Electric tool and detection circuit

Abstract

The embodiment of the utility model provides an electric tool and a detection circuit, the electric tool comprises a shaft body, and the shaft body comprises a fixing part; the rotating part is rotatably connected with the fixed part; the simulation part is connected with the rotating part and used for generating a corresponding angle signal according to the rotating angle of the rotating part; and the reading piece is electrically connected with the simulation piece and is used for receiving the angle signal and displaying the rotation angle value of the rotating piece. And the rotation angle in the working process can be measured.

Description

Technical Field

[0001] This disclosure relates to a power tool, and more particularly to a cutting tool. Background Technology

[0002] Cutting tools can be categorized into vertical cutting machines and beveling machines based on the relative angle of the saw blade to the worktable. A vertical cutting machine's saw blade cuts perpendicular to the worktable. A beveling machine is a cutting machine where the saw blade, mounted on the machine body, can be adjusted at the cutting angle relative to the worktable.

[0003] However, when cutting with a cutting machine, the angle of the saw blade is often determined by visual inspection, which cannot accurately determine the cutting angle of the saw blade.

[0004] Therefore, it is necessary to provide a cutting tool that can measure the rotation angle of the saw blade during the cutting process. Utility Model Content

[0005] This disclosure provides an embodiment of a power tool and a detection circuit that can at least measure the rotation angle during the cutting process.

[0006] According to some embodiments of this disclosure, one aspect of this disclosure provides a power tool, which includes a shaft, the shaft comprising: a fixing member; a rotating member rotatably connected to the fixing member; a simulation member connected to the rotating member for generating a corresponding angle signal based on the rotation angle of the rotating member; and a reading member electrically connected to the simulation member for receiving the angle signal and displaying the rotation angle value of the rotating member.

[0007] In some embodiments, the analog component is a capacitive grating sensor, which includes: a fixed grating fixed to the surface of the fixed component and corresponding to the rotation track of the rotating component; and a movable grating fixed to the surface of the rotating component. When the fixed grating and the movable grating are relatively stationary, the capacitive grating sensor is turned on and outputs the angle signal based on the position of the movable grating and the fixed grating facing each other.

[0008] In some embodiments, the rotating component includes a rotating shaft, and the analog component is a potentiometer. The potentiometer includes: a fixed portion, which is fixedly connected to the fixed component; and a movable portion, which is fixedly connected to the rotating shaft. The rotating shaft drives the movable portion to rotate, and the movable portion generates the angle signal based on the change in the rotation angle.

[0009] In some embodiments, the potentiometer is a sliding rheostat, the sliding end of the sliding rheostat is fixedly connected to the rotating component, and the fixed end of the sliding rheostat is fixedly connected to the fixing component.

[0010] In some embodiments, the rotating component includes a rotating shaft, the analog component is an encoder, the encoder is fixed on the fixing component to receive the angle of rotation of the rotating shaft and generate the angle signal, and the angle signal is the encoded signal generated by the encoder.

[0011] In some embodiments, the simulation element is a strain gauge, one end of which is fixed to the rotating element and the other end to the fixed element. When the rotating element rotates, the strain gauge deforms, and the angle signal is the deformation of the strain gauge.

[0012] In some embodiments, the power tool is a circular saw.

[0013] According to some embodiments of this disclosure, another aspect of this disclosure also provides a detection circuit for use in the shaft as described above, comprising: a measurement circuit, the measurement circuit being configured to generate a corresponding angle signal based on the rotation angle of the rotating component; and a read chip, the read chip being electrically connected to the measurement circuit, receiving the angle signal generated by the measurement circuit and generating the rotation angle value of the rotating component.

[0014] In some embodiments, the circuit further includes a capacitor connected in parallel with the measurement circuit.

[0015] In some embodiments, the measuring circuit includes: a resistor, one end of which is in contact with a power supply voltage; and a strain gauge, one end of which is electrically connected to the other end of the resistor, and the other end is grounded.

