CN2187822Y

CN2187822Y - Photoelectric time counting tester

Info

Publication number: CN2187822Y
Application number: CN 94227085
Authority: CN
Inventors: 丁定华; 陈福平
Original assignee: Individual
Current assignee: Individual
Priority date: 1994-01-20
Filing date: 1994-01-20
Publication date: 1995-01-18
Anticipated expiration: 2004-01-20

Abstract

The utility model relates to a photoelectric time counting tester which is composed of a test desk 1, a guide rail 2, a carrier 3, photosensitive tubes 7, a timer 8, a counterweight 6, etc. The photoelectric time counting tester is characterized in that the carrier 3 move on the guide rail 2. A light beam lamp 13 on the carrier is orderly irradiated to the photosensitive tubes 7. The three photosensitive tubes 7 generates respectively a switching signal to control the timing of the timer 8 to measure the movement time of the carrier. The displacement of the carrier 3 can directly be readout from a scale 11. The utility model has the advantages of simple structure, low cost, and convenient operation, is an ideal medium physical teaching experimental device.

Description

Photoelectric time counting tester

The utility model relates to a kind of tester, tester when holding concurrently the photoelectrometer that location moves in particular for a kind of timing of physics teaching experiment.

At present, be to adopt dotted timer and air track that exercise parameter is measured in physics teaching.These instruments are operated cumbersome in utilization, are difficult for regulating, and precision is low, and error is big, is difficult to teaching and obtains satisfied effect.Chinese patent 87215593 has been announced a kind of " small-sized track knotmeter ", this knotmeter is formed by being installed at interval two magnetoelectric sensors and the self-clocking printing calculator surveyed in the rails, it has adopted the single chip microcomputer that the large scale integrated circuit technology makes and the anti-jamming circuit device of filtering interference signals, thereby its cost height, and it can only test speed, can not test other kinematic parameter, so it can not carry out Physical Experiment as instruments used for education.

The purpose of this utility model provides a kind of simple in structure, and is easy to use, tester in the time of making the photoelectrometer of multiple Physical Experiment.It can be by the time and the displacement of test object motion, checking object of which movement rule and law of conservation.

The purpose of this utility model is achieved in that makes a guide rail, dolly and graduated test board.Guide rail is positioned on the table top of test board; One end of test board is installed up and down screw, and an end is installed roller.Regulate the angle of test board and surface level by up and down screw.Place dolly on guide rail, dolly is connected with weights through fine rule and roller.Power switch and Line beam lamp are arranged on the dolly.Three identical photosensitive tubes of clamping on the rule of test board insert the connection plug of three photosensitive tubes in the timer jack.

When the power switch on the dolly was closed, the Line beam lamp on the dolly was turned on, and dolly moves from left to right along guide rail, Line beam on the car shines on the photosensitive tube successively, three photosensitive tubes produce a switching signal separately, control the start and stop of timer timing, thereby reach the purpose of timing.Moving of car can directly be read from the rule of examination platform through the displacement between the photosensitive tube.

By regulating the distance and the quality that changes dolly and weights between the photosensitive tube, can measure different time and displacement, thereby the kinetic property of demonstration object analysis is verified relevant physical law.

Adopt such scheme, simple in structure, cost is low, and is easy to use, and error is little in physics teaching experiment, can obtain effect preferably, and it can do following Physical Experiment:

1. the demonstration object is done linear uniform motion;

2. study the rule of uniformly accelrated rectilinear motion;

3. checking Newton second law;

4. the checking law of conservation of momentum;

5. the checking law of conservation of mechanical energy.

Below in conjunction with drawings and Examples the utility model is further described.

Fig. 1 is one-piece construction figure of the present utility model, also is an embodiment of the present utility model.

Fig. 2 is that the utility model is used to demonstrate object and makees linear uniform motion experiment principle synoptic diagram.

Fig. 3 is that the utility model is used to study uniformly accelrated rectilinear motion and checking Newton second law experiment principle synoptic diagram.

Fig. 4 is that the utility model is used to verify law of conservation of momentum experiment principle synoptic diagram.

