A resistor with overload protection

Abstract

The present invention relates to the field of resistors, and in particular to a resistor with overload protection, including a housing, a terminal, a rotating shaft and a limit plate; the housing is fixed with a terminal; the housing is rotatably connected with a rotating shaft; the upper side of the housing is fixed with a limit plate; the rotating shaft is rotatably connected to the limit plate, and a scale block is provided on the limit plate. The present invention realizes a plurality of resistance wires wound in an S shape, so that workers can adjust the position of the first brush by rotating the rotating shaft and then adjusting the position of the first brush by adjusting the plurality of resistance wires, thereby adjusting across the plurality of resistance wires and realizing cross-region adjustment of the resistance value of the potentiometer. A large range of resistance value adjustment can be realized by rotating a small range, and it is convenient to use without rotating multiple circles for adjustment. At the same time, the first brush can be adjusted in the same resistance wire area by adjusting the first brush by adjusting the first brush by adjusting the first brush, thereby performing a small range of precision adjustment, which greatly improves the resistance value adjustment accuracy of the potentiometer.

Description

Technical Field

[0001] The invention relates to the field of resistors, and in particular to a resistor with overload protection. Background Art

[0002] Potentiometer is a resistance element whose resistance value can be adjusted according to a certain law of change. It can also be called a resistor. Potentiometer is an electrical component often used in daily life. It is usually composed of a resistor and a rotating or sliding system, that is, a moving contact moves on the resistor to obtain partial voltage output.

[0003] The existing carbon film potentiometer can usually only rotate one circle, so the resistance range is limited, and only a small range of resistance adjustment can be achieved, and the precision is not high. When a larger range of resistance adjustment is to be achieved, multiple potentiometers need to be connected in series to increase the resistance range for use, which is more troublesome. The existing multi-turn adjustable potentiometer has a large resistance range and can be adjusted in multiple turns, and is more precise. However, when the resistance span to be adjusted is large, workers need to rotate multiple turns to adjust to the corresponding resistance value, which is inconvenient to use. In addition, during the rotation process, the brushes constantly rub against the resistor, which greatly reduces the life of the brushes.

[0004] Moreover, the potentiometer is usually installed on a circuit board. Once the existing potentiometer is overloaded, it will cause a short circuit and burn out, which is very likely to affect the electrical components around the circuit board and expand the loss. Summary of the invention

[0005] In order to overcome the problem that the existing carbon film potentiometer can only achieve a small range of resistance adjustment and has low precision, although the multi-turn adjustable potentiometer has a large resistance range and can be adjusted by multiple turns, and is relatively precise, when the resistance span to be adjusted is large, the worker needs to turn it multiple times to adjust to the corresponding resistance, which is inconvenient to use, and during the rotation process, the brush constantly rubs against the resistor, greatly reducing the disadvantage of a shorter brush life, the present invention provides a resistor with overload protection.

[0006] The technical scheme is: a resistor with overload protection, including a shell, a terminal, a rotating shaft and a limit plate; the shell is fixed with a terminal; the shell is rotatably connected with a rotating shaft; the upper side of the shell is fixed with a limit plate; the rotating shaft is rotatably connected with the limit plate, and a scale block is arranged on the limit plate; it also includes a first fixed block, a first brush, a second brush, a fixed ring, a first copper wire sheet and an adjustment component; a fixed ring is fixed inside the shell, and a ring array of a plurality of resistance wires is arranged on the fixed ring, and each resistance wire is connected to each other; and each resistance wire is divided into eleven arc contact wires from the inside to the outside, and each resistance wire is divided into S-shaped contact wires. cloth; a first copper sheet of conductive wire is fixedly connected in the shell; the first copper sheet of conductive wire is located on the inner side of the fixing ring; a first terminal, a second terminal and a third terminal are fixedly connected to the terminal; the first terminal and the third terminal are respectively fixedly connected to the two ends of the fixing ring; the second terminal is fixedly connected to the first copper sheet of conductive wire; an adjusting component is connected to the rotating shaft; a first brush is connected to the adjusting component, the first brush contacts with two adjacent arc-shaped contact lines on the resistance line at the same time, and ten contact points are formed on the eleven arc-shaped contact lines; and the resistance values ​​at the ten contact points are all integer values; a second brush is fixedly connected to the first fixing block; the second brush contacts with the first copper sheet of conductive wire.

