CN102236998A

CN102236998A - Demonstration device of short circuit experiment

Info

Publication number: CN102236998A
Application number: CN2010101623995A
Authority: CN
Inventors: 雷海平
Original assignee: Individual
Current assignee: Individual
Priority date: 2010-05-05
Filing date: 2010-05-05
Publication date: 2011-11-09

Abstract

The invention discloses a demonstration device of a short circuit experiment. The demonstration device is a teaching aid for middle school physics and comprises a bulb and a resistance wire connected with the bulb in series, wherein the bulb is a low-voltage bulb, such as an automobile bulb and the like. The demonstration device is characterized by also comprising matches of which the head powder contacts the resistance wire and a match stick fixing device for fixing the matches. When the demonstration device is in use, the two ends of the bulb are set in a short circuit state, and then the bulb goes out, which indicates that current dose not pass through the bulb any more, the current of a wire is sharply increased (indicated by an ampere meter), the wire is heated, and the matches in contact with the resistance wire are on fire after several seconds. The demonstration device has the beneficial effects that a low-voltage power supply is adopted, thus safety is high; the heating comparison of the resistance wire is obvious before and after short circuit, the phenomenon that the burning of matches can be seen by all students in a class, and the intenseness of the experimental phenomenon is moderate, thereby increasing the interests of the students and hardly intensifying the psychological fear of the students (especially girl students) for studying electrical science; and the demonstration device is simple in structure, is low in cost and is convenient for popularization.

Description

The short circuit experiment apparatus for demonstrating

Affiliated technical field

The present invention relates to a kind of physics teaching in secondary school instrument, particularly short circuit experiment apparatus for demonstrating.

Background technology

Short circuit experiment is the important experiment in the junior physics electricity, and during short circuit, electric current is without electrical appliance, and only passes through lead, and lead is with heating up, and even breaking out of fire.The difficult point of student on understanding is: during partial short-circuit, whether electric current directly flows through from lead without electrical appliance; When circuit analysis, can the student not be subjected to length, position and the influence in shape of short-circuit conductors, judges whether there is short circuit exactly.

Existing experimental program is: incandescent lamp bulb and fuse are connected in the lighting circuit, when bulb side directly is communicated with by short-circuit line, bulb does not work and with the disconnected sound of the fuse of strong electric arc flame and little sound, the shortcoming of this experiment is: the one, because of dangerous and explosive (generation electric arc), the teacher is afraid to do sth, even avoids and not doing; The 2nd, the pavid psychology (particularly schoolgirl) that " loud noise, the strong electric lonely flame with a loud crash " in the experiment can the aggravation student causes the student that there is the feared state of mind in other Experiments of Electricity operation; The 3rd, improper in the experiment if the fuse specification is selected, can cause whole teaching building to have a power failure; The 4th, the lead heating in the time of can't demonstrating short circuit.Therefore, this experiment should not be demonstrated on the classroom, forbids making grouping experiment.

Another experimental program is that the mains lighting supply with 220V changes low-tension supply into and does experiment, security lifting, phenomenon are no longer violent, the needs that are suitable for imparting knowledge to students, but still there is a shortcoming: the one, the lead heating situation when showing short circuit with still failing visual pattern, reason is that the lead heating should not can not reach red vehement state, and this heating is invisible; Be anti-scald, can not make certain student touch again with hand.The 2nd, phenomenon is too gentle, the electric current of student during to short circuit sharply increases, the perceptual knowledge of lead heating is not dark, cause the student not enough to the understanding of short circuit harm, in life, experiment, work, cause the generation probability of short circuit accident to increase, very harmful, in addition, the gentleness of experimental phenomena has also reduced the interest that the student learns.

Summary of the invention

The objective of the invention is: a kind of safe, easy to operate, obvious, interesting strong short circuit experiment apparatus for demonstrating of heating phenomenon is provided.

The technical solution adopted in the present invention is: a kind of short circuit experiment apparatus for demonstrating, the resistance wire of comprise bulb, connecting with bulb is characterized in that: it also comprises the match that its head medicinal powder contacts with resistance wire and the fixing matchstick stationary installation of match.

Described bulb is that rated voltage is several volts to tens volts a low voltage bulb, as autobulb etc.

After adopting said structure, less by the electric current of resistance wire before the short circuit, the resistance wire heating is not obvious, and match can not lighted; After the bulb side short circuit, bulb extinguishes immediately, shows to no longer include the electric current process, and current in wire sharply increases (indication of available current table), lead heating, after the several seconds, the match that contacts with resistance wire all fire burns.

The invention has the beneficial effects as follows: adopt low-tension supply, safe; Before and after the short circuit heating of resistance wire contrast obviously, the full class of the ablaze phenomenon of match as seen, the violent degree of experimental phenomena is moderate, can improve student's interest, is unlikely the psychology fear of aggravation student (particularly schoolgirl) to electricity study again; Simple in structure, cost is low, be beneficial to popularization.

