage division circuit when the first switch circuit is conducted. The invention can realize the detection of the short-circuit state of the circuit in advance and effectively prevent the damage of the short-circuit heavy current to the circuit device.
Description
Technical Field
The present invention relates to the field of electronic circuit technologies, and in particular, to a short circuit detection circuit, an electronic device, and a short circuit detection method.
Background
In the use process of the power supply circuit, the short circuit of the working circuit may occur to damage the power supply. Current BMS, power supplies, etc. output, which typically employ current sensing to determine whether a short circuit condition has occurred. Because the power output is short-circuited, a large current can be generated, the current also has a certain time delay, and the delayed large current can generate a larger stress on devices in the circuit, so that the failure of the devices is easily caused, the service life of the circuit is reduced, and safety accidents are caused during the circuit.
Disclosure of Invention
The present invention is directed to a short circuit detection circuit, an electronic device and a short circuit detection method, which are used to overcome some of the above technical disadvantages of the prior art.
The technical scheme adopted by the invention for solving the technical problems is as follows: a short circuit detection circuit is configured for connection between a power supply circuit and a load circuit, comprising: the voltage divider comprises a first connecting end, a second connecting end, a voltage dividing circuit, a voltage sampling circuit, a first switch circuit, a second switch circuit, a first switch driving circuit and a second switch driving circuit;
the first connecting end is used for connecting the output end of the power supply circuit;
the second connecting end is used for connecting the input end of the load circuit;
the first connecting end is connected with the second connecting end through the voltage dividing circuit and the first switch circuit which are connected in series, and is conducted with the second connecting end when the first switch circuit is conducted;
the first switch driving circuit is connected with the first switch circuit and used for receiving a first control level to output a first driving level to drive the first switch circuit to be switched on or switched off;
the first connecting end is also connected with the second connecting end through the second switch circuit and is conducted with the second connecting end when the second switch circuit is conducted;
the second switch driving circuit is connected with the second switch circuit and used for receiving a second control level to output a second driving level to drive the second switch circuit to be switched on or switched off;
the voltage sampling circuit is connected with the voltage division circuit and used for acquiring the voltage division of the voltage division circuit when the first switch circuit is conducted.
Preferably, in the short-circuit detection circuit of the present invention, the first connection terminal is configured to connect to a negative output terminal of the power supply circuit, and the second connection terminal is configured to connect to a negative input terminal of the load circuit; the voltage division circuit comprises a resistor R1 and a resistor R2;
a first end of the resistor R2 is connected to the first connection terminal, a second end of the resistor R2 is connected to the second connection terminal through the first switch circuit and the resistor R1, which are connected in series, and a second end of the resistor R2 is connected to the voltage sampling circuit.
Preferably, in the short circuit detection circuit of the present invention, the first switch circuit includes a MOS transistor M1;
the first end of the MOS transistor M1 is connected with the second end of the resistor R2, the second end of the MOS transistor M1 is connected with the second connection end through the resistor R1, and the third end of the MOS transistor M1 is connected with the first switch driving circuit; or
The first end of the MOS transistor M1 is connected to the second end of the resistor R2 through the resistor R1, the second end of the MOS transistor M1 is connected to the second connection terminal, and the third end of the MOS transistor M1 is connected to the first switch driving circuit.
Preferably, in the short circuit detection circuit of the present invention, the first switch driving circuit includes a transistor Q1, a transistor Q2, a transistor Q3, a diode D2, a resistor R3, a resistor R4, a resistor R5, a resistor R6, a resistor R7, a resistor R8, and a resistor R9;
a base of the transistor Q2 is connected to a first terminal of the resistor R4 and a first terminal of the resistor R3, a second terminal of the resistor R4 is configured to receive the first control level, a second terminal of the resistor R3 and an emitter of the transistor Q2 are grounded, and a collector of the transistor Q2 is connected to the first terminal of the resistor R5;
a second terminal of the resistor R5 is connected to the base of the transistor Q1 and the first terminal of the resistor R6, a second terminal of the resistor R6 is connected to the emitter of the transistor Q1, a second terminal of the resistor R6 is configured to receive a supply voltage, and a collector of the transistor Q1 is connected to the first terminal of the resistor R7;
the second end of the resistor R7 is connected to the anode of the diode D2, the base of the transistor Q3 and the first end of the resistor R8, the second end of the resistor R18 and the collector of the transistor Q3 are grounded, the emitter of the transistor Q3 is connected to the cathode of the diode D2 and the first end of the resistor R9, and the second end of the resistor R9 is connected to the third end of the MOS transistor M1.
Preferably, in the short circuit detection circuit of the present invention, the first switching circuit includes a transistor Q8, a resistor R25, and a resistor R26;
a collector of the transistor Q8 is connected to the second terminal of the resistor R2, an emitter of the transistor Q8 is connected to the second connection terminal through the resistor R1, a base of the transistor Q8 is connected to the first terminal of the resistor R25 and the first terminal of the resistor R26, the second terminal of the resistor R25 is connected to the first switch driving circuit, and the second terminal of the resistor R26 is connected to the emitter of the transistor Q8;
or
The collector of the triode Q8 is connected to the second end of the resistor R2 through the resistor R1, the emitter of the triode Q8 is connected to the second connection terminal, the base of the triode Q8 is connected to the first end of the resistor R25 and the first end of the resistor R26, the second end of the resistor R25 is connected to the first switch driving circuit, and the second end of the resistor R26 is connected to the emitter of the triode Q8.
