Low-voltage chip type PTC (Positive Temperature Coefficient) thermistor
By designing a low-voltage chip PTC thermistor, using thermal expansion blocks to change the contact situation at different temperatures, accurate temperature detection under low voltage conditions is achieved, and the problem of small current variation in the prior art is solved.
Patent Information
- Application Number
- CN202420928988.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-04-30
- Publication Date
- 2025-03-07
- Estimated Expiration
- 2034-04-30
AI Technical Summary
Under high temperature and low voltage conditions, the resistance value of existing PTC thermistors is high, resulting in a small change in current and making it difficult to accurately detect temperature changes.
A low voltage chip PTC thermistor is designed, through a combined structure of a first resistor, a first contact, a thermal expansion block, a second resistor, a fixed plate, a second contact, and a third contact, the first contact contact comes into contact with the third contact at a low temperature, and at a high temperature, the first contact comes into contact with the second contact, respectively forming a loop to realize temperature detection at a low voltage.
In the low temperature state, the resistance values of the first resistor and the second resistor are not high, and the changes in passing current can be accurately detected and the temperature changes can be reflected; in the high temperature state, the resistance values of the first resistor and the second resistor can be increased, and the temperature change can be detected by the current of the first resistor alone, thereby improving the accuracy of temperature detection.
Smart Images
Figure CN222580876U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the field of PTC thermistors, in particular to a low-voltage chip-type PTC thermistor. Background Art
[0002] PTC thermistor is a typical temperature-sensitive semiconductor resistor. When the temperature exceeds a certain level, its resistance value increases in a step-like manner as the temperature rises. PTC thermistors are generally used in combination with other devices. The devices detect the current size and current changes passing through the PTC thermistor to reflect the temperature size and changes.
[0003] The characteristic of thermistors is that their resistance will change with the change of temperature. For example, the resistance of PTC thermistors will increase with the increase of temperature. Under high temperature and low voltage conditions, the resistance value is high and the current passing through the resistor is small, resulting in a small change in the current, which is not conducive to other equipment to detect the current passing through the resistor to determine the size and change of temperature. Utility Model Content
[0004] The utility model aims to solve the shortcomings in the prior art and proposes a low-voltage chip PTC thermistor.
[0005] In order to achieve the above-mentioned purpose, the utility model adopts the following technical scheme: a low-voltage chip PTC thermistor, comprising a shell, a first resistor is fixedly connected to the inner wall of the shell, a first contact is fixedly connected to the right end of the first resistor, a thermal expansion block is fixedly connected to the lower surface of the first resistor, a second resistor is fixedly connected to the bottom of the thermal expansion block, a fixed plate is fixedly connected to the right end of the second resistor, a second contact is fixedly connected to the left side of the fixed plate, a third contact is fixedly connected to the left side of the fixed plate, and the third contact is located below the second contact.
[0006] As a further description of the above technical solution:
[0007] A first pin is fixedly connected inside the shell, one end of the first pin is fixedly connected to the left end of the first resistor, and the other end of the first pin extends to the outside of the shell.
[0008] As a further description of the above technical solution:
[0009] The fixed plate includes an upper section, a middle section, and a lower section. The second contact is located in the upper section of the fixed plate, and the third contact is located in the lower section of the fixed plate. The upper section and the lower section are made of conductive materials, and the middle section is made of insulating material. The length of the middle section is equal to the length of the first contact.
[0010] As a further description of the above technical solution:
[0011] A second pin is fixedly connected to the bottom of the shell, one end of the second pin is located inside the shell, and the other end of the second pin is located outside the shell.
[0012] As a further description of the above technical solution:
[0013] The upper section of the fixing plate is fixedly connected with a first wire, and the other end of the first wire is fixedly connected with one end of the second pin.
[0014] As a further description of the above technical solution:
[0015] A second wire is fixedly connected to the bottom of the second resistor, and the other end of the second wire is fixedly connected to one end of the second pin.
[0016] As a further description of the above technical solution:
[0017] The shell is a sheet-like structure.
