JP3050891U - Experimental unit for learning the principle of DC motor - Google Patents

Abstract

(57) [Abstract] (Modified) [Problem] To provide an easy and inexpensive experimental device for learning the principle of a DC motor that is faithful to the operating principle of a DC motor described in a textbook for science and technology training in junior high school . SOLUTION: A cylindrical transparent container 3 having a through hole 2 at one end and an open end at the other end is horizontally arranged on a base 4, and a pair of electrode terminals 5-1 and 5-2 and a brush piece 6-1 and 6-1. 2 is arranged. The armature coil ⇔ is formed by winding into a rectangular frame shape, and a part of the conductor portion that does not contribute to the generated torque at both ends is extended, and one end is armature coil support protrusion 8 and the other end is positive and negative. Lead wires 9-1 and 2-1 connected to the power supply side are formed, the former is supported in the through hole 2, and the latter is mounted in sliding contact with a pair of brush pieces to rotatably support the armature coil. N-pole and S-pole magnetic poles (10N and 10N) face the side of the cylindrical transparent container 3.
The field magnetic pole 10 is provided so that S) faces each other.

Description

[Detailed description of the invention]

[0001]

[Technical field to which the invention belongs]

 This invention particularly relates to a DC motor principle learning experimental device for making the principles of a DC motor (electric motor) learned in a junior high school textbook very easy to understand through assembly training.

[0002]

[Prior art]

 Around us, DC motors are used in large numbers as an essential power source. And now it is even said that the number of motors used is the standard for barometers in cultures such as homes. For example, it is said that the number of motors employed in automobiles is 40 to 70 when counted regardless of the type of motor. Therefore, having only one car in the kitchen would want to benefit from the culture of cars through many motors.

[0003] Among such useful motors, DC motors have become very useful in the education process of junior high schools for the purpose of teaching the basics of electromagnetism in science, particularly physics.

In order to teach the mechanism of such a DC motor, the textbooks of junior high schools almost all show the operation principle diagram of the DC motor as shown in FIG. As is clear from FIG. 5, in the state shown in FIG. 5, currents in the directions shown in FIG. 5 were formed in the lead terminals 9-1 and 9-2 by the power supply battery 11 in the electrode terminals 5'-1 and 5'-2. When the current flows through the commutator pieces 12-1 and 12-2 via the brush pieces 6'-1 and 6'-2, the current flows through the armature coil 7 in the order of A → A → W → D. If the magnetic field is generated by arranging the field poles 10 composed of the pole magnetic pole 10N and the S pole 10S in a state as shown in the figure, the rotational force (torque) in the directions shown by arrows 13 and 14 is Occur.

In the armature coil 7, reference numeral 7a denotes a conductor portion that contributes to the generated torque. In the conductor portion 7a, as is clear from the partial view indicated by reference numeral 15 in FIG. When flowing, torque in the direction indicated by arrow 13 is generated, and reference numeral 7b denotes a conductor portion that contributes to the generated torque. As is clear from the partial diagram indicated by reference numeral 16 in FIG. A current flows in the opposite direction to the direction a, and the force received from the magnetic field is also reversed, so that a torque is generated in the direction indicated by the arrow 14, so that the armature coil 7 rotates half in the directions indicated by the arrows 13 and 14.

[0006] In the state where the armature coil 7 is rotated by half, the directions of the currents flowing through the conductor portions 7a and 7b of the armature coil 7 are reversed. By repeating the above operation, the armature coil 7 rotates continuously. From the above, the principle of rotation of the DC motor can be known. However, in order to understand this, it is desirable that the students understand through practice that the armature coil 7 is actually rotating.

[0007] Therefore, in a practical training in science at a junior high school, the operation principle diagram of the DC motor shown in FIG. 5 allows an experiment to confirm that the armature coil 7 can actually rotate, so that the understanding can be deepened. .

However, in the operation principle diagram of the DC motor in FIG. 5, the armature coil 7 is formed by one conductor for the sake of understanding, but the armature coil 7 is actually formed in this manner. It is difficult to rotate the child coil 7. Also, it does not show how the armature coil 7 is rotatably supported. The connection method between the armature coil 7 and the commutator pieces 12-1 and 12-2 is not shown or is troublesome. Therefore, there is no experimental unit for learning the principle of the DC motor in FIG.

[0009] Even though there are many problems as described above, in a science training process at a junior high school, in order to know the rotation principle of the DC motor shown in FIG. Will be needed.

