CN219999031U - Overheat protection circuit with self-locking function for switching power supply - Google Patents
Overheat protection circuit with self-locking function for switching power supply Download PDFInfo
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- CN219999031U CN219999031U CN202321655123.XU CN202321655123U CN219999031U CN 219999031 U CN219999031 U CN 219999031U CN 202321655123 U CN202321655123 U CN 202321655123U CN 219999031 U CN219999031 U CN 219999031U
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- power supply
- optocoupler
- resistor
- overheat protection
- protection circuit
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- 238000010586 diagram Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
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Abstract
The utility model discloses an overheat protection circuit with a self-locking function for a switching power supply, which comprises a voltage stabilizing reference source N1, an optocoupler V1 and a temperature relay K1, wherein the positive electrode of a direct current power supply is connected with the reference end of the voltage stabilizing reference source N1 through a resistor R1 and a resistor R2, the cathode of the voltage stabilizing reference source N1 and the positive input end of the optocoupler V1 are both connected with a connection point between the resistor R1 and the resistor R2, a resistor R3 is connected between the reference end of the voltage stabilizing reference source N1 and an anode, and the anode is connected with the negative input end and the positive output end of the optocoupler V1; the negative electrode of the direct current power supply is connected with the negative output end of the optocoupler V1 and one contact of the temperature relay K1, and the positive output end of the optocoupler V1 is connected with the other contact of the temperature relay K1 and is used as the control signal output end of the overheat protection circuit. The utility model utilizes the self-locking circuit of the temperature relay and the optocoupler to realize the overheat protection function of the DC-DC converter.
Description
Technical Field
The utility model relates to the technical field of switching power supplies, in particular to an overheat protection circuit with a self-locking function for a switching power supply.
Background
In the technical field of switching power supplies, when the DC-DC converter does not have an overheat protection function, or in other cases, a temperature relay is required to be adopted to realize overheat protection, and the temperature relay is at a critical protection point and can generate on-off back and forth actions. When the surface temperature of the DC-DC converter is higher than a set temperature protection critical point, the temperature relay can turn off the DC-DC converter, and after the DC-DC converter does not work, the surface temperature of the DC-DC converter can be reduced to be lower than the temperature protection critical point, at the moment, the temperature relay can turn on the DC-DC converter, and the DC-DC converter can be frequently turned on and off at the set temperature protection critical point, so that the DC-DC converter is damaged.
Disclosure of Invention
In order to solve the problems, the utility model aims to provide the overheat protection circuit with the self-locking function for the switching power supply, which has the advantages of simple structure, adjustable parameters and convenient debugging.
In order to achieve the aim of the utility model, the utility model adopts the following technical scheme:
the overheat protection circuit with the self-locking function for the switching power supply comprises a voltage stabilizing reference source N1, an optocoupler V1 and a temperature relay K1, wherein the positive electrode of a direct current power supply is connected with the reference end of the voltage stabilizing reference source N1 through a resistor R1 and a resistor R2, the cathode of the voltage stabilizing reference source N1 and the positive input end of the optocoupler V1 are both connected with a connection point between the resistor R1 and the resistor R2, a resistor R3 is connected between the reference end and the positive electrode of the voltage stabilizing reference source N1, and the positive input end and the positive output end of the optocoupler V1 are connected with the positive electrode of the voltage stabilizing reference source N1; the negative electrode of the direct current power supply is connected with the negative output end of the optocoupler V1 and one contact of the temperature relay K1, and the positive output end of the optocoupler V1 is connected with the other contact of the temperature relay K1 and is used as the control signal output end of the overheat protection circuit.
Further, the positive electrode and the negative electrode of the direct current power supply are respectively connected with the positive power supply voltage input end and the negative power supply voltage input end of the DC-DC converter, and the positive output end of the optocoupler V1 is connected with the on/off control end of the DC-DC converter.
Further, the model number of the stabilized voltage reference source N1 is TL431.
Further, the model of the optocoupler relay V1 is M211.
By adopting the technical scheme, the utility model has the following advantages:
the overheat protection circuit with the self-locking function for the switching power supply has the advantages of simple structure, fewer used components and high reliability, realizes the overheat protection function of the DC-DC converter by utilizing the self-locking circuit of the temperature relay and the optocoupler, and can be widely applied to the switching power supply.
Drawings
FIG. 1 is a schematic diagram of an overheat protection circuit with self-locking function for a switching power supply of the present utility model;
fig. 2 is a schematic diagram of an example of the use of the overheat protection circuit with self-locking function for the switching power supply of the present utility model.
Detailed Description
The technical scheme of the utility model is further described in detail below with reference to the accompanying drawings and examples.