[0018] The utility model has the following beneficial effects:
[0019] Compared with the prior art, the low-voltage chip PTC thermistor is provided with a first resistor, a first contact, a heat expansion block, a second resistor, a fixing plate, a second contact, and a third contact. When in use, the heat expansion block is deformed by heat. At low temperatures, the heat expansion block is not deformed. The first contact is in contact with the third contact to form a loop. At this time, the resistance values of the first resistor and the second resistor are both small. Under low voltage conditions, the current passing through the first resistor and the second resistor can be accurately detected, and the temperature can be detected according to the change in the current. At high temperatures, the heat expansion block expands and deforms. The first contact is in contact with the second contact to form a loop. At this time, the resistance values of the first resistor and the second resistor increase in a step-like manner. Under low voltage conditions, the current passing through the first resistor and the second resistor can be detected separately. The current is used to detect the temperature according to the change of the current. Compared with the conventional low-voltage thermistor, when in use, the resistance value is small in the low temperature state and can be detected normally. The resistance value is large in the high temperature state, and the current passing through the resistor is small, so the current change amplitude is also small. It is not possible to reflect the temperature change state through the current change amplitude well, and it is not convenient to use. When the resistance values of the first resistor and the second resistor are not high in the low temperature state, the current passing through the first resistor and the second resistor can be detected to reflect the temperature change. When the resistance values of the first resistor and the second resistor increase in the high temperature state, the current passing through the first resistor can be detected to reflect the temperature change. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Figure 1 This is a schematic diagram of the overall structure of the low voltage chip PTC thermistor proposed by the utility model;
[0021] Figure 2 This is a cross-sectional view of the internal structure of the low-voltage chip PTC thermistor proposed by the utility model;
[0022] Figure 3 The low voltage chip PTC thermistor proposed by the utility model Figure 2 A magnified view of the structure at center;
[0023] Figure 4 The utility model provides a circuit diagram of a low-voltage chip PTC thermistor.
[0024] Legend:
[0025] 1. Housing; 2. First resistor; 3. First pin; 4. First contact; 5. Thermal expansion block; 6. Second resistor; 7. Fixing plate; 8. Second contact; 9. Third contact; 10. First wire; 11. Second wire; 12. Second pin. DETAILED DESCRIPTION
[0026] Reference Figure 1-4The utility model provides a low-voltage chip PTC thermistor: comprising a shell 1, a first resistor 2 is fixedly connected to the inner wall of the shell 1, a first contact 4 is fixedly connected to the right end of the first resistor 2, a thermal expansion block 5 is fixedly connected to the lower surface of the first resistor 2, an insulating coating is arranged between the first resistor 2 and the thermal expansion block 5, the thermal expansion block 5 can be made of metal materials such as copper and platinum, or can be made of polymer plastics, etc., by utilizing the characteristics of different materials with different deformation amplitudes when heated, and selecting suitable materials, the position between the first resistor 2 and the second resistor 6 can be changed at high temperature, so that different contacts are in contact, so as to achieve the purpose of low voltage detection of high temperature, a second resistor 6 is fixedly connected to the bottom of the thermal expansion block 5, an insulating coating is arranged between the second resistor 6 and the thermal expansion block 5, the first resistor 2 and the second resistor 6 are both PTC thermistors, the right end of the second resistor 6 is fixedly connected to a fixing plate 7, the left side of the fixing plate 7 is fixedly connected to a second contact 8, and the left side of the fixing plate 7 is fixedly connected to a third contact 9. The third contact 9 is located below the second contact 8. When in use, the thermal expansion block 5 will be deformed by heat. At low temperature, the thermal expansion block 5 does not deform. The first contact 4 contacts the third contact 9 to form a loop. At this time, the resistance values of the first resistor 2 and the second resistor 6 are both small. Under low voltage conditions, the current passing through the first resistor 2 and the second resistor 6 can be accurately detected (the resistance values of the first resistor 2 and the second resistor 6 are small at low temperatures. If the current only passes through the first resistor 2, the problem of low resistance and excessive current burning the circuit may occur. Detecting the current passing through the first resistor 2 and the second resistor 6 under low temperature conditions can protect the circuit while detecting the temperature). The temperature is detected according to the change in current. At high temperature, the thermal expansion block expands and deforms. The first contact 4 contacts the second contact 8 to form a loop. At this time, the resistance values of the first resistor 2 and the second resistor 6 increase in a step-like manner. Under low voltage conditions, the current passing through the first resistor 2 can be detected separately, and the temperature is detected according to the change in current.
[0027] The fixed plate 7 includes an upper section, a middle section, and a lower section. The second contact 8 is located in the upper section of the fixed plate 7, and the third contact 9 is located in the lower section of the fixed plate 7. The upper section and the lower section are made of conductive materials, and the middle section is made of insulating materials. The length of the middle section is equal to the length of the first contact 4, so that the first contact 4 will not contact the second contact 8 and the third contact 9 at the same time. The temperature changes all the time, and the time after the first contact 4 completely overlaps with the middle section is very short, which will not affect the normal detection of the temperature by the resistor.
