Combination switch overheat protection circuit

Abstract

The utility model discloses an overheat protection circuit of a combination switch, and relates to the technical field of combination switch circuits. According to the utility model, functions of rapid and stable temperature detection alarm and overheat protection are realized; by optimizing circuit design and selecting a high-performance comparator and a high-performance thermistor, relatively accurate temperature measurement and control are realized, the safety of equipment, elements and users is protected, the service life of the equipment is prolonged, and the reliability and safety of the equipment are improved; a zero-cross detection circuit composed of pure electrical components is designed through circuit combination of a differential voltage comparator and a thermistor, and compared with traditional negative coefficient triode overheat protection, the combination of the comparator and the thermistor is added, so that the combination has very high temperature sensitivity; the change of the resistance value can be obviously caused by the temperature change, so that the accurate temperature measurement and control can be realized; the combination has good stability and durability, and can provide long-term reliable overheating protection.

Description

Technical Field

[0001] The utility model relates to the technical field of composite switch circuits, in particular to a composite switch overheat protection circuit. Background Art

[0002] A composite switch is a switch that integrates multiple switch elements and is usually used to control current or power in an AC circuit. A composite switch is a switch device that integrates multiple functions, usually including switching, protection, control and monitoring functions. It integrates a variety of different functions into one device, such as switching, short circuit protection, overload protection, undervoltage protection, overvoltage protection, current measurement, voltage measurement, communication interface, etc. This can simplify the installation and wiring process, reduce the number of devices and occupy space. At the same time, the composite switch integrates multiple protection functions in one device, such as short circuit protection, overload protection and overvoltage protection. These protection functions can detect and respond to electrical faults in a timely manner, protect electrical equipment and systems, reduce the occurrence of accidents, and improve the reliability and safety of the system.

[0003] The significance of overheat protection is to protect electrical equipment, electronic components or systems from overheating damage and prevent situations that may cause safety hazards. Overheating is one of the common causes of damage to electrical equipment. By implementing overheat protection, the operating temperature of the equipment can be controlled to prevent the equipment from running in a high temperature environment for a long time, thereby extending the service life of the equipment. Overheating can cause the performance of various electronic components to degrade or even burn, causing serious damage to the equipment. Overheat protection measures can monitor the temperature of the equipment and take measures such as cutting off the power supply or reducing the power when the temperature exceeds the safety threshold to avoid equipment damage caused by overheating. Overheating may cause electrical equipment or electronic components to cause safety hazards such as fire and short circuit. Through the implementation of overheat protection, the temperature of the equipment can be controlled in time to prevent safety accidents caused by overheating, thereby improving the safety of the equipment. Overheat protection can effectively control the temperature of the equipment, avoid unnecessary energy consumption and heat loss, and achieve the goals of energy saving and environmental protection.

[0004] In summary, the significance of overheat protection of compound switches is to protect the safety of equipment, components and users, extend the life of equipment, and improve the reliability and safety of equipment. It is crucial for various types of electrical equipment and electronic systems and should be taken into account in design, manufacturing and use. Utility Model Content

[0005] The purpose of the utility model is to provide a composite switch overheat protection circuit to solve the problems raised in the above background technology.

[0006] In order to solve the above technical problems, the utility model provides the following technical solutions:

[0007] A composite switch overheat protection circuit comprises a comparator circuit and a thermistor circuit, wherein the comparator circuit is electrically connected to the thermistor circuit.

[0008] Preferably, the comparator circuit includes a differential voltage comparator U1A.

[0009] Preferably, the thermistor circuit includes a thermistor R1 and a resistor R2, the thermistor R1 and the resistor R2 are connected in series, one end of the thermistor R1 away from the resistor R2 is grounded, one end of the resistor R2 away from the thermistor R1 is connected to the VCC terminal, and the + end interface of the differential voltage comparator U1A is connected to the thermistor R1.

[0010] Preferably, the thermistor circuit also includes a resistor R3 and a resistor R4, the resistor R3 and the resistor R4 are connected in series, the end of the resistor R4 away from the resistor R3 is grounded, the end of the resistor R3 away from the resistor R4 is connected to the VCC end, and the -end interface of the differential voltage comparator U1A is electrically connected between the resistor R3 and the resistor R4.

[0011] Preferably, the 1 interface of the differential voltage comparator U1A is electrically connected to the A port of the oscilloscope XSC1, the 4 interface of the differential voltage comparator U1A is grounded, and the 5 interface of the differential voltage comparator U1A is connected to the VCC terminal.

