The difference between impedance and complex impedance resistance

The difference between impedance and complex impedance is as follows:

1. Conceptual differences:

The ratio of the voltage at both ends of a passive branch to the current in it is called the complex impedance of the branch, and the unit is in ohms ( ), which is a physical quantity that reflects the electrical properties of a passive circuit or a passive network at both ends.

In circuits with resistance, inductance, and capacitance, the impedance that acts as a hindrance to the current in the circuit is called. The impedance is commonly represented by z and is a complex number, the real part is called resistance, and the imaginary part is called reactance.

2. The difference in phasor:

Impedance is the magnitude of the complex impedance. The impedance is not a phasor and its magnitude is z= (r +x). When you only need to calculate the magnitude of the current, you can use the impedance.

The complex impedance is a phasor, which not only has a magnitude, but also an amplitude angle (i.e., the impedance angle, which is also the power factor angle), =arctgx r. When the phase of the current and voltage needs to be considered, the compound impedance must be used.

3. The difference between the promotion content:

The concept of complex impedance can be generalized to any passive two-terminal network, and the ratio of complex voltage to complex current on the passive two-terminal network is called the complex impedance of the passive two-terminal network, and the table is z=u i. where u is the voltage complex rms value between the two lead-out terminals of the passive two-terminal network; i is the complex rms value of the current through the two-terminal network.

The complex impedance reflects both the magnitude of the impedance of the circuit (expressed in the mode of the complex impedance) and the phase difference between the voltage and the current on the circuit (expressed in the radial angle of the complex impedance). So complex impedance has more content than impedance.

This is an AC circuit, the voltage and current impedance are complex numbers, and there should be two parts of modulus and amplitude angle in the calculation and description, so of course there must be an angle in the result.

Impedance is the abbreviation of resistance and reactance, it has a variety of expressions, and complex impedance refers to the complex expression of impedance.

Impedance is strictly all the resistance to current in a circuit and is measured in ohms. Complex impedance is not only the resistance in the ideal state (pure resistance), but also capacitive and inductive reactance. The complex impedance of a capacitor refers to the capacitive reactance. zc=1/woc

There is no difference, the complex impedance is the impedance z x r. Resistance r, reactance x 2*pi*f*l 1 (2*pi*f*c).

1. Impedance is often expressed in the form of a plural number, z=r+jx (in units ).

2. where the real part r is the resistance (in units).

3. The imaginary part is composed of capacitive reactance and inductive reactance, (capacitance c, unit f.) Capacitive reactance xc in . Inductance l in h. Inductive reactance XL in . ）

4. Since the capacitive reactance and the inductive reactance are two opposite quantities in the vector (the electrical angle is 180 degrees apart), we have x=(xl-xc).

5. Capacitive reactance xc = 1 C, inductive reactance xl = l, where: angular frequency = 2* *f, f is the frequency. Therefore, the magnitude of the inductive reactance or capacitive reactance value is not only related to the size of the inductance or capacitor itself, but also related to the working frequency in the circuit where they are located, for example, the working frequency of China's power grid is 50 cycles, while the United States is 60 cycles, so although the values of resistance, inductance, and capacitance are the same, the calculated inductive reactance, capacitive reactance, and impedance are different.

6. So we get the complex impedance of: z=r+j(xl-xc), and his modulus (scalar) z =(r 2+x 2).

Impedance is a quantitative measure of the ability to block the flow of electric current. Taking the highway as an example, the wider and flatter the road, the more complex the impedance, containing two parts: the resistance is the real part, and the inductive reactance and capacitive reactance are commonly called reactance.

Resistance refers to the resistance of a linear element (not an energy storage element) to the current, i.e., r=u i

The reactance refers to the resistance of nonlinear components (energy storage elements) to the current in the AC state, such as the inductive reactance of the inductive element and the capacitive reactance of the capacitive element.

Resistance, because of the hindering effect of the substance on the electric current, so it is called the resistive substance under the action.

In circuits with resistance, inductance, and capacitance, the impedance that acts as a hindrance to alternating current is called impedance.

In physics, resistance is used to express the magnitude of a conductor's resistance to an electric current. The greater the resistance of a conductor, the greater the resistance of the conductor to the current. The resistance of different conductors is generally different, and resistance is a characteristic of the conductor itself.

A resistive element is an energy-dissipating element that hinders the current current. The magnitude of the resistance value of the resistive element is generally related to the temperature, and the physical quantity that measures the magnitude of the resistance affected by temperature is the temperature coefficient, which is defined as the percentage of the change in the resistance value for every 1 increase in temperature. Resistors are used in all electronic circuits.

Resistance Units In circuits with resistance, inductance, and capacitance, the impedance that acts as a barrier to alternating current is called impedance. The impedance is commonly represented by z, which is a complex number, the real part is called resistance, and the imaginary part is called reactance, in which the obstructive effect of capacitance on alternating current in the circuit is called capacitive reactance, the obstructive effect of inductance on alternating current in the circuit is called inductive reactance, and the obstructive effect of capacitance and inductance on alternating current in the circuit is collectively called reactance. The unit of impedance is ohm.