Preferably, in the short circuit detection circuit of the present invention, the first switch driving circuit includes a transistor Q7, a resistor R23, and a resistor R24;
the base of the transistor Q7 is connected to the first terminal of the resistor R24 and the first terminal of the resistor R23, and the second terminal of the resistor R24 is used for receiving the first driving level.
Preferably, in the short-circuit detection circuit of the present invention, the first connection terminal is configured to be connected to a positive output terminal of the power supply circuit, the second connection terminal is configured to be connected to a positive input terminal of the load circuit, the voltage dividing circuit includes a resistor R38 and a resistor R39, a first end of the resistor R38 is connected to the second connection terminal, a second end of the resistor R38 is connected to the first end of the resistor R39 and the voltage sampling circuit, and a second end of the resistor R39 is grounded.
Preferably, in the short circuit detection circuit of the present invention, the first switch circuit includes a MOS transistor M4 and a resistor R37;
the first end of the MOS transistor M4 is connected to the first connection end, the second end of the MOS transistor M4 is connected to the first end of the resistor R37, the second end of the resistor R37 is connected to the second connection end, and the third end of the MOS transistor M4 is connected to the first switch driving circuit.
Preferably, in the short circuit detection circuit of the present invention, the first switch driving circuit includes a transistor Q11, a resistor R35, a resistor R36, and a resistor R32;
an emitter of the transistor Q11 is grounded, a base of the transistor Q11 is connected to a first end of the resistor R32, a second end of the resistor R32 is configured to receive the first driving level, a collector of the transistor Q11 is connected to a third end of the MOS transistor M4 and a first end of the resistor R36 through the resistor R35, and a second end of the resistor R36 is connected to the first connection terminal.
Preferably, in the short circuit detection circuit of the present invention, the second switch circuit includes a MOS transistor M2;
the first end of the MOS transistor M2 is connected to the first connection end, the second end of the MOS transistor M2 is connected to the second connection end, and the third end of the MOS transistor M2 is connected to the second driving circuit.
Preferably, in the short circuit detection circuit of the present invention, the second switch driving circuit includes a transistor Q4, a transistor Q5, a transistor Q6, a diode D3, a resistor R10, a resistor R11, a resistor R12, a resistor R13, a resistor R14, a resistor R15, and a resistor R16;
a base of the transistor Q5 is connected to a first terminal of the resistor R11 and a first terminal of the resistor R10, a second terminal of the resistor R11 is configured to receive the second control level, a second terminal of the resistor R10 and an emitter of the transistor Q5 are grounded, and a collector of the transistor Q5 is connected to the first terminal of the resistor R13;
a second terminal of the resistor R13 is connected to the base of the transistor Q4 and the first terminal of the resistor R14, a second terminal of the resistor R14 is connected to the emitter of the transistor Q4, a second terminal of the resistor R14 is configured to receive a supply voltage, and a collector of the transistor Q4 is connected to the first terminal of the resistor R15;
the second end of the resistor R15 is connected to the anode of the diode D3, the base of the transistor Q6 and the first end of the resistor R12, the second end of the resistor R12 and the collector of the transistor Q6 are grounded, the emitter of the transistor Q6 is connected to the cathode of the diode D3 and the first end of the resistor R16, and the second end of the resistor R16 is connected to the third end of the MOS transistor M2.
Preferably, in the short circuit detection circuit of the present invention, the second switch driving circuit includes a transistor Q10, a resistor R31, a resistor R33, and a resistor R34;
the base of the triode Q10 is connected to the first end of the resistor R31, the second end of the resistor R31 is configured to receive the second driving level, the collector of the triode Q10 is connected to the first end of the resistor R33, the second end of the resistor R33 is connected to the first end of the resistor R34 and the third end of the MOS transistor M2, and the second end of the resistor R34 is connected to the first connection terminal.
Preferably, in the short circuit detection circuit of the present invention, a controller is further included,
the controller is used for outputting the first control level or the second control level, or
The voltage sampling circuit is integrated with the controller.
In addition, the present invention also provides an electronic device including: a supply circuit, a load circuit and a short circuit detection circuit as described in any of the above; wherein the content of the first and second substances,
the first connecting end of the short-circuit detection circuit is connected with the output end of the power supply circuit, and the second connecting end of the short-circuit detection circuit is connected with the input end of the load circuit.
In addition, the present invention provides a short circuit detection method applied to the short circuit detection circuit as described in any one of the above, including the steps of:
s1, when the first connection end has power input, triggering the first switch driving unit to drive the first switch circuit to be conducted, and triggering the second switch driving unit to drive the second switch circuit to be turned off;
s2, obtaining the voltage division of the voltage division circuit, judging whether the voltage division meets a preset range, if so, executing S3, and if not, executing S4;
s3, judging that the load circuit is short-circuited, triggering the first switch driving unit to drive the first switch circuit to be turned off, and ending;
and S4, judging that the load circuit is normal, triggering the first switch driving unit to drive the first switch circuit to be turned off, and triggering the second switch driving unit to drive the second switch circuit to be turned on.
