Electromagnetic induction timing door

Abstract

An electromagnetic induction timing gate includes a container, a timer, a first circuit and a second circuit. The first circuit and the second circuit have the same structure, and both include an oscillator, an amplifier circuit and a NE555 chip. The inductor of the oscillator of the first circuit The coil is wound around the upper part of the container, and the inductance coil of the oscillator of the second circuit is wound around the lower part of the container. The present invention uses an oscillation circuit to form an inductor by winding the coil around the container, and adjusts the component parameters to make the oscillator work normally. When the metal ball When passing through the inductor coil, the inductance of the inductor coil changes, destroying the oscillation conditions, making the oscillation amplitude smaller or stopping the oscillation. According to this amplitude change, an appropriate level is output after amplification and shaping, and is transmitted to the timer, thereby achieving The purpose of timing is to reduce the accuracy requirements required for ball delivery, simplify the test operation, and improve the success rate of the test.

Description

technical field [0001] The invention belongs to the technical field of teaching and scientific research, and relates to the measurement of liquid viscosity coefficient, in particular to an electromagnetic induction timing gate. Background technique [0002] Liquid viscosity coefficient is an important parameter to characterize the ability of liquid to resist deformation, and has important applications in production, life, engineering technology and medicine. There are many methods for measuring the viscosity coefficient, such as falling ball method, capillary method, rotating drum method, etc. Among them, the falling ball method is the most basic method, and the method of measuring the viscosity coefficient of a liquid by the falling ball method is only suitable for measuring the viscosity coefficient. Transparent or translucent liquids, such as castor oil, glycerin, etc., but because of the obvious physical phenomena, intuitive principles, and more experimental operations a...

AI Technical Summary

Problems solved by technology

[0003] The falling ball method experiment requires the ball to fall along the central axis of the container, and the time for the ball to pass through a certain distance at a uniform speed is measured through the photogate, so as to reflect the viscosity coefficient of the liquid. Narrow, requires the metal balls to be placed along the axis of the oil barrel (that is, aligned with the photoelectric gate), which is difficult to control and the success rate of operation is not high

Images