Impedance is the sum of resistance and reactance on a vector.

Impedance is the sum of resistance and reactance on a vector. For a specific circuit, the impedance is not constant, but changes with frequency. In resistor, inductive, and capacitive series circuits, the impedance of the circuit is generally greater than the resistance.

That is, the impedance is reduced to a minimum. In inductive and capacitor parallel circuits, the impedance increases to the maximum value during resonance, as opposed to series circuits.

Resistance calculation formula.

1) r = l s (where the resistivity of the resistor is determined by its own properties, l is the length of the resistor, and s is the cross-sectional area of the resistance).

2) Definition: r=u i

3) Total resistance in series circuit: r=r1+r2+r3+......rn4) total resistance in parallel circuit: 1 r=1 r1+1 r2+......1 rn5) find the resistance by the electrical power: r=u p; r=p/i²

1. Relationship.

In AC circuits, in addition to resistors, inductors and capacitors have the effect of blocking the current, and the part that usually prevents the AC current from acting is called the impedance.

2. Differences. Resistance is the value in the pure DC state, and resistance is the total value of DC resistance plus AC reactance.

ImpedanceIn circuits with resistance, inductance, and capacitance, the impedance that acts as a hindrance to the current in the circuit is called impedance. The impedance is commonly represented by z, which is a complex number, which is actually called resistance, and the virtual response is called reactance, in which the obstruction effect of capacitance on alternating current in the circuit is called capacitive reactance, the obstruction effect of inductance on alternating current in the circuit is called inductive reactance, and the obstruction effect of capacitance and inductance on alternating current in the circuit is collectively called reactance. The unit of impedance is ohms.

The concept of impedance exists not only in electrical circuits, but also in mechanical vibration systems.

Resistance is abbreviated as R, which is a basic property of a conductor and is related to the size, material, and temperature of the conductor. Ohm's law states that the relationship between voltage, current, and resistance is i=u r, i.e., r=u i. The basic unit of resistance is the ohm, which is represented by the Greek letter " ".

Usually "resistance" has two meanings, one is the physical quantity of "resistance" in physics, and the other refers to the electronic component of resistance. The resistance value of the resistive element is generally related to the temperature, material, length, and cross-sectional area, and the physical quantity that measures the influence of the resistance by temperature is the temperature coefficient, which is defined as the percentage of the change in the resistance value for every 1 increase in temperature. The main physical characteristic of the resistor is that it transforms electrical energy into thermal energy, which can also be said to be an energy-dissipating element, and the internal energy is generated when the current passes through it.

Resistors usually play the role of voltage division and shunt in circuits. For signals, both AC and DC signals can pass through resistors.

Difference Between Impedance and Resistance:

1. The nature is different

ImpedanceIn circuits with resistance, inductance, and capacitance, the impedance that acts as a hindrance to the current in the circuit is called impedance.

Resistor: The resistor is a current-limiting element, after the resistor is connected to the circuit, the resistance value of the resistor is fixed, generally two pins, which can limit the amount of current through the branch it is connected to.

2. Influencing factors

Impedance: The ratio of the peak voltage (or RMS) um at both ends of a passive circuit in an AC circuit to the peak current value (or RMS value of the spine) IM through the circuit is called impedance, which is expressed by Z and is in ohms ( ) In the case of U, the larger Z is, the smaller I is, and the impedance has a limiting effect on the current.

Resistance: The resistance value of the resistive element is generally related to the temperature, material, length, and cross-sectional area, and the physical quantity that measures the resistance affected by temperature is the temperature coefficient, which is defined as the percentage of the resistance value change when the temperature rises by 1.

3. Difference in role

Impedance: In audio equipment, impedance is an important parameter that is often mentioned. For example, the impedance of the amplifier and the horn is mostly designed to be 8 ohms, because at this impedance value, the machine has the best working condition.

In fact, the impedance of the speaker is changed with the different frequencies, and the speaker specifications are usually marked with a rough average value, and most of the products on the market are four ohms, six ohms or eight ohms.

Resistance: If the resistance value of a resistor is close to zero ohms (e.g., a large cross-section wire between two points), then the resistor has no blocking effect on the current, and the circuit of the resistor connected in parallel is shorted and the current is infinite. If a resistor has an infinite or large resistance, the circuit connected in series to the resistor can be considered an open circuit with zero current.

To put it simply, impedance is resistance plus reactance, so it is called impedance; In the general state, the conductor has the effect of blocking the flow of current, and the one that indicates the degree of resistance is called resistance, and the unit value is ohm, and the code is

In AC circuits, in addition to resistors, inductors and capacitors have the effect of blocking the current, and the part that usually prevents the AC current from acting is called the impedance.