What does a choke do in a DC circuit?

A choke, also known as an inductor, is used to block higher-frequency while passing direct current (DC) and lower-frequencies of alternating current (AC) in an electrical circuit. The name comes from blocking, or “choking”, high frequencies while passing low frequencies.

Why is choke coil preferred over a resistance in AC?

A choke coil is preferred over resistances in a.c. circuit because a choke coil has large value of self inductance and hence, the power dissipation is 0 for choke coil. 1 there will be no effect on the flow of current as resistance is independent of frequency.

What is a DC choke?

A DC link choke is an electrical device that filters and controls the DC bus voltage and current in a variable frequency drive. The function similarly to AC line reactors, in that they smooth the current flow to the VFD and reduce harmonic distortion on the power line.

Why can we not use an ordinary resistor instead of the choke coil?

Why can we not use an ordinary resistor instead of the choke coil? A choke coil is needed in the use of fluorescent tubes to reduce alternating current without loss of power. If we use an ordinary resistor, a.c. will reduce, but loss of power due to heating will be there.

How does an AC choke work?

The choke coil works because it acts as an inductor. When the current passing through changes, as AC currents do, it typically creates a magnetic field in the coil that works against that current. This property, known as inductance, blocks most of the AC current from passing through.

What is choke what are its important application?

A choke is a power magnetics component which is used in electronic circuits. It is an inductor that is utilized to block high-frequency, alternating current (AC) in a circuit while allowing lower frequencies, or direct current (DC), through.

What is the disadvantage of resistance of a choke coil?

It is not useful for very low load currents. There is a loss of power in the series inductor due to its DC resistance. It has low output D.C. voltage than that of π type filter. It becomes costly due to the use of large value of an inductor L and a capacitor C.

What is the best method of reducing current in an AC circuit and why?

increasing the resistance is the best method of reducing current in a circuit bcoc current is inversely proportional to resistance.

Why does inductor block AC and allows DC?

Since inductor behaves like a resistor, DC flows through an inductor. The AC flowing through L produces timevarying magnetic field which in turn induces self- induced emf (back emf). This back emf, according to Lenz’s law, opposes any change in the current. Therefore L blocks AC.

When a fluorescent tube is used in an AC circuit?

A choke coil is needed in the use of fluorescent tubes with ac mains because it reduces the voltage across the tube without wasting much power. An ordinary resistor cannot be used instead of a choke coil for this purpose because it wastes power in the form of heat.

Which is a choke coil connected to AC source?

Some power is dissipated in coil. Now a capacitor is connected in series with the coil and source is same, then average power dissipated in the circuit does not changes. If ratio of inductive reactance of coil and capacitive reactance of capacitor is 1/x then find x.

What is the difference between input choke and output choke?

Input choke is used as filter for VFD input. By which VFD can be saved from disturbance or interference in supply. Output choke is used when cable length is longer then few metres (defer from company to company) For e.g if cable length from VFD…

What is the difference between DC resistance and AC resistance?

But resistance is always associated with DC circuits so to distinguish DC resistance from AC resistance the term Reactance is generally used. Just like resistance, the value of reactance is also measured in Ohm’s but is given the symbol X, (uppercase letter “X”), to distinguish it from a purely resistive value.

What are the advantages of VFD with output choke?

By which VFD can be saved from disturbance or interference in supply. Output choke is used when cable length is longer then few metres (defer from company to company) For e.g if cable length from VFD to pump is 300 meters then there will be cable capacitance which can back fire toward drive, to protect this output choke is installed.

What is the opposition to current flow through a coil?

Now in an AC circuit, the opposition to current flow through the coils windings not only depends upon the inductance of the coil but also the frequency of the AC waveform. The opposition to current flowing through a coil in an AC circuit is determined by the AC resistance, more commonly known as Impedance (Z), of the circuit.