Self-inductive phenomenon demonstration instrument

Abstract

The invention provides a physics teaching instrument. The same set of apparatus can demonstrate a power-on self-inductive phenomenon and a power-off self-inductive phenomenon and can intuitively reflect the directions of self-inductive electromotive force and self-inductive current. The used technical scheme is as follows: a wound enameled coil is sleeved on an inverted U-shaped ferrite core which is symmetric from up to down and can be separated from each other; and two ends of the enameled coil are connected with two LEDs (light-emitting diodes) which are reversely connected in parallel, and a small high-light tube with the work voltage of 2-3V is utilized in each LED. The coil and the LEDs are connected to the circuit, when a switch is turned on or turned off, the current flowing through the coil changes so as to generate the self-inductive electromotive force and the self-inductive current in the coil to act on the LEDs so that the LEDs can alternatively blink. The demonstration instrument has the advantages of simple structure, clear work principle and obvious phenomenon, and a student can start the experiment easily and can obtain the rule of the self-inductive phenomenon by analyzing the experimental phenomenon. Components used in the manufacturing process of the demonstration instrument have low technical parameter requirement, low cost, safety and reliability, and the demonstration instrument has the teaching practicality.

Description

technical field [0001] The invention belongs to the field of physics teaching, in particular to the experimental demonstration of self-induction phenomenon in electromagnetic induction. It is suitable for classroom teaching demonstration and student group experiment use. [0002] Background technique [0003] At present, most of the self-induction experiment teaching in the middle school physics electromagnetic induction chapter uses the "J2446 self-induction phenomenon demonstrator". The demonstrator uses two sets of independent equipment to install the "power-on self-inductance phenomenon" and "power-off self-inductance phenomenon" on the same demonstration board. In order to achieve the demonstration effect, the self-inductance coil is made of enameled wire wound on a larger iron core, so the equipment can only be produced by professional manufacturers, and the cost is high and the volume is large. Especially the power-on self-inductance device requires a higher power ...

AI Technical Summary

Problems solved by technology

In fact, whether the power is on or off, the current flowing through the coil has changed, which will cause the generation of self-inductance electromotive force, and there is self-induction phenomenon; but the original demonstrator can see the self-inductance phenomenon when the power is on. The self-inductance phenomenon when the power is off, those who can see the self-induction phenomenon when the power is off, but cannot see the self-induction phenomenon when the power is on; therefore, the method of separate demonstration is used to make students still have many doubts while accepting new knowledge, which is not conducive to students' understanding of all knowledge. Understanding and acceptance of knowledge points

Furthermore, when the demonstrator demonstrates the self-inductance phenomenon of power-on and power-off, it cannot directly reflect the direction of self-induction electromotive force and self-induction current.

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