DC Electromagnetic Chuck
Excitation Method: Powered by direct current (DC), with a constant current direction.
Magnetic Field Characteristics: The magnetic field is stable and without fluctuations; the magnetic flux density (B) remains constant, and the magnetic field lines are evenly distributed.
Once the magnetic circuit is closed, the attractive force remains constant and does not change over time.
Key Design Considerations for Magnetic Circuit: Eddy current losses caused by alternating magnetic fields do not need to be considered; the core can be made of a single piece of high-permeability material (such as pure iron) or a laminated design.
AC Electromagnetic Chuck
Excitation Method: Powered by alternating current (AC), with the current magnitude and direction changing periodically according to a sinusoidal law (e.g., 50Hz/60Hz).
Magnetic Field Characteristics: The magnetic field strength fluctuates periodically with the current, and the magnetic flux density changes sinusoidally, resulting in pulsating attractive force.
While the peak attractive force is comparable to that of DC, the average attractive force is approximately 70%~80% of the peak value.
Key points of magnetic circuit design: To reduce eddy current losses, the core must be made of thin silicon steel sheets (e.g., 0.35mm thick) and coated with insulating varnish.
