CN214314524U - Protection circuit, switching power supply and electronic equipment - Google Patents
Protection circuit, switching power supply and electronic equipment Download PDFInfo
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- CN214314524U CN214314524U CN202022647831.1U CN202022647831U CN214314524U CN 214314524 U CN214314524 U CN 214314524U CN 202022647831 U CN202022647831 U CN 202022647831U CN 214314524 U CN214314524 U CN 214314524U
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Abstract
The utility model discloses a protection circuit, switching power supply and electronic equipment belongs to the circuit field. The protection circuit comprises an input module, a control module, an auxiliary module, a detection module and a voltage division module, wherein the input module is used for being connected with an input end of an external power supply, the control module is connected with the input module and used for outputting a control instruction, the auxiliary module is respectively connected with the input module and the control module and used for assisting the external power supply to supply power, and the detection module is respectively connected with the auxiliary module and the control module and used for detecting whether the external power supply is under-voltage or not; the voltage division module comprises a first voltage division resistor, the first end of the first voltage division resistor is respectively connected with the input module, the control module and the auxiliary module, and the second end of the first voltage division resistor is grounded. The protection circuit can supply power to the detection module under the condition that an auxiliary power supply is not additionally added, so that the external power supply is controlled to be turned off, the operation is simple, and the cost is low.
Description
Technical Field
The utility model relates to a circuit field especially relates to a protection circuit, switching power supply and electronic equipment.
Background
At present, in the process of performing undervoltage protection on a switch power supply, an auxiliary power supply is often required to be additionally added so as to supply power to an undervoltage protection circuit, so that the power supply is controlled to be turned off, and the problem of high cost exists in the mode.
SUMMERY OF THE UTILITY MODEL
The utility model discloses aim at solving one of the technical problem that exists among the prior art at least. Therefore, the utility model provides a protection circuit can supply power to detection module under the condition that need not additionally increase auxiliary power source to control power supply turn-offs, easy operation, the cost is lower.
The utility model discloses still provide a switching power supply who has above-mentioned protection circuit.
The utility model discloses still provide an electronic equipment who has above-mentioned switching power supply.
According to utility model's first aspect embodiment's protection circuit, include:
the input module is used for connecting the input end of an external power supply;
the control module is connected with the input module and is used for outputting a control instruction;
the auxiliary module is respectively connected with the input module and the control module and is used for assisting the external power supply to supply power;
the detection module is respectively connected with the auxiliary module and the control module and is used for detecting whether the external power supply is under-voltage or not;
the voltage dividing module comprises a first voltage dividing resistor, a first end of the first voltage dividing resistor is respectively connected with the input module, the control module and the auxiliary module, and a second end of the first voltage dividing resistor is grounded.
According to the utility model discloses protection circuit has following beneficial effect at least: the protection circuit can supply power to the detection module under the condition that an auxiliary power supply is not additionally added, and detects whether the external power supply is under-voltage or not through the detection module, so that the power supply is controlled to be turned off through the control module, the operation is simple, and the cost is lower.
According to some embodiments of the invention, the protection circuit further comprises:
and the power module is respectively connected with the input module and the control module and is used for power conversion when the external power supply supplies power.
According to some embodiments of the invention, the auxiliary module comprises:
a transformer for powering the detection module.
According to some embodiments of the invention, the control module comprises:
and a first pin of the PWM chip is respectively connected with the input module, the auxiliary module and a first end of the first divider resistor, a second pin of the PWM chip is connected with the detection module, and the PWM chip is used for controlling the power supply of the external power supply.
According to some embodiments of the invention, the voltage divider module further comprises:
a second voltage-dividing resistor, a first end of the second voltage-dividing resistor being connected to the auxiliary module, the first pin of the PWM chip, and a first end of the first voltage-dividing resistor, respectively, and a second end of the second voltage-dividing resistor being connected to the input module;
and a first end of the third voltage-dividing resistor is connected with a second end of the second voltage-dividing resistor, and a second end of the third voltage-dividing resistor is connected with the input module.
According to some embodiments of the present invention, the model of the PWM chip is UC 3842.
According to some embodiments of the invention, the detection module comprises:
and the comparator is used for detecting whether the external power supply is under-voltage or not and outputting a detection signal to the control module.
According to some embodiments of the invention, the comparator is of type LM 119.
According to the utility model discloses a switching power supply of second aspect embodiment includes the protection circuit according to the first aspect embodiment.