Description of drawings

Fig. 1 is a structural representation of the present invention;

Among the figure: 1. first riser, 2. binding post, 3. base, 4. match, 5. hole, 6. resistance wire, 7. second riser, 8. fuse, 9. lead, 10. switch, 11. bulbs.

Embodiment

As shown in Figure 1, be fixed with on the base 3 on first riser 1 and second riser, 7, the first risers 1 and be fixed with post D, be fixed with bulb 11, binding post A, binding post B, binding post C above second riser 7.Be used to be electrically connected bulb 11 between binding post A, the binding post B, be used to be electrically connected fuse 8 between binding post B, the binding post C, just binding post B is the common termial between bulb 11 and the fuse 8 simultaneously, is used to be electrically connected resistance wire 6 between binding post C, the post D.Have holes 5 that or several insert for matchsticks on the base 3, the appropriate depth in hole 5 so that after in the end patchhole 5 of match 4, the match end that scribbles medicinal powder all can both closely contact with resistance wire 6, guarantees that the resistance wire adstante febre can light match.

Bulb 11 can be selected autobulb for use, is used for the low-tension supply of external 6-30V between binding post A and the post D, reometer that also can an external wide range.

Illustrate one, the short circuit mode of bulb has following two kinds:

1, fixed: as shown in Figure 1, the two ends of bulb are parallel with short circuit branch, and this short circuit branch is made of the switch 10 of lead 9 that is attempted by bulb side and serial connection.This lead 9 and switch 10 also are fixed on second riser above 7 together.

2, circumscribed: this short circuit branch is external short-circuit conductors, and described bulb side is provided with binding post (as binding post A among Fig. 1 and binding post B), and this binding post can be electrically connected short-circuit conductors when needed.Because of simple and genus known technology, mapping.

Illustrate two, the fixed form of match has 5 kinds of following two classes:

The first kind, jack type:

Described match stationary installation is the perforate thing, has 1 or several holes for the matchstick insertion on this perforate thing, and described bulb, resistance wire are fixed on the support, and the connected mode between this perforate thing and support has following 3 kinds:

1, as shown in Figure 1, described perforate thing is the part of support, promptly has 1 or several holes 5 of inserting for matchstick near the support the resistance wire;

2, described perforate thing is fixed on the same support with bulb, resistance wire, and promptly the perforate thing is for being fixed on the thing piece on the support in addition; Because of simple, not mapping.

3, described perforate thing separates with support, and during experiment, this perforate thing is manually controlled by the experimenter, makes match end contact or leave resistance wire at needs, because of simple, and mapping.

Second class, clipping:

Described match stationary installation is the matchstick gripping object, and this matchstick gripping object is any in the iron clamp, test tube clamp in metal clip, plastic clip, wood clamp, the Square seat bracket accessory, and the connected mode between this matchstick gripping object and support can be divided into following 2 kinds again:

1, the matchstick gripping object is fixed on the same support with bulb, resistance wire, because of simple, and not mapping;

2, the matchstick gripping object separates with support, and during experiment, this matchstick gripping object is manually controlled by the experimenter, because of simple, and not mapping.

Claims

1. short circuit experiment apparatus for demonstrating, the resistance wire of comprise bulb, connecting with bulb is characterized in that: it also comprises the match that its head medicinal powder contacts with resistance wire and the fixing matchstick stationary installation of match.

2. short circuit experiment apparatus for demonstrating as claimed in claim 1 is characterized in that: described bulb is that rated voltage is several volts to tens volts a bulb, and the two ends of described bulb are parallel with short circuit branch, and:

This short circuit branch is made of the switch of lead that is attempted by bulb side and serial connection;

Perhaps this short circuit branch is external short-circuit conductors, and described bulb side is provided with binding post, and this binding post can be electrically connected short-circuit conductors when needed.

3. short circuit experiment apparatus for demonstrating as claimed in claim 2 is characterized in that: described match stationary installation is the perforate thing, has 1 or several holes for the matchstick insertion on this perforate thing, and described bulb, resistance wire are fixed on the support, and:

Described perforate thing is the part of support, promptly has 1 or several holes of inserting for matchstick near the support the resistance wire;

Perhaps described perforate thing is fixed on the same support with bulb, resistance wire;

Perhaps described perforate thing separates with support, and during experiment, this perforate thing is manually controlled by the experimenter.

4. short circuit experiment apparatus for demonstrating as claimed in claim 2, it is characterized in that: described match stationary installation is the matchstick gripping object, this matchstick gripping object is a kind of in the iron clamp, test tube clamp in metal clip, plastic clip, wood clamp, the Square seat bracket accessory, described bulb, resistance wire are fixed on the support, and:

Described matchstick gripping object is fixed on the same support with bulb, resistance wire;

Perhaps described matchstick gripping object separates with support, and during experiment, this matchstick gripping object is manually controlled by the experimenter.