[0012] Preferably, an external resistor R5 is connected between the 1 interface of the differential voltage comparator U1A and the A port of the oscilloscope XSC1, and the resistor R5 is connected to the VDD terminal.

[0013] Compared with the prior art, the beneficial effects achieved by the utility model are:

[0014] The circuit in the utility model includes the functions of fast and stable temperature detection alarm and overheat protection; the main circuit includes a comparator circuit and a thermistor circuit; by optimizing the circuit design and selecting high-performance comparators and thermistors, more accurate temperature measurement and control can be achieved, the safety of equipment, components and users can be protected, the life of the equipment can be extended, and the reliability and safety of the equipment can be improved; by combining the circuit with a differential voltage comparator and a thermistor, a zero-crossing detection circuit composed of pure electrical components is designed, and compared with the traditional negative coefficient triode overheat protection, by adding a combination of a comparator and a thermistor, the combination has a very high temperature sensitivity, and temperature changes can more obviously cause changes in resistance values, thereby achieving more accurate temperature measurement and control; the thermistor only needs to be simply used as a variable resistor in the circuit, without other complex components or circuit configurations, and is relatively simple to use; the combination has good stability and durability, and can provide long-term and reliable overheat protection; the negative coefficient triode needs to be used in combination with other components, and appropriate circuit configuration and control logic design are required, which is relatively complex. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0016] Figure 1 It is a circuit diagram of the entire utility model. DETAILED DESCRIPTION

[0017] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0018] refer to Figure 1The utility model provides a technical solution: a composite switch overheat protection circuit, including a comparator circuit and a thermistor circuit, the comparator circuit is electrically connected to the thermistor circuit; the comparator circuit includes a differential voltage comparator U1A; the thermistor circuit includes a thermistor R1 and a resistor R2, the thermistor R1 and the resistor R2 are connected in series, the end of the thermistor R1 away from the resistor R2 is grounded, the end of the resistor R2 away from the thermistor R1 is connected to the VCC end, and the + end interface of the differential voltage comparator U1A is connected to the thermistor R1; the thermistor circuit also includes a resistor R3 and a resistor R4, the resistor R3 and the resistor R4 are connected in series, the resistor R4 is away from the electrical One end of the resistor R3 is grounded, and one end of the resistor R3 away from the resistor R4 is connected to the VCC end, and the - end interface of the differential voltage comparator U1A is electrically connected between the resistor R3 and the resistor R4; the 1 interface of the differential voltage comparator U1A is electrically connected to the A port of the oscilloscope XSC1, the 4 interface of the differential voltage comparator U1A is grounded, and the 5 interface of the differential voltage comparator U1A is connected to the VCC end; an external resistor R5 is connected between the 1 interface of the differential voltage comparator U1A and the A port of the oscilloscope XSC1, and the resistor R5 is connected to the VDD end; VCC and VDD are two isolated power supplies, VCC is the collector power supply and VDD is the drain power supply.

[0019] Specific working principle: The circuit in the utility model includes the functions of fast and stable temperature detection alarm and overheat protection; the main circuit includes a comparator circuit and a thermistor circuit; by optimizing the circuit design and selecting high-performance comparators and thermistors, more accurate temperature measurement and control can be achieved, the safety of equipment, components and users can be protected, the life of the equipment can be extended, and the reliability and safety of the equipment can be improved; by combining the circuit with a differential voltage comparator and a thermistor, a zero-crossing detection circuit composed of pure electrical components is designed. Compared with the traditional negative coefficient triode overheat protection, by adding a combination of a comparator and a thermistor, the combination has a very high temperature sensitivity, and temperature changes can more obviously cause changes in resistance values, thereby achieving more accurate temperature measurement and control; the thermistor only needs to be used as a variable resistor in the circuit, without other complex components or circuit configurations, and is relatively simple to use; the combination has good stability and durability, and can provide long-term and reliable overheat protection; the negative coefficient triode needs to be used in combination with other components, and appropriate circuit configuration and control logic design are required, which is relatively complex;

[0020] Comparator: can be used to monitor and compare the relationship between the temperature signal and the set threshold, thereby triggering the corresponding protection measures; the comparator receives the temperature signal from the thermistor and compares it with the set threshold. It can monitor the temperature change in real time to determine whether it reaches or exceeds the set overheating threshold;

