What is impedance?
Also known as nominal impedance. The impedance is the AC resistance of the coils of loudspeakers and headphones in ohms. Since impedance depends on the frequency, it is always specified at a frequency of one kilohertz. If you take a look at the offerings of dynamic headphones, you will find a very wide range of impedances. The spectrum ranges from 16 ohm headphones to 600 ohm headphones. Where does this wide range come from? And which headphones are suitable for what applications? In order to get to the bottom of these questions, a power evaluation method must first be established. The basic task of the headphone is to convert the arriving electrical signal into sound pressure. The extent that this succeeds is described by the nominal sound pressure level of the headphones. This value (specified in the unit dB SPL) describes how high the generated sound pressure is when 1 mW of electrical power is supplied. If you take a look at the nominal sound pressure level of similar headphones wi
A. Impedance is defined as the vector sum of resistance and reactance which limits the current flow in an AC circuit. When dealing with a transformer, impedance indicates the current limiting effect should you have a short circuit on the secondary. Expressed as a percentage and usually designated as %IZ, impedance along with X/R ratio is used for coordination of fuses and/or circuit breakers. It is also used for calculating the proper interrupting rating of overcurrent protection devices.
If you pretend that the signals in electric circuits are of the form A*exp(s*t), where A and s are constants, and t is time, then derivatives of the signal and integrations of the signal are always just a scaled version of the signal. So, the ratio of voltage to current, when the signals are of this form, is just a (possibly complex) constant. This number is called impedance, and it depends on the value of the constant “s” in the signal.
And why does it do those terrible things? Beginners with electronics get down Ohm’s law pretty quickly. The concept that Voltage, Current, and Resistance to electrical flow are related by the simple expression V=IR seems to set pretty easily. They usually learn about capacitors and inductors as “something else”, not like resistors at all, but as perhaps a way to store energy or filter some frequencies from others. But sooner or later, they run up against the need to understand the effect of source impedance and/or load impedance, and things get un-simple quickly. Impedance seems to become a vague concept of something like electrical strength or drive capability, not simple at all, especially if the impedance in question involves capacitors or inductors, or (ugh!) both. It’s not that complicated. Impedance is the generalization of the concept of resistance from DC to AC. That is, it’s a way to represent how much current will flow with a specified (AC) voltage across the impedance. That
Impedance is the resistance found in all circuits where alternating current is used. Electrically, impedance is made up of three components- DC resistance, inductance and capacitance. The inductance and capacitance can be added directly when converted to like units. One is positive and the other negative. The result of the quantity is then added vectorally to the resistance. (Vectoral addition is done the same way that sides are added to a triangle when trying to obtain the hypotenuse.) The impedance of most ordinary transformers runs between 3% and 6%. Very low impedance transformers tend to give better regulation. If the secondary of the transformer should be accidentally short-circuited and the impedance of the transformer is low, there would be a very high current flow on both the primary and secondary windings. This may cause mechanical displacement of the windings and a short circuit between adjacent turns. With a transformer that had an impedance of 5% and the secondary short ci
