How does RL high pass work?
Hi, I have a problem understanding how exactly an RL (or CR) high pass filter works.
The structure is quite simple, R and L in a series but L parallel to the output voltage or voltmeter
XL becomes larger the higher the frequency of UE
My question now is:
Low frequency:
Ue experiences a voltage drop across the resistor. Since I have the setup shown in the diagram above, the same voltage is now present at both L and my voltmeter.
High frequency:
Ue experiences the same voltage drop across the resistor as before, but XL increases significantly.
However, the wiring is such that (according to my logic) I measure the same voltage at L and Ua….
So specifically, how does my output voltage increase if my XL also increases?
(1 votes)
Loading...
You compare the output of the circuit with the output itself. Of course you always have the same. The voltage across L, no matter what Ue is, is always the output variable Ua.
The high pass is a passage for high frequency input voltages. It thus functions as a filter for deep signals. The opposite would be a low pass that lets deep signals pass and filters high again.
The arrangement is nothing more than a voltage divider in which the voltage is applied once to R and once to L or XL split.
How much the division is depends on the frequency due to XL=jwL. When this is high, XL rises and when XL rises, a higher voltage is present above it.
Language spoken: The “curve” at the second resistance of the series connection is very high, so that the pressure increases.
Thus, at high XL, which you only have at high frequencies, you have a high output voltage or it is closer to what is present at the input. Thus, the input signal could pass “impacter”.
In the case of low signals, XL becomes smaller so that the “pressure” can be reduced more easily. Why? Because XL is small and does not represent a large hurdle for what walks through the entrance. There is little hanging at the output.
hmm okay, I can start with something thanks.
But so that I get the right, the voltage always splits up depending on the size of the resistance. In the case of large XL, higher voltage at L.
Is there somehow a quick explanation or something you can read about why the tension is split? This is kind of hard to understand
Voltages in a series circuit split up. Whether the series circuit consists of ohmic, inductive or ohmic/inductive/capacitive resistors.
In addition, the same amount of current flows through all elements in a series connection. A current flow through a resistor, whether ohmic or inductive or capacitive, causes a voltage drop across this resistor. The voltage “over” or “on” to measure a resistance always means that you measure the voltage drop across this element.
You de facto measure the potential difference.
In addition to the other two responses, the transmission function (frequency-dependent voltage division) can also help in understanding:
H=Uaus/Uin=jwL/(jwL+R) with w=2Pi*f
jwL is of course the impedance of the coil. The formula follows from the voltage divider rule.
I don’t understand where you see a problem.