The short circuit detection circuit and the electronic device have the following beneficial effects: the short-circuit state of the circuit can be detected in advance, and the circuit device is effectively prevented from being damaged by short-circuit large current.
Drawings
The invention will be further described with reference to the accompanying drawings and examples, in which:
FIG. 1 is a schematic diagram of a short circuit detection circuit according to an embodiment of the present invention;
FIG. 2 is a schematic circuit diagram of an embodiment of a short circuit detection circuit of the present invention;
FIG. 3 is a circuit schematic of another embodiment of a short detection circuit of the present invention;
FIG. 4 is a circuit schematic of another embodiment of a short detection circuit of the present invention;
fig. 5 is a schematic flowchart of an embodiment of a short circuit detection method according to the present invention.
Detailed Description
For a more clear understanding of the technical features, objects and effects of the present invention, embodiments of the present invention will now be described in detail with reference to the accompanying drawings.
As shown in fig. 1, in a first embodiment of a short circuit detection circuit of the present invention, for connecting between a power supply circuit 210 and a load circuit 220, the short circuit detection circuit includes: a first connection terminal 110, a second connection terminal 160, a voltage dividing circuit 120, a voltage sampling circuit 150, a first switch circuit 131, a second switch circuit 132, a first switch driving circuit 141, and a second switch driving circuit 142; the first connection terminal 110 is used for connecting an output terminal of the power supply circuit 210; the second connection terminal 160 is used for connecting the input terminal of the load circuit 220; the first connection terminal 110 is connected to the second connection terminal 160 through the voltage dividing circuit 120 and the first switch circuit 131 connected in series, and is conducted with the second connection terminal 160 when the first switch circuit 131 is conducted; the first switch driving circuit 141 is connected to the first switch circuit 131, and configured to receive a first control level to output a first driving level to drive the first switch circuit 131 to turn on or turn off; the first connection terminal 110 is further connected to the second connection terminal 160 through the second switch circuit 132, and is conducted with the second connection terminal 160 when the second switch circuit 132 is conducted; the second switch driving circuit 142 is connected to the second switch circuit 132, and configured to receive a second control level to output a second driving level to drive the second switch circuit 132 to turn on or turn off; the voltage sampling circuit 150 is connected to the voltage dividing circuit 120, and is configured to obtain a divided voltage of the voltage dividing circuit 120 when the first switch circuit 131 is turned on. Specifically, the short circuit detection circuit is used for being connected between the power supply circuit 210 and the load circuit 220, wherein the first connection end 110 is connected to the output end of the power supply circuit 210, the second connection end 160 is connected to the input end of the load circuit 220, the first connection end 110 and the second connection end 160 are connected through two paths, one path is composed of the voltage dividing circuit 120 and the first switch circuit 131 which are connected in series, the first switch circuit 131 is driven to be turned on or turned off through the first switch driving circuit 141, the other path is composed of the second switch circuit 132, and the second switch circuit 132 is driven to be turned on or turned off through the second switch driving circuit 142. In the process of detecting the short circuit, the first switch driving unit may output the first driving level to drive the first switch circuit 131 to be turned on, and the voltage sampling circuit 150 may obtain the divided voltage of the voltage dividing circuit 120 at this time, and may determine whether the load circuit 220 has a short circuit according to the divided voltage. For example, in an embodiment, under normal conditions, when the load circuit 220 is not short-circuited, the divided voltage of the voltage dividing circuit 120 is small, and when the load circuit 220 is short-circuited, the divided voltage of the voltage dividing circuit 120 is large, so that the short-circuit determination result of the load circuit 220 can be obtained according to the voltage.
As shown in fig. 2 and fig. 3, in an embodiment, the first connection terminal 110 is used for connecting to the negative output terminal of the power supply circuit 210, and the second connection terminal 160 is used for connecting to the negative input terminal of the load circuit 220; the voltage divider circuit 120 includes a resistor R1 and a resistor R2; the first terminal of the resistor R2 is connected to the first connection terminal 110, the second terminal of the resistor R2 is connected to the second connection terminal 160 through the first switch circuit 131 and the resistor R1 connected in series, and the second terminal of the resistor R2 is connected to the voltage sampling circuit 150. Specifically, one end of the detection circuit is connected to the negative output terminal of the power supply circuit 210, and the other end is connected to the negative input terminal of the load circuit 220, that is, the detection circuit is connected to the negative terminal of the power supply path of the load circuit 220. The voltage divider circuit 120 is composed of a resistor R1 and a resistor R2 which are directly or indirectly connected in series, and is connected in series with the first switch circuit 131, and when the first switch circuit 131 is turned on, the voltage sampling circuit 150 obtains a voltage division between the resistor R1 and the resistor R2.