Fig. 5 is that the utility model is used to verify the signal of law of conservation of mechanical energy experiment principle.

In Fig. 1, the utility model is made up of test board 1, guide rail 2, dolly 3, weights 6, three photosensitive tubes 7, timer 8 etc.Baffle plate 5 and rule 11 are arranged on test board 1.On the surface of contact of dolly 3 and baffle plate 5, post velcro.Prevent that dolly 3 from running off table top and the paste of making collision experiment.Guide rail 2 is positioned on test board 1 table top, and one of testing stand is installed up and down screw 4, and roller 14 is installed in the other end.Dolly 3 is placed on the guide rail 2, and power switch 12 and Line beam lamp 13 are arranged on the dolly 3, can pack No. 5 batteries of two joints in the dolly 3 in battery case.One end of dolly 3 is connected with weights 6 through fine rule 15 and roller 14.Three photosensitive tubes 7 are three phototriode BG ₁, BG ₂, BG ₃, they are clipped in respectively on the rule 11 on track next door, and the connection plug of afterbody inserts in the jack of timer 8.In timer 8 inside electronic stopclock is arranged, display window 16 is arranged, return-to-zero button 9 and starting stop button 10 in timer 8 outsides.

The utility model can be used for doing following Physical Experiment:

(1). the demonstration object is done linear uniform motion (as shown in Figure 2):

1: assembling instrument and balance friction

Fine rule in the utility model 15 and weights 6 are taken off, with guide rail 2 horizontal positioned, regulate up and down screw 4, any one can both be just static to make dolly 3 place track; Three photosensitive tube BG ₁, BG ₂, BG ₃Equidistant clipping on the other rule 11 of track, and connecting with timer 8, pressing return-to-zero button 9 on the timer 8, to make the number of display window 16 all be 0.The power switch 12 of closed dolly 3, make dolly 3 on rail with certain initial velocity along photosensitive tube BG ₁→ BG ₃The direction free movement.After car is crossed three photosensitive tubes, read two times of timer 8, if t=2t ₁, friction that dolly is subjected to balance is described, otherwise adjusts up and down screw 4 again that examination again is up to t=2t ₁

2. demonstration linear uniform motion

In balance after the friction, increase or reduce three equidistances between the photosensitive tube and (remain S ₁=S ₂), two periods of measuring each time moving of car, t=2t is always arranged ₁(be t ₁=t ₂).Illustrate that dolly all equated by the used time of any equidistance, so be linear uniform motion.

(2) research uniformly accelrated rectilinear motion (as shown in Figure 3)

1. judge whether dolly makes uniformly accelrated rectilinear motion:

Initial velocity is zero uniformly accelrated rectilinear motion, equates that continuously the ratio of the displacement in alternate is 1:3:5:7.......Otherwise if initial velocity is 0, the ratio of the displacement of continuous adjacent time is 1:3:5:7......, and the time that each section moves equates that then this motion must be a uniformly accelrated rectilinear motion.

Dolly is placed the high order end of track, write down i.e. 0 point in the residing position of line source, three photosensitive tubes are sandwiched in track at a distance of being OBG ₁=S, BG ₁BG ₂=3S, BG ₂BG ₃=5S three places.Make dolly by static setting in motion, through photosensitive tube BG ₁, BG ₂, BG ₃After, read t ₁, t, if t=2t ₁(t ₁=t ₂) illustrate it is uniformly accelrated rectilinear motion.

2. survey the acceleration and the instantaneous velocity of dolly:

Because of dolly is done uniformly accelrated rectilinear motion, so have:

3S＝V ₁t ₁＋at ² ₁／2

8S＝V ₁t ₁＋at ² ₁／2

: a=2s/t ² ₁V ₁=2S/t ₁

V ₂=V ₁+ at ₁=4S/t ₁V in like manner ₃=6S/t ₁

(3). checking Newton second law (being F=ma):

As shown in Figure 3, after finishing first experiment, add fine rule 15 and weights 6, regulate dolly initial position (0 point) and phototriode BG ₁, BG ₂, BG ₃Between distance, make distance between them than for 1:3:5, i.e. OBG ₁Be S, BG ₁BG ₂Be 3S, BG ₂BG ₃Be 5S.The quality of supposing dolly 3 is M, and the quality of weights 6 is m.

