CN218957288U - Novel slide rheostat effect demonstration instrument - Google Patents

Abstract

The utility model discloses a novel slide rheostat action demonstration instrument, which comprises a slide rheostat and a tested resistor, wherein the slide rheostat comprises a guide sliding frame, a conductive sliding block and a resistor unit, the guide sliding frame comprises a guide sliding rod, the conductive sliding block is slidably arranged on the guide sliding rod and slides along the guide sliding rod, the resistor unit comprises a plurality of equivalent fixed-value resistors and a plurality of wire segments, the fixed-value resistors are uniformly distributed below the guide sliding rod along the extending direction of the guide sliding rod and are connected in series through the wire segments, the lower end of the conductive sliding block is abutted against the resistor unit, and the conductive sliding block is abutted against the wire segments corresponding to the lower part and is electrically conducted through the sliding conductive sliding block so as to adjust the serial or parallel number of the tested resistor and the fixed-value resistors, and further change the voltage of the tested resistor. This novel slide rheostat effect demonstration appearance can very audio-visual show slide rheostat at bleeder circuit's selection problem to the student.

Description

Novel slide rheostat effect demonstration instrument

Technical Field

The utility model relates to the technical field of novel slide rheostat action demonstrators, in particular to a novel slide rheostat action demonstrator.

Background

Slide varistors are commonly used in physical teaching in junior and senior high school, and are often used in electrical experimental courses, while slide varistors are commonly used in circuits. The current common slide rheostat is of a winding type structure, after a slide sheet slides to a certain position, students cannot directly obtain the resistance value of a resistor on the slide rheostat, the slide rheostat needs to be independently measured after power is off, the measuring mode is complicated, and the resistance value of an access circuit of the slide rheostat cannot be directly displayed in an experiment.

Disclosure of Invention

In view of the above, the present utility model is necessary to provide a novel demonstration instrument for the action of the sliding rheostat, which can intuitively obtain the resistance value of the sliding rheostat by students, and further can effectively solve the problem of selecting the sliding rheostat in the voltage dividing circuit by students.

The utility model provides a novel slide rheostat action demonstration instrument which comprises a circuit board, a power supply, a slide rheostat, a measured resistor, a digital voltmeter and an ammeter, wherein the power supply, the slide rheostat, the measured resistor, the digital voltmeter and the ammeter are arranged on the circuit board, two ends of the slide rheostat are respectively connected with the positive electrode and the negative electrode of the power supply, the digital voltmeter is connected with two ends of the measured resistor so as to measure the voltage of the measured resistor in real time, the slide rheostat comprises a sliding guide frame, the sliding guide frame comprises a sliding guide rod, a plurality of conductive sliding blocks and a plurality of conductive wire sections, the conductive sliding guide frame is slidably arranged on the sliding guide rod and slides along the sliding guide rod, the plurality of fixed resistors are distributed below the sliding guide rod at equal intervals along the extending direction of the sliding guide rod, the plurality of fixed resistors are connected in series through the plurality of conductive wire sections, two ends of the resistor units formed in series are connected with two ends of the power supply, the lower ends of the conductive sliding guide block are abutted against the resistor units, the conductive sliding guide blocks are abutted against the corresponding conductive wire sections below the conductive wire sections and are electrically conducted so as to adjust the number of the measured resistor and the fixed resistor in parallel, the sliding guide frame comprises a plurality of fixed resistor, the sliding guide frame and the sliding guide rail is correspondingly arranged, and the sliding resistor, and the fixed resistor are correspondingly.

Further, the sliding position sensing assembly comprises light blocking strips and photoelectric doors matched with the light blocking strips, each light blocking strip is vertically arranged on the circuit board and located between two adjacent fixed-value resistors, and the photoelectric doors are connected to the conductive sliding blocks and are sensed with the corresponding light blocking strips after the conductive sliding blocks slide to the required positions, so that the positions where the conductive sliding blocks slide to reach can be confirmed.

Further, the photoelectric door comprises a mounting frame, a signal transmitting unit, a signal receiving unit and a signal prompting piece, wherein the mounting frame is provided with a U-shaped opening with a downward opening, the signal transmitting unit is arranged on one side in the U-shaped opening, the signal receiving unit is arranged on the other side of the U-shaped opening, after the photoelectric door slides to one position of the light blocking strip, the light blocking strip stretches into the U-shaped opening to block the signal receiving unit to receive signals, and the signal prompting piece sends out signals to confirm the sliding arrival position of the conductive sliding block.

