DC electromagnet, the presence or absence of electromagnetic field can be controlled by on/off current, which includes an iron core, armature mechanism, excitation coil (L), and excitation coil (L) wound around the iron core.

A direct current electromagnet, which includes an iron core, an armature mechanism, and an excitation coil (L). The excitation coil (L) is wound around the iron core, and is characterized in that the excitation coil (L) is connected in series with a positive temperature coefficient thermistor (RT) and connected to a direct current power supply (DCV). The utility model can save a large amount of electrical energy in use.

Electromagnets have many advantages: the presence or absence of electromagnetic field can be controlled by on/off current; The strength of the magnetic field can be controlled by the strength of the current or the number of turns in the coil (or by controlling the size of the iron core); Its magnetic poles can be controlled by changing the direction of the current, and so on. That is, the strength of the magnetic field can be changed, the presence or absence of the magnetic field can be controlled, the direction of the magnetic poles can be changed, and the magnetic field can disappear due to the disappearance of current.