Optionally, as shown in fig. 2, the first switching circuit 131 includes a MOS transistor M1; the first end of the MOS transistor M1 is connected to the second end of the resistor R2, the second end of the MOS transistor M1 is connected to the second connection terminal 160 through the resistor R1, and the third end of the MOS transistor M1 is connected to the first switch driving circuit 141; specifically, the first switch circuit 131 may be formed by a MOS transistor M1, the resistor R1 and the resistor R2 are indirectly connected in series through the MOS transistor M1, and the gate (corresponding to the third terminal) of the MOS transistor M1 is connected to the first switch driving circuit 141 to drive the first switch driving circuit to turn on or off, and when the MOS transistor M1 is turned on, the resistor R1 and the resistor R2 are connected in series to form a voltage divider. When the output is short-circuited, the voltage Vout-of the second connection terminal is pulled to be at a high potential, which is close to Vout +, and the voltage across the detection resistor R2 can be used to determine the Vout-potential, thereby determining that the circuit corresponding to the output terminal is short-circuited.
Optionally, the first terminal of the MOS transistor M1 is connected to the second terminal of the resistor R2 through the resistor R1, the second terminal of the MOS transistor M1 is connected to the second connection terminal 160, and the third terminal of the MOS transistor M1 is connected to the first switch driving circuit 141. That is, the resistor R1 and the resistor R2 may be directly connected in series. And is connected to the second connection terminal 160 through the MOS transistor M1 after the series connection.
Optionally, the first switch driving circuit 141 includes a transistor Q1, a transistor Q2, a transistor Q3, a diode D2, a resistor R3, a resistor R4, a resistor R5, a resistor R6, a resistor R7, a resistor R8, and a resistor R9; a base of the transistor Q2 is connected to a first end of the resistor R4 and a first end of the resistor R3, a second end of the resistor R4 is configured to receive a first control level, a second end of the resistor R3 is grounded to an emitter of the transistor Q2, and a collector of the transistor Q2 is connected to a first end of the resistor R5; a second end of the resistor R5 is connected to the base of the transistor Q1 and a first end of the resistor R6, a second end of the resistor R6 is connected to the emitter of the transistor Q1, a second end of the resistor R6 is configured to receive a supply voltage, and a collector of the transistor Q1 is connected to the first end of the resistor R7; the second end of the resistor R7 is connected with the anode of the diode D2, the base of the triode Q3 and the first end of the resistor R8, the second end of the resistor R18 and the collector of the triode Q3 are grounded, the emitter of the triode Q3 is connected with the cathode of the diode D2 and the first end of the resistor R9, and the second end of the resistor R9 is connected with the third end of the MOS transistor M1. Specifically, the first switch driving circuit 141 is formed by a transistor Q1, a transistor Q2, a transistor Q3, and peripheral circuits thereof. The transistor Q2 is turned off when its base receives a low level, the transistor Q1 is turned off, and the discharge of the gate voltage of the MOS transistor M1 is accelerated through the resistor R9 and the transistor Q3, so that the MOS transistor M1 is turned off. The transistor Q2 is turned on when its base receives a high level, and further the transistor Q1 is turned on, and the diode D2 is turned on, driving the gate of the MOS transistor M1 to a high level, so that the MOS transistor M1 is turned on.
As shown in fig. 3, in an embodiment, the first switch circuit 131 includes a transistor Q8, a resistor R25, and a resistor R26; a collector of the transistor Q8 is connected to the second end of the resistor R2, an emitter of the transistor Q8 is connected to the second connection terminal 160 through the resistor R1, a base of the transistor Q8 is connected to the first end of the resistor R25 and the first end of the resistor R26, the second end of the resistor R25 is connected to the first switch driving circuit 141, and the second end of the resistor R26 is connected to an emitter of the transistor Q8; specifically, the first switch circuit 131 may also be composed of a transistor Q8 and a peripheral circuit thereof, the resistor R1 and the resistor R2 are indirectly connected in series via the transistor Q8, and when the transistor Q8 is turned on, the resistor R1 and the resistor R2 are connected in series to form a voltage divider. When the output is short-circuited, the voltage Vout-of the second connection terminal is pulled to be at a high potential, which is close to Vout +, and the voltage across the detection resistor R2 can be used to determine the Vout-potential, thereby determining that the circuit corresponding to the output terminal is short-circuited. When the voltage is greater than a preset value, the short circuit of the output end can be judged.
Optionally, a collector of the transistor Q8 is connected to the second end of the resistor R2 through the resistor R1, an emitter of the transistor Q8 is connected to the second connection terminal 160, a base of the transistor Q8 is connected to the first end of the resistor R25 and the first end of the resistor R26, the second end of the resistor R25 is connected to the first switch driving circuit 141, and the second end of the resistor R26 is connected to an emitter of the transistor Q8. That is, the resistor R1 and the resistor R2 may be directly connected in series. And connected in series to second connection 160 via transistor Q8.
Optionally, the first switch driving circuit 141 includes a transistor Q7, a resistor R23, and a resistor R24; the base of the transistor Q7 is connected to the first terminal of the resistor R24 and the first terminal of the resistor R23, and the second terminal of the resistor R24 is configured to receive the first driving level. Specifically, the first switch circuit 131 may be driven to be turned on or off by the transistor Q7 and its peripheral circuits, and when the base of the transistor Q7 receives a high level, the transistor Q7 is turned on to drive the transistor Q8 to be turned on.