Further, the resistor unit comprises metal contact blocks, wherein the metal contact blocks are arranged on each wire segment at one side of the circuit board, and each metal contact block is arranged on the corresponding wire segment so as to be in butt connection and conduction with the conductive sliding block.

Furthermore, the fixed resistors are arranged on the front side of the upper surface of the circuit board at equal intervals, the wire segments and the metal contact blocks are arranged on the front side of the lower surface of the circuit board, two ends of each wire segment penetrate through the circuit board and are respectively connected to corresponding adjacent fixed resistors on the upper surface of the circuit board, and one end of each conductive slider conductive resistor unit forms a bending part and is hooked on the lower surface of the front side of the circuit board so as to be used for conductive connection with the metal contact blocks.

Further, the sliding rheostat comprises hot melt adhesive, and is formed between adjacent fixed value resistors on the upper surface of the circuit board, so that the light blocking strip and the fixed value resistors are fixed on the circuit board.

Further, the conducting rod is a conducting rod, the other end of the measured resistor is connected to the conducting rod, and the other end of the measured resistor is connected to the conducting slide block of the slide rheostat instead of the other end of the measured resistor.

Further, the novel slide rheostat action demonstration instrument comprises a resistance measuring device and a resistance display module, wherein the resistance measuring device is used for measuring resistance values of a plurality of fixed-value resistors connected in series with the measured resistor, and the resistance display module is used for displaying the number of the resistors connected in parallel with the measured resistor.

Further, the novel slide rheostat action demonstration instrument comprises a digital ammeter which is arranged between a power supply and a measured resistor and used for displaying the current passing through the measured resistor.

Further, the resistance value of the measured resistor is 5 omega-100 omega, and the resistance value of the constant resistor is 0 omega-20 omega.

Compared with the prior art, this novel slide rheostat effect demonstration instrument, as an electricity experiment teaching instrument, the resistance unit that adopts is established ties through a plurality of wire sections through a plurality of fixed value resistance, the resistance of every point value resistance is fixed, how many resistance of slip process can read out directly perceivedly, so can see directly perceivedly the number of series connection or parallelly connected resistance in the circuit, for traditional slide rheostat, need not outage detection slide rheostat's resistance, be favorable to the student to know the slide rheostat when sliding directly perceivedly, the change relation of measured resistance both ends voltage and resistance, when slide rheostat resistance selection is less, when the difference is big with measured resistance, the measured resistance both ends voltage is close to linear relation with the gleitbretter travel distance more, this is the root cause that slide rheostat is less more convenient for adjust. In addition, through setting up strip and the photoelectricity door structure of blocking, can confirm the position that electrically conductive slider slided to accurately, slide position control is accurate, and this teaching instrument has better teaching meaning.

Drawings

In order to more clearly illustrate the technical solutions of the present utility model, the drawings that are needed in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present utility model, and that other drawings can be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic circuit diagram of the present utility model;

FIG. 2 is a schematic perspective view of the present utility model;

FIG. 3 is an enlarged view of the utility model at A in a perspective configuration;

FIG. 4 is a schematic diagram of the bottom surface of a circuit board according to the present utility model;

FIG. 5 is a graph showing the relationship between the voltage at two ends of a measured resistor and the resistance of a parallel part of the sliding rheostat in the voltage division connection method;

fig. 6 is a graph (r=100Ω) of the relationship between the voltage at two ends of the measured resistor and the resistance of the parallel portion of the sliding resistor in the voltage division method of the sliding resistor;

fig. 7 is a graph (r=5Ω) of the relationship between the voltage across the resistor under test and the resistance of the parallel portion of the sliding resistor in the partial voltage connection method of the sliding resistor;

FIG. 8 is a graph showing the relationship between the voltage across the resistor under test and the resistance of the resistor connected to the resistor;

fig. 9 is a graph (r=5Ω) of the voltage across the resistor under test versus the varistor on resistance in the varistor current limiting method;

fig. 10 shows a relationship between the voltage across the resistor under test and the varistor on resistance (r=100Ω) in the varistor current limiting method.

In the figure: 1. a circuit board; 2. a power supply; 3. a slide rheostat; 31. a conductive slider; 32. a carriage; 321. a support rod; 322. a slide guiding rod; 323. an auxiliary lever; 33. a resistor unit; 331. a fixed value resistor; 332. a wire segment; 333. a metal contact block; 34. a sliding position sensing assembly; 341. a light blocking strip; 342. a photoelectric gate; 4. a measured resistance; 5. a digital voltmeter; 6. resistance measuring means; 7. a resistance display module; 8. digital ammeter.