[0007] As a further preferred scheme, the adjusting assembly includes a sliding rod, a first spring, an adjusting rod, a limit block and a second spring; an adjusting rod is slidably connected in the rotating shaft, and a lever is arranged on the adjusting rod; a limit block is slidably connected on the lever; a second spring is fixedly connected between the adjusting rod and the rotating shaft; a multi-layer wedge-shaped surface is arranged on the side of the adjusting rod facing the first fixed block; a second sliding groove is provided on the upper side of the rotating shaft; the lever of the adjusting rod slides in the second sliding groove, and a plurality of limit grooves are provided on the upper side of the rotating shaft; a first sliding groove is provided in the first fixed block; a sliding rod is slidably connected in the first sliding groove, one end of the sliding rod is fixedly connected to the first brush; the other end contacts the multi-layer wedge surface; the middle part of the sliding rod is connected to the second brush; a plurality of square grooves are provided in the first fixed block; a plurality of first springs are fixedly connected between the sliding rod and the first fixed block, and each first spring is located in the corresponding square groove.

[0008] As a further preferred solution, a scale block is provided on the limit plate.

[0009] As a further preferred solution, it also includes a second copper conductor sheet; the second copper conductor sheet is fixedly connected to the middle of the slide rod; the second copper conductor sheet is fixedly connected to the first brush, and the second copper conductor sheet is slidably connected to the second brush.

[0010] As a further preferred solution, it also includes a rotating roller; the sliding rod is rotatably connected to the rotating roller on one side in contact with the multi-layer wedge surface.

[0011] As a further preferred solution, a plurality of protrusions are provided in an annular array on the outer side of the upper portion of the rotating shaft.

[0012] As a further preferred solution, it also includes a protective shell; the protective shell is fixedly connected to the outer shell; and the protective shell is located outside the fixing ring.

[0013] As a further preferred solution, micro balls are also included; a plurality of micro balls are rotatably connected to the lower side of each first brush.

[0014] As a further preferred embodiment, a fuse block is also included; a fuse block with an overload protection function is fixedly connected at the connection between the first end and the third end and the fixing ring; a fuse block is also fixedly connected at the connection between the second end and the first copper wire sheet; the protective shell is located on the inner side of the outer shell, and an isolation cavity is formed between the protective shell and the outer shell; each fuse block is located in the isolation cavity.

[0015] As a further preferred scheme, it also includes a second fixed block, an isolation block and a third spring; a number of second fixed blocks are fixedly connected to the outside of the protective shell; each second fixed block is located on the upper side of the corresponding fuse block; each second fixed block is slidably connected with an isolation block, and the isolation block is made of insulating material; a third spring is fixedly connected between each isolation block and the corresponding second fixed block.

[0016] The present invention has the following advantages: the present invention realizes that through the multiple resistance wires wound in an S shape, the worker can adjust the position of the first brush by rotating the rotating shaft and then adjusting the position of the first brush by the adjusting component, and the resistance value of the potentiometer can be adjusted across the multiple resistance wires. The resistance value adjustment of a large range can be achieved by rotating a small range, and it is convenient to use without rotating multiple circles. At the same time, the first brush can be adjusted in the same resistance wire area by the adjusting component, and then a small range of precise adjustment can be performed, which greatly improves the resistance value adjustment accuracy of the potentiometer;

[0017] At the same time, through leap-forward adjustment, the first brush does not need to pass through all the resistance wires before the corresponding resistance value, which greatly reduces the wear of the first brush and the resistance wire and increases the service life of the equipment;

[0018] When the first brush slides on the fixed ring, the friction between the first brush and the fixed ring and the resistance wire is greatly reduced through the micro ball bearings, thereby increasing the service life of the first brush; and there are bumps in the annular array on the outer side of the upper part of the rotating shaft, which increases the friction between the worker's fingers and the rotating shaft, making it easier for the worker to rotate the rotating shaft;

[0019] Through the fuse block, when the current flowing into the potentiometer is too large and the potentiometer is overloaded and generates huge heat, the fuse block will burn and melt, so the wire connected to the terminal will be disconnected from the potentiometer to protect the potentiometer from overload; and the fuse block is located in the gap between the outer shell and the protective shell, so when the fuse block burns and melts, it will not affect the parts in the protective shell, greatly improving the service life of the potentiometer;

