Introduction to electromagnets
Electromagnet definition and working principle: The magnetic field generated by the coil electrification attracts or repeals the magnetic parts and the external mechanical work device called electromagnet, which uses the principle of electromagnetic induction to convert electrical energy into mechanical energy, can directly achieve linear movement, rotation, swing and linear plus rotation composite motion, in industrial automation is quite popular today, electromagnet has been widely used in all kinds of automatic devices.
Second, the typical structure of electromagnets
A linear electromagnet is a pull device in the sense that it moves the load towards the core when it is energized. However, if a top rod is installed in the section of the pole and passes through the hole deep in the core, when it is sucked in, the top rod will be extended away from the core to push the external load a specified distance, so the electromagnet can provide force and pull.
Third, the electromagnet magnetic field direction determination
Magnetic field direction determination: According to ampere's right hand rule, the direction of the magnetic field generated by the current cycle can be determined by using the right hand rule, which considers the direction of the four fingers outside the thumb bending to the palm as the direction of the current, then the direction pointed by the thumb is the North Pole of the magnetic field.
Four, electromagnet terminology
1. Force: the thrust or pull force and suction generated by the electromagnet coil after it is energized;
2. Stroke: the distance from the starting point of slide rod movement to the final stopping position;
3. Holding force: the pull or thrust of the slide rod at the end of the stroke;
4. Working cycle: the ratio of the sum of power-on time and power-off time;
5. Continuous power: 100% working cycle;
6. Gap working cycle: less than 100% of the working cycle, it has a maximum allowable power time so that its temperature is not too high;
7. Remanence: the magnetic force remaining after the electromagnet is cut off;
8. Coil maximum operating temperature: coil maximum operating temperature can not adversely affect the organization and function of the material, this temperature is the sum of ambient temperature and coil temperature rise, usually 130 degrees Celsius;
9. Ampere-turns: the product of current and coil turns;
10 Response time: The time for the slide rod to pull into place after the power is switched on.