It’s like having a bouncer at a club for sound waves if your frequency is too high, you get turned away at the door (or in this case, filtered out).

So how does it work? Well, let me explain with some examples. Imagine we have an input signal that looks something like this:

[insert graph of a sine wave]

This signal has both low and high frequencies, but our two pole filter is only going to allow the lower ones through. To do this, we’re going to use two capacitors (C1 and C2) and two resistors (R1 and R2). The capacitors act as “storage tanks” for electrical charge, while the resistors control how quickly that charge flows in or out of the circuit.

Here’s what our filter looks like:

[insert diagram of a two pole low pass filter]

The input signal (Vin) enters at the top and gets split into two branches by R1. One branch goes through C1, while the other goes straight to ground. The output signal (Vo) is taken from the bottom left corner where both branches meet again after passing through their respective components.

Now how this filter affects different frequencies of our input signal. For low frequencies (like the ones we want to keep), the capacitors act as open circuits and allow them to pass through without any resistance. This means that they won’t be affected by R1 or C2, so their amplitude will remain unchanged:

[insert graph showing how a low frequency signal passes through the filter]

However, for high frequencies (like the ones we want to block out), the capacitors act as short circuits and prevent them from passing through. This means that they’ll be shunted off by C1 and won’t have any effect on Vo:

[insert graph showing how a high frequency signal is filtered out]

It may not sound like much, but this little circuit can make a big difference when it comes to cleaning up noisy signals and isolating specific frequencies. And the best part? You don’t need a degree in electrical engineering to understand how it works (although that might help).