[0020] When the fuse block burns and melts, the third spring stretches and resets, thereby squeezing the isolation block downward into the area where the fuse block was originally located, thereby sealing the connection between the terminal and the fixing ring. The isolation block is made of insulating material, and insulates and shields the arc generated by the larger current, thereby preventing the arc generated by the larger current from still being connected to the fixing ring and causing damage to the potentiometer. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the three-dimensional structure of a resistor with overload protection according to the present invention;

[0022] Figure 2 is a cross-sectional view of a housing of the present invention;

[0023] Figure 3 It is a schematic diagram of the three-dimensional structure of the first brush, the second brush and the copper wire sheet combination of the present invention;

[0024] Figure 4 It is a cross-sectional view of the rotation axis of the present invention;

[0025] Figure 5 is a cross-sectional view of a first fixing block of the present invention;

[0026] Figure 6 It is a schematic diagram of the three-dimensional structure of the fixing ring and the resistance wire combination of the present invention;

[0027] Figure 7 It is a schematic diagram of the combined three-dimensional structure of the housing, the second fixing block and the protective shell of the present invention;

[0028] Figure 8 It is a cross-sectional view of the second fixing block of the present invention.

[0029] The markings in the accompanying drawings are: 1-housing, 1001-isolating cavity, 2-terminal, 2001-first terminal, 2002-second terminal, 2003-third terminal, 3-rotating shaft, 3001-bump, 3002-second slide groove, 3003-limiting groove, 4-limiting plate, 101-first fixing block, 10101-first slide groove, 10102-square groove, 102-first brush, 103-second brush, 104- Fixed ring, 10401-resistance wire, 105-first conductor copper sheet, 106-protective shell, 107-micro ball, 108-sliding rod, 109-first spring, 110-second conductor copper sheet, 111-rotating roller, 201-adjusting rod, 20101-multi-layer wedge surface, 202-limiting block, 203-second spring, 301-second fixed block, 302-isolating block, 303-third spring, 304-fuse block. DETAILED DESCRIPTION

[0030] The technical solution is further described below in conjunction with specific embodiments. It should be noted that the words indicating directions such as up, down, left, and right mentioned in this article are only for the position of the structure shown in the corresponding drawings. The serial numbers of the parts in this article, such as first, second, etc., are only used to distinguish the objects described and do not have any order or technical meaning. The words such as connection and coupling in this application include direct and indirect connection (coupling) unless otherwise specified.

[0031] Example 1

[0032] A resistor with overload protection, such as Figure 1-Figure 7 As shown, it includes a housing 1, a terminal 2, a rotating shaft 3 and a limit plate 4; the housing 1 is fixedly connected with the terminal 2; the housing 1 is rotatably connected with the rotating shaft 3; the upper side of the housing 1 is fixedly connected with the limit plate 4; the rotating shaft 3 is rotatably connected with the limit plate 4, and a scale block is arranged on the limit plate 4. When the rotating shaft 3 is rotated to a fixed angle, the limit plate 4 will generate an obvious limit prompt for the rotating shaft 3, prompting the user that the rotation has been turned to a different resistance value range;

[0033] It also includes a first fixed block 101, a first brush 102, a second brush 103, a fixed ring 104, a first copper conductor sheet 105 and an adjustment component; a fixed ring 104 is fixedly connected in the housing 1, and ten resistance wires 10401 are distributed in a C shape on the fixed ring 104, and each resistance wire 10401 is connected to each other; and each resistance wire 10401 is divided into eleven arc-shaped contact wires from the inside to the outside, and each resistance wire 10401 is distributed in an S shape, and the first brush 102 contacts with two adjacent arc-shaped contact wires on the resistance wire 10401 at the same time, forming ten contact points on the eleven arc-shaped contact lines, ten contact points; and the resistance values ​​at the ten contact points are all integer values, and the adjacent resistance wires 10401 are connected to each other; a first copper conductor sheet 105 is fixedly connected in the housing 1; The first copper sheet 105 is located on the inner side of the fixed ring 104; the first terminal 2001, the second terminal 2002 and the third terminal 2003 are fixedly connected to the terminal 2; the first terminal 2001 and the third terminal 2003 are fixedly connected to the two ends of the fixed ring 104 respectively, and the connection between the fixed ring 104 and the first terminal 2001 and the third terminal 2003 is set to be made of copper sheet material; the second terminal 2002 is fixedly connected to the first copper sheet 105; an adjustment component is connected to the rotating shaft 3; the first brush 102 is connected to the adjustment component, and the worker drives the first brush 102 to slide between the inner circle and the outer circle of the resistance wire 10401 by adjusting the adjustment component, thereby changing the resistance value; the second brush 103 is fixedly connected to the first fixed block 101; the second brush 103 is in contact with the first copper sheet 105.