Detailed Description

The technical solutions of the embodiments of the present utility model will be clearly and completely described below with reference to the drawings in the embodiments of the present utility model, and it is apparent that the described embodiments are only some embodiments of the present utility model, but not all embodiments, and the embodiments and features in the embodiments in the present application may be combined with each other without conflict, and the present utility model will be described in detail below with reference to the drawings and with reference to the embodiments.

Referring to fig. 1, a novel slide rheostat action demonstration instrument comprises a circuit board 1, a power supply 2, a slide rheostat 3, a tested resistor 4 and a digital voltmeter 5, wherein the power supply 2, the slide rheostat 3, the tested resistor 4 and the digital voltmeter 5 are arranged on the circuit board 1, one end of the tested resistor 4 is connected with the positive pole of the power supply 2, the other end of the tested resistor is connected with the conductive slider 31 of the slide rheostat 3, the two ends of the slide rheostat 3 are respectively connected with the positive pole and the negative pole of the power supply 2, and the digital voltmeter 5 is connected with the two ends of the tested resistor 4 so as to measure the voltage of the tested resistor 4 in real time.

The slide rheostat 3 comprises a slide guiding rack 32, the slide guiding rack 31 and a resistor unit 33, the slide guiding rack 32 comprises supporting rods 321, a slide guiding rack 322 and an auxiliary rod 323, the two supporting rods 321 are vertically arranged on the upper surface of one side (such as the front side) of the circuit board 1, the slide guiding rack 322 and the auxiliary rod 323 are parallel to the surface of the circuit board 1 and are respectively connected between the two supporting rods 321, the slide guiding rack 322 is located above the auxiliary rod 323, the slide guiding rack 31 is slidably arranged on the slide guiding rack 322 and slides along the slide guiding rack 322, the lower end of the slide guiding rack 31 extends to be abutted to the circuit board 1, and the auxiliary rod 323 is used for assisting the slide of the slide guiding rack 31 and improving the slide stability of the slide guiding rack 31.

The resistor unit 33 includes a plurality of fixed resistors 331 and a plurality of wire segments 332, the fixed resistors 331 are arranged under the guide rod 322 at equal intervals along the extending direction of the guide rod 322, and the fixed resistors 331 are connected in series through the plurality of wire segments 332, two ends of the resistor unit 33 formed in series are connected with two ends of the power supply 2, in this embodiment, the fixed resistors 331 are mounted on the upper surface of the front side of the circuit board 1, the wire segments 332 are mounted on the lower surface of the front side of the circuit board 1, and two ends of each wire segment 332 penetrate through the circuit board 1 and are respectively connected to corresponding two adjacent fixed resistors 331 on the upper surface of the circuit board 1. Further, the resistor unit 33 includes a metal contact block 333, the metal contact block 333 is mounted on each wire segment 332 on the lower surface of the front side of the circuit board 1, and is used for electrically conducting with the conductive slider 31, it can be understood that each wire segment 332 may be formed by two segments, the metal contact block 333 is connected between the two segments, the two segments may be in a straight line or in a splayed shape, and the two segments may be covered with an insulating sleeve.

The lower end of the conductive sliding block 31 is abutted on the resistor unit 33, the conductive sliding block 31 is abutted on the wire segment 332 corresponding to the lower part and is electrically conducted, so as to adjust the number of series connection or parallel connection of the tested resistor 4 and the fixed value resistors 331, further change the voltage of the tested resistor 4, and correspondingly read the instant voltage value of the tested resistor 4 by the digital voltmeter 5. Specifically, in the present embodiment, the conductive slider 31 is connected to the metal contact 333 in an abutting manner, a bent portion is formed at one end of the conductive slider 31 abutting against the resistor unit 33, and the bent portion is hooked on the lower surface of the front side of the circuit board 1, so that the conductive slider 31 can slide smoothly, and no blocking interference is generated for the constant value resistor 331 at intervals during sliding.

Further, the sliding rheostat 3 includes a sliding position sensing assembly 34 for prompting the conductive slider 31 to slide in place, the sliding position sensing assembly 34 includes light blocking strips 341 and photo gates 342 for cooperating with the light blocking strips 341, each light blocking strip 341 is vertically arranged on the upper surface of the circuit board 1 and located between two adjacent fixed resistors 331, the photo gates 342 are arranged on the conductive slider 31 and slide together with the conductive slider 31, so that after the conductive slider 31 slides to a required position, the photo gates 342 are sensed with the corresponding light blocking strips 341 to send out an in-place prompting signal to confirm that the conductive slider 31 slides in place.