[0016] The technical solution provided by the embodiments of this disclosure has at least the following advantages: by setting up a simulation component, which is used to rotate with the rotating component, the simulation component can know the rotation angle of the rotating component and generate a corresponding angle signal. The angle signal is transmitted to the reading component, which generates and displays the rotation angle of the rotating component. This makes it easier for the operator to adjust the rotating component according to the displayed rotation angle, thereby improving the convenience and accuracy of power tool operation. Attached Figure Description

[0017] One or more embodiments are illustrated by way of example with corresponding pictures in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Unless otherwise stated, the pictures in the accompanying drawings do not constitute a limitation on scale. In order to more clearly illustrate the technical solutions in the embodiments of this disclosure or the conventional technology, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1This is a schematic diagram of a first structure of a shaft provided in an embodiment of the present disclosure;

[0019] Figure 2 This is a schematic diagram of a second structure of a shaft provided in one embodiment of the present disclosure;

[0020] Figure 3 This is a schematic diagram of a third structure of a shaft provided in an embodiment of the present disclosure;

[0021] Figure 4 This is a schematic diagram of a fourth structure of a shaft provided in one embodiment of the present disclosure;

[0022] Figure 5 A first circuit diagram of a detection circuit provided in an embodiment of this disclosure;

[0023] Figure 6 A second circuit diagram of a detection circuit provided in an embodiment of this disclosure;

[0024] Figure 7 A third circuit diagram of a detection circuit provided in an embodiment of this disclosure;

[0025] Figure 8 This is a fourth circuit diagram of a detection circuit provided in one embodiment of the present disclosure. Detailed Implementation

[0026] As can be seen from the background art, there is a need to provide a power tool for measuring the rotation angle of a saw blade in order to improve the convenience and accuracy of operation.

[0027] This embodiment of the invention includes a simulation component that rotates alongside the rotating component. The simulation component learns the rotation angle of the rotating component and generates a corresponding angle signal. The angle signal is transmitted to a reader, which generates and displays the rotation angle of the rotating component. This allows the operator to adjust the rotating component according to the displayed rotation angle, thereby improving the convenience and accuracy of power tool operation.

[0028] In the description of the embodiments of this disclosure, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary or secondary relationship of the indicated technical features. In the description of the embodiments of this disclosure, "a plurality of" means two or more, unless otherwise explicitly defined.

[0029] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this disclosure. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0030] In the description of the embodiments of this disclosure, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three cases: A exists, A and B exist simultaneously, and B exists. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0031] In the description of the embodiments of this disclosure, the term "multiple" refers to two or more (including two), similarly, "multiple groups" refers to two or more (including two groups), and "multiple pieces" refers to two or more (including two pieces).

[0032] In the description of the embodiments of this disclosure, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this disclosure and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this disclosure.

[0033] In the description of the embodiments of this disclosure, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this disclosure according to the specific circumstances.

[0034] In the accompanying drawings corresponding to the embodiments of this disclosure, the thickness and area of ​​the layers are enlarged for better understanding and ease of description. When describing a component (such as a layer, film, region, or substrate) on or on the surface of another component, the component may be "directly" located on the surface of the other component, or there may be a third component between the two components. Conversely, when describing a component on the surface of another component, or when another component is formed or disposed on the surface of a component, it indicates that there is no third component between the two components. Furthermore, when describing a component as being "generally" formed on another component, it means that the component is not formed on the entire surface (or front surface) of the other component, nor is it formed on a portion of the edge of the entire surface.

[0035] In the description of embodiments of this disclosure, when a component "includes" another component, other components are not excluded unless otherwise stated, and may be further included. Furthermore, when a component such as a layer, film, region, or plate is referred to as being "on / located" on another component, it can be "directly" on the other component (i.e., located on the surface of the other component with no other components between them), or another component may be present therein. Additionally, when a component such as a layer, film, region, or plate is "directly located" on another component, or when a component such as a layer, film, region, or plate is located on the surface of another component, it indicates that no other components are located therein.

[0036] The terminology used in the description of the various embodiments herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used in the description of the various embodiments and the appended claims, the term "component" is also intended to include the plural form unless the context clearly indicates otherwise. Components include layers, films, regions, or plates, etc.