As shown in fig. 4, in an embodiment, the first connection terminal 110 is used for connecting to the positive output terminal of the power supply circuit 210, the second connection terminal 160 is used for connecting to the positive input terminal of the load circuit 220, the voltage dividing circuit 120 includes a resistor R38 and a resistor R39, a first terminal of the resistor R38 is connected to the second connection terminal 160, a second terminal of the resistor R38 is connected to the first terminal of the resistor R39 and the voltage sampling circuit 150, and a second terminal of the resistor R39 is grounded. Specifically, one end of the detection circuit is connected to the positive output terminal of the power supply circuit 210, and the other end is connected to the positive input terminal of the load circuit 220, that is, the detection circuit is connected to the positive terminal of the power supply path of the load circuit 220. The voltage divider circuit 120 is composed of a resistor R38 and a resistor R39 connected in series, and is connected in series with the first switch circuit 131, and when the first switch circuit 131 is turned on, the voltage sampling circuit 150 obtains a voltage division between the resistor R38 and the resistor R39. If the output is short-circuited, the output voltage Vout + of the second connection terminal is pulled to a low potential, which is close to Vout-, and the voltage at the two ends of the resistor R39 is detected to determine the Vout + potential, so as to determine the output short-circuit. Wherein a lower voltage across the resistor R39 indicates a more severe output short at the second connection.
Optionally, on the basis of the above embodiment, the first switch circuit 131 includes a MOS transistor M4 and a resistor R37; the first end of the MOS transistor M4 is connected to the first connection terminal 110, the second end of the MOS transistor M4 is connected to the first end of the resistor R37, the second end of the resistor R37 is connected to the second connection terminal 160, and the third end of the MOS transistor M4 is connected to the first switch driving circuit 141. Specifically, the first switch circuit 131 may be composed of a MOS transistor M4 and a resistor R37, wherein the circuit R37 is used to limit the current flowing when a short circuit occurs, so as to protect the entire circuit. When the MOS transistor M4 is turned on, the resistor R37 and the resistor R38 form a voltage division.
Optionally, the first switch driving circuit 141 includes a transistor Q11, a resistor R35, a resistor R36, and a resistor R32; the emitter of the transistor Q11 is grounded, the base of the transistor Q11 is connected to the first end of the resistor R32, the second end of the resistor R32 is used for receiving the first driving level, the collector of the transistor Q11 is connected to the third end of the MOS transistor M4 and the first end of the resistor R36 through the resistor R35, and the second end of the resistor R36 is connected to the first connection terminal 110. Specifically, the first switch driving circuit 141 may be formed by a transistor Q11 and its peripheral circuits. The transistor Q11 is turned on when its base receives a high level, and the resistor R36 and the resistor R35 form a divided voltage to drive the MOS transistor M4 to be turned on.
In one embodiment, the second switch circuit 132 includes a MOS transistor M2; the first end of the MOS transistor M2 is connected to the first connection terminal 110, the second end of the MOS transistor M2 is connected to the second connection terminal 160, and the third end of the MOS transistor M2 is connected to the second driving circuit. Specifically, the second switch circuit 132 may be formed by a MOS transistor M2, which is turned on when the MOS transistor M2 is turned on, and turned off when the MOS transistor M2 is turned off.
As shown in fig. 2 and fig. 3, in an embodiment, the second switch driving circuit 142 includes a transistor Q4, a transistor Q5, a transistor Q6, a diode D3, a resistor R10, a resistor R11, a resistor R12, a resistor R13, a resistor R14, a resistor R15, and a resistor R16; the base of the triode Q5 is connected with the first end of the resistor R11 and the first end of the resistor R10, the second end of the resistor R11 is used for receiving a second control level, the second end of the resistor R10 is grounded with the emitter of the triode Q5, and the collector of the triode Q5 is connected with the first end of the resistor R13; a second end of the resistor R13 is connected to a base of the transistor Q4 and a first end of the resistor R14, a second end of the resistor R14 is connected to an emitter of the transistor Q4, a second end of the resistor R14 is configured to receive a supply voltage, and a collector of the transistor Q4 is connected to the first end of the resistor R15; the second end of the resistor R15 is connected with the anode of the diode D3, the base of the triode Q6 and the first end of the resistor R12, the second end of the resistor R12 and the collector of the triode Q6 are grounded, the emitter of the triode Q6 is connected with the cathode of the diode D3 and the first end of the resistor R16, and the second end of the resistor R16 is connected with the third end of the MOS transistor M2. That is, the second switch driving circuit 142 may be composed of a transistor Q5, a transistor Q4, and a transistor Q6, and peripheral circuits thereof. The triode Q5 is turned off when the base electrode of the triode Q5 receives low level, the triode Q4 is turned off, the over-resistance R12 and the triode Q6 accelerate the discharge of the grid voltage of the MOS transistor M2, and the MOS transistor M2 is turned off. The transistor Q5 is turned on when its base receives a high level, and further the transistor Q4 is turned on, the diode D3 is turned on, and the gate of the MOS transistor M2 is driven to a high level, so that the MOS transistor M2 is turned on.