According to the utility model discloses switching power supply has following beneficial effect at least: the switching power supply adopts the protection circuit of the embodiment, can supply power to the detection module without additionally increasing an auxiliary power supply, and detects whether the external power supply is under-voltage or not through the detection module, so that the switching power supply is controlled to be switched off through the control module, the operation is simple, the cost is lower, and the working stability of the switching power supply is improved.
According to the utility model discloses an electronic equipment of third aspect embodiment includes the switching power supply according to the second aspect embodiment.
According to the utility model discloses electronic equipment has following beneficial effect at least: the protection circuit of the above embodiment of the electronic device can supply power to the detection module without additionally increasing an auxiliary power supply, and detect whether the external power supply is under-voltage or not through the detection module, so that the power supply is controlled to be turned off through the control module, the operation is simple, the cost is low, and the working stability of the electronic device is improved.
Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.
Drawings
The invention will be further described with reference to the following drawings and examples, in which:
fig. 1 is a schematic structural diagram of a protection circuit according to an embodiment of the present invention;
fig. 2 is a schematic structural diagram of a protection circuit according to another embodiment of the present invention;
fig. 3 is a schematic circuit diagram of a protection circuit according to another embodiment of the present invention.
Reference numerals: 110. an input module; 120. a control module; 130. an auxiliary module; 140. a detection module; 150. a voltage division module; 210. a power module; 310. a transformer; 320. a comparator; 330. and a PWM chip.
Detailed Description
Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are exemplary only for the purpose of explaining the present invention, and should not be construed as limiting the present invention.
In the description of the present invention, it should be understood that the orientation or positional relationship indicated with respect to the orientation description, such as up, down, front, rear, left, right, etc., is based on the orientation or positional relationship shown in the drawings, and is only for convenience of description and simplification of description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention.
In the description of the present invention, a plurality of means is one or more, a plurality of means is two or more, and the terms greater than, less than, exceeding, etc. are understood as not including the number, and the terms greater than, less than, within, etc. are understood as including the number. If the first and second are described for the purpose of distinguishing technical features, they are not to be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated or implicitly indicating the precedence of the technical features indicated.
In the description of the present invention, unless there is an explicit limitation, the words such as setting, installation, connection, etc. should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meanings of the above words in combination with the specific contents of the technical solution.
In the description of the present invention, reference to the description of the terms "one embodiment," "some embodiments," "an illustrative embodiment," "an example," "a specific example," or "some examples" or the like means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.
In a first aspect, referring to fig. 1, the embodiment of the present invention provides a protection circuit including an input module 110, a control module 120, an auxiliary module 130, a detection module 140 and a voltage dividing module 150, the input module 110 is used for connecting an input terminal of an external power source, the control module 120 connects the input module 110, the control module 120 is used for outputting a control command, the auxiliary module 130 connects the input module 110 and the control module 120, the auxiliary module 130 is used for assisting the external power source to supply power, the detection module 140 connects the auxiliary module 130 and the control module 120, the detection module 130 is used for detecting whether an external power source is under-voltage, the voltage dividing module 150 includes a first voltage dividing resistor R1, the input module 110 is connected to a first end of a first voltage dividing resistor R1, the control module 120 and the auxiliary module 130, and a second end of the first voltage dividing resistor R1 is grounded. In the process of performing under-voltage protection on an external power supply, when the input voltage of the external power supply drops below a set threshold, the detection module 140 can detect the under-voltage of the external power supply, and output a detection signal to the control module 120, so that the control module 120 outputs a control instruction to turn off the external power supply, because the voltage division module 150 exists in the protection circuit, the voltage of the control module 120 can be kept constant by increasing the first voltage division resistor R1, so that after the under-voltage protection is performed on the external power supply, the control module 120 is kept in a closed state, the condition of false start cannot occur, and the stability of the under-voltage protection is ensured. It should be noted that the set threshold may be set according to actual situations, and is not limited. This kind of protection circuit can be under the condition that need not additionally increase auxiliary power supply, supplies power to detection module 140, detects whether the external power source appears under-voltage through detection module 140 to control the power supply shutoff through control module 120, easy operation, the cost is lower, is provided with first divider resistance R1 simultaneously and can makes control module 120 keep closing after accomplishing under-voltage protection, guarantees under-voltage protection's stability.
Referring to fig. 2, in some embodiments, the protection circuit further includes a power module 210, the power module 210 is connected to the input module 110 and the control module 120, respectively, and the power module 210 is used for power conversion when the external power source supplies power. By arranging the power module 210 in the protection circuit, when the external power supply is detected to supply power normally, the power can be quickly converted to provide the voltage required by the normal work of the load, so that the working stability of the external power supply is ensured.
