Earthquake Alarm

   The earliest seismometer - the seismometer was invented by Zhang Heng. The seismometer is cast in copper and shaped like a wine jar, with eight dragon heads around it, facing the eight directions of east, south, west, north, southeast, southwest, northeast, and northwest. The dragon mouth is movable, each holding a small copper ball. Below each dragon head, there is a copper toad with its mouth wide open, and in the center of the instrument, there is a copper "pendulum suspended". There are eight channels beside the column, called "eight paths", and there are also clever mechanisms. After the year of the Gregorian calendar,134The earthquake test in the southwest of Gansu Province in the year completely confirmed its accuracy in detecting earthquakes. It was earlier than the similar seismometer created in Europe.1700Over the years. Unfortunately, the seismometer from the Eastern Han Dynasty has been lost, and the seismometers we see are all reconstructions based on historical records by later generations.

Experimental Cognition

  Battery box: As the name suggests, it is a box used to install and fix the batteries, which is a device for outputting battery power.

LEDLamp:LED(Light Emitting DiodeLED, which stands for Light-Emitting Diode, is a solid-state semiconductor device that can directly convert electricity into light.LEDThe heart of a computer is a semiconductor chip, which is attached to a support at one end and is one end of the anode, while the other end is connected to the positive pole of the power supply, enabling the entire chip to be encapsulated in epoxy resin. The semiconductor chip is composed of three parts, one part isPP-type semiconductor, in which holes dominate, and the other end isNType of semiconductor, over here it's mainly electrons, and in the middle it's usually1to5A quantum well within a certain period. When an electric current passes through the wire and acts on this chip, electrons and holes will be pushed towards the quantum well. Within the quantum well, electrons and holes will recombine, and then they will emit energy in the form of photons, which is known asLEDThe principle of light emission. The wavelength of light, which is also the color of light, is determined by the formation.P-NThe material of the knot determines it.

    Resistance: The resistance of a conductor to the flow of current is called resistance!Factors Affecting the Size of ResistanceLength, cross-section, area, material, temperature, related, general metal materials, with the temperature riseHigh and growing larger.

  Speaker: It's a very simple principle. It uses a mouth to output square waves, and when these waves are input into a buzzer, it will produce sound. By controlling the frequency and duration of the square waves, it can also produce simple music.

Experimental steps:

1.Experimental Preparation: Understanding Experimental Equipment:Screw hole plate, resistance, wire, LEDLamps, battery box, speaker, screwdriver, and pliers.

Experiment Report: When shaking the small model, the glass beads will touch each other.OShaped ring, circuit is connected.LEDBlink, and the buzzer emits a beeping sound.

Installation Manual