Excavator parts EC55 pilot safety lock rotating solenoid valve coil

Function of coil

1. Current-blocking effect: The self-induced electromotive force in the inductor coil always counteracts the current change in the coil. The inductance coil has a blocking effect on AC current, and the size of the blocking effect is called inductance xl, and the unit is ohm. Its relationship with inductance L and AC frequency F is xl=2πfl. Inductors can be mainly divided into high-frequency choke coils and low-frequency choke coils.

2. Tuning and frequency selection: an lc tuning circuit can be formed by connecting an inductance coil and a capacitor in parallel. That is, the natural oscillation frequency f0 of the circuit is equal to the frequency f of the non-alternating signal, so the inductive reactance and capacitive reactance of the circuit are also equal, so the electromagnetic energy oscillates back and forth in the inductance and capacitance, which is the resonance phenomenon of the lc circuit. At resonance, the inductive reactance and capacitive reactance of the circuit are equivalent and opposite. The inductance of the total current in the loop is the smallest, and the current is the largest (referring to the AC signal with F = "F0"). The lc resonant circuit has the function of frequency selection, which can select the AC signal with a certain frequency F..

As far as the conductivity of the coil is concerned, why is copper coil better than aluminum coil? First of all, in terms of conductivity, the conductivity of aluminum is lower than that of copper. In order to keep up with copper coils, aluminum magnetic wires may need a larger cross section so that they can provide the same level of conductivity. That is to say, compared with the copper coil of the same size, the winding wound with aluminum wire needs more volume.

Secondly, in terms of chemical properties, the oxidation rate of aluminum is much faster than that of other metals. If aluminum powder is exposed to air, it will be completely oxidized in just a few days, leaving a fine white powder. Therefore, in order to make proper connection to ensure good conductivity, it is necessary to pierce the oxide layer of aluminum electromagnetic wire to prevent further contact between aluminum and air. Finally, from the perspective of cost-effectiveness, coil aluminum with the same performance needs more turns and larger diameter wires, which is more expensive and less economical than copper coil.