The different impedances: resistor, inductor, capacitor

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Resistance

     A lamp filament, the heating wire of a toaster or an auxiliary electric heater, etc. constitute pure resistances R. All the energy provided by the source is fully converted into heat. We talk about heating by Joule effect.

    A resistor slows down, opposes the passage of current. The importance of this brake is measured in Ohms (Ω).

   In this type of impedance, the generated current is always in phase with the voltage. From there, the vector representation shown below:

 

Inductance

A coil of conductive wire constitutes an inductance, also called "self" or "inductive reactance". It is found in motors (windings), in fluorescent tube ballasts, etc. This coil constantly reacts to variations in the current flowing through it, following a magnetic phenomenon. If this coil (considered as a pure choke) is subjected to a direct current, it will have no effect on this one. If, on the other hand, we want to make it pass current of variable intensity (this is the case in alternating circuits), it will react by opposing a resistance to the passage of the current.

The importance of this brake is measured by the value of the inductance L, expressed in Henry.

This type of impedance will have a second effect on the current: a coil delays the current with respect to the voltage. It is said to phase out the current. Thus, a pure inductance will see its current phase shifted by 90° lagging behind the voltage.

Here is the vector representation of this property:

Capacitor

A capacitor, also called "capacitance" or "capacitive reactance", is a reservoir of electrical charges. If subjected to the voltage of a generator, it will accumulate charges. These loads will be returned to the grid when the supply voltage decreases. If it is an alternating voltage, the capacitor charges and discharges at the rate of the alternating frequency...

The value of a capacitor C is expressed in Farad.

This type of impedance will also have an effect of phase shifting the current with respect to the voltage, but this time the current is phase shifted ahead of the voltage by 90°.

Here is the vector representation of this property:

 

Resistance

     A lamp filament, the heating wire of a toaster or an auxiliary electric heater, etc. constitute pure resistances R. All the energy provided by the source is fully converted into heat. We talk about heating by Joule effect.

    A resistor slows down, opposes the passage of current. The importance of this brake is measured in Ohms (Ω).

   In this type of impedance, the generated current is always in phase with the voltage. From there, the vector representation shown below:

 

Inductance

A coil of conductive wire constitutes an inductance, also called "self" or "inductive reactance". It is found in motors (windings), in fluorescent tube ballasts, etc. This coil constantly reacts to variations in the current flowing through it, following a magnetic phenomenon. If this coil (considered as a pure choke) is subjected to a direct current, it will have no effect on this one. If, on the other hand, we want to make it pass current of variable intensity (this is the case in alternating circuits), it will react by opposing a resistance to the passage of the current.

The importance of this brake is measured by the value of the inductance L, expressed in Henry.

This type of impedance will have a second effect on the current: a coil delays the current with respect to the voltage. It is said to phase out the current. Thus, a pure inductance will see its current phase shifted by 90° lagging behind the voltage.

Here is the vector representation of this property:

Capacitor

A capacitor, also called "capacitance" or "capacitive reactance", is a reservoir of electrical charges. If subjected to the voltage of a generator, it will accumulate charges. These loads will be returned to the grid when the supply voltage decreases. If it is an alternating voltage, the capacitor charges and discharges at the rate of the alternating frequency...

The value of a capacitor C is expressed in Farad.

This type of impedance will also have an effect of phase shifting the current with respect to the voltage, but this time the current is phase shifted ahead of the voltage by 90°.

Here is the vector representation of this property: