CN217282185U - Protection circuit and electronic device - Google Patents
Protection circuit and electronic device Download PDFInfo
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- CN217282185U CN217282185U CN202220417748.1U CN202220417748U CN217282185U CN 217282185 U CN217282185 U CN 217282185U CN 202220417748 U CN202220417748 U CN 202220417748U CN 217282185 U CN217282185 U CN 217282185U
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Abstract
The utility model provides a protection circuit and electronic equipment, protection circuit connects in power input end and protected between the product input, include: the rectification voltage-stabilizing module is connected with the power supply input end; the protection module is respectively connected with the rectifying and voltage-stabilizing module and the input end of the protected product and comprises a voltage dividing unit, a first switching unit, a second switching unit and a third switching unit; when the input voltage is higher than the power supply voltage of the protected product, the voltage dividing unit divides the input voltage, so that the second switching unit is conducted and the first switching unit and the third switching unit are not conducted to perform power-off protection on the protected product. The utility model discloses a thereby the systematic damage that the user leads to with high-pressure mistake access low pressure input system is avoided to the protection module who provides, has ensured low pressure power supply system and customer premises equipment's safety.
Description
Technical Field
The utility model relates to a power protection field especially relates to a protection circuit and electronic equipment.
Background
The power supply voltage of the low-voltage input system on the market is generally 12 Vdc-24 Vdc. However, the low-voltage input system is often inadvertently connected with the high voltage of 220V to 50Hz, so that the product fails due to high-voltage breakdown. Moreover, because the low-voltage input system is designed to be low-voltage, when high voltage is accessed, the product is necessarily damaged, more devices are damaged, the maintenance possibility is low, or unnecessary maintenance is caused due to overhigh maintenance cost.
Disclosure of Invention
The utility model provides a protection circuit and electronic equipment for solve among the prior art low voltage input system and lead to its device impaired problem because of inserting the high pressure.
In a first aspect, the present invention provides a protection circuit, which is connected between a power input terminal and a protected product input terminal, including:
the rectification and voltage stabilization module is connected with the power supply input end and is provided with a first output end used for outputting a first voltage and a second output end used for outputting a second voltage, and the second voltage is input voltage of the protected product input end;
the protection module is respectively connected with the rectification voltage-stabilizing module and the input end of the protected product and comprises a voltage dividing unit, a first switching unit and a second switching unit which are respectively connected with the voltage dividing unit and a third switching unit which is connected with the first switching unit, and the third switching unit is connected between the second output end and the input end of the protected product in series;
when the input voltage is higher than the power supply voltage of the protected product, the voltage dividing unit divides the input voltage to enable the second switch unit to be conducted and the first switch unit to be not conducted, and then the third switch unit is in a non-conducting state to conduct power-off protection on the protected product.
The utility model discloses an in the embodiment, the partial pressure unit includes first partial pressure unit and second partial pressure unit, and the second switch unit is the second triode, first switch unit is first triode, the second voltage warp of second output the second partial pressure after the second partial pressure unit partial pressure export extremely the base of second triode, the projecting pole ground connection of second triode, the collecting electrode of second triode connect in the base of first triode, the first voltage warp of first output export output behind the first partial pressure unit partial pressure export extremely the base of first triode, the projecting pole ground connection of first triode, the collecting electrode of first triode is connected the control end of third switch unit, in order to control the switching on/off of third switch unit.
The utility model discloses an in the embodiment, first partial pressure unit includes second resistance and third resistance, the second partial pressure unit includes fourth resistance and fifth resistance, the one end of second resistance with the second output is connected, the other end of second resistance with third resistance connects, the other end ground connection of third resistance, the one end of fourth resistance with first output is connected, the other end of fourth resistance with fifth resistance connects, the other end ground connection of fifth resistance.
In an embodiment of the present invention, the protection module further includes a second voltage regulator tube, a cathode of the second voltage regulator tube is connected to the second resistor, an anode of the second voltage regulator tube is connected to the third resistor, and a breakdown voltage of the second voltage regulator tube is greater than a maximum value of a power supply voltage of the protected product.
