1, the role of current blocking: coil self-induced electromotive force in the coil is always with the coil current changes against. Mainly can be divided into high-frequency current-blocking coil and low-frequency current-blocking coil.
2, tuning and frequency selection: inductive coil and capacitor in parallel can be composed of LC tuned circuit. That is, the circuit's intrinsic oscillation frequency f0 and non-AC signal frequency f is equal, the circuit inductive reactance and capacitive reactance is also equal, so the electromagnetic energy in the inductor, capacitor oscillation back between, this is the resonance phenomenon of the LC circuit.
The use of chip inductors: mainly used in consumer electronics, medical equipment, computer products and peripherals, network xDSL filter, modem, GPS, DC-DC converter, step-up/step-down converter, amplifiers, audio-visual equipment, audio equipment, noise filters, power supplies, analyzers, monitors, switching regulators, SCR and TRIAC. control circuits, automation systems, EMI/RFI choke filters, speaker servo networks, input filters, voice processors, SMPS and switching AC adapters, amplifiers, and more.
Two, chip inductors how to measure the good and bad
1, first we need to make a label on the chip inductor. Do marking method a *** there are two kinds, one is the straight marking method, the other is the color marking method. Straight labeling method: in the inductor coil shell directly with digital and text marking the inductance of the inductor coil, the allowable error and the maximum operating current and other major parameters; color-coded method: that is, the inductance with a color ring, the unit of mH, the first two said that the effective number, the third said that the multiplier, and the fourth for the error.
2, then we need a multimeter. The multimeter will be played to the beeping secondary tube file, put the pen on both ends, observe the multimeter readings. Normal chip inductor reading should be zero, if the multimeter reading is large or infinity means that the chip inductor has been damaged. For inductors with more turns and finer diameter coils, the readings will be in the tens or tens of hundreds, and usually the DC resistance of the coil is only a few ohms. Damage is also manifested as hot or inductive magnetic ring is obviously damaged, if the inductor coil is not very serious damage, and can not be determined, the inductance meter can be used to measure its inductance or use the replacement method to determine.