1. verify the proportional relation of a and F:

Keep the dolly mass M certain, change the size (being weights quality m) of tensile force f, measure the acceleration a(a=2s/t of each time ² ₁).

Compare the corresponding ratio Fn/Fn+1 of each time, an/an+1(n is a number of times), if they equate that can draw: acceleration is directly proportional with pulling force.

Annotate: when doing this experiment with this instrument, the ratio of M/m approximately gets 10～20, and experimental error is just less, can be less than 5%.

2. verify the inverse relation of a and M:

Keep tensile force f (being weights m) certain, change the dolly mass M, measure each time acceleration (method is the same).

Compare the corresponding Mn/Mn-1 of each time, a _N-1/ an is if they equate that can draw: acceleration and quality are inversely proportional to.

Annotate: the ratio of M/F is approximately got about 10～15, and experimental error is just less, can be less than 5%.

(4). the checking law of conservation of momentum:

The experimental provision synoptic diagram appears the step of finishing experiment one for the first time as shown in Figure 4.Again the A car is placed photosensitive tube BG ₁Left end, the B car places BG ₂Neighbouring and static.Make the A car with certain initial velocity V then _ATo the motion of B car, be connected as a single entity after A and the B collision and continue motion through photosensitive tube BG ₃Read the A car through BG from timer ₁, BG ₂2 used time and A, B car are connected as a single entity through BG ₂, BG ₃Between the used time, read BG again ₁With BG ₂, BG ₂With BG ₃Between distance, then can calculate the A car at BG ₁With BG ₂Between speed V _AThe speed V that moves together with A, B car _AB, further calculate to such an extent that the A car bumps preceding momentum M _AV _AWith aggregate momentum (MA+MB) VAB of two cars after linking to each other, M is arranged relatively _AV _A=(M _A+ M _B) V _AB, illustrate that collision front and back momentum equates, i.e. momentum conservation.

(5). the checking law of conservation of mechanical energy

The experimental provision signal is shown in Figure 5, with photosensitive tube BG ₁And BG ₃Be sandwiched in by the track,, finish the process of experiment one again at a distance of suitably.Before dolly begins to move, Line beam and BG ₁On same vertical curve, block unthreaded hole with the thing piece, and block dolly.Closed then power switch is extracted the light-blocking matter piece simultaneously out and is discharged dolly.Read BG at last ₁With BG ₃Between apart from S and dolly through BG ₁With BG ₃Between used time t, then can calculate V=2s/t, calculate the total kinetic energy E of dolly, counterweight again _K=(M+m) V ²/ 2 potential energy E that descend to reduce with counterweight _P=mgs relatively equates, conservation of mechanical energy is described.

Claims

1, tester during a kind of photoelectrometer comprises guide rail (2), photosensitive tube (7), timer (8), it is characterized in that:

(1). guide rail (2) is positioned on the table top of test board (1), and test board (1) one end is installed up and down screw (4), and an end is installed roller (14);

(2). go up placement dolly (3) at guide rail (2), dolly (3) is connected with counterweight (6) through fine rule (15) and roller (14), and power switch (12) and Line beam lamp (13) are arranged on the dolly (3);

(3). the rule (11) of test board (1) is gone up three identical photosensitive tubes of clamping (7), the connection plug of three photosensitive tubes (7) is inserted in the jack of timer (8).

Tester during 2, according to the described photoelectrometer of claim 1 is characterized in that plate washer (5) is arranged on the test board (1), posts Buddhist nun's hasp on the surface of contact of dolly (3) and baffle plate (5).

3, tester during photoelectrometer according to claim 1 is characterized in that in timer (8) inside electronic stopclock being arranged, and display window (16), return-to-zero button (9) and starting stop button (10) are arranged in timer (8) outside.

4, tester during photoelectrometer according to claim 1 is characterized in that three photosensitive tubes (7) are three phototriode BG ₁, BG ₂, BG ₃