As shown in fig. 4, in another embodiment, the second switch driving circuit 142 includes a transistor Q10, a resistor R31, a resistor R33, and a resistor R34; the base of the triode Q10 is connected to the first end of the resistor R31, the second end of the resistor R31 is used for receiving the second driving level, the collector of the triode Q10 is connected to the first end of the resistor R33, the second end of the resistor R33 is connected to the first end of the resistor R34 and the third end of the MOS transistor M2, and the second end of the resistor R34 is connected to the first connection terminal 110. Specifically, the second switch driving circuit 142 may be composed of a transistor Q10 and its peripheral circuit, the transistor Q10 is turned on when its base receives a high level, and the resistor R33 and the resistor R34 form a divided voltage to drive the MOS transistor M2 to be turned on.
Optionally, in an embodiment of the present invention, the short circuit detection circuit further includes a controller, and the controller is configured to output the first control level or the second control level, or the voltage sampling circuit 150 is integrated in the controller. That is, the controller may be configured to output a first control level and a second control level, which may be a common controller output level process. The voltage sampling circuit 150 may also be integrated into the controller, and the voltage may be identified by the ADC function corresponding to the controller or other voltage acquisition or comparison function carried by the controller. In addition, the controller can be connected with an input end electrifying circuit, and the short-circuit detection circuit can be triggered to work by detecting the electrifying of the input end.
An electronic device of the present invention includes: a supply circuit 210, a load circuit 220, and a short detection circuit as described above; the first connection terminal 110 of the short-circuit detection circuit is connected to the output terminal of the power supply circuit 210, and the second connection terminal 160 of the short-circuit detection circuit is connected to the input terminal of the load circuit 220. That is, the short circuit detection circuit is disposed between the power supply circuit 210 and the load circuit 220 of the electronic device or the electronic apparatus, and before the electronic device enters a normal power-on working state, the short circuit state of the electronic device is confirmed, so that the use safety of the electronic device can be effectively ensured.
As shown in fig. 5, a short circuit detection method of the present invention is applied to the short circuit detection circuit described in any one of the above, and includes the following steps:
s1, when the first connection end has power input, triggering the first switch driving unit to drive the first switch circuit to be conducted, and triggering the second switch driving unit to drive the second switch circuit to be turned off;
s2, obtaining the voltage division of the voltage division circuit, judging whether the voltage division meets a preset range, if so, executing S3, and if not, executing S4;
s3, judging that the load circuit is short-circuited, triggering the first switch driving unit to drive the first switch circuit to be turned off, and finishing detection;
and S4, judging that the load circuit is normal, triggering the first switch driving unit to drive the first switch circuit to be turned off, and triggering the second switch driving unit to drive the second switch circuit to be turned on.
Specifically, the process of performing short circuit detection through the short circuit detection circuit includes triggering the first switch driving unit to drive the first switch circuit to be turned on when the first connection end has power input, and driving the second switch circuit to be kept turned off through the second switch driving unit, at this time, the power input of the first connection end forms partial voltage on the voltage dividing circuit through a path formed by the turned-on first switch circuit, and obtains the partial voltage of the voltage dividing circuit through the voltage sampling unit, so that whether the load circuit has a short circuit can be determined according to the partial voltage. The preset range of the partial voltage can be set through the value which the voltage of the circuit should meet when the circuit is in a normal state, the preset range is set, and once the preset range is exceeded, the load circuit can be judged to be short-circuited. For example, in an embodiment, under normal conditions, when the load circuit is not short-circuited, the divided voltage of the voltage dividing circuit is small, and when the load circuit is short-circuited, the divided voltage of the voltage dividing circuit is large, so that the short-circuit determination result of the load circuit can be obtained through the voltage magnitude. When the short circuit is judged, the second switch circuit is kept turned off at the moment, and the first switch driving unit is triggered to drive the first switch circuit to be turned off, so that the whole working circuit is protected. When the load circuit is judged to be normal, the second switch driving unit can be triggered to drive the second switch circuit to be conducted, the load circuit is powered on when working normally, and meanwhile, the first switch circuit is cut off. The process can automatically judge whether the first connection end has power input or not and trigger the short circuit detection circuit to detect work based on a judgment result.
It is to be understood that the foregoing examples, while indicating the preferred embodiments of the invention, are given by way of illustration and description, and are not to be construed as limiting the scope of the invention; it should be noted that, for those skilled in the art, the above technical features can be freely combined, and several changes and modifications can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention; therefore, all equivalent changes and modifications made within the scope of the claims of the present invention should be covered by the claims of the present invention.