[0010] As described above, since the experimental device for learning the principle of the DC motor in FIG. 5 cannot be easily constructed, a textbook for practical training in science at a junior high school contains information on the principle of rotation of the DC motor as shown in FIG. An experimental unit for learning the principle of a DC motor that actually moves is shown, manufactured, and moved so that the principle of rotation of the DC motor can be learned. This will be described below.

The experimental device for learning the principle of rotation of a DC motor shown in FIG. 6 has a pair of armature coil support columns 19 erected on a plate-like base 4 ′ made of an insulator such as wood. To The armature coil support strut 19 can be easily erected on the base 4 'by removing one side of the safety pin and fixing a stopper at one end to the base 4' with a thumbtack 20. Since the other end of the safety pin constituting the armature coil support column 19 is formed in an annular shape, the annular portion 21 can be used for supporting the armature coil which also serves as a bearing and a brush. I have. Since the safety pin is made of a conductive material, the armature coil support strut 19 forms a path for electricity.

The armature coil 7 used here is formed in an annular shape for easy manufacture. The armature coil 7 can be formed very easily by, for example, winding an enameled wire having a wire diameter of 0.4 mm with a size AA battery as a core, winding about 10 turns around the outer periphery thereof, and then removing it. Both ends of the annular armature coil 7 formed as described above are formed by extending in opposite directions symmetrically by 180 degrees to form lead wires 9-1 and 9-2 for energization. 1 and 9-2 are passed through the annular portion 21. The outer periphery of the lead wire 9-1 is stripped of enamel using a paper file or the like, and the outer periphery of the lead wire 9-1 is stripped of enamel only at a half circumference thereof using a paper file or the like. This is to make the lead wire 9-2 have a commutator function.

Reference numerals 22 and 23 denote battery cases in each of which a power supply battery 11 is set. Each of the battery cases 22 and 23 has a negative (negative) power supply terminal at one end and a positive (plus) power supply terminal at the other end. Therefore, as shown in FIG. By connecting the cases 22 and 23, two power batteries 11 can be connected in series. Reference numerals 24 and 25 denote a power cord with a clip having a holding portion 26 made of a conductor at both ends, and a pair of armature coil support posts at the holding portion 26 at one end of each of the power cords 24 and 25. 19 is sandwiched between the negative power supply terminal of the battery case 22 and the positive power supply terminal of the battery case 22 by the holding portion 26 at the other end, so that the power supply battery 11 is connected via the power cords 24 and 25 with clips. , The armature coil support column 19 and the armature coil 7 are electrically connected.

A single-pole field pole 10 ′ formed of one disk-shaped ferrite magnet is fixed to the base 4 ′ surface at the lower position of the armature coil 7 with an adhesive or detachably mounted. I do. Since the field pole 10 'is a single pole, only the N pole or the S pole can be opposed to the armature coil 7 on the armature coil 7 side.

[0015]

[Issues of the invention]

 The experimental device for learning the principle of rotation of the DC motor shown in FIG. 6 is very convenient because it has a simple configuration, is easy to assemble, and is inexpensive. Since the principle diagram and the experimental device for principle learning in FIG. 6 are quite different in structure, it is easy for a first-time learner to assume that the one in FIG. 5 and the one in FIG. 6 are the same. The reality is that you cannot do that.

The reason is that the shape of the armature coil 7 is different. However, even if this point can be explained, the brush pieces 6′-1, 6′-2 and the commutator pieces 12-1, There is no 12-2. Next, the field pole 10 'is a single pole. For example, in the case of FIG. 6, only the field pole 10' of the N pole is opposed to the armature coil 7 side. Thus, the field pole 10 'of the S pole does not exist. In particular, although FIG. 5 explains that the magnetic pole requires both an N pole and an S pole, there is only one magnetic pole, so this point is particularly difficult for students to understand. I have.

Further, since only one field pole 10 ′ having only one magnetic pole is used, the magnetic force is weak, and the armature coil 7 is an inefficient annular coil into which anti-torque enters. Since it has a linear shape, it generates only a small torque, and because it rotates in reaction, it cannot perform smooth continuous rotation. Alternatively, since the torque is small, the armature coil 7 must be manually turned at first, and moreover, the armature coil 7 can be rotated only half a turn. In this case, in order to rotate further by 180 degrees, there is only one N-pole or S-pole, and the magnetic force of the field magnetic field is weak. The electronic cases 22 and 23 must be reverse-connected so as to face the secondary coil 7 or to reverse the positive power supply battery 11 and the negative power supply polarity. That is, after the power is supplied, the armature coil 7 cannot be automatically and smoothly rotated continuously, and is not optimal as an experimental device for learning the principle of a DC motor.

