# Help designing a RC passive high pass filter

• bengaltiger14
In summary, the conversation discusses the design of a RC passive high pass filter with a cutoff of 3kHz. The formula for determining the cutoff frequency is mentioned, and the poster is unsure of what values to use for the capacitor and resistor. It is suggested to use standard ranges for electronic components and to determine the units for R and C. An example of a common tone control circuit is given, with a 500k ohm potentiometer and a .022uf capacitor. The proper units for R and C are questioned.

## Homework Statement

I was asked to desing a RC passive high pass fiilter with a cutoff of 3KhZ.

## Homework Equations

The formula for Fc = 1/(2piRC)

## The Attempt at a Solution

I set 3kHz = (1/(2piRC)) but am not sure what to do next. Do I pick a random cap or resistor value and solve?

Is that it? Nothing else, no mention of impedances, voltages, anything?

Since resistors cover a larger range of commercial values, you should pick a reasonable value for the capacitor and calculate the corresponding resistor.

Look up the standard ranges for electronic components, E12, E24 etc...

Sorry to dig up a really old thread... I found this site via Google.

I want to use this formula:

Fc = 1/(2piRC)

to determine the corner frequency of a passive 'tone control' circuit as commonly used in electric guitars (a low-voltage AC circuit).

What I don't know about the formula is what the proper units are for R and C.

Is R in ohms? Thousand ohms?

An example would be a very common one:

A 500k ohm potentiometer, and a .022uf capacitor.

Plugging the numbers into a the formula isn't a problem - I just don't know what the units are supposed to be...

## 1. What is a RC passive high pass filter?

A RC passive high pass filter is a type of electronic circuit that allows high frequency signals to pass through while attenuating low frequency signals. It consists of a resistor (R) and a capacitor (C) connected in series.

## 2. How does a RC passive high pass filter work?

A RC passive high pass filter works by using the properties of the resistor and capacitor to create a voltage divider. At high frequencies, the capacitor acts as a short circuit and most of the input voltage is dropped across the resistor, allowing the signal to pass through. At low frequencies, the capacitor acts as an open circuit, blocking the signal.

## 3. What are the key components needed to design a RC passive high pass filter?

The key components needed to design a RC passive high pass filter are a resistor, a capacitor, and a power source. The values of the resistor and capacitor can be calculated based on the desired cutoff frequency and input impedance of the circuit.

## 4. What are the advantages of using a RC passive high pass filter?

One advantage of using a RC passive high pass filter is that it is a simple and cost-effective way to remove unwanted low frequency signals from a circuit. It also has a wider range of frequency response compared to other types of filters.

## 5. Are there any limitations to using a RC passive high pass filter?

One limitation of using a RC passive high pass filter is that it has a low input impedance, which means it may not be suitable for driving low impedance loads. Additionally, it has a less steep cutoff compared to active filters, which may not be ideal for applications that require precise filtering.