Claims (15)
1. A short circuit detection circuit for connecting between a power supply circuit and a load circuit, comprising: the voltage divider comprises a first connecting end, a second connecting end, a voltage dividing circuit, a voltage sampling circuit, a first switch circuit, a second switch circuit, a first switch driving circuit and a second switch driving circuit;
the first connecting end is used for connecting the output end of the power supply circuit;
the second connecting end is used for connecting the input end of the load circuit;
the first connecting end is connected with the second connecting end through the voltage dividing circuit and the first switch circuit which are connected in series, and is conducted with the second connecting end when the first switch circuit is conducted;
the first switch driving circuit is connected with the first switch circuit and used for receiving a first control level to output a first driving level to drive the first switch circuit to be switched on or switched off;
the first connecting end is also connected with the second connecting end through the second switch circuit and is conducted with the second connecting end when the second switch circuit is conducted;
the second switch driving circuit is connected with the second switch circuit and used for receiving a second control level to output a second driving level to drive the second switch circuit to be switched on or switched off;
the voltage sampling circuit is connected with the voltage division circuit and used for acquiring the voltage division of the voltage division circuit when the first switch circuit is conducted.
2. The short-circuit detection circuit of claim 1, wherein the first connection terminal is configured to connect to a negative output terminal of the power supply circuit, and the second connection terminal is configured to connect to a negative input terminal of the load circuit; the voltage division circuit comprises a resistor R1 and a resistor R2;
a first end of the resistor R2 is connected to the first connection terminal, a second end of the resistor R2 is connected to the second connection terminal through the first switch circuit and the resistor R1, which are connected in series, and a second end of the resistor R2 is connected to the voltage sampling circuit.
3. The short circuit detection circuit of claim 2, wherein the first switching circuit comprises a MOS transistor M1;
the first end of the MOS transistor M1 is connected with the second end of the resistor R2, the second end of the MOS transistor M1 is connected with the second connection end through the resistor R1, and the third end of the MOS transistor M1 is connected with the first switch driving circuit; or
The first end of the MOS transistor M1 is connected to the second end of the resistor R2 through the resistor R1, the second end of the MOS transistor M1 is connected to the second connection terminal, and the third end of the MOS transistor M1 is connected to the first switch driving circuit.
4. The short circuit detection circuit of claim 3, wherein the first switch driving circuit comprises a transistor Q1, a transistor Q2, a transistor Q3, a diode D2, a resistor R3, a resistor R4, a resistor R5, a resistor R6, a resistor R7, a resistor R8, and a resistor R9;
a base of the transistor Q2 is connected to a first terminal of the resistor R4 and a first terminal of the resistor R3, a second terminal of the resistor R4 is configured to receive the first control level, a second terminal of the resistor R3 and an emitter of the transistor Q2 are grounded, and a collector of the transistor Q2 is connected to the first terminal of the resistor R5;
a second terminal of the resistor R5 is connected to the base of the transistor Q1 and the first terminal of the resistor R6, a second terminal of the resistor R6 is connected to the emitter of the transistor Q1, a second terminal of the resistor R6 is configured to receive a supply voltage, and a collector of the transistor Q1 is connected to the first terminal of the resistor R7;
the second end of the resistor R7 is connected to the anode of the diode D2, the base of the transistor Q3 and the first end of the resistor R8, the second end of the resistor R18 and the collector of the transistor Q3 are grounded, the emitter of the transistor Q3 is connected to the cathode of the diode D2 and the first end of the resistor R9, and the second end of the resistor R9 is connected to the third end of the MOS transistor M1.
5. The short circuit detection circuit of claim 2, wherein the first switch circuit comprises a transistor Q8, a resistor R25, and a resistor R26;
a collector of the transistor Q8 is connected to the second terminal of the resistor R2, an emitter of the transistor Q8 is connected to the second connection terminal through the resistor R1, a base of the transistor Q8 is connected to the first terminal of the resistor R25 and the first terminal of the resistor R26, the second terminal of the resistor R25 is connected to the first switch driving circuit, and the second terminal of the resistor R26 is connected to the emitter of the transistor Q8;
or
The collector of the triode Q8 is connected to the second end of the resistor R2 through the resistor R1, the emitter of the triode Q8 is connected to the second connection terminal, the base of the triode Q8 is connected to the first end of the resistor R25 and the first end of the resistor R26, the second end of the resistor R25 is connected to the first switch driving circuit, and the second end of the resistor R26 is connected to the emitter of the triode Q8.
6. The short circuit detection circuit of claim 5, wherein the first switch driver circuit comprises a transistor Q7, a resistor R23, and a resistor R24;
the base of the transistor Q7 is connected to the first terminal of the resistor R24 and the first terminal of the resistor R23, and the second terminal of the resistor R24 is used for receiving the first driving level.
7. The short-circuit detection circuit as claimed in claim 1, wherein the first connection terminal is configured to connect to a positive output terminal of the power supply circuit, the second connection terminal is configured to connect to a positive input terminal of the load circuit, the voltage divider circuit includes a resistor R38 and a resistor R39, a first terminal of the resistor R38 is connected to the second connection terminal, a second terminal of the resistor R38 is connected to the first terminal of the resistor R39 and the voltage sampling circuit, and a second terminal of the resistor R39 is grounded.