[0018]

[Means for Solving the Problems]

 The problem of the present invention is that a cylindrical transparent container 3 having an open end 1 at the other end and a through-hole 2 for supporting an armature coil at one end is laid on a base 4, and the positive and negative conductors are respectively provided by conductors. A pair of electrode terminals 5-1 and 5-2 for connection to the negative power supply side are provided on the base 4. Each of the electrode terminals 5-1 and 5-2 is extended upward to form a brush piece 6-1. The armature coil 7 formed in a rectangular frame shape is formed in the transparent transparent container 3, and a part of the conductor 6c that does not contribute to the generated torque at one end is extended. To form the armature coil supporting projections 8, and lead wires 9-1 and 9-2 for connecting a pair of positive and negative power sources respectively from the conductor 6d which does not contribute to the generated torque at the other end. Is extended, and the armature coil support protrusion 8 is guided to the inner peripheral portion of the armature coil support through hole 2. The armature coil 7 is rotatably supported by slidingly contacting the pair of lead wires 9-1 and 9-2 with the pair of brush pieces 6-1 and 6-2, respectively. 3 can be achieved by providing an experimental device for learning the principle of a DC motor in which the field magnetic poles 10 are provided so that the N pole and the S pole face each other.

(Operation) A pair of electrode terminals 5-1 and 5-2 for connection to the positive and negative power sources are fixed to the upper surface of the other end of the base 4 with screws 27 made of a conductor. . In this case, the conductor 30 at one end of each of the lead wires 31-1, 31-2 is also screwed at the same time with the screw 27, so that the conductor 30 and the power supply terminals 5-1 and 5-2 are electrically connected. .

The cylindrical transparent container 3 is laid on the base 4, and the Ω-shaped stopper 18 is put on the outer periphery of the transparent container 3. By screwing the screw 29 into the base 4, the transparent container 3 is fixed on the surface of the base 4.

The power supply battery 11 is interposed between the conductive wires 30 at the other end of each of the lead wires 31-1 and 31-2, and the lead wires 31-1 and 31-2 are electrically connected to the power supply battery 11. You. This method can be easily performed by appropriate means. However, since the method is simple using the battery cases 22 and 23 shown in FIG. 6, a method similar to the method shown in FIG. 5 is adopted.

For example, in this case, the lead 30 of the other terminal of the lead wires 31-1 and 31-2 is sandwiched between the holding portions 26 provided at one end of the power cords 24 and 25 with clips, and the other end is provided. The battery cases 22 and 23 having the power supply battery 11 may be interposed between the holding portions 26. Alternatively, the lead wires 31-1 and 31-2 are deleted, and the power supply terminals 5-1 and 5-2 are directly sandwiched by the holding portions 26 provided at one end of the power cords 24 and 25 with clips. The battery cases 22 and 23 having the power supply battery 11 may be interposed between the holding portions 26 of the battery.

The armature coil 7 is inserted from the opening end 1 provided at the other end of the transparent container 3 with the armature coil supporting projection 8 at the top, and the armature coil 7 is inserted into one end of the transparent container 3. The armature coil support projection 8 is passed through the formed armature coil support through hole 2. The lead wires 9-1 and 9-2 of the armature coil 7 are mounted in contact with the brush pieces 6-1 and 6-2 formed by the power supply terminals 5-1 and 5-2, respectively. Thus, the armature coil 7 is rotatably supported by the armature coil supporting through-hole 2 and the brush pieces 6-1 and 6-2.

The field poles 10 are installed by arranging N poles 10N and S poles 10S opposite each other on both sides of the transparent container 3 via the transparent vessel 3. In order to facilitate the installation of the magnetic poles 10N and 10S, a recess into which the lower ends of the magnetic poles 10N and 10S enter is previously formed on the base 4, and the lower ends of the magnetic poles 10N and 10S are formed in the recesses. Part is inserted with an adhesive. Further, since the base 4 has a threaded hole formed in the side surface thereof, the screw 17 is screwed into the threaded hole, and the magnetic poles 10N and 10S are pressed and fixed from the side surface.