[0034] The adjusting assembly includes a slide bar 108, a first spring 109, an adjusting rod 201, a limit block 202 and a second spring 203; the adjusting rod 201 is slidably connected in the rotating shaft 3, and a lever is arranged on the adjusting rod 201; the limit block 202 is slidably connected on the lever; the second spring 203 is fixedly connected between the adjusting rod 201 and the rotating shaft 3; a multi-layer wedge surface 20101 is arranged on the side of the adjusting rod 201 facing the first fixed block 101; a second slide groove 3002 is provided on the upper side of the rotating shaft 3; the lever of the adjusting rod 201 slides in the second slide groove 3002, and ten limit grooves 3003 are provided on the upper side of the rotating shaft 3. When the adjusting rod 201 is adjusted to different positions, the limit block 20 2 enters the corresponding second slide groove 3002, and is limited by the limit block 202 in the second slide groove 3002, thereby limiting and fixing the adjusting rod 201; a first slide groove 10101 is provided in the first fixing block 101; a slide bar 108 is slidably connected in the first slide groove 10101, one end of the slide bar 108 is fixedly connected to the first brush 102; the other end is in contact with the multi-layer wedge surface 20101; the middle part of the slide bar 108 is connected to the second brush 103; two square grooves 10102 are provided in the first fixing block 101; two first springs 109 are fixedly connected between the slide bar 108 and the first fixing block 101, and each first spring 109 is located in the corresponding square groove 10102.

[0035] The limit plate 4 is provided with a scale block. When the rotating shaft 3 is rotated to a fixed angle, the limit plate 4 will produce an obvious limit prompt for the rotating shaft 3, prompting the user that the rotation has reached different resistance value intervals.

[0036] The second copper conductor sheet 110 is also included; the second copper conductor sheet 110 is fixedly connected to the middle of the slide bar 108; the second copper conductor sheet 110 is fixedly connected to the first brush 102, and the second copper conductor sheet 110 is slidably connected to the second brush 103.

[0037] It also includes a rotating roller 111; the side of the sliding rod 108 that contacts the multi-layer wedge surface 20101 is rotatably connected to the rotating roller 111.

[0038] There are eight protrusions 3001 in a circular array on the outer side of the upper part of the rotating shaft 3. When the worker has no tools, he can grasp and rotate the rotating shaft 3 with his fingers to adjust the resistance value. At this time, the protrusions 3001 can increase the friction between the fingers and the rotating shaft 3, making it easier for the worker to rotate.

[0039] It also includes a protective shell 106 ; the protective shell 106 is fixedly connected to the outer shell 1 , and the protective shell 106 is made of fireproof and explosion-proof materials; the protective shell 106 is located outside the fixing ring 104 .

[0040] It also includes micro balls 107; three micro balls 107 are rotatably connected to the lower side of each first brush 102.

[0041] The multi-turn precision adjustable potentiometer is usually composed of a resistor and a sliding system. It can rotate multiple turns to adjust the resistance value, so the adjusted resistance value has high precision. However, the more turns it rotates, the longer the contact friction time between the brush and the resistor, and the shorter the life of the brush. Moreover, workers can only adjust the resistance value in a small range by rotating it multiple times. Therefore, when the resistance adjustment range is large, workers need to rotate it continuously to speed up the adjustment speed, which is more troublesome.