[0037] The embodiments of this disclosure will now be described in detail with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details have been provided in the embodiments of this disclosure to facilitate a better understanding of the disclosure. However, the technical solutions claimed in this disclosure can be implemented even without these technical details and various variations and modifications based on the following embodiments.

[0038] refer to Figures 1 to 4 , Figure 1 This is a schematic diagram of a first structure of a shaft provided in an embodiment of the present disclosure; Figure 2 This is a schematic diagram of a second structure of a shaft provided in one embodiment of the present disclosure; Figure 3 This is a schematic diagram of a third structure of a shaft provided in an embodiment of the present disclosure; Figure 4 This is a schematic diagram of a fourth structure of a shaft provided in one embodiment of the present disclosure.

[0039] refer to Figures 1 to 4 , Figure 1 This is a schematic diagram of the structure of a first type of shaft provided in an embodiment of the present disclosure; Figure 2 This is a schematic diagram of the structure of a second type of shaft provided in an embodiment of the present disclosure; Figure 3 This is a schematic diagram of the structure of a third type of shaft provided in an embodiment of the present disclosure; Figure 4 This is a schematic diagram of the structure of a fourth type of shaft provided in an embodiment of the present disclosure.

[0040] In some embodiments, the shaft is used inside a power tool, such as a circular saw or a cutting machine, and may include a fastener 100.

[0041] The shaft may also include a rotating component 101, which is rotatably connected to the fixed component 100.

[0042] The shaft may also include a simulation component 102, which is connected to the rotating component 101 and is used to generate a corresponding angle signal according to the rotation angle of the rotating component 101.

[0043] The shaft may also include a reader, which is electrically connected to the analog component 102, receives angle signals and displays the angle value of the rotation of the rotating component 101.

[0044] The technical solution provided by the embodiments of this disclosure has at least the following advantages: by setting up a simulation component 102, the simulation component 102 is used to rotate with the rotating component 101, so that the simulation component 102 knows the rotation angle of the rotating component 101 and generates a corresponding angle signal. The angle signal is transmitted to the reading component, and the reading component generates and displays the rotation angle of the rotating component 101, thereby facilitating the operator to adjust the rotating component 101 according to the displayed rotation angle, thereby improving the convenience and accuracy of power tool operation.

[0045] refer to Figure 1 In some embodiments, the simulation component 102 is a capacitive grating sensor 112, which includes: a fixed grating 1121, fixed to the surface of the fixed component 100 and corresponding to the rotation track of the rotating component 101; and a movable grating 1122, fixed to the surface of the rotating component 101. When the fixed grating 1121 and the movable grating 1122 are relatively stationary, the capacitive grating sensor 112 is turned on and outputs an angle signal based on the position of the movable grating 1122 facing the fixed grating 1121. The main function of the capacitive grating sensor 112 is to convert the mechanical displacement into a phase change of an electrical signal, which is then transmitted to the reader. The reader can determine the angle of rotation of the rotating component 101 based on the phase change.

[0046] For example, if the rotation track of the rotating component 101 is 360°, the fixed grid 1121 can be set with 360 corresponding signals at 1° intervals, and these corresponding signals can be set on the rotation track corresponding to the rotating component 101. The moving grid 1122 is only connected to one corresponding signal at a time. When the rotating component 101 is stationary, the moving grid 1122 is also stationary, so that one of the corresponding signals of the moving grid 1122 and the fixed grid 1121 is connected. At this time, the capacitive grid sensor 112 is connected and outputs the angle signal represented by the corresponding signal.

[0047] As for the capacitive grating sensor 112, it has a large range and high resolution. The capacitive grating sensor 112 also has the advantages of a non-contact sensor, such as minimizing frictional resistance during measurement and preventing a decrease in measurement accuracy due to surface wear of the measuring component. The capacitive grating sensor 112 has a simple structure. The sensitive element of the capacitive grating sensor 112 is mainly composed of a moving grating 1122 and a stationary grating. The signal lines can all be led out from the stationary grating. The moving grating 1122, as a moving part, does not need to have leads, which facilitates the installation of the capacitive grating sensor 112.

[0048] In some embodiments, the shaft may further include: a base 103, which is fixedly connected to a fixing member, and the rotating member 101 is spaced apart from the base 103.

