Digital display compasses

Abstract

The utility model discloses a digital display compass which comprises a left foot, a right foot and a shell arranged on the upper portion of the left foot and the upper portion of the right foot, a circuit board, a battery, a potentiometer, a first rotary disc and a second rotary disc are arranged in the shell, the first rotary disc and the second rotary disc can rotate relatively, a display screen is arranged on the surface of the shell, and one side of the first rotary disc extends downwards to form the right foot. A potentiometer is mounted in the middle of the first turntable; a circular sliding chute is formed in the first turntable by taking a rotating shaft of the potentiometer as a circle center; the side, opposite to the right foot, of the second rotating disc extends downwards to form a left foot, a prism used for inserting a rotating shaft of the potentiometer is arranged in the middle of the second rotating disc, and a sliding rail matched with the sliding groove is arranged on the second rotating disc with the prism as the circle center. The resistance value in the potentiometer changes along with the distance between the left foot and the right foot and is displayed through the display screen after A / D conversion, and when a circle is drawn, the arc attaching position of the sliding groove and the sliding rail disperses force acting on the first rotary disc and the second rotary disc, so that relative rotation is not prone to occurring when the circle is drawn, and the circle drawing device is more stable and reliable.

Description

Technical Field

[0001] The utility model relates to a compass, in particular to a digital display compass which can display the value of the compass opening angle. Background Art

[0002] A compass is a commonly used mathematical tool and drawing tool, suitable for geometry and geography teaching, intuitive calculation of trigonometric functions and determination of map line length, especially a must-have stationery for middle school students in daily classes. At present, the compass commonly used by middle school students requires a ruler to measure the distance between the two supporting legs, with one of the supporting legs as the center of the circle, and the other supporting leg rotates around it to draw a circle. If the force is uneven during the drawing process, the distance between the two supporting legs will change slightly, and the user cannot perceive it, which causes the drawn circle to deform. Utility Model Content

[0003] The utility model provides a digital display compass which can detect the distance between compass feet in real time and display the value.

[0004] The digital display compass described in the utility model comprises a left foot, a right foot and a shell arranged on the upper parts of the left foot and the right foot, wherein a circuit board, a battery, a potentiometer and a first turntable and a second turntable which can rotate relatively are arranged in the shell, and a display screen is arranged on the surface of the shell, the right foot extends downward from one side of the first turntable, the potentiometer is installed in the middle of the first turntable, and a circular slide groove is arranged on the first turntable with the rotating shaft of the potentiometer as the center of the circle; the left foot extends downward from the side of the second turntable relative to the right foot, a prism for inserting the rotating shaft of the potentiometer is arranged in the middle of the second turntable, and a slide rail matching the slide groove is arranged on the second turntable with the prism as the center of the circle.

[0005] The digital display compass, when the distance between the toes of the left foot and the right foot increases or decreases, the first turntable and the second turntable are driven to rotate relative to each other under the cooperation of the slide groove and the slide rail, and the rotating shaft of the potentiometer is driven by the prism, thereby changing the resistance value inside the potentiometer. This resistance value is converted into a value representing the opening angle of the left and right feet of the compass through A / D conversion, and then the distance between the needle tips of the left and right feet of the compass is calculated according to the vertex angle and the waist length, and finally displayed on a small display screen. At the same time, the circular slide grooves and slide rails that cooperate with each other are arranged on the first turntable and the second turntable. When the first turntable and the second turntable are rotated to draw a circle, the arc fitting position of the slide groove and the slide rail disperses the force acting on the first turntable and the second turntable. Therefore, relative rotation is not easy to occur when the circle is rotated, and it is more stable and reliable, and it is simple and easy to operate to draw a complete circle. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1 This is a schematic diagram of an explosion of a digital display compass structure.

[0007] Figure 2 The figure is a schematic diagram of the structure of a digital display compass.

[0008] Figure 3 This is a schematic diagram of the right foot structure. DETAILED DESCRIPTION

[0009] like Figure 1-3 As shown, a digital display compass comprises a left foot 1, a right foot 2 and a shell 3 arranged on the upper parts of the left foot and the right foot, wherein a circuit board 4, a battery 5, a potentiometer 6 and a first turntable 7 and a second turntable 8 which can rotate relatively are arranged in the shell, and a display screen 9 is arranged on the surface of the shell, the right foot 2 extends downward from one side of the first turntable 7, the potentiometer is installed in the middle of the first turntable, and a circular slide groove 11 is arranged on the first turntable with the rotating shaft 10 of the potentiometer as the center of the circle; the left foot extends downward from the side of the second turntable relative to the right foot, a prism 12 for inserting the rotating shaft of the potentiometer is arranged in the middle of the second turntable, and a slide rail 13 is arranged on the second turntable with the prism as the center of the circle and matches the slide groove. When the distance between the toes of the left foot and the right foot increases or decreases, the first turntable and the second turntable are driven to rotate relative to each other under the cooperation of the slide groove and the slide rail, and the rotating shaft of the potentiometer is driven by the prism, thereby changing the resistance value inside the potentiometer. This resistance value is converted into a value representing the opening angle of the left and right feet of the compass through A / D conversion, and then the distance between the needle tips of the left and right feet of the compass is calculated according to the vertex angle and the waist length, and finally displayed on a small display screen. At the same time, the circular slide grooves and slide rails that cooperate with each other on the first turntable and the second turntable, when rotating to draw a circle, the arc fitting position of the slide groove and the slide rail disperses the force acting on the first turntable and the second turntable, so relative rotation is not easy to occur when rotating to draw a circle, which is more stable and reliable, and it is simple and easy to operate to draw a complete circle.