Still further, the photoelectric door 342 includes a mounting frame (not shown), a signal transmitting unit (not shown), a signal receiving unit (not shown) and a signal prompting member (not shown), the mounting frame is connected to the conductive slider 31, the mounting frame has a U-shaped opening with a downward opening, the signal transmitting unit is mounted on one side of the U-shaped opening, the signal receiving unit is mounted on the other side of the U-shaped opening, after the photoelectric door 342 slides to a position of the light blocking strip 341, the light blocking strip 341 extends into the U-shaped opening to block the signal receiving unit from receiving signals, and the signal prompting member of the photoelectric door sends out signals to confirm that the conductive slider 31 slides in place. In this embodiment, the signal prompting member preferably adopts a signal lamp, and after the photoelectric gate 342 and the light blocking strip 341 sense, the signal lamp emits light to flash.

Further, the sliding resistor 3 includes a hot melt adhesive (not shown) formed between adjacent fixed resistors 331 on the upper surface of the circuit board 1, for fixing the light blocking strip 341 and the fixed resistors 331 on the circuit board 1.

Further, the novel slide rheostat action demonstration instrument comprises a resistance measurement device 6 and a resistance display module 7, wherein the resistance measurement device 6 is used for instantly measuring the sum of resistance values of a plurality of fixed-value resistors 331 connected in series with the measured resistor 4, it can be understood that the resistance value of the resistors connected in series can be intuitively obtained as the fixed-value resistors 331 are fixed, the number of the fixed-value resistors 331 connected in series after sliding is intuitively known, the resistance measurement device plays a verification role, and when the resistance measurement device is to be tested, the resistance measurement device 6 can be directly connected to two ends of the fixed-value resistors 331 connected in series with the measured resistor 4, for example, one end of the resistance measurement device 6 is connected to the conductive slider 31, and the other end of the resistance measurement device is connected to a lead at the negative end of the power supply 2, so that the resistance value of the resistors connected in series can be measured. The resistance display module 7 may be a counter, and is configured to display the number of the fixed resistors 331 connected in series or parallel to the measured resistor 4 in real time, for example, the number of the fixed resistors 331 connected in series to the measured resistor 4 is counted.

Further, the novel slide rheostat action demonstration instrument comprises a digital ammeter 8 which is arranged between the power supply 2 and the measured resistor 4 and is used for displaying the current passing through the measured resistor 4.

When the electrical test teaching instrument is used, the resistance value of the fixed value resistor 331 on the sliding rheostat 3 connected in series or in parallel with the measured resistor 4 is changed by sliding the conductive sliding block 31, so that the current passing through the measured resistor 4 is changed, the voltage on the corresponding measured resistor 4 is changed, as in fig. 1, when the conductive sliding block 31 of the sliding rheostat 3 slides to the leftmost end completely, the measured resistor 4 is short-circuited, and no voltage exists; when the conductive slider 31 of the sliding rheostat 3 slides to the rightmost end completely, the measured resistor 4 is completely parallel to the fixed resistor 331 of the sliding rheostat 3, and when the sliding rheostat slides to any position in the middle, one part of the fixed resistor 331 is connected in parallel, and the other part of the fixed resistor 331 is connected in series.

According to the utility model, the resistance units adopted in the utility model are connected in series through a plurality of fixed-value resistors 331 and a plurality of wire segments, the resistance value of each fixed-value resistor 331 is fixed, the number of resistors which are connected in series or in parallel in a circuit can be intuitively read out, so that students can conveniently and clearly know the change of the resistance value of the sliding rheostat 3 in the sliding process of the conductive slide block, the corresponding change relation of the voltage of the tested resistor 4 can also be easily known, the significance of the change of the voltage value of the tested resistor 4 in the circuit in the sliding process of the conductive slide block 31, such as the selection of the large-resistance tested resistor 4 and the small-resistance sliding rheostat 3, and the curve change of the voltage of the tested resistor 4 in the sliding process of the conductive slide block 31 is more approximate to the linear relation. Further, the resistance of the measured resistor 4 is 5 Ω -100deg.Ω, the resistance of each fixed resistor 331 is 1Ω, and the number of fixed resistors 331 is 20.

