CN2286907Y

CN2286907Y - Instrument for demonstrating meal resistance changing with temp.

Info

Publication number: CN2286907Y
Application number: CN 97203793
Authority: CN
Inventors: 廖振威; 谭明清
Original assignee: Individual
Current assignee: Individual
Priority date: 1997-01-20
Filing date: 1997-01-20
Publication date: 1998-07-29
Anticipated expiration: 2007-01-20

Abstract

The utility model relates to an instrument for demonstrating metal resistance changing with temperature. The utility model is characterized in that a module is arranged in a box body, and the box body is connected in series with a bulb, power supply, and a special alloy wire of a heating attachment to form an entire circuit; an obvious effect can be aroused by the slight variation of the resistance in the circuit, and the effect is displayed by the lightness of the bulb, conveniently and visually demonstrating the experiment that the metal resistance changes with temperature. The utility model has the advantages of excellent demonstrating effect, high teaching quality, simple circuit, high sensitivity, low cost, convenient operation, and good repeatability.

Description

Metallic resistance varies with temperature demonstrator

The utility model belongs to the physics teaching model.

In physics teaching in secondary school, the P84-85 page or leaf of China's existing People's Education Publishing House's junior three physics teaching material has one about the temperature variant lecture experiment of metallic resistance.This requirement of experiment uses dry cell batteries, amp gauge and filament of fluorescent lamp or thin wire to demonstrate.Because the filament of fluorescent lamp difficulty is got and easily broken, and variation of temperature causes that the iron wire changes in resistance is very little, thereby the reading of amp gauge changes many reasons such as very little, so that most of teacher does not carry out this lecture experiment in teaching; Even there is the minority teacher to demonstrate this experiment reluctantly, real fine horse effect is also very poor.Like this, just influenced quality of instruction.

In order to solve the difficult problem of this long-term numerous Physical Education Teacher of puzzlement in teaching, the purpose of this utility model is to provide a kind of metallic resistance temperature variant demonstrator, the change small by resistance in the circuit causes positive effect, with bulb bright, show that secretly intuitive and convenient ground demonstration metallic resistance varies with temperature and the experiment that changes.Fabulous demonstration effect is arranged, improve the quality of teaching.

The utility model is realized with following mode: feature is that it has box body 1, module 2 is arranged in box body 1, this module 2 is connected in series with the special alloy silk AB of bulb L, power switch S, power supply E and heating annex 3 and constitutes integrated circuit, heating annex 3 is 2 leads special alloy silk in parallel AB, " 1 " contact inserts special alloy silk AB one end in this integrated circuit, " 4 " contact and " 5 " contact respectively insert bulb L, " 2 " contact and " 3 " contact all insert the negative pole of power supply E, and bulb L is contained on box body 1 watchcase.Module 2 is by resistance R ₁R ₂R ₃, triode BG ₁BG ₂The circuit that constitutes; Resistance R wherein ₁One breathes heavily and resistance R ₃One end connects, and inserts " 5 " contact in the integrated circuit, inserts power supply E positive pole again, resistance R ₁In addition end and R ₂One end connects, and inserts " 1 " contact in the integrated circuit, resistance R ₂In addition end and triode BG ₁Base stage connect triode BG ₁Collector and resistance R ₃In addition end, triode BG ₂Base stage link triode BG ₁Emitter insert integrated circuit " 2 " contact, triode BG ₂Collector insert " 4 " contact in the integrated circuit, triode BG ₂Emitter insert " 3 " contact in the integrated circuit, and " 2 " contact, " 3 " contact insert the negative pole of power supply E in the integrated circuit.

The utility model varies with temperature with the bright metallic resistance of secretly demonstrating of bulb, and experiment effect is very obvious.Circuit is simple, and is highly sensitive, cheap, easy to operate, good reproducibility.Power supply adopts No. 5 batteries or the 6V voltage stabilizing power supply of 4 joint 1.5V.

Now in conjunction with the accompanying drawings the utility model is described in further detail.

Fig. 1 is the utility model structural representation;

Fig. 2 is integrated circuit figure of the present utility model;

Fig. 3 is module 2 circuit diagrams of the present utility model;

Fig. 4 is heating annex 3 structural representations of the present utility model.

With reference to Fig. 1-Fig. 3, in the utility model box body 1 integrated circuit is arranged, module 2 is serially connected in the integrated circuit, when teaching and experimental demonstration, with reference to Fig. 4, along A, B place that the small arrow direction is slowly inserted Fig. 1, at this moment special alloy silk AB is connected in series integrated circuit and is exposed at outward outside the box body 1 with heating annex 3.Can use firing equipment heating special alloy silk AB such as spirit lamp, kerosene lamp or candle during experiment.Before this special alloy silk AB was not heated, metallic resistance was minimum, resistance R ₁On voltage be higher than certain voltage, triode BG ₁End triode BG ₂Base stage is a noble potential, makes BG ₂Conducting, bulb L is luminous.If this special alloy silk AB is heated, it is big that metallic resistance becomes, then R ₁On voltage reduce to below the certain value BG ₁Saturation conduction, BG ₂Base stage is a low-voltage, makes BG ₂End, bulb L is not luminous.More than just can show intuitively that by the demonstration of bulb metallic resistance changes with temperature.

Claims

1, a kind of metallic resistance varies with temperature demonstrator, it is characterized in that:

It has box body [1], module [2] is arranged in box body [1], this horizontal piece [2] is connected in series with the special alloy silk [AB] of bulb [L], power switch [S], power supply [E] and heating annex [3] and constitutes integrated circuit, heating annex [3] is 2 leads special alloy silks [AB] in parallel, " 1 " contact inserts special alloy silk [AB] end in this integrated circuit, " 4 " contact and " 5 " contact respectively insert bulb [L], " 2 ' contact and " 3 " contact all insert the negative pole of power supply [E]; And bulb [L] is contained on box body [1] watchcase;

Module [2] is by resistance [R ₁] [R ₂] [R ₃], triode [BG ₁] [BG ₂] circuit that constitutes; Resistance [R wherein ₁] end and resistance [R ₃] end connects, and " 5 " contact in the access integrated circuit, inserts power supply [E] positive pole again, resistance [R ₁] in addition end and [R ₂] end connects, and " 1 " contact in the access integrated circuit, resistance [R ₂] in addition end and triode [BG ₁] base stage link triode [BG ₁] collector and resistance [R ₃] in addition end, triode [BG ₂] base stage link triode [BG ₁] emitter insert " 2 " contact in the integrated circuit, triode [BG ₂] collector insert integrated circuit " 4 " contact, triode [BG ₂] emitter insert integrated circuit " 3 " contact, and integrated circuit " 2 " contact, " 3 " contact insert the negative pole of power supply [E].