1. What is magnetic fluid
Magnetic fluid (also known as ferromagnetic fluid or magnetic fluid) is a brownish black liquid magnet, which is formed by uniformly suspending magnetic particles with a diameter of about 10 nm in the synthetic oil carrier.
2. Brief history of magnetic fluid
Magnetic fluid comes out with mystery. It was classified as highly confidential. In order to solve the problem of fuel flow and control of liquid rocket under weightlessness in space program, magneto - hydraulic technology was developed. Magnetohydraulic technology was removed only after solid fuel rocket technology matured and replaced liquid rocket technology. After more than 30 years of development, magnetic fluid has been widely used in speaker manufacturing, stepping motor, large power transformer, audio and video tape manufacturing, computer hard disk and floppy disk manufacturing, etc.
3. Efficacy of magnetic fluid
Adding magnetic fluid into the gap formed by the PA loudspeaker T-iron and the loudspeaker Voss will obviously increase the bearing capacity of the loudspeaker and prolong the life of the loudspeaker. Generally speaking, the bearing capacity of loudspeakers is restricted by the heat resistance of voice coils. The higher the power, the greater the heat generated, resulting in a sharp rise in voice coil temperature. The voice coil will be burned. However, the thermal conductivity of the magnetic fluid is far greater than that of the air. It can emit heat energy into the air through T-iron, filigree, and pot rack, thus preventing the voice coil from burning, delaying the aging of voice coil materials and adhesives, and thus extending the life of the horn speaker.
Improved frequency response and reduced distortion. The magnetic fluid has damping characteristics. The loudspeaker has a peak value on the frequency response curve near its resonant frequency (f0), which is distorted due to the excessive amplitude of the diaphragm. This is a defect that speaker manufacturers hope to overcome. The frequency response curve of loudspeaker at f0 can be smoothed by using the damping effect of magnetic fluid with proper viscosity on voice coil movement. Therefore, the frequency response characteristic is improved, and it is beneficial to the design of frequency divider circuit. Magnetic fluid has centering function, which can prevent large friction of voice coil.