It is understood that the conductive rod 322 may be a conductive rod, and the other end of the measured resistor 4 is connected to the conductive rod 322 instead of the other end of the measured resistor 4 being connected to the conductive slider 31 of the sliding resistor 3.

The specific demonstration effect is as follows:

1) Display of partial pressure connection effect

The circuit is connected according to the voltage division connection method, the maximum resistance value of the sliding rheostat is 20Ω, the power supply voltage is 5V, the measured resistance is respectively 5, 10, 20, 50, 100 and 200Ω, the resistance value of the parallel connection part of the sliding rheostat and the measured resistance is the abscissa, the voltage at two ends of the measured resistance is the ordinate, in the experiment, the sliding vane records corresponding data, and an image is drawn, as shown in fig. 5 (when U5 is the voltage image at two ends of the measured resistance which is 5Ω, and the like). Through analysis, the voltage change of the measured resistor above 50Ω is uniform, and when the measured resistor is 5Ω, the resistance value of the portion of the slide rheostat connected in parallel with the controlled portion is smaller, and the voltage change along with the resistor is slow; and when the resistance value is larger, the change is obvious and the adjustment is not easy. Therefore, by means of the experiment demonstrated by the resistances above 5 omega and 50 omega, the tested resistance is larger than the resistance value of the sliding rheostat, namely 'with small control and large' when the sliding rheostat is connected by voltage division.

Comparing the experimental data with the theoretical calculation, it can be seen from the images 6 and 7 that the experimental data has the same theoretical trend, and the experimental image voltage is slightly lower (the other groups are similar, and the space is limited and not shown). Considering internal resistance, experimental lead resistance and errors, the device basically accords with physical reality rules, so the device can be used as an experimental device for teaching in class.

2) Display of current limiting connection effect

The circuit is connected according to the current limiting connection method, and the measured resistors are respectively 5, 10, 20, 50, 100 and 200Ω, and the experimental images are shown in fig. 8-10. Experiments show that when the sliding rheostat with the maximum resistance value of 20Ω is used for controlling a constant resistance of 100deg.OMEGA, the voltage change range of two ends is small, so that experimental data with a larger range can not be obtained, and the linearity is better when the resistance is controlled below 20Ω. The adjustable range is wide, and when the access resistance value of the slide rheostat changes, the voltage change at two ends of a controlled object is obvious, and the adjustable range meets the requirement of experiments on data. Therefore, when the resistance of the controlled object is small, a current limiting connection method is generally adopted.

In addition, experimental data are compared with theoretical calculation data, and an image shows that the experimental voltage change trend is higher in accordance with the theory, so that the method can be used for teaching demonstration in classroom teaching.

To sum up, this novel slide rheostat effect demonstration appearance is used as an electricity experiment teaching instrument, and the slide rheostat of design has adopted 20 fixed value resistance series connection of 1Ω together, and then the mode that digital sensor combined together to simulate the slide rheostat to realize showing the purpose of slide rheostat resistance. In addition, students can more intuitively and clearly know that the slide rheostat is used in the voltage division circuit, the smaller the resistance value of the slide rheostat is, the larger the difference between the slide rheostat and the measured resistor is, the more uniform the voltage at two ends of the measured resistor is along with the movement of the sliding sheet, the closer the voltage is to the linear change, and the adjustment is more convenient.

The foregoing description is only illustrative of the present utility model and is not intended to limit the scope of the utility model, and all equivalent structures or equivalent processes or direct or indirect application in other related arts are included in the scope of the present utility model.

Claims (10)