As shown IN fig. 1, the overheat protection circuit with self-locking function for a switching power supply comprises a voltage stabilizing reference source N1, an optocoupler V1 and a temperature relay K1, wherein the positive electrode +in of the direct current power supply is connected with a reference end of the voltage stabilizing reference source N1 through a current limiting resistor R1 and a resistor R2, the cathode of the voltage stabilizing reference source N1 and the positive input end of the optocoupler V1 are both connected with a connection point between the resistor R1 and the resistor R2, a resistor R3 is connected between the reference end and the anode of the voltage stabilizing reference source N1, and the anode of the voltage stabilizing reference source N1 is connected with the negative input end and the positive output end of the optocoupler V1; the negative pole-IN of the direct current power supply is connected with the negative output end of the optocoupler V1 and one contact A1 of the temperature relay K1, and the positive output end of the optocoupler V1 is connected with the other contact A2 of the temperature relay K1 and serves as a control signal output end of the overheat protection circuit.
As shown in fig. 2, the positive and negative poles of the DC power supply are respectively connected to the positive power supply voltage input terminal +vin and the negative power supply voltage input terminal-VIN of the DC-DC converter, and the positive output terminal of the optocoupler V1 is connected to the on/off control terminal of the DC-DC converter.
The model number of the voltage stabilizing reference source N1 is TL431, which is a high-precision three-terminal adjustable shunt reference source with good heat stability, and the output voltage of the high-precision three-terminal adjustable shunt reference source can be set to any value within the range of 2.5V-36V through the adjusting resistor R2 and the adjusting resistor R3; when the input voltage is unstable or too high, the voltage stabilizing reference source N1 can stabilize the input voltage at an accurate value, and in the overheat protection circuit, the resistor R2 and the resistor R3 are resistors with the resistance value of 10KΩ and can stabilize the input voltage at 5V, so that after the optocoupler V1 is conducted, the input high voltage can be stabilized to 5V and then applied to the ON/OFF control end of the DC-DC converter, and the ON/OFF control end of the DC-DC converter is not damaged due to the introduction of the high voltage.
The model of the optocoupler relay V1 is M211.
The utility model relates to an overheat protection circuit with a self-locking function for a switching power supply, which has the following working principle: under normal conditions, the contact of the temperature relay K1 is in a normally open state, at the moment, the optocoupler V1 is not conducted, the ON/OFF control end of the DC-DC converter is in a suspended state, and the DC-DC converter works normally; when the temperature relay is switched from a normally open state to a closed state after overheat, the optocoupler V1 is conducted, the ON/OFF control end of the DC-DC converter is pulled down, and the DC-DC converter stops working; at this time, the output end of the optocoupler V1 bypasses the contact of the temperature relay K1, if the contact of the temperature relay K1 is disconnected again, the optocoupler V1 is still kept ON by utilizing the self-locking function of the optocoupler V1, the ON/OFF control end of the DC-DC converter is still pulled down, and the DC-DC converter is still kept in a non-working state, so that the DC-DC converter is protected from being damaged.
The above description is only of the preferred embodiments of the present utility model and is not intended to limit the present utility model, but various modifications and variations can be made to the present utility model by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present utility model should be included in the protection scope of the present utility model.
Claims (4)
1. An overheat protection circuit with a self-locking function for a switching power supply is characterized in that: the direct-current power supply comprises a voltage-stabilizing reference source N1, an optocoupler V1 and a temperature relay K1, wherein the positive electrode of the direct-current power supply is connected with the reference end of the voltage-stabilizing reference source N1 through a resistor R1 and a resistor R2, the cathode of the voltage-stabilizing reference source N1 and the positive input end of the optocoupler V1 are both connected with a connection point between the resistor R1 and the resistor R2, a resistor R3 is connected between the reference end of the voltage-stabilizing reference source N1 and the anode, and the anode of the voltage-stabilizing reference source N1 is connected with the negative input end and the positive output end of the optocoupler V1; the negative electrode of the direct current power supply is connected with the negative output end of the optocoupler V1 and one contact of the temperature relay K1, and the positive output end of the optocoupler V1 is connected with the other contact of the temperature relay K1 and is used as the control signal output end of the overheat protection circuit.
2. The overheat protection circuit with a self-locking function for a switching power supply of claim 1, wherein: the positive and negative poles of the DC power supply are respectively connected with the positive and negative power supply voltage input ends of the DC-DC converter, and the positive output end of the optocoupler V1 is connected with the on/off control end of the DC-DC converter.
3. The overheat protection circuit with a self-locking function for a switching power supply of claim 1, wherein: the model number of the voltage stabilizing reference source N1 is TL431.
4. The overheat protection circuit with a self-locking function for a switching power supply of claim 1, wherein: the model of the optocoupler relay V1 is M211.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202321655123.XU CN219999031U (en) | 2023-06-28 | 2023-06-28 | Overheat protection circuit with self-locking function for switching power supply |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202321655123.XU CN219999031U (en) | 2023-06-28 | 2023-06-28 | Overheat protection circuit with self-locking function for switching power supply |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN219999031U true CN219999031U (en) | 2023-11-10 |
Family
ID=88614029
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202321655123.XU Active CN219999031U (en) | 2023-06-28 | 2023-06-28 | Overheat protection circuit with self-locking function for switching power supply |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN219999031U (en) |
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2023
- 2023-06-28 CN CN202321655123.XU patent/CN219999031U/en active Active
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