In the above-described manner, the student can easily assemble and rotate the armature coil 7 automatically after the armature coil 7 is energized, so that the student can assemble and test the operation principle of the DC motor. The best thing can be made as a vessel. Note that the principle of the continuous rotation of the armature coil 7 is exactly the same as that shown in FIG. 5, and a description of the principle will be omitted. Further, since the container 3 is transparent, the rotation of the armature coil 7 can be easily confirmed from the outside.

[0026]

[Embodiment of the invention]

 FIG. 1 is a perspective view of a DC motor principle learning experimental device partially omitted, FIG. 2 is a partial longitudinal sectional view of the DC motor principle learning experimental device viewed from the side, and FIG. FIG. 4 is a diagram of a DC motor principle learning experiment device viewed from the other end, and FIG. 4 is a diagram of a DC motor principle learning experiment device viewed from one end direction. An experimental device for learning the principle of a DC motor as one embodiment of the present invention will be described.

A pair of plate-shaped monopolar N poles (also called field magnets or permanent magnets) are provided near both sides of the upper surface of the long plate-shaped base 4 made of an insulator such as wood. A concave portion (not shown) for inserting the lower end of 10S of the 10N and S poles is formed. The lower ends of the N and S magnetic poles 10N and 10S are respectively applied to the pair of recesses by applying an adhesive and inserted into the pair of recesses, thereby forming the N and S magnetic poles 10N and 10S formed with the different poles facing each other. The field pole 10 is installed perpendicular to the upper surface of the base 4.

Screws 17 are screwed onto the side surfaces of the N and S magnetic poles 10N and 10S inserted in the concave portions, into screw holes formed on the side surface of the base 4, and the N and S magnetic poles are formed at their tips. By pressing 10N and 10S from the side, the magnetic poles 10N and 10S of the N and S are vertically fixed on the base 4.

One field pole 10 is formed by a pair of N and S magnetic poles 10N and 10S. In this case, as shown by a dotted line in FIG. 3, a horseshoe-shaped field pole 10 'is formed. 'May be used. However, in the case of such a horseshoe-shaped field pole 10 ″, a general inexpensive one having a strong magnetic force is not commercially available. If a horseshoe-shaped field pole 10 ″ having a strong magnetic force is required, it becomes very expensive and is not suitable for use in a DC motor principle learning experimental device for junior high school physics and chemistry experiments.

Therefore, in this embodiment, a plate-like magnet made of an inexpensive and easily available ferrite magnet that generates a strong magnetic force of 5 mm in thickness × 30 mm in width × 30 mm in height, which can generate a strong magnetic force. The field pole 10 is formed by using the N and S magnetic poles 10N and 10S.

Particularly, it is very convenient to form the field pole 10 using the N and S magnetic poles 10N and 10S described above. In this embodiment, the magnetic paths of the N and S magnetic poles 10N and 10S are closed. Although no back yoke is used, a back yoke made of an iron plate or other magnetic material plate is attached to or separated from the back surface due to the shape of the plate-like N and S magnetic poles 10N and 10S. In this way, it is possible to learn the case where there is no back yoke and the difference in the efficiency of the magnetic force when using the back yoke.

A transparent resin on the surface of the base 4 between the N and S magnetic poles 10N and 10S (in this embodiment, transparent is defined as a transparent material as long as the inside can be seen through). The transparent container 3 made of glass or glass is laid down, the Ω-shaped stopper 18 is put on the outer periphery of the transparent container 3, and the screw 29 is mounted on the base through a through hole provided in the stopper 28 at the end. 4, the transparent container 3 is fixed on the base 4. The reason why the transparent container 3 is used is that the rotation of the armature coil 7 from the outside can be easily confirmed. In this embodiment, the transparent container 3 has a cylindrical shape. However, the transparent container 3 is not necessarily required to have a cylindrical shape, but may be a rectangular cylinder or the like. What is necessary is just to use the thing of an appropriate shape.

The transparent container 3 has an opening 32 protruding at one end having an armature coil supporting through hole 2 at one end, and the other end as the open end 1.