[0010] The potentiometer is a rotary potentiometer, which includes a saddle-shaped resistor body made of metal film or carbon film, a sliding arm, a sliding end (also called a contact or brush), a rotating shaft, a rotating handle, a welding piece, etc. The resistance value between welding pieces A and C is the total resistance value of the potentiometer. One end of the sliding end is connected to welding piece B, and the other end is in close contact with the resistor body. When the position of the sliding end changes, the resistance value between AB and BC changes.

[0011] The slide groove on the first turntable can be a groove formed by two circular rings, and the slide rail is embedded in the groove to realize rotation; the slide groove can also be a circular side wall extending upward from the edge of the first turntable, and the circular side wall fits well with the outer side of the slide rail, so as to realize the rotation of the first turntable relative to the second turntable.

[0012] The circuit board can be divided into a first circuit board 101 electrically connected to the potentiometer and a second circuit board 102 connected to the display screen. The first circuit board and the second circuit board are also electrically and communicatively connected to each other. The first circuit board is mainly used to send the resistance value of the potentiometer to the second circuit board, and the second circuit board converts the resistance value through A / D into a value representing the opening angle of the left and right legs of the compass, and finally sends it to the display screen for display.

[0013] The middle part of the left foot and the right foot is provided with a through hole 14 in the shape of a strip facing longitudinally, a cylinder 15 is arranged in the through hole transversely, a threaded hole is arranged in the middle part of the cylinder, and an adjusting rod 16 is also included to pass through the threaded hole of the left foot and the right foot cylinder, and the adjusting rod is provided with a thread matched with the threaded hole, and when the adjusting rod is rotated to adjust the distance between the left foot and the right foot, the cylinder also rotates. By arranging the adjusting rod between the left foot and the right foot, not only can the distance between the left foot and the right foot be adjusted, but also a supporting effect can be played to prevent the distance between the left foot and the right foot from changing during the circle drawing process. In addition, when the adjusting rod is rotated, the distance between the left foot and the right foot will be relatively far away or close, and in this process, the angle between the left foot and the right foot will change, and the angle between the adjusting rod and the left foot and the adjusting rod and the right foot needs to change to allow the distance between the left foot and the right foot to continue to change, so it is necessary to arrange a cylinder that can rotate with the rotation of the adjusting rod on the left foot and the right foot, and the cylinder can change the angle between the left foot or the right foot and the adjusting rod by rotating.

[0014] The adjusting rod between the left foot and the right foot is also provided with a gear 17 for rotating the adjusting rod. The adjusting rod can be better rotated by the gear.

[0015] A fixing plate 18 for fixing the circuit board is also provided in the housing, and a battery bracket 19 for fixing the battery is provided on the fixing plate, so that the circuit board and the battery can be fixed in the housing more stably.

Claims

1. A digital display compass, comprising a left foot (1), a right foot (2), and a housing (3) arranged above the left foot and the right foot, characterized in that: A circuit board (4), a battery (5), a potentiometer (6), and a first rotating disk (7) and a second rotating disk (8) which can rotate relative to each other are arranged in the housing, and a display screen (9) is arranged on the surface of the housing. A right foot (2) extends downward from one side of the first rotating disk (7), a potentiometer is installed in the middle of the first rotating disk, and a circular slide groove (11) is arranged on the first rotating disk with the rotating shaft (10) of the potentiometer as the center of the circle; a left foot extends downward from the side of the second rotating disk opposite to the right foot, a prism (12) for inserting the rotating shaft of the potentiometer is arranged in the middle of the second rotating disk, and a slide rail (13) which matches the slide groove is arranged on the second rotating disk with the prism as the center of the circle.

2. The digital compass according to claim 1, characterized in that: A longitudinally oriented strip-shaped through hole (14) is provided in the middle of the left foot and the right foot, a cylinder (15) is transversely provided in the through hole, a threaded hole is provided in the middle of the cylinder, and an adjustment rod (16) passes through the threaded holes of the left foot and right foot cylinders, the adjustment rod is provided with threads matching the threaded holes, and when the adjustment rod is rotated to adjust the distance between the left foot and the right foot, the cylinder also rotates.

3. The digital compass according to claim 2, characterized in that: A gear (17) for rotating the adjusting rod is also provided on the adjusting rod between the left foot and the right foot.

4. The digital compass according to claim 1, characterized in that: A fixing plate (18) for fixing the circuit board is also provided in the housing.

5. The digital compass according to claim 4, characterized in that: A battery bracket (19) for fixing the battery is provided on the fixing plate.

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