[0042] Therefore, the present invention proposes the following method: first, the worker connects the wire to the potentiometer. When the maximum resistance value of the potentiometer needs to be fixed, the worker can connect the power line to the third terminal 2003, and then connect the output line to the first terminal 2001. The second terminal 2002 does not need to be connected. At this time, the first conductor copper sheet 105 is not connected to the outside world, so the power will pass through the entire resistance line 10401, and the resistance value reaches the maximum value; when the worker needs an adjustable resistance value, the worker connects the power line to the third terminal 2003, and then connects the output line to the second terminal 2002. At this time, the first conductor copper sheet 105 is connected to the output line through the second terminal 2002; therefore, Figure 3 As shown: at this time, the power entering the potentiometer will enter the second brush 103 through the first brush 102, and then flow out from the output line through the first copper wire 105. In this process, the current will only flow through the resistance wire 10401 in front of the contact point of the first brush 102, so the first brush 102 can be driven to rotate by rotating the rotating shaft 3, thereby changing the resistance value;

[0043] When the worker rotates the rotating shaft 3 to change the resistance value, Figure 3-Figure 6 As shown: the resistance value of each resistor line 10401 is the same, and the midpoint position of the arc contact line is exactly consistent with the position of the limit plate 4 for the fixed angle of rotation of the rotating shaft 3. Therefore, when the rotating shaft 3 rotates to a fixed angle, the first brush 102 also rotates to the center position of the arc contact line of the corresponding resistor line 10401; in the initial state, the adjustment rod 201 is squeezed by the second spring 203 and is located at the uppermost side. At this time, the sliding rod 108 contacts the lowermost layer of the multi-layer wedge surface 20101, and the first brush 102 is located at the innermost circle of the resistor line 10401. Taking the resistance range of the resistor as 0-100 as an example, at this time, the resistance range of each resistor line 10401 is 0-10, so as shown in FIG. Figure 4 As shown, based on the view from top to bottom, after each resistance wire 10401 is connected in series, the resistance values ​​in the area where each resistance wire 10401 is located are superimposed in a counterclockwise direction, and are 0-10, 10-20, 20-30, ..., 90-100, for example:

[0044] When the worker rotates the rotating shaft 3 to reach the first limit point of the limit plate 4, that is, the position of the first resistance line 10401 in the counterclockwise direction, the first brush 102 reaches the midpoint of the arc contact line of the innermost circle of the first resistance line 10401. At this time, the resistance is 1. When the worker needs to adjust the resistance value in a small range, that is, to adjust the value within 1-10, the worker only needs to move the adjustment rod 201 up and down. Figure 4 As shown: the limit block 202 contracts and exits the corresponding limit slot 3003, the adjusting rod 201 is pushed upward or downward, the second spring 203 contracts and stretches, so that the multi-layer wedge surface 20101 squeezes the slide bar 108, and then the slide bar 108 slides in the first slide slot 10101, and then drives the first brush 102 to slide between the inner and outer circles on the upper side of the resistance wire 10401, and contacts with different arc-shaped contact lines, so as to achieve precise adjustment in a small range; and every time the adjusting rod 201 is adjusted to a gear, the limit block 202 will also enter the corresponding limit slot 3003 to limit and fix the adjusting rod 201;

[0045] When a larger range of adjustment is required, the existing multi-turn precision potentiometer can only be adjusted by rotating a very large number of turns, which is more troublesome. In addition, during the rotation process, the first brush 102 will pass through all the resistance wires 10401 before the corresponding resistance value, resulting in greater friction, which seriously affects the service life of the first brush 102. However, the present invention only needs to rotate the rotating shaft 3 to rotate the first brush 102 to the corresponding resistance wire 10401. When the rotating shaft 3 is rotated to the second gear in the counterclockwise direction, the first brush 102 is located on the second resistance wire 10401 in the counterclockwise direction. At this time, the resistance range jumps directly from 1-10 to 1 0-20, when the rotating shaft 3 rotates to the fifth gear in the counterclockwise direction, the first brush 102 is located on the fifth resistance line 10401 in the counterclockwise direction. At this time, the resistance range jumps directly from 1-10 to 40-50; thereby achieving leapfrog adjustment. This method can achieve a wide range of resistance value adjustment without rotating multiple circles. At the same time, the first brush 102 does not need to pass through all the resistance lines 10401 before the corresponding resistance value, which greatly reduces the wear of the first brush 102 and improves the service life of the equipment. After completing a large range of resistance adjustment, the worker fine-tunes the first brush 102 through the adjustment component to adjust the resistance value more precisely.

[0046] The first brush 102 and the second brush 103 are connected by the second copper wire 110. The slide bar 108 is made of insulating material. The current will quickly enter the second brush 103 through the second copper wire 110, so as to avoid the resistance of the slide bar 108, which will affect the accuracy of the potentiometer after adjusting the position of the first brush 102.