A pair of electrode terminals 5-1 and 5-2 for connection to the positive side and the negative side power supply side by conductor plates are provided on both sides of the upper surface on the other end side of the base 4 respectively. The screw 27 made of a conductor is screwed into the through hole to fix the conductor. The brush terminals 6-1 and 6-2 are formed by extending the electrode terminals 5-1 and 5-2 upward, respectively. In this case, the brush pieces 6-1 and 6-2 are electrode terminals 5-1 made of a conductor plate having an appropriate thickness so as to obtain elasticity suitable for receiving lead wires 9-1 and 9-2 described later. 5-2. Since the pair of brush pieces 6-1 and 6-2 need to receive and support the lead wires 9-1 and 9-2, the upper end of the pair of brush pieces 6-1 and 6-2 has a Y-shape. It is formed in an open shape. The opening angle of the pair of brush pieces 6-1 and 6-2 is formed so that the lead wires 9-1 and 9-2 do not fall into the recesses between them. In this case, a lid having a mouth similar to the mouth 32 is attached to the opening end 1 so that the lead wires 9-1 and 9-2 do not fall between the brush pieces 6-1 and 6-2 at the mouth. It may be. Although the lead wires 9-1 and 9-2 themselves have the function of a commutator, the commutator pieces are separately attached to the lead wires 9-1 and 9-2, respectively. It may be formed.

When the pair of electrode terminals 5-1 and 5-2 are fixed to the base 4 by the screws 27, lead wires 31-1 and 3-1 for connecting to the positive side and the negative side power supply side, respectively. By simultaneously screwing the lead wire 30 at one end of the lead wire 1-2, the lead wire 30-1, of the lead wire 31-1, 31-2 is electrically connected to the electrode terminals 5-1 and 5-2.

The power supply battery 11 is interposed between the conductors 30 at the other end of each of the lead wires 31-1 and 31-2, and the lead wires 31-1 and 31-2 are electrically connected to the power supply battery 11. You. This method can be easily performed by appropriate means. However, since the method is simple if the battery cases 22 and 23 shown in FIG. 6 are used as described above, a method similar to the method shown in FIG. 5 is employed. .

For example, in this case, the lead 30 of the other terminal of the lead wires 31-1 and 31-2 is sandwiched between the holding portions 26 provided at one end of the power cords 24 and 25 with clips, and the other end is connected to the other end. The battery cases 22 and 23 having the power supply battery 11 may be interposed between the holding portions 26. Alternatively, the lead wires 31-1 and 31-2 are deleted, and the power supply terminals 5-1 and 5-2 are directly sandwiched by the holding portions 26 provided at one end of the power cords 24 and 25 with clips. The battery cases 22 and 23 having the power battery 11 may be interposed between the holding portions 26 of the battery. Incidentally, it is desirable to connect a power switch or a voltage regulator between the lead wire 9-1 or 9-2 and the power battery 11, so that various experiments can be performed. However, they are not illustrated in this embodiment. If a power switch is provided, the operation is facilitated. If a voltage regulator is interposed, the voltage is adjusted to change the rotation speed of the motor, that is, the rotation speed of the armature coil 7. Experiment can be performed.

The armature coil 7 is formed in a rectangular frame shape as shown in FIG. 5, which is formed by appropriately winding several turns of a wire such as an enamel wire having a wire diameter of 0.4 to 0.5 mm. doing. In this case, when the armature coil 7 is formed to be solid, a self-bonding wire (cement wire) is used as a conductive wire, and a hot air is applied to the outer peripheral fusion agent, or alcohol or the like is used. This is possible by solidifying the conductors with a fusion agent by melting them together.

The conductors 7a and 7b parallel to the N and S magnetic poles 10N and 10S of the armature coil 7 are conductors that contribute to the generated torque, and the gap length between the conductors 7a and 7b and the magnetic poles 10N and 10S. The armature coil 7 is formed in a shape having a size as small as possible. When the armature coil 7 is formed, a conductor may be wound around the outer periphery of an appropriate material such as a square material or a cubic having an appropriate surface, and may be taken out after winding.

The conductors 7 c and 7 d perpendicular to the N and S magnetic poles 10 N and 10 S of the armature coil 7 are conductors that do not contribute to the generated torque. A part of the body part 6c is extended to form an armature coil support protrusion 8, and a lead wire 9-1 for connecting a pair of positive and negative power sources from the conductor part 6d on the other end, respectively. I'm pulling out 9-2. The lengths of the lead wires 9-1 and 9-2 are different. The reason for this is that the armature coil 7 is stopped in the dead state described later, or when the brass pieces 6-1 and 6-2 are in poor contact with the lead wires 9-1 and 9-2. Even when the rotation of the coil 7 is stopped, the lead wires 9-1 and 9-2 are picked up, the armature coil 7 is manually turned, and the brass pieces 6-1 and 6-2 and the lead wire 9 are again rotated. -1, 9-2 to make it easier to rotate the armature coil 7 continuously. In particular, a two-pole, one-coil type DC motor principle learning experimental device always has a dead center. Therefore, if the armature coil 7 is stopped at this dead center position, the armature coil 7 is energized. Even in this case, the armature coil 7 may not rotate, so this measure is effective.

