define

   Absorbing magnetic ring, also known as ferrite magnetic ring, referred to as magnetic ring. As a common anti-interference element in electronic circuits, it has a good inhibitory effect on high frequency noise. Generally, it is made of ferrite material (mn-zn). The magnetic ring has different impedance characteristics at different frequencies. Generally, the impedance is very small at low frequencies. The magnetic ring of jiangmen powder has little effect on the temperature, while the 220V energy-saving lamp needs to reduce the power at high temperature, so the drive current of the audion needs to be reduced, so as to avoid burning the lamp at high temperature and high pressure. At this time, it is necessary to adjust the power properly, and choose zhitong 3K magnetic ring, which is sensitive to the rise of temperature. When the temperature rises, BS rises with the rise of temperature. The drive current of the audion decreases and the lamp power decreases, ensuring the contradiction between the temperature rise and the lamp power.

Selection of magnetic loop turns

   Passing the whole cable through a ferrite magnetic ring constitutes a common mode choke, which can also be wound around the magnetic ring for several turns as required. The higher the number of turns, the better the interference suppression effect on the lower frequency, and the weaker the noise suppression effect on the higher frequency. In practical engineering, the turns of the magnetic ring should be adjusted according to the frequency characteristics of the interference current. Generally, when the frequency band of the interference signal is relatively wide, two magnetic rings can be sleeved on the cable, each of which has different turns, so that both high-frequency and low-frequency interference can be suppressed. From the mechanism of the common mode choke, the higher the impedance, the more obvious the interference suppression effect. And the impedance of the common-mode choke comes from the common-mode inductance Lcm=jwLcm. It is not difficult to see from the formula that, for a certain frequency noise, the greater the inductance of the magnetic ring, the better. This is not the case because there is a parasitic capacitance on the actual magnetic ring, which exists in parallel with the inductance. When encountering high frequency interference signals, the capacitance is small, short-circuiting the inductance of the magnetic ring, which makes the common mode choke lose its effect.