In an embodiment of the present invention, the third switch unit is a relay, the first end of the relay is connected to the second output terminal, the second end is connected to the first output terminal, the third end is connected to the protected product input terminal, and the fourth end is connected to the collector of the first triode.
The utility model discloses an in the embodiment, protection module still includes the second electric capacity, the one end of second electric capacity with the base of first triode is connected, the other end ground connection of second electric capacity.
In an embodiment of the present invention, the rectifying and voltage-stabilizing module includes a voltage-stabilizing unit, the voltage-stabilizing unit includes a first resistor, a first voltage-stabilizing tube and a first capacitor, the first resistor is connected to the cathode of the first voltage-stabilizing tube, the anode of the first voltage-stabilizing tube is grounded, one end of the first capacitor is connected to the first output end, and the other end of the first capacitor is grounded, the voltage-stabilizing unit is used for stabilizing the voltage of the first voltage, and the first voltage is equal to the breakdown voltage of the first voltage-stabilizing tube.
The utility model discloses an in the embodiment, rectification voltage stabilizing module still includes the rectification unit, the rectification unit include rectifier bridge and electrolytic capacitor the input of rectifier bridge with power input end connects, the output of rectifier bridge respectively with electrolytic capacitor's positive pole first resistance and the second output is connected, electrolytic capacitor's negative pole ground connection, the rectifier bridge includes first diode, second diode, third diode and fourth diode, the third diode with third connecting node ground connection between the fourth diode, first diode with fourth connecting node between the second diode is regarded as the output of rectifier bridge, the second diode with fifth connecting node between the fourth diode with power input end's first end is connected, first diode with sixth connecting node between the third diode with power input end's second end is connected .
In an embodiment of the invention, the protection circuit further comprises a fuse, the fuse is connected to the power input terminal.
In a second aspect, the present invention further provides an electronic device, the electronic device includes the protection circuit as in any one of the first aspect the present invention provides a protection circuit and an electronic device, which avoid the systematic damage caused by the user mistakenly accessing the high voltage low voltage input system through the protection module provided, thereby ensuring the safety of the low voltage power supply system and the user end device.
Drawings
In order to more clearly illustrate the technical solutions of the present invention or the prior art, the following briefly introduces the drawings required for the embodiments or the prior art descriptions, and obviously, the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other embodiments can be obtained according to the drawings without creative efforts.
Fig. 1 is a block diagram of a protection circuit provided by the present invention;
fig. 2 is a schematic circuit diagram of a protection circuit provided by the present invention;
fig. 3 is a schematic diagram of a simulation circuit of the protection circuit provided by the present invention;
fig. 4 is a schematic diagram of a simulation result of 12V voltage of the protection circuit provided by the present invention;
fig. 5 is a schematic diagram of a simulation result of a 24V voltage of the protection circuit provided by the present invention;
fig. 6 is a schematic diagram of a simulation structure of a 220V voltage of the protection circuit provided by the present invention.
Detailed Description
To make the objects, technical solutions and advantages of the present invention clearer, the drawings of the present invention are combined to clearly and completely describe the technical solutions of the present invention, and obviously, the described embodiments are some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by a person skilled in the art without making creative efforts belong to the protection scope of the present invention.
The terms "first," "second," and the like in the description and in the claims, and in the drawings described above, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It will be appreciated that the data so used may be interchanged under appropriate circumstances such that the embodiments described herein may be practiced otherwise than as specifically illustrated or described herein.
The power supply is used as power supply equipment of an electronic product, the protection circuit is an indispensable component of the power supply product, the traditional control method can perform overcurrent protection through the fuse, and when the current reaches the fuse fusing current, the fuse can be fused to form cut-off due to overcurrent, so that the whole circuit is powered off, and the effect of protecting the circuit is achieved. However, when the circuit power supply is turned off by adopting a fuse fusing mode, the fused fuse cannot be self-repaired, and the circuit can be protected again only once after being fused and needs to be replaced.
In order to solve the problem that low voltage input system leads to its device impaired because of inserting the high pressure among the prior art, the utility model provides a protection circuit and electronic equipment through the protection module who provides, thereby avoid the user to insert the systematic damage that low voltage input system leads to with the high pressure mistake, ensured low pressure power supply system and customer premises equipment's safety.
The protection circuit and the electronic device of the present invention are described below with reference to fig. 1 to 6.
Fig. 1 is a block diagram of a protection circuit according to the present invention, as shown in fig. 1. A protection circuit is connected between a power input end and an input end of a protected product and comprises a rectification voltage-stabilizing module and a protection module.
Illustratively, the rectifying and voltage-stabilizing module is connected to the power input terminal and performs a rectifying and voltage-stabilizing function, and the rectifying and voltage-stabilizing module has a first output terminal and a second output terminal, the first output terminal is used for outputting a first voltage, the second output terminal is used for outputting a second voltage, and the second voltage is an input voltage of the input terminal of the protected product.
Illustratively, one end of the protection module is connected with the rectifying and voltage-stabilizing module, and the other end of the protection module is connected with the input end of the protected product, and the protection module may include a voltage dividing unit, a first switching unit and a second switching unit respectively connected with the voltage dividing unit, and a third switching unit connected with the first switching unit, where the third switching unit is connected in series between the second output end and the input end of the protected product.
When the input voltage is within the power supply voltage range of the protected product, the input voltage is rectified and stabilized by the rectifying and voltage stabilizing module, and then divided by the voltage dividing unit to provide proper voltage, so that the first switching unit is conducted, the third switching unit is conducted and works, and the required working voltage can be output to the protected product.
When the input voltage is higher than the power supply voltage range of the protected product, the input voltage is rectified and stabilized through the rectification and voltage stabilization module, and then is subjected to voltage division through the voltage division unit, so that the second switch unit is switched on, and the voltage of the first switch unit is pulled down due to the switching-on of the second switch unit, so that the first switch unit is not switched on, and further the third switch unit is not switched on and does not work, so that the output end of the protection circuit has no voltage, namely, the output voltage cannot be output to the protected product, and the purpose of protecting the protected product is achieved.
Illustratively, the first switching unit is a first triode, the second switching unit is a second triode, and the third switching unit is a relay.
It should be noted that, the first switch unit the second switch unit and the third switch unit can adopt other components and parts according to the actual circuit needs, the utility model discloses do not restrict to above-mentioned switch unit.
The protection circuit of the present invention is described below with an embodiment.
Fig. 2 is a schematic circuit diagram of the protection circuit provided by the present invention, as shown in fig. 2. A protection circuit comprises a power input end of Vin1, an output end of Vin2 connected with the input end of a protected product, a rectifying and voltage-stabilizing module and a protection module.
Illustratively, the rectifying and voltage-stabilizing module comprises a rectifying unit and a voltage-stabilizing unit, wherein the rectifying unit comprises a rectifying bridge BD and an electrolytic capacitor EC1, and the voltage-stabilizing unit comprises a first resistor R1, a first voltage-stabilizing tube ZD1 and a first capacitor C1. The output of the rectifying and voltage stabilizing module comprises a first voltage (V1) and a second voltage, and the second voltage is an input voltage Vin2 of the input end of the protected product.
The rectifier bridge BD comprises a first diode D1, a second diode D2, a third diode D3 and a fourth diode D4, a third connection node C between the third diode D3 and the fourth diode D4 is grounded, a fourth connection node D between the first diode D1 and the second diode D2 serves as an output end of the rectifier bridge BD, a fifth connection node E between the second diode D2 and the fourth diode D4 is connected with a first end of the power input end Vin1, and a sixth connection node F between the first diode D1 and the third diode D3 is connected with a second end of the power input end Vin 1.
The input terminals of the rectifier bridge BD (i.e., the first terminal connected to the fifth connection node E and the second terminal connected to the sixth connection node F) are the power input terminal Vin 1. The output end of the rectifier bridge BD is respectively connected with the anode (+) of the electrolytic capacitor EC1 and the first resistor R1, the cathode (-) of the electrolytic capacitor EC1 is grounded, the first resistor R1 is connected with the cathode of the first voltage-regulator tube ZD1, the anode of the first voltage-regulator tube ZD1 is grounded, one end of the first capacitor C1 is connected with a first connection node A between the first resistor R1 and the first voltage-regulator tube ZD1, and the other end of the first capacitor C1 is grounded. The voltage stabilizing unit is configured to stabilize a voltage of a first connection node a (i.e., a voltage of V1 in fig. 3, which is also a first voltage output by the rectifying and voltage stabilizing module), where the voltage of the first connection node a is equal to a breakdown voltage of the first voltage regulator tube ZD 1.
Illustratively, the protection module includes a second resistor R2, a second voltage regulator ZD2, a third resistor R3, a second transistor Q2, a fourth resistor R4, a fifth resistor R5, a second capacitor C2, a first transistor Q1, and a relay K1.
The first voltage division unit formed by the second resistor R2 and the third resistor R3 is used as a voltage division and current limiting resistor of the second triode Q2, and the second voltage division unit formed by the fourth resistor R4 and the fifth resistor R5 is used as a voltage division and current limiting resistor of the first triode Q1.
One end of the second resistor R2 is connected with the output end of the rectifier bridge BD, the other end of the second resistor R2 is connected with the cathode of a second voltage regulator tube ZD2, the anode of the second voltage regulator tube ZD2 is connected with the third resistor R3, and the other end of the third resistor R3 is grounded. The breakdown voltage of the second zener ZD2 is greater than the maximum value of the supply voltage of the protected product. For example, the supply voltage of the protected product is 12V-24Vdc, and the breakdown voltage of the second regulator ZD2 needs to be greater than 24V to avoid the circuit from operating abnormally due to false triggering.
The base electrode of the second triode Q2 is connected with the anode of the second voltage regulator tube ZD2, the emitter electrode of the second triode Q2 is grounded, and the collector electrode of the second triode Q2 is connected with a second connection node B between the fourth resistor R4 and the fifth resistor R5. One end of the fourth resistor R4 is connected to the first connection node a, the other end of the fourth resistor R4 is connected to the fifth resistor R5, and the other end of the fifth resistor R5 is grounded.
One end of the second capacitor C2 is connected to the second connection node B, and the other end of the second capacitor C2 is grounded.
The first end of the relay K1 is connected with the output end of the rectifier bridge BD, the second end of the relay K1 is connected with the first connection node A, the output end of the relay K1 is Vin2, the output end Vin2 (the third end) is connected with the input end of a protected product, and the fourth end of the relay K1 is connected with the first triode Q1.
The base electrode of the first triode Q1 is connected with the second connection node B, the emitting electrode of the first triode Q1 is grounded, and the collecting electrode of the first triode Q1 is connected with the fourth end of the relay K1.
As can be seen from fig. 2, the second voltage output by the second output terminal of the rectifying and voltage-stabilizing module is divided by the second voltage-dividing unit and then output to the base of the second transistor Q2, the emitter of the second transistor Q2 is grounded, and the collector of the second transistor Q2 is connected to the base of the first transistor Q1; the first voltage output by the first output end of the rectifying and voltage-stabilizing module is divided by the first voltage dividing unit and then output to the base electrode of the first triode Q1, the emitting electrode of the first triode Q1 is grounded, and the collecting electrode of the first triode Q1 is connected with the control end of the relay K1 so as to control the on/off of the relay K1.
Exemplarily, the protection circuit of the present invention further includes a FUSE, and the FUSE is connected to the fifth connection node E. When the protection circuit is short-circuited, for example, the rectifier bridge BD is short-circuited, or the electrolytic capacitor EC1 is short-circuited, the FUSE blows.
The working principle of the protection circuit is that:
the power input terminal Vin1 is normally input with a low-voltage dc voltage (for example, 12V-24V dc voltage), and then regulated by the first voltage regulator ZD1 and then divided by the fourth resistor R4 and the fifth resistor R5 to provide a suitable voltage, and at the same time, a suitable current is supplied through the fourth resistor R4 to turn on the first triode Q1, so that the relay K1 is closed, that is, the working voltage (V1) at one end of the coil of the relay K1 is normal, the base voltage (V2) of the first triode Q1 is normal, the voltage (V3) at the other end of the coil of the relay K1 is normal, and the base voltage (V4) of the second triode Q2 is 0 at the beginning, the Q2 is not turned on, and the output terminal Vin2 has a voltage, which can supply power to the following circuits.
Because the voltage of the second voltage regulator ZD2 is higher than the voltage under normal conditions, the second triode Q2 does not operate at this time, and the first triode Q1 is not affected because the voltage is normally 12V-24V.
When the power input end Vin1 is connected by mistake to a voltage higher than the power supply voltage of a protected product (for example, 220V-/50 Hz is input), the second triode Q2 is turned on after the voltage is divided by the second resistor R2, the second voltage regulator ZD2 and the third resistor R3, because of the existence of the first capacitor C1, the base voltage (V4) of the second triode Q2 is established earlier than the base voltage (V2) of the first triode Q1, the base voltage (V2) of the first triode Q1 is pulled down after the second triode Q2 is turned on, so that the first triode Q1 cannot be turned on, and at the moment, the working voltage (V1) of one end of the coil of the relay K1 is the same as the voltage (V3) of the other end of the coil of the relay K1, so that the relay K1 cannot be turned on, the relay K1 does not work, the output end 2 has no voltage, and the purpose of protecting a circuit behind is achieved.
It should be noted that the breakdown voltage of the second zener diode ZD2 must be greater than the highest voltage of the power input terminal Vin1, so as to avoid the circuit from being out of operation due to the false turn-on.
Fig. 3 is a schematic diagram of a simulation circuit of the protection circuit provided by the present invention, as shown in fig. 3. The first voltage V1 is an operating voltage at one end (i.e., the second end) of the coil of the relay K1, the second voltage V2 is a base voltage of the first transistor Q1, the third voltage V3 is a voltage at the other end (i.e., the fourth end) of the coil of the relay K1, the third voltage V3 is a voltage for determining whether the first transistor Q1 is turned on (e.g., turned on when the voltage is lower than a predetermined voltage), and the fourth voltage V4 is a base voltage of the second transistor Q2.
Assume that the voltage input at the power input is 220 Vac. The four diodes D1-D4 in the simulation circuit are equivalent to the rectifier bridge BD in FIG. 2, the withstand voltage of the rectifier bridge BD needs to meet the condition of high-voltage input, 600V or more can be selected, and the current magnitude can be evaluated according to the loss of practical application.
The electrolytic capacitor EC1 is a filter capacitor after rectification, and its capacitance value can be selected according to the required ripple size, and its withstand voltage is selected to meet the high-voltage input, for example, 400V or more. The capacitance value of the electrolytic capacitor EC1 shown in fig. 3 is 22 μ F.
The first resistor R1 is used as a current limiting resistor of the first voltage regulator ZD1, the voltage across it should be greater than 320V, and the resistance value of the first resistor R1 shown in fig. 3 is 10 k. The first zener ZD1 may select a suitable power based on losses at a predetermined maximum voltage (e.g. a normal grid voltage which may be up to 264V, higher than 220V) input, the voltage value of the first zener ZD1 shown in figure 3 being 5V.
The first capacitor C1 ensures that the first voltage V1 in fig. 3 is maintained within the rated voltage range of the relay K1, so the capacitance of the electric-capacitor C1 must be greater than 10 μ F. The second capacitor C2 serves as a delay timing for the rise of the second voltage V2 in fig. 3 to ensure that the fourth voltage V4 is established prior to the second voltage V2 in case of high voltage input, otherwise the protection circuit will lose its protection. The capacitance value of the second capacitor C2 shown in fig. 3 is 1 μ F.
The second resistor R2 and the third resistor R3 serve as voltage dividing and current limiting resistors of the second transistor Q2, the resistance of the second resistor R2 is 1k, and the resistance of the third resistor R3 is 10k as shown in fig. 3. The fourth resistor R4 and the fifth resistor R5 serve as voltage dividing and current limiting resistors of the first transistor Q1, the fourth resistor R4 shown in fig. 3 has a resistance value of 10k, and the fifth resistor R5 has a resistance value of 50 k.
The breakdown voltage of the second voltage-regulator tube ZD2 needs to be greater than the maximum value of the power supply voltage of the protected product, for example, the power supply voltage is 12V-24Vdc, then the voltage of the second voltage-regulator tube ZD2 needs to be greater than 24V, and a certain margin is kept, so that the circuit can be prevented from working abnormally due to false triggering. The voltage value of the second zener tube ZD2 shown in figure 3 is 33V, i.e. 33V is greater than 24V.
The following is a diagram based on the results of the simulation circuit shown in fig. 3 described above.
Fig. 4 is a schematic diagram of a simulation result of 12V voltage of the protection circuit provided by the present invention, as shown in fig. 4. The simulation circuit results of fig. 4 show that when a voltage of 12Vdc is inputted, the relay K1 operates normally and the line is normal.
Fig. 5 is a schematic diagram of a simulation result of a 24V voltage of the protection circuit provided by the present invention, as shown in fig. 5. The simulation circuit results of fig. 5 show that with the 24Vdc voltage input, relay K1 is operating normally and the line is normal.
Fig. 6 is a schematic diagram of a simulation structure of a 220V voltage of the protection circuit provided by the present invention, as shown in fig. 6. The simulation result of fig. 6 shows that, when the 220Vac voltage is input, the fourth voltage V4 is established earlier than the second voltage V2, and then the second voltage V2 is pulled low, so that the first triode Q1 cannot be turned on, at this time, the voltage values of the first voltage V1 and the third voltage V3 are both about 5V, the relay K1 does not work, the circuit is disconnected, and the circuit behind the circuit can be protected, so that the protected product can be protected.
The abscissa in fig. 4 to 6 represents time, and the ordinate represents voltage.
Exemplarily, the present invention further provides an electronic device, which includes the protection circuit as described above.
Illustratively, the electronic device may be a mobile phone, a tablet computer, a notebook computer, a palm computer, a wearable device, a pedometer, and other electronic devices.
Because the utility model provides an electronic equipment includes any kind of protection circuit that above-mentioned protection circuit embodiment part provided, consequently, the utility model discloses the implementation provides electronic equipment can realize the same function with any kind of protection circuit that above-mentioned protection circuit embodiment part provided.
It is to be noted that, in the present invention, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. The term "comprising" is used to specify the presence of stated features, integers, steps, operations, elements, components, operations, components, or the components, and/components.
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; 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; such modifications and substitutions do not depart from the spirit and scope of the present invention in its corresponding aspects.
Claims (10)
1. A protection circuit connected between a power input and a protected product input, comprising:
the rectification and voltage stabilization module is connected with the power supply input end and is provided with a first output end used for outputting a first voltage and a second output end used for outputting a second voltage, and the second voltage is input voltage of the protected product input end;
the protection module is respectively connected with the rectification voltage-stabilizing module and the input end of the protected product and comprises a voltage dividing unit, a first switching unit and a second switching unit which are respectively connected with the voltage dividing unit and a third switching unit which is connected with the first switching unit, and the third switching unit is connected between the second output end and the input end of the protected product in series;
when the input voltage is higher than the power supply voltage of the protected product, the voltage dividing unit divides the input voltage to enable the second switch unit to be conducted and the first switch unit to be not conducted, and then the third switch unit is in a non-conducting state to conduct power-off protection on the protected product.
