SU1485292A1 - Teaching aid on mechanics - Google Patents

Description

The invention relates to textbooks on mechanics and physics and can be used to demonstrate the forced oscillations of a material point. The purpose of the invention is the expansion of the didactic capabilities of the device by taking into account the influence of a change in the weight of the load on the oscillation frequency. The manual contains a base, a switching unit, a rack, a transparent cylinder in which a load with a permanent magnet is placed, suspended on a spring that is connected to a solenoid electrically connected through an amplifier and multivibrator with a power source, as well as an inductance coil located outside the cylinder and connected to a power source. 1 hp f-ly, 2 ill. '

The invention relates to textbooks on mechanics and physics and can be used to demonstrate the forced oscillations of a material point.

The purpose of the invention is the expansion of didactic possibilities by demonstrating the effect of a change in gravity on the oscillation frequency.

Figure 1 presents the training manual, a general view; figure 2 is a circuit diagram.

The manual on mechanics contains a base 1, a switching unit 2 mounted on the base 1, a rack 3, and a transparent cylinder 4 with holes 5 on the side surface. Inside the cylinder 4 is placed a load 6 made of a non-magnetic material and suspended on the spring 7, the spring being passed through the opening of the cantilever rail 8 and connected to the movable core 9 of the solenoid 10, the electromagnetic coil 11 of which is rigidly fixed to the rack 3. Inside the load 6 a permanent magnet is pressed 12, the magnetization vector of which coincides with the axis of the spring, outside the cylinder 4 there is applied an inductor 13 connected through a potentiometer 14 and a switch 15 to the power supply 16. The potentiometer slider can be connected to the pro-program mechanism 17. Electrically coil 11 of the solenoid 10 is connected to the output of amplifier 18, and the input of the amplifier is connected to the output of multivibrator 19, two inputs of which are connected to power supply 16 and switching unit 2, respectively.

Winding coil 13 implemented

so that when passing through it current ^ _.

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The magnetic vector H inside the winding is directed upwards when switch 15 is in position I. In this case, the magnetic field generated by the coil 13 tends to push the magnet 12 with the load 6 up, which is equivalent to reducing the force of gravity. In position II of the switch 15, the magnetic field of the winding of the carcass 13 tends to push the magnet with the load down, which is equivalent to an increase in the force of gravity.

The manual works as follows. 15

On the switching unit 2, the "network" switch is turned on and the I button is pressed, thereby turning on the power in the multivibrator 19, which, through the amplifier 18, supplies the solenoid-20 solenoid 10 and 10 with a predetermined voltage, causing the core 9 to periodically move vertically.

In this case, the spring force 7, acting on load 6, is a disturbing force. Under the action of this force, the load 6 begins forced oscillations when the frequencies of natural oscillations and disturbances of the force do not coincide.

When the button II is pressed on the switching unit 2, the frequency of the disturbing force is set using the multivibrator 19 many times greater than the frequency of the own 5 oscillations of the load 6. In this case, forced vibrations with a small amplitude but with a higher frequency are obtained (the trainees observe ). 40

When you press button III on the switching unit 2, the frequencies of the disturbing force are equal to the frequency of natural oscillations of the load 6 (the students observe the phenomenon of resonance). 45

Then, without turning off the "network" switch, set switch 15 to position I or II and by smoothly moving the lever of potentiometer 14 increase the current of inductor 13, thereby creating a violation of the equality mode of the frequencies of the disturbing force with the frequency of natural oscillations of the load due to the apparent change in the weight of the load.

output of oscillatory system from resonance).

In the same way, it is possible in the first mode when pressing the button to observe the occurrence of the oscillating system in resonance due to the apparent change in the weight of the load, all other conditions being equal. When you turn on the switch In the movement of the lever of the potentiometer 14 is a software device 17 "

The invention makes it possible to demonstrate with greater clarity and convincingly the dynamics of oscillations of bodies with variable weight (the influence of the dynamic characteristics of the oscillatory system on the parameters of the oscillations), as well as the effect of a change in gravity on the oscillation frequency (resonant oscillations) of mechanical systems.

Claims (2)

Claim 1. A manual on mechanics containing a power source, a base with a stand on which a solenoid is mounted, the coil of which is connected via a series-connected amplifier and multivibrator to a power source, and a load placed with a gap is suspended to the solenoid anchor in vertical guides, characterized in that, in order to expand functionality by demonstrating the effect of changing gravity, contains a standing magnet, a current polarity switch and potentiometer, connected in series with a power source, in the load, and an inductance coil made in the form of a cylinder of a non-magnetic transparent material, with the axis of the magnet parallel to the axis of the cylinder, the inductor is placed on the cylinder and connected to the switch. 2. Tutorial on π. 1, characterized in that it contains a software mechanism, kinematically connected with the potentiometer engine. 1485292 Phage.1 15 1485292 .