[0049] In some embodiments, a virtual axis 104 is also present on the rotating member 101. The virtual axis 104 is the center of rotation of the rotating member 101. It should be noted that the virtual axis 104 is not an actual existing axis, but an axis calculated based on the rotation center of the rotating member 101.

[0050] refer to Figure 2 In some embodiments, the rotating component 101 includes a rotating shaft 111, and the analog component 102 is a potentiometer 122. The potentiometer 122 includes: a fixed portion, which is fixedly connected to the fixed component 100; and a movable portion, which is fixedly connected to the rotating shaft 111. The rotating shaft 111 drives the movable portion to rotate, and the movable portion generates an angle signal based on the change in the rotation angle. The rotating shaft 111 drives the movable portion of the potentiometer 122 to rotate. As the movable portion rotates, the resistance value changes, and the rotation angle of the rotating component 101 can be calculated based on this resistance value. This can be used in power tools to calculate the cutting angle of a circular saw or to calculate the cutting depth of a circular saw based on trigonometric functions.

[0051] In some embodiments, potentiometer 122 is a sliding rheostat, with its sliding end fixedly connected to rotating component 101 and its fixed end fixedly connected to fixing component 100. It is understood that the sliding rheostat changes its resistance by altering the length of the resistance wire connected to the circuit, thereby gradually changing the magnitude of the current in the circuit. Therefore, the larger the rotation angle, the larger the resistance value of the sliding rheostat can be set. Thus, the analog component 102 and the reading component can deduce the rotation angle based on the detected current.

[0052] Similarly, for example, if the resistance of the sliding rheostat increases by 1Ω for every 1° of rotation, the resistance of the sliding rheostat stabilizes after the rotating component 101 comes to a stop. The change in the resistance of the sliding rheostat can be inferred by measuring the current signal output by the analog component 102, thereby inferring the change in the angle of the rotating component 101.

[0053] refer to Figure 3 In some embodiments, the rotating component 101 includes a rotating shaft 111, and the analog component 102 is an encoder 132. The encoder 132 is fixed on the fixing component 100, receives the rotation angle of the rotating shaft 111, and generates an angle signal. The angle signal is the encoded signal generated by the encoder 132. The encoder 132 is connected to the rotating shaft 111 and generates physical displacement as the rotating shaft 111 rotates. The sensing element (such as an optical grating, magnetic grating, etc.) inside the encoder 132 detects this displacement. The sensing element converts the detected displacement into an electrical signal, which is then converted into a digital code, and finally outputs a digital code corresponding to the rotation angle for precise measurement and control.

[0054] Taking incremental encoder 132 and absolute encoder 132 as examples, incremental encoder 132 measures rotation angle by outputting pulses. Each pulse represents a fixed angular increment. For example, an encoder 132 might have 100 pulses per revolution (PPR). This means that it outputs 100 pulses per revolution. To calculate the angle, the number of pulses detected since the last reference point (such as the index pulse) needs to be known and multiplied by the angle represented by each pulse. For example, if encoder 132 is 100 PPR, then each pulse represents 360° / 100 = 3.6°. If 25 pulses are detected, then the rotation angle is 25 pulses * 3.6 degrees / pulse = 90 degrees. Here, * indicates multiplication, and / indicates division.

[0055] The absolute encoder 132 directly outputs a digital code representing the current absolute position. This code is typically binary, but can also be in other formats, such as Gray code. The resolution of the encoder 132 determines the minimum angle it can measure. For example, a 10-bit absolute encoder 132 can provide 1024 distinct positions (2^10). To calculate the angle, the position code output by the encoder 132 needs to be converted into an angle. For example, if the encoder 132 is 10-bit (1024 positions), then each position represents 360 degrees / 1024 = 0.3515625 degrees. If the encoder 132 displays a position code of 512, then the angle is 512 * 0.3515625 degrees = 180 degrees. Here, * represents multiplication and / represents division.

