"Electromagnetic Relay and Automatic Control" Electromagnet and Automatic Control PPT Courseware 2

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"Electromagnetic Relay and Automatic Control" Electromagnet and Automatic Control PPT Courseware 2

1. Understanding electromagnetic relays

Please write the Chinese name of each component in the corresponding position on the picture.

Activity 1 Observe electromagnetic relays

The function of the main parts:

Electromagnet: When energized, it generates magnetism and attracts the armature.

Armature: and the movable contact form a lever that rotates around the fulcrum, driving the movable contact to move up and down.

Return spring: When the magnetism of the electromagnet disappears, it drives the armature to bounce away from the electromagnet.

Contact: equivalent to the switch of the controlled circuit (A, C static contacts, B: moving contacts)

Automatic control using electromagnetic relays

Working principle of electromagnetic relay:

When energized, the electromagnet generates magnetism and attracts the armature to move toward... (working conditions of electrical appliances);

When the power is off, the electromagnet loses its magnetism and the armature moves toward due to elasticity... (working conditions of electrical appliances)

Connection of electromagnetic relay circuit

1. Connect the control circuit

2. Connect the working circuit

A. Connect the two static contacts in series with the power supply and electrical appliances.

B. The moving contact is connected in series with one pole of the power supply and the switch.

The upper and lower static contacts connect the corresponding electrical appliances to the other pole of the power supply.

Use what you learn

1. Use electromagnetic relays to control high-voltage switches. Its main function is ( ).

A. Save electricity B. easy to use

C. Protect electrical appliances D. avoid danger

2. The main function of the electromagnetic relay is equivalent to ( ) in the working circuit

A. Power supply b. Electrical appliances

C. switch D． wire

3. The physical principle based on the electromagnetic relay is ( )

A. The effect of magnetic field on current B. magnetic effect of electric current

C. Interaction of charges D. None of the above statements are correct

Apply what you learn and believe in yourself

1. The picture is the schematic diagram of an automatic temperature alarm. Make a (fill in "alcohol", "kerosene" or "mercury") thermometer and insert a piece of metal wire. When the temperature reaches the temperature pointed by the lower end of the metal wire, the electromagnet It has ____, which attracts the armature and causes the bell to send out an alarm signal. Please mark the "+" and -" poles of the power supply in the control circuit according to the polarity of the electromagnet in the picture.

2. The picture below is an anti-theft alarm designed by Xiaoqiang for a warehouse during a research study activity. The pedal is placed at the door of the warehouse, and the bell and light bulb are placed in the duty room. Observing the circuit, we can see that the working principle of this alarm is: ________ when someone steps on the pedal; ________ when no one steps on the pedal.

3. A classmate designed an "overheating automatic alarm circuit" using PTC resistors: Install the PTC resistor where the temperature needs to be detected. When the ambient temperature is normal, the indicator light will turn on; when the ambient temperature exceeds the Curie point temperature of the PTC resistor, Due to the change in resistance, the magnetism of the electromagnet weakens, causing the alarm to sound. Please help him connect the circuit in the picture completely.

(PTC: a new type of semiconductor ceramic material. Below a certain temperature (Curie point temperature), its resistance decreases as the temperature increases. Above this temperature, the resistance increases as the temperature increases.)

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For more information about the PPT courseware "Electromagnets and Automatic Control Electromagnetic Relays and Automatic Control", please click the Electromagnets and Automatic Control ppt Electromagnetic Relays and Automatic Control ppt tag.

"Electromagnetic Relays and Automatic Control" Electromagnets and Automatic Control PPT courseware:

"Electromagnetic Relays and Automatic Control" Electromagnets and Automatic Control PPT Courseware Review 1. What parts does an electromagnet consist of? Coil, iron core 2. What factors are related to the magnetic strength of electromagnet? Number of coil turns, current size 3. List application examples of electromagnets. ..

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Update Time: 2024-10-22

This template belongs to Physics courseware Guangdong and Shanghai Edition Ninth Grade Physics Volume 2 industry PPT template

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