[0028] A first pin 3 is fixedly connected to the inside of the shell 1, one end of the first pin 3 is fixedly connected to the left end of the first resistor 2, and the other end of the first pin 3 extends to the outside of the shell 1. A second pin 12 is fixedly connected to the bottom of the shell 1, one end of the second pin 12 is located inside the shell 1, and the other end of the second pin 12 is located outside the shell 1. A first wire 10 is fixedly connected to the upper section of the fixing plate 7, and the other end of the first wire 10 is fixedly connected to one end of the second pin 12. A second wire 11 is fixedly connected to the bottom of the second resistor 6, and the other end of the second wire 11 is fixedly connected to one end of the second pin 12, so that the low-voltage chip PTC thermistor can be connected to other devices to detect the temperature.
[0029] The housing 1 is a sheet-like structure.
[0030] Working principle: when in use, the heat expansion block 5 will be deformed by heat. At low temperatures, the heat expansion block 5 will not be deformed. The first contact 4 is in contact with the third contact 9 to form a loop. At this time, the resistance values of the first resistor 2 and the second resistor 6 are both small. Under low voltage conditions, the current passing through the first resistor 2 and the second resistor 6 can be accurately detected (at low temperatures, the resistance values of the first resistor 2 and the second resistor 6 are small. If the current only passes through the first resistor 2, the resistance value may be low and the current may be too large to burn the circuit. Detecting the current passing through the first resistor 2 and the second resistor 6 at low temperatures can protect the circuit while detecting the temperature). The temperature can be detected according to the change in current. At high temperatures, The thermal expansion block expands and deforms, and the first contact 4 contacts the second contact 8 to form a loop. At this time, the resistance values of the first resistor 2 and the second resistor 6 increase in a step-like manner. Under low voltage conditions, the current passing through the first resistor 2 can be detected separately, and the temperature can be detected according to the change in current. When the resistance values of the first resistor 2 and the second resistor 6 are not high under low temperature conditions, the current passing through the first resistor 2 and the second resistor 6 can be detected to reflect the temperature change. Under high temperature conditions, after the resistance values of the first resistor 2 and the second resistor 6 increase, the current passing through the first resistor 2 can be detected to reflect the temperature change.
[0031] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.
Claims
1. A low voltage chip PTC thermistor, comprising a housing (1), characterized in that: A first resistor (2) is fixedly connected to the inner wall of the housing (1); a first contact (4) is fixedly connected to the right end of the first resistor (2); a heat expansion block (5) is fixedly connected to the lower surface of the first resistor (2); a second resistor (6) is fixedly connected to the bottom of the heat expansion block (5); a fixing plate (7) is fixedly connected to the right end of the second resistor (6); a second contact (8) is fixedly connected to the left side of the fixing plate (7); a third contact (9) is fixedly connected to the left side of the fixing plate (7); and the third contact (9) is located below the second contact (8).
2. The low voltage chip PTC thermistor according to claim 1, characterized in that: A first pin (3) is fixedly connected inside the housing (1), one end of the first pin (3) is fixedly connected to the left end of the first resistor (2), and the other end of the first pin (3) extends to the outside of the housing (1).
3. The low voltage chip PTC thermistor according to claim 1, characterized in that: The fixed plate (7) comprises an upper section, a middle section and a lower section, the second contact (8) is located in the upper section of the fixed plate (7), and the third contact (9) is located in the lower section of the fixed plate (7), the upper section and the lower section are made of conductive material, the middle section is made of insulating material, and the length of the middle section is equal to the length of the first contact (4).
4. The low voltage chip PTC thermistor according to claim 3, characterized in that: A second pin (12) is fixedly connected to the bottom of the housing (1), one end of the second pin (12) is located inside the housing (1), and the other end of the second pin (12) is located outside the housing (1).
5. The low voltage chip PTC thermistor according to claim 4, characterized in that: The upper section of the fixing plate (7) is fixedly connected to a first wire (10), and the other end of the first wire (10) is fixedly connected to one end of a second pin (12).
6. The low voltage chip PTC thermistor according to claim 4, characterized in that: A second wire (11) is fixedly connected to the bottom of the second resistor (6), and the other end of the second wire (11) is fixedly connected to one end of the second pin (12).
7. The low voltage chip PTC thermistor according to claim 1, characterized in that: The shell (1) is a sheet-like structure.