8. The short circuit detection circuit of claim 7, wherein the first switch circuit comprises a MOS transistor M4 and a resistor R37;
the first end of the MOS transistor M4 is connected to the first connection end, the second end of the MOS transistor M4 is connected to the first end of the resistor R37, the second end of the resistor R37 is connected to the second connection end, and the third end of the MOS transistor M4 is connected to the first switch driving circuit.
9. The short circuit detection circuit of claim 8, wherein the first switch driving circuit comprises a transistor Q11, a resistor R35, a resistor R36, and a resistor R32;
an emitter of the transistor Q11 is grounded, a base of the transistor Q11 is connected to a first end of the resistor R32, a second end of the resistor R32 is configured to receive the first driving level, a collector of the transistor Q11 is connected to a third end of the MOS transistor M4 and a first end of the resistor R36 through the resistor R35, and a second end of the resistor R36 is connected to the first connection terminal.
10. The short detection circuit of claim 1, wherein the second switching circuit comprises a MOS transistor M2;
the first end of the MOS transistor M2 is connected to the first connection end, the second end of the MOS transistor M2 is connected to the second connection end, and the third end of the MOS transistor M2 is connected to the second driving circuit.
11. The short circuit detection circuit of claim 10, wherein the second switch driving circuit comprises a transistor Q4, a transistor Q5, a transistor Q6, a diode D3, a resistor R10, a resistor R11, a resistor R12, a resistor R13, a resistor R14, a resistor R15, and a resistor R16;
a base of the transistor Q5 is connected to a first terminal of the resistor R11 and a first terminal of the resistor R10, a second terminal of the resistor R11 is configured to receive the second control level, a second terminal of the resistor R10 and an emitter of the transistor Q5 are grounded, and a collector of the transistor Q5 is connected to the first terminal of the resistor R13;
a second terminal of the resistor R13 is connected to the base of the transistor Q4 and the first terminal of the resistor R14, a second terminal of the resistor R14 is connected to the emitter of the transistor Q4, a second terminal of the resistor R14 is configured to receive a supply voltage, and a collector of the transistor Q4 is connected to the first terminal of the resistor R15;
the second end of the resistor R15 is connected to the anode of the diode D3, the base of the transistor Q6 and the first end of the resistor R12, the second end of the resistor R12 and the collector of the transistor Q6 are grounded, the emitter of the transistor Q6 is connected to the cathode of the diode D3 and the first end of the resistor R16, and the second end of the resistor R16 is connected to the third end of the MOS transistor M2.
12. The short circuit detection circuit of claim 10, wherein the second switch driving circuit comprises a transistor Q10, a resistor R31, a resistor R33, and a resistor R34;
the base of the triode Q10 is connected to the first end of the resistor R31, the second end of the resistor R31 is configured to receive the second driving level, the collector of the triode Q10 is connected to the first end of the resistor R33, the second end of the resistor R33 is connected to the first end of the resistor R34 and the third end of the MOS transistor M2, and the second end of the resistor R34 is connected to the first connection terminal.
13. The short detection circuit of claim 1, further comprising a controller,
the controller is used for outputting the first control level or the second control level, or
The voltage sampling circuit is integrated with the controller.
14. An electronic device, comprising: a supply circuit, a load circuit and a short circuit detection circuit as claimed in any one of claims 1 to 13; wherein the content of the first and second substances,
the first connecting end of the short-circuit detection circuit is connected with the output end of the power supply circuit, and the second connecting end of the short-circuit detection circuit is connected with the input end of the load circuit.
15. A short-circuit detection method applied to the short-circuit detection circuit according to any one of claims 1 to 13, comprising the steps of:
s1, when the first connection end has power input, triggering the first switch driving unit to drive the first switch circuit to be conducted, and triggering the second switch driving unit to drive the second switch circuit to be turned off;
s2, obtaining the voltage division of the voltage division circuit, judging whether the voltage division meets a preset range, if so, executing S4, and if not, executing S3;
s3, judging that the load circuit is short-circuited, triggering the first switch driving unit to drive the first switch circuit to be turned off, and ending;
and S4, judging that the load circuit is normal, triggering the first switch driving unit to drive the first switch circuit to be turned off, and triggering the second switch driving unit to drive the second switch circuit to be turned on.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
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| CN202110826079.3A CN113820619A (en) | 2021-07-21 | 2021-07-21 | Short circuit detection circuit, electronic device and short circuit detection method |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110826079.3A CN113820619A (en) | 2021-07-21 | 2021-07-21 | Short circuit detection circuit, electronic device and short circuit detection method |
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| CN113820619A true CN113820619A (en) | 2021-12-21 |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116047324A (en) * | 2023-03-07 | 2023-05-02 | 宁波阔野科技有限公司 | Matrix switch short circuit detection circuit and detection method for battery pack |
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2021
- 2021-07-21 CN CN202110826079.3A patent/CN113820619A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116047324A (en) * | 2023-03-07 | 2023-05-02 | 宁波阔野科技有限公司 | Matrix switch short circuit detection circuit and detection method for battery pack |
| CN116047324B (en) * | 2023-03-07 | 2023-10-10 | 宁波阔野科技有限公司 | Matrix switch short circuit detection circuit and detection method for battery pack |
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