The armature coil 7 is formed at one end of the transparent container 3 by inserting the armature coil support projection 8 of the conductor portion 7 c at the head from the open end 1 provided at the other end of the transparent container 3. The armature coil support projections 8 are passed through the armature coil support through holes 2. The lead wires 9-1 and 9-2 of the armature coil 7 are mounted in contact with the brush pieces 6-1 and 6-2 formed by the power supply terminals 5-1 and 5-2, respectively. Thus, the armature coil 7 is rotatably supported by the armature coil supporting through-hole 2 and the brush pieces 6-1 and 6-2.

[0042]

【effect】

 Although the experimental device for learning the principle of the DC motor has a very simple configuration, it can be assembled into a faithful configuration based on the operating principle of the DC motor shown in FIG. 5 in a junior high school textbook. The principle can be easily confirmed and understood from outside, and the structure and the material are very inexpensive. Therefore, it is the most suitable as a laboratory machine for the principle learning of DC motors in junior high schools.

[Brief description of the drawings]

FIG. 1 is a perspective view of an experimental device for learning the principle of a DC motor partially omitted as an embodiment of the present invention.

FIG. 2 is a partial longitudinal sectional view of the experimental unit for learning the principle of the DC motor, viewed from the side.

FIG. 3 is a view of the experimental device for learning the principle of the DC motor viewed from the other end direction.

FIG. 4 is a view of the experimental device for learning the principle of the DC motor viewed from one end direction.

FIG. 5 is a principle diagram of a DC motor.

FIG. 6 is an explanatory view of a conventional DC learning principle experiment device. (Explanation of reference numerals) 1 Open end 2 Through-hole for supporting armature coil 3 Cylindrical transparent container 4, 4 'base 5-1 5-2, 5'-1, 5'-2 Electrode terminal 6-1 , 6-2, 6'-1, 6'-2 Brush pieces 7 Armature coils 7a, 7b Conductor portions 7c, 7d that contribute to the generated torque Conductor portions that do not contribute to the generated torque 8 Armature coil support protrusions 9-1, 9-2 Lead wire 10, 10 'Field pole 10N N pole 10S S pole 11 Power battery 12-1.1.2-2 Commutator strip 13, 14 Arrow 15, 16 Reference sign 17 Screw 18 Ω-shaped stop Hardware 19 Armature coil support strut 20 Thumbtack 21 Ring part 22, 23 Battery case 24, 25 Power cord with clip 26 Narrowing part 27 Screw 28 Stop piece 29 Screw 30 Conductor 31-1, 31-2 Lead wire 32 port

Claims (1)

[Utility model registration claims] A cylindrical transparent container (3) having an open end (1) at the other end and a through hole (2) for supporting an armature coil at one end.
On the base (4), and a pair of electrode terminals (5) for connecting to the positive side and the negative side power supply side by conductors, respectively.
5-1 and 5-2) are provided on the base (4), and the electrode terminals (5-1 and 5-2) are formed to extend upward to form brush pieces (6-1 and 6-2). Then, the armature coil (7) wound and formed in a rectangular frame shape is connected to the cylindrical transparent container (3).
The conductor (6) that does not contribute to the torque generated at one end
forming part of c) as an extension to form an armature coil support protrusion (8)
And a conductor portion (6) that does not contribute to the generated torque on the other end side.
d), lead wires (9-1, 9-2) for connection to a pair of positive and negative power supply sides are formed to extend, and the armature coil supporting projections (8) are connected to the armature coil supporting projections. A pair of lead wires (9-1, 9) leading to the inner peripheral portion of the hole (2).
-2) The armature coil (7) is rotatably supported by being slidably mounted on the pair of brush pieces (6-1, 6-2), and the side of the cylindrical transparent container (3). An experimental device for learning the principle of a DC motor, wherein a field magnetic pole (10) is provided so that N and S magnetic poles (10N and 10S) face each other.