[0056] refer to Figure 4 In some embodiments, the simulation element 102 is a strain gauge 142. One end of the strain gauge 142 is fixed to the rotating element 101, and the other end is fixed to the fixed element 100. When the rotating element 101 rotates, the strain gauge 142 deforms, and the angle signal is the deformation of the strain gauge 142. When the strain gauge 142 undergoes mechanical deformation under the action of external force, its resistance value changes accordingly. Based on this, the deformation of the strain gauge 142 can also be determined according to the change in current caused by the change in resistance value. And based on the determination of the deformation of the strain gauge 142, the rotation angle of the rotating element 101 can be determined, so as to realize the detection of the angle of the rotating element 101.

[0057] In some embodiments, when the simulation element 102 is a strain gauge 142, a base 103 is also present, and the base 103 is fixedly connected to the fixing element.

[0058] It is understandable that when the simulation component 102 is a capacitive grating sensor 112 and a strain gauge 142, the design of the rotating shaft 111 in the shaft body is also eliminated, and a virtual shaft 104 exists in the shaft body, which facilitates the assembly of the shaft body and improves the versatility of the shaft body.

[0059] The technical solution provided by the embodiments of this disclosure has at least the following advantages: by setting up a simulation component 102, the simulation component 102 is used to rotate with the rotating component 101, so that the simulation component 102 knows the rotation angle of the rotating component 101 and generates a corresponding angle signal. The angle signal is transmitted to the reading component, and the reading component generates and displays the rotation angle of the rotating component 101, thereby facilitating the operator to adjust the rotating component 101 according to the displayed rotation angle, thereby improving the convenience and accuracy of power tool operation.

[0060] Another embodiment of this disclosure also provides a detection circuit, which can be used in the shaft body as described in some or all of the above embodiments. The detection circuit provided in another embodiment of this disclosure will be described in detail below with reference to the accompanying drawings. It should be noted that the parts that are the same as or similar to the above embodiments can be referred to the above embodiments, and will not be described again below.

[0061] In some embodiments, the detection circuit may include a measurement circuit 200, which is used to generate a corresponding angle signal based on the angle of rotation of the rotating component.

[0062] The detection circuit may also include: a reading chip 201, which is electrically connected to the measurement circuit 200, receives the angle signal generated by the measurement circuit 200 and generates the angle value of the rotation of the rotating part.

[0063] refer to Figures 5 to 8 , Figure 5 A first circuit diagram of a detection circuit provided in an embodiment of this disclosure; Figure 6 A second circuit diagram of a detection circuit provided in an embodiment of this disclosure; Figure 7 A third circuit diagram of a detection circuit provided in an embodiment of this disclosure; Figure 8 This is a fourth circuit diagram of a detection circuit provided in one embodiment of the present disclosure.

[0064] refer to Figure 5 The measurement circuit 200 includes a capacitive grating sensor 210. The first end of the capacitive grating sensor 210 is connected to a power supply, the second end is grounded, and the third and fourth ends are respectively connected to the first and second ends of the reading chip 201. The internal components of the capacitive grating sensor 210 generate a signal corresponding to the rotation angle according to the rotating component and transmit it to the reading chip 201 through the third and fourth ends. The reading chip 201 acquires the angle signal and generates the angle value of the rotating component.

[0065] refer to Figure 6 The measuring circuit 200 includes a potentiometer 220. The first end of the potentiometer 220 is connected to a power supply, the second end is grounded, and the sliding end is electrically connected to the reading chip 201. Thus, when the rotating part rotates, the sliding end of the potentiometer 220 changes, and the resistance R1 of the potentiometer 220 changes, causing a change in the voltage or current value received by the reading chip 201. In this way, the resistance value of the potentiometer 220 can be calculated, and then the rotation angle of the rotating part can be calculated.

[0066] refer to Figure 7The measurement circuit 200 may include an encoder 230. The first end of the encoder 230 is connected to a power supply, the second end is grounded, and the third end is electrically connected to the reading chip 201. As the rotating part rotates, the components inside the encoder 230 detect the rotational displacement and convert the displacement into an electrical signal. Then, the electrical signal is encoded into a digital code and transmitted to the reading chip 201. The reading chip 201 decodes the signal to obtain the rotation angle of the rotating part.