[0021] When the comparator detects that the temperature signal exceeds the set overheat threshold, it generates an alarm signal to alert the user or system operator that the temperature has exceeded the safe range. This can help avoid damage or danger caused by overheating of the equipment. Once the comparator detects an overheating condition, it triggers the corresponding protection measures, such as turning off the power, cutting off the circuit, starting the fan or reducing the power; the output signal of the comparator can be used as a signal to control the switch or trigger other protection devices to protect the equipment from damage caused by overheating; the comparator usually has an adjustable threshold setting function, which can adjust the overheating threshold according to the specific application needs and temperature requirements; this makes the overheating protection circuit flexible to adapt to different temperature control requirements;

[0022] Thermistor: In overheat protection circuits, thermistors are used to sense temperature changes and convert them into resistance changes, thereby triggering corresponding protection measures; thermistors can produce changes in resistance value according to temperature changes, and temperature information can be indirectly obtained by measuring the change in resistance; it can be used as a temperature sensor, and provide temperature signals by connecting to the detection circuit; thermistors are suitable for overheat protection circuits, and they can detect and sense whether the temperature exceeds the safe range; when the temperature rises to the set threshold or exceeds the set upper limit, the resistance value of the thermistor changes, and through the comparator or controller in the circuit, the corresponding protection measures are triggered, such as turning off the power or cutting off the circuit, to avoid damage or danger caused by overheating of the equipment;

[0023] Thermistor R1 is used to sense temperature changes and convert them into resistance changes. Resistors R2, R3 and R4 are ordinary resistors, and their main function is voltage division. When the temperature is normal, thermistor R1 does not change. According to the ratio voltage division relationship between thermistor R1 and resistor R2, the voltage input to the + port of the differential voltage comparator U1A is V1. According to the ratio voltage division relationship between resistor R3 and resistor R4, the voltage input to the - port of the differential voltage comparator U1A is V2. V1>V2, the differential voltage comparator U1A outputs a high level, and resistor R5 is a pull-up resistor; the differential voltage comparator U1A outputs a high level, the electromagnetic relay works normally, the corresponding circuit is connected, and the chip works normally.

[0024] When the temperature is abnormal, the thermistor R1 changes and starts to become smaller. According to the voltage division relationship of the ratio of the thermistor R1 and the resistor R2, the voltage input to the + port of the differential voltage comparator U1A is V1, and V1 starts to become smaller. According to the voltage division relationship of the ratio of the resistor R3 and the resistor R4, the voltage input to the - port of the differential voltage comparator U1A is V2. Since V1 < V2, the differential voltage comparator U1A outputs a high level, and the resistor R5 is a pull-up resistor; when the differential voltage comparator U1A outputs a low level, the electromagnetic relay is disconnected, the corresponding circuit is disconnected, and the chip stops working and enters the protection state.

[0025] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not used to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, for those skilled in the art, they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A composite switch overheat protection circuit, comprising a comparator circuit and a thermistor circuit, characterized in that: The comparator circuit is electrically connected to the thermistor circuit.

2. A composite switch overheat protection circuit according to claim 1, characterized in that: The comparator circuit includes a differential voltage comparator U1A.

3. A composite switch overheat protection circuit according to claim 2, characterized in that: The thermistor circuit includes a thermistor R1 and a resistor R2. The thermistor R1 and the resistor R2 are connected in series. One end of the thermistor R1 away from the resistor R2 is grounded. One end of the resistor R2 away from the thermistor R1 is connected to the VCC terminal. The + end interface of the differential voltage comparator U1A is connected to the thermistor R1.

4. A composite switch overheat protection circuit according to claim 3, characterized in that: The thermistor circuit also includes a resistor R3 and a resistor R4, wherein the resistor R3 and the resistor R4 are connected in series, an end of the resistor R4 away from the resistor R3 is grounded, an end of the resistor R3 away from the resistor R4 is connected to the VCC end, and a -end interface of the differential voltage comparator U1A is electrically connected between the resistor R3 and the resistor R4.

5. A composite switch overheat protection circuit according to claim 4, characterized in that: Interface 1 of the differential voltage comparator U1A is electrically connected to port A of the oscilloscope XSC1, interface 4 of the differential voltage comparator U1A is grounded, and interface 5 of the differential voltage comparator U1A is connected to the VCC terminal.

6. A composite switch overheat protection circuit according to claim 5, characterized in that: An external resistor R5 is connected between the 1 interface of the differential voltage comparator U1A and the A port of the oscilloscope XSC1, and the resistor R5 is connected to the VDD terminal.

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