[0047] When the first brush 102 slides on the fixed ring 104, the friction between the first brush 102 and the fixed ring 104 and the resistance wire 10401 is greatly reduced through the micro ball 107, thereby increasing the service life of the first brush 102; and there are bumps 3001 in the annular array on the outer side of the upper part of the rotating shaft 3, which increases the friction between the worker's fingers and the rotating shaft 3, making it convenient for the worker to rotate the rotating shaft 3.

[0048] At the same time, through the protective shell 106 in the outer shell 1, when the current flowing in the potentiometer is too large, that is, the potentiometer is overloaded and a short circuit occurs, causing the resistor to burn out, the protective shell 106 made of fireproof and explosion-proof materials can prevent the potentiometer from exploding or burning and spreading to surrounding electrical components, while preventing the explosion or burning from causing harm to workers.

[0049] Example 2

[0050] On the basis of Example 1, Figure 2 , Figure 7 and Figure 8 As shown, a fuse block 304 is also included; the connection between the first end 2001 and the third end 2003 and the fixing ring 104 is fixedly connected with the fuse block 304; the connection between the second end 2002 and the first conductor copper sheet 105 is also fixedly connected with the fuse block 304; the protective shell 106 is located on the inner side of the outer shell 1, and an isolation cavity 1001 is formed between the protective shell 106 and the outer shell 1; each fuse block 304 is located in the isolation cavity 1001.

[0051] It also includes a second fixed block 301, an isolation block 302 and a third spring 303; three second fixed blocks 301 are fixedly connected to the outside of the protective shell 106; each second fixed block 301 is located on the upper side of the corresponding fuse block 304; each second fixed block 301 is slidably connected with an isolation block 302, and the isolation block 302 is made of insulating material; a third spring 303 is fixedly connected between each isolation block 302 and the corresponding second fixed block 301.

[0052] When the current flowing in the potentiometer is too large, the potentiometer is overloaded and generates huge heat, and then short-circuit, causing the potentiometer to explode and burn, which is also one of the reasons for the short service life of the potentiometer; Figure 7 As shown: through the fuse block 304, when the current flowing into the potentiometer is too large and the potentiometer is overloaded and generates huge heat, the fuse block 304 will burn and melt, so the wire connected to the terminal 2 will be disconnected from the potentiometer, and the current cannot enter the potentiometer at this time, so the potentiometer is overload protected; and the fuse block 304 is located in the gap between the housing 1 and the protective shell 106, so when the fuse block 304 burns and melts, the spark will be blocked by the protective shell 106, and will not affect the parts in the protective shell 106, which greatly improves the service life of the potentiometer;

[0053] However, the potentiometer is usually small; therefore, the fuse block 304 is also small. When the current is large, the fuse block 304 will melt instantly, but the arc generated by the large current may still be connected to the fixing ring 104, causing damage to the potentiometer. Figure 7 As shown: in the initial state, the isolation block 302 is located on the upper side of the corresponding fuse block 304. At this time, the third spring 303 is compressed and contracted. When the fuse block 304 burns and melts, the third spring 303 stretches and resets, thereby squeezing the isolation block 302 downward and into the area where the fuse block 304 was originally located, thereby sealing the connection between the terminal 2 and the fixing ring 104. The isolation block 302 is made of insulating material, and the arc generated by the larger current is insulated and shielded to prevent the arc generated by the larger current from still being connected to the fixing ring 104 and causing damage to the potentiometer.