Referring to fig. 3, in some embodiments, the auxiliary module 130 includes a transformer 310, the transformer 310 being used to power the detection module 140. After the under-voltage protection is realized, the detection module 140 still detects the input voltage of the external power supply in real time, when the detection module 140 detects that the input voltage of the external power supply exceeds a set threshold, it indicates that the input voltage has departed from an under-voltage protection point, at this moment, the input voltage of the external power supply reaches the voltage required by the normal start of the control module 120, the control module 120 restarts, the transformer 310 can assist the external power supply to supply power, the transformer 310 supplies power to the detection module 140, so that the detection module 140 is in a normal working state, and the under-voltage recovery of the protection circuit to the external power supply is realized.
Referring to fig. 3, in some embodiments, the detection module 140 includes a comparator 320, and the comparator 320 is configured to detect whether the external power source is under-voltage and output a detection signal to the control module 120. In the process of undervoltage protection of the external power supply, when the input voltage of the external power supply drops below the set threshold, the comparator 320 can detect that undervoltage occurs in the external power supply, so as to output a detection signal at a high level to the control module 120, so that the control module 120 stops working and outputs a control instruction to turn off the external power supply, because the voltage division module 150 exists in the protection circuit, the voltage of the control module 120 can be kept constant by increasing the first voltage division resistor R1, so that after the undervoltage protection is performed on the external power supply, the control module 120 is kept in a closed state, the condition of false start cannot occur, and the stability of undervoltage protection is ensured.
In some embodiments, comparator 320 is model LM 119. The model is LM 119's comparator sensitivity height, can compare weak small signal, consequently, selects the model to detect the undervoltage of external power supply for LM 119's comparator, is favorable to improving the detection precision, advances to guarantee external power supply job stabilization nature a stout. It should be noted that in some other embodiments, other types of comparators can be selected, and are not limited to this.
Referring to fig. 3, in some embodiments, the control module 120 includes a PWM chip 330, a first pin of the PWM chip 330 is connected to the input module 110, the auxiliary module 130, and a first terminal of the first voltage-dividing resistor R1, respectively, a second pin of the PWM chip 330 is connected to the detection module 140, and the PWM chip 330 is used to control the external power supply. The output end of the comparator 320 is connected to the second pin3 of the PWM chip 330, in the under-voltage protection process of the external power supply, when the input voltage of the external power supply drops to a set threshold value, the comparator 320 can detect that the external power supply is under-voltage, thereby outputting a detection signal at a high level to the second pin3 of the PWM chip 330, so that the PWM chip 330 stops working and outputs a control instruction to turn off the external power supply, the voltage of the PWM chip 330 can be kept constant by increasing the first voltage-dividing resistor R1, so that after the under-voltage protection is performed on the external power supply, the control module 120 keeps a closed state, the condition of false start cannot occur, and the stability of the under-voltage protection is ensured.
Referring to fig. 3, in some embodiments, the voltage dividing module 150 further includes a second voltage dividing resistor R2 and a third voltage dividing resistor R3, a first end of the second voltage dividing resistor R2 is connected to the auxiliary module 130, the first pin of the PWM chip 330, and a first end of the first voltage dividing resistor R1, respectively, and a second end of the second voltage dividing resistor R2 is connected to the input module 110; a first end of the third voltage dividing resistor R3 is connected to a second end of the second voltage dividing resistor R2, and a second end of the third voltage dividing resistor R3 is connected to the input module 110. A first end of the second voltage-dividing resistor R2 is connected to the first ends of the auxiliary module 130, the first pin7 of the PWM chip 330, and the first voltage-dividing resistor R1, respectively, and a second end of the second voltage-dividing resistor R2 is connected to the input module 110; the first end of the third voltage-dividing resistor R3 is connected to the second end of the second voltage-dividing resistor R2, the second end of the third voltage-dividing resistor R3 is connected to the input module 110, and the start voltage of the PWM chip 330 can be kept constant by the first voltage-dividing resistor R1, the second voltage-dividing resistor R2 and the third voltage-dividing resistor R3, that is, V _ Pin7 is R1/(R1+ R2+ R3) × Vin, where V _ Pin7 is the start voltage of the PWM chip 330 and Vin is the input voltage of the external power supply, and thus, by setting the voltage-dividing ratios of the first voltage-dividing resistor R1, the second voltage-dividing resistor R2 and the third voltage-dividing resistor R3, the start voltage-starting voltage of the PWM chip 330 after the under-voltage protection is completed can be further not greater than the start voltage threshold, so that the PWM chip 330 remains in a closed state after the external power supply is under-voltage protected, and the situation of false start cannot occur, and the stability of the under-voltage protection is ensured.
