What is choke coil
A choke coil is essentially a copy of a coil.The choke coil can be divided into low frequency choke coil and high frequency choke coil.It is used in low frequency circuit and high frequency circuit respectively.
The low frequency choke coil is generally large in size and has an iron core inserted in the coil to increase its inductance.
An FM core is usually inserted into a high frequency choke, or is simply a hollow coil.
In low frequency 100 or dc circuit, the main function of the choke is to prevent the ac component from passing through, so that the dc power supply is more pure.
In an FM circuit, high frequency electromagnetic waves can be prevented from radiating into the circuit, or as a load on the high frequency circuit, from which the desired if signal can be extracted.
Frequency modulation choke and low frequency choke can be used as a divider circuit, such as a large speaker divider.
Both high frequency and low frequency choke coils are inductance coils.The inductance coil has the characteristic of restraining current change, the bigger the inductance is, the more obvious this effect is.This effect on the current impeding action inductance, the magnitude of the inductance and the working frequency of the inductance and its own inductance size.In the old class a audio power amplifier, the low frequency choke coil, its function is "on dc, off ac".
But this ideal cannot be satisfied, and can only be approximated to "on dc, off ac".A small loss of ac components is allowed as long as the amplifier needs are met.The inductance of the choke is greater here.The frequency is certain (the audio range is 20khz-20hz) when the inductance is required to be relatively large.
The action of the common mode choke coil
The common-mode choke coil is essentially a two-way filter: on the one hand to filter out the common-mode electromagnetic interference on the signal line, on the other hand to suppress itself not to send out electromagnetic interference, to avoid affecting the normal work of other electronic equipment in the same electromagnetic environment.Common mode choke coil can transmit differential mode signal, dc and very low frequency common mode signal can pass, and for high frequency common mode noise presents a large impedance, can be used to suppress common mode current disturbance.
Common mode choke characteristics
The common mode choke coil is made of ferrite core with double wires and has the capability of high common mode noise suppression and low differential mode noise signal suppression.In addition, the working frequency impedance is small, the interference frequency impedance is large, the inductance value is stable, and the thermal stability is good.
Application of common mode choke coil
1. Switching power supply noise suppression filter
2. Electrostatic noise filter for power line and signal line
3. Radiation interference suppressor such as converter and ultrasonic equipment
The above is about the choke coil and the use of a simple introduction, I hope you have a certain help;We are specialized in providing radial type nucleus inductor, rod inductor, toroidal coil, etc. Welcome to consult ~
Post time: Apr-13-2020