[0054] 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, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments or to 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 resistor with overload protection, comprising a housing (1), a terminal (2), a rotating shaft (3) and a limit plate (4); the housing (1) is fixedly connected with the terminal (2); the housing (1) is rotatably connected with the rotating shaft (3); the upper side of the housing (1) is fixedly connected with the limit plate (4); the rotating shaft (3) is rotatably connected with the limit plate (4), and a scale block is provided on the limit plate (4); wherein: The invention also comprises a first fixed block (101), a first brush (102), a second brush (103), a fixed ring (104), a first copper wire sheet (105) and an adjustment component; a fixed ring (104) is fixedly connected inside the housing (1), and ten resistance wires (10401) are distributed in a C shape on the fixed ring (104), and each resistance wire (10401) is connected to each other; each resistance wire (10401) is divided into eleven arc-shaped contact wires from the inside to the outside, and each resistance wire (10401) is distributed in an S shape, and adjacent resistance wires (10401) are connected to each other; a first copper wire sheet (105) is fixedly connected inside the housing (1); the first copper wire sheet (105) is located on the inner side of the fixed ring (104); a A first end (2001), a second end (2002) and a third end (2003); the first end (2001) and the third end (2003) are respectively fixedly connected to two ends of a fixing ring (104); the second end (2002) is fixedly connected to a first conductor copper sheet (105); an adjustment component is connected to the rotating shaft (3); a first brush (102) is connected to the adjustment component, the first brush (102) is in contact with two adjacent arc-shaped contact lines on the resistance line (10401) at the same time, and ten contact points are formed on the eleven arc-shaped contact lines; and the resistance values ​​at the ten contact points are all integer values; a second brush (103) is fixedly connected to the first fixing block (101); the second brush (103) is in contact with the first conductor copper sheet (105); The adjusting assembly comprises a sliding rod (108), a first spring (109), an adjusting rod (201), a limit block (202) and a second spring (203); the adjusting rod (201) is slidably connected inside the rotating shaft (3), and a lever is arranged on the adjusting rod (201); the limit block (202) is slidably connected on the lever; a second spring (203) is fixedly connected between the adjusting rod (201) and the rotating shaft (3); a multi-layer wedge-shaped surface (20101) is arranged on the side of the adjusting rod (201) facing the first fixed block (101); a second sliding groove (3002) is opened on the upper side of the rotating shaft (3); the lever of the adjusting rod (201) slides in the second sliding groove (3002), and rotates A plurality of limit grooves (3003) are provided on the upper side of the shaft (3); a first slide groove (10101) is provided in the first fixed block (101); a slide rod (108) is slidably connected in the first slide groove (10101), one end of the slide rod (108) is fixedly connected to the first brush (102); the other end is in contact with the multi-layer wedge surface (20101); the middle part of the slide rod (108) is connected to the second brush (103); a plurality of square grooves (10102) are provided in the first fixed block (101); a plurality of first springs (109) are fixedly connected between the slide rod (108) and the first fixed block (101), and each first spring (109) is located in a corresponding square groove (10102).

2. A resistor with overload protection according to claim 1, characterized in that: It also includes a second copper conductor sheet (110); the second copper conductor sheet (110) is fixedly connected to the middle of the sliding rod (108); the second copper conductor sheet (110) is fixedly connected to the first brush (102), and the second copper conductor sheet (110) is slidably connected to the second brush (103).

3. A resistor with overload protection according to claim 2, characterized in that: It also includes a rotating roller (111); the side of the sliding rod (108) in contact with the multi-layer wedge surface (20101) is rotatably connected to the rotating roller (111).

4. A resistor with overload protection according to claim 1, characterized in that: A plurality of protrusions (3001) are provided in a circular array on the outer side of the upper portion of the rotating shaft (3).

5. A resistor with overload protection according to claim 1, characterized in that: It also includes a protective shell (106); the protective shell (106) is fixedly connected inside the outer shell (1); and the protective shell (106) is located outside the fixing ring (104).

6. A resistor with overload protection according to claim 1, characterized in that: It also includes micro balls (107); a plurality of micro balls (107) are rotatably connected to the lower side of each first brush (102).

7. A resistor with overload protection according to claim 5, characterized in that: It also includes a fuse block (304); a fuse block (304) having an overload protection function is fixedly connected to the connection between the first end (2001) and the third end (2003) and the fixing ring (104); a fuse block (304) is also fixedly connected to the connection between the second end (2002) and the first conductor copper sheet (105); a protective shell (106) is located inside the outer shell (1), and an isolation cavity (1001) is formed between the protective shell (106) and the outer shell (1); and each fuse block (304) is located in the isolation cavity (1001).

8. A resistor with overload protection according to claim 7, characterized in that: It also includes a second fixing block (301), an isolating block (302) and a third spring (303); a plurality of second fixing blocks (301) are fixedly connected to the outside of the protective shell (106); each second fixing block (301) is located on the upper side of the corresponding fuse block (304); each second fixing block (301) is slidably connected to an isolating block (302), and the isolating block (302) is made of insulating material; and a third spring (303) is fixedly connected between each isolating block (302) and the corresponding second fixing block (301).

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