[0067] refer to Figure 8 The measuring circuit 200 includes: a resistor R1, one end of which is in contact with the power supply voltage; and a strain gauge 240, one end of which is electrically connected to the other end of the resistor R1, and the other end is grounded. The resistor R1 protects the measuring circuit 200 and the reading chip 201, preventing the reading chip 201 from being damaged due to excessively low resistance when the strain gauge 240 is not deformed, which would cause excessive circuitry in the transmission from the measuring circuit 200 to the reading chip 201. The strain gauge 240 deforms differently depending on the angle of rotation of the rotating component, resulting in different resistance values. The reading chip 201 can calculate the change in deformation of the strain gauge 240 by receiving changes in voltage or current values, and thus calculate the angle of rotation of the rotating component.

[0068] In some embodiments, the detection circuit further includes a capacitor C1 connected in parallel with the measurement circuit 200. The capacitor C1 is used to filter the signal transmitted from the measurement circuit 200 to the readout chip 201, thereby improving the reliability of the signal transmitted from the measurement circuit 200 to the readout chip 201, and thus improving the reliability of the entire detection circuit.

[0069] Those skilled in the art will understand that the above embodiments are specific examples of implementing this disclosure, and in practical applications, various changes in form and detail may be made without departing from the spirit and scope of the embodiments of this disclosure. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the embodiments of this disclosure; therefore, the scope of protection of the embodiments of this disclosure should be determined by the scope defined in the claims.

Claims

1. A power tool, characterized in that, The power tool includes a shaft, the shaft comprising: Fasteners; A rotating component, wherein the rotating component and the fixed component are rotatably connected; A simulation component, which is connected to the rotating component, is used to generate a corresponding angle signal based on the rotation angle of the rotating component; A reader is electrically connected to the analog component, receives the angle signal, and displays the angle value of the rotating component's rotation.

2. The power tool according to claim 1, characterized in that, The analog component is a capacitive grating sensor, which includes: A fixed grid is fixed to the surface of the fixing member, and the fixed grid corresponds to the rotation track of the rotating member; The moving grid is fixed on the surface of the rotating component. When the fixed grid and the moving grid are stationary relative to each other, the capacitive grid sensor is turned on and outputs the angle signal based on the position of the moving grid and the fixed grid facing each other.

3. The power tool according to claim 1, characterized in that, The rotating component includes a rotating shaft, and the analog component is a potentiometer, which includes: A fixing part, wherein the fixing part is fixedly connected to the fixing member; The movable part is fixedly connected to the rotating shaft, and the rotating shaft drives the movable part to rotate. The movable part generates the angle signal based on the change of the rotation angle.

4. The power tool according to claim 3, characterized in that, The potentiometer is a sliding rheostat, with the sliding end of the rheostat fixedly connected to the rotating component, and the fixed end of the rheostat fixedly connected to the fixing component.

5. The power tool according to claim 1, characterized in that, The rotating component includes a rotating shaft, and the analog component is an encoder. The encoder is fixed on the fixing component, receives the angle of rotation of the rotating shaft, and generates the angle signal. The angle signal is the encoded signal generated by the encoder.

6. The power tool according to claim 1, characterized in that, The simulation component is a strain gauge. One end of the strain gauge is fixed to the rotating component, and the other end is fixed to the fixed component. When the rotating component rotates, the strain gauge deforms, and the angle signal is the deformation of the strain gauge.

7. The power tool according to claim 1, characterized in that, The power tool is a circular saw.

8. A detection circuit, characterized in that, The power tool used in any one of claims 1 to 7 comprises: A measuring circuit, wherein the measuring circuit is used to generate a corresponding angle signal based on the rotation angle of the rotating component; A reading chip is electrically connected to the measurement circuit, which receives the angle signal generated by the measurement circuit and generates the angle value of the rotation of the rotating component.

9. The detection circuit according to claim 8, characterized in that, Also includes: A capacitor, which is connected in parallel with the measuring circuit.

10. The detection circuit according to claim 8, characterized in that, The measurement circuit includes: A resistor, one end of which is in contact with the power supply voltage; A strain gauge, one end of which is electrically connected to the other end of the resistor, and the other end is grounded.

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