1. The utility model provides a novel slide rheostat effect demonstration appearance, including circuit board (1), install power (2) on circuit board (1), slide rheostat (3), by survey resistance (4) and digital voltmeter (5), be equipped with slidable conductive slider (31) on slide rheostat (3), be connected power (2) positive pole by survey resistance (4) one end, the other end is connected to conductive slider (31), the positive and negative pole of power (2) are connected respectively at the both ends of slide rheostat (3), digital voltmeter (5) are connected at survey resistance (4) both ends in order to survey the voltage of survey resistance (4) in real time, its characterized in that: the slide rheostat (3) comprises a guide slide rack (32), a conductive slide block (31) and a resistor unit (33), wherein the guide slide rack (32) comprises a guide slide bar (322), the conductive slide block (31) is slidably arranged on the guide slide bar (322) along the guide slide bar (322), the resistor unit (33) comprises a plurality of fixed-value resistors (331) and a plurality of guide line segments (332), the fixed-value resistors (331) are distributed below the guide slide bar (322) at equal intervals along the extending direction of the guide slide bar (322), the fixed-value resistors (331) are connected in series through the guide line segments (332), two ends of the resistor unit (33) formed in series are connected with two ends of a power supply (2), the lower end of the conductive slide block (31) is abutted on the resistor unit (33), the conductive slide block (31) is abutted on the guide line segments (332) corresponding to the lower side and is electrically conducted, the number of the fixed-value resistors (331) to be measured is adjusted, the number of the fixed-value resistors (4) connected in series or in parallel is changed, the voltage of the measured resistors (4) is further changed, the voltage of the measured resistors (4) is sensed by the number of the fixed-value resistors (331), and the digital resistor (4) is correspondingly read to the slide rheostat (3) and the slide assembly (3) and the slide rheostat comprises a sliding component.

2. The novel slide rheostat action demonstration instrument according to claim 1, wherein the sliding position sensing assembly (34) comprises light blocking strips (341) and photoelectric gates (342) matched with the light blocking strips (341), each light blocking strip (341) is vertically arranged on the circuit board (1) and located between two adjacent fixed-value resistors (331), and the photoelectric gates (342) are fixed on the conductive sliding blocks (31) to sense with the corresponding light blocking strips (341) after the conductive sliding blocks (31) slide to a required position so as to confirm the sliding arrival position of the conductive sliding blocks (31).

3. The novel slide rheostat action demonstration instrument according to claim 2, wherein the photoelectric door (342) comprises a mounting frame, a signal transmitting unit, a signal receiving unit and a signal prompting piece, the mounting frame is provided with a U-shaped opening with a downward opening, the signal transmitting unit is arranged on one side in the U-shaped opening, the signal receiving unit is arranged on the other side in the U-shaped opening, after the photoelectric door (342) slides to a position of the light blocking strip (341), the light blocking strip (341) stretches into the U-shaped opening to block the signal receiving unit from receiving signals, and the signal prompting piece displays corresponding numbers to reflect the sliding resistance value of the slide rheostat.

4. A novel slide rheostat action demonstrating instrument according to claim 1, characterized in that the resistance unit (33) comprises metal contact blocks (333), the metal contact blocks (333) are mounted on each wire segment (332) on one side of the circuit board (1), and each metal contact block (333) is mounted on the corresponding wire segment (332) for connection and conduction of the conductive slider (31).

5. The novel slide rheostat action demonstration instrument according to claim 4, wherein a plurality of fixed resistors (331) are equidistantly arranged on the front side of the upper surface of the circuit board (1), a plurality of wire segments (332) and metal contact blocks (333) are arranged on the front side of the lower surface of the circuit board (1), two ends of each wire segment (332) penetrate through the circuit board (1) and are respectively connected to corresponding adjacent fixed resistors (331) on the upper surface of the circuit board (1), and one end of each conductive slider (31) connected with a resistor unit (33) forms a bending part and is hooked on the lower surface of the front side of the circuit board (1) so as to be connected with the metal contact block (333).

6. The novel slide rheostat action demonstration instrument according to claim 1, wherein the slide rheostat (3) comprises a hot melt adhesive, is formed between adjacent fixed resistors (331) on the upper surface of the circuit board (1), and is used for fixing the light blocking strip (341) and the fixed resistors (331) on the circuit board (1).

7. The novel slide rheostat action demonstration instrument according to claim 1, wherein the guide slide bar (322) is a conductive bar, the other end of the measured resistor (4) is connected to the guide slide bar (322), and the other end of the measured resistor (4) is connected to the conductive slide block (31) of the slide rheostat (3).

8. The novel slide rheostat action demonstration instrument according to claim 1, comprising a resistance measuring device (6) and a resistance display module (7) for measuring resistance values of a plurality of fixed-value resistors (331) connected in series with the measured resistor (4), wherein the resistance display module (7) is used for displaying resistance values of the slide rheostat connected to a voltage dividing circuit.

9. A novel slide rheostat action demonstrating instrument according to claim 1, characterized by comprising a digital ammeter (8) connected in series in the circuit for measuring the current of the measured resistor (4).

10. The novel slide rheostat action demonstration instrument according to claim 1, wherein the resistance value of the measured resistor (4) is 5-100 Ω, and the resistance value of the slide rheostat (3) is 0-20 Ω.

Images