In some embodiments, the PWM chip has a model of UC 3842. The PWM chip pin that the model is UC3842 is few, peripheral circuit is simple, the PWM chip of this model can reduce the circuit complexity as control module 140's main electronic component, advance one's ground, the PWM chip that the model is UC3842 still has good undervoltage locking characteristic, PWM chip 330 can in time stop work and output control command when undervoltage appears in external power supply like this and make external power supply turn-off, and PWM chip 330 is in the off-state before the undervoltage protection finishes all the time, the condition of false start can not appear, guarantee undervoltage protection's stability.
In a second aspect, an embodiment of the present invention further provides a switching power supply, including the protection circuit shown in the first aspect.
The switching power supply adopts the protection circuit of the embodiment to supply power to the detection module without additionally increasing the auxiliary power supply, and detects whether the external power supply is under-voltage or not through the detection module, so that the power supply is controlled to be switched off through the control module, the operation is simple, the cost is lower, and the working stability of the switching power supply is improved.
In a third aspect, the present invention further provides an electronic device, including the switching power supply shown in the second aspect.
The electronic equipment adopts the switch power supply to supply power to the detection module under the condition that an auxiliary power supply is not additionally arranged, and detects whether the external power supply is under-voltage or not through the detection module, so that the power supply is controlled to be turned off through the control module, the operation is simple, the cost is lower, and the working stability of the electronic equipment is improved.
The embodiments of the present invention have been described in detail with reference to the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made without departing from the spirit of the present invention within the knowledge of those skilled in the art. Furthermore, the embodiments of the present invention and features of the embodiments may be combined with each other without conflict.
Claims (10)
1. A protection circuit, comprising:
the input module is used for connecting the input end of an external power supply;
the control module is connected with the input module and is used for outputting a control instruction;
the auxiliary module is respectively connected with the input module and the control module and is used for assisting the external power supply to supply power;
the detection module is respectively connected with the auxiliary module and the control module and is used for detecting whether the external power supply is under-voltage or not;
the voltage dividing module comprises a first voltage dividing resistor, a first end of the first voltage dividing resistor is respectively connected with the input module, the control module and the auxiliary module, and a second end of the first voltage dividing resistor is grounded.
2. The protection circuit of claim 1, further comprising:
and the power module is respectively connected with the input module and the control module and is used for power conversion when the external power supply supplies power.
3. The protection circuit of claim 1, wherein the auxiliary module comprises:
a transformer for powering the detection module.
4. The protection circuit of claim 1, wherein the control module comprises:
and a first pin of the PWM chip is respectively connected with the input module, the auxiliary module and a first end of the first divider resistor, a second pin of the PWM chip is connected with the detection module, and the PWM chip is used for controlling the power supply of the external power supply.
5. The protection circuit of claim 4, wherein the voltage divider module further comprises:
a second voltage-dividing resistor, a first end of the second voltage-dividing resistor being connected to the auxiliary module, the first pin of the PWM chip, and a first end of the first voltage-dividing resistor, respectively, and a second end of the second voltage-dividing resistor being connected to the input module;
and a first end of the third voltage-dividing resistor is connected with a second end of the second voltage-dividing resistor, and a second end of the third voltage-dividing resistor is connected with the input module.
6. The protection circuit according to claim 4, wherein the model of the PWM chip is UC 3842.
7. The protection circuit of claim 1, wherein the detection module comprises:
and the comparator is used for detecting whether the external power supply is under-voltage or not and outputting a detection signal to the control module.
8. The protection circuit of claim 7, wherein the comparator is of type LM 119.
9. Switching power supply, characterized in that it comprises a protection circuit according to any one of claims 1 to 8.
10. Electronic device, characterized in that it comprises a switching power supply according to claim 9.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202022647831.1U CN214314524U (en) | 2020-11-16 | 2020-11-16 | Protection circuit, switching power supply and electronic equipment |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202022647831.1U CN214314524U (en) | 2020-11-16 | 2020-11-16 | Protection circuit, switching power supply and electronic equipment |
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| Publication Number | Publication Date |
|---|---|
| CN214314524U true CN214314524U (en) | 2021-09-28 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN202022647831.1U Active CN214314524U (en) | 2020-11-16 | 2020-11-16 | Protection circuit, switching power supply and electronic equipment |
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| CN (1) | CN214314524U (en) |
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