2. The protection circuit according to claim 1, wherein the voltage dividing unit includes a first voltage dividing unit and a second voltage dividing unit, the second switching unit is a second transistor, the first switching unit is a first transistor, the second voltage outputted from the second output terminal is divided by the second voltage dividing unit and then outputted to a base of the second transistor, an emitter of the second transistor is grounded, a collector of the second transistor is connected to a base of the first transistor, the first voltage outputted from the first output terminal is divided by the first voltage dividing unit and then outputted to a base of the first transistor, the emitter of the first transistor is grounded, and the collector of the first transistor is connected to a control terminal of the third switching unit to control on/off of the third switching unit.
3. The protection circuit according to claim 2, wherein the first voltage dividing unit includes a second resistor and a third resistor, the second voltage dividing unit includes a fourth resistor and a fifth resistor, one end of the second resistor is connected to the second output terminal, the other end of the second resistor is connected to the third resistor, the other end of the third resistor is grounded, one end of the fourth resistor is connected to the first output terminal, the other end of the fourth resistor is connected to the fifth resistor, and the other end of the fifth resistor is grounded.
4. The protection circuit according to claim 3, wherein the protection module further comprises a second regulator tube, a cathode of the second regulator tube is connected with the second resistor, an anode of the second regulator tube is connected with the third resistor, and breakdown voltage of the second regulator tube is larger than the maximum value of the power supply voltage of the protected product.
5. The protection circuit according to claim 2, wherein the third switching unit is a relay, a first terminal of the relay is connected to the second output terminal, a second terminal of the relay is connected to the first output terminal, a third terminal of the relay is connected to the input terminal of the protected product, and a fourth terminal of the relay is connected to the collector of the first triode.
6. The protection circuit of claim 2, wherein the protection module further comprises a second capacitor, one end of the second capacitor is connected to the base of the first transistor, and the other end of the second capacitor is grounded.
7. The protection circuit according to claim 1, wherein the rectifying and voltage-stabilizing module comprises a voltage-stabilizing unit, the voltage-stabilizing unit comprises a first resistor, a first voltage-stabilizing tube and a first capacitor, the first resistor is connected with a cathode of the first voltage-stabilizing tube, an anode of the first voltage-stabilizing tube is grounded, one end of the first capacitor is connected with the first output end, the other end of the first capacitor is grounded, the voltage-stabilizing unit is used for stabilizing the first voltage, and the first voltage is equal to the breakdown voltage of the first voltage-stabilizing tube.
8. The protection circuit according to claim 7, wherein the rectifying and voltage-stabilizing module further comprises a rectifying unit, the rectifying unit comprises a rectifying bridge and an electrolytic capacitor, an input terminal of the rectifying bridge is connected with the power input terminal, an output terminal of the rectifying bridge is respectively connected with an anode of the electrolytic capacitor, the first resistor and the second output terminal, a cathode of the electrolytic capacitor is grounded, the rectifying bridge comprises a first diode, a second diode, a third diode and a fourth diode, a third connection node between the third diode and the fourth diode is grounded, a fourth connection node between the first diode and the second diode is used as an output terminal of the rectifying bridge, a fifth connection node between the second diode and the fourth diode is connected with the first terminal of the power input terminal, a sixth connection node between the first diode and the third diode is connected with the second end of the power input terminal.
9. The protection circuit of claim 1, further comprising a fuse connected to the power input.
10. An electronic device characterized in that it comprises a protection circuit according to any one of claims 1 to 9.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202220417748.1U CN217282185U (en) | 2022-02-28 | 2022-02-28 | Protection circuit and electronic device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202220417748.1U CN217282185U (en) | 2022-02-28 | 2022-02-28 | Protection circuit and electronic device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN217282185U true CN217282185U (en) | 2022-08-23 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202220417748.1U Active CN217282185U (en) | 2022-02-28 | 2022-02-28 | Protection circuit and electronic device |
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| Country | Link |
|---|---|
| CN (1) | CN217282185U (en) |
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2022
- 2022-02-28 CN CN202220417748.1U patent/CN217282185U/en active Active
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