Building a RC circuit to pick up radio waves

In summary, the student is trying to design a band-pass filter using resistors and capacitors. He is having trouble finding the value for L or C, and is looking for feedback on his current design.
  • #1
freshcoast
185
1

Homework Statement


2gwxb9k.jpg



Homework Equations



w = 1 / sqrt(LC)

The Attempt at a Solution



hi there, I

1. I decided to choose, 93.3 MHz so 93.3 x 10^6 Hz is my freq.
2. I googled how a band pass filter diagram should look like and I found this,
02121.png


is the only way to create a low pass combined with a high pass filter is using 2 resistors and 2 capacitors only? is it possible to just have 1 inductor and 1 capacitor with alternating current in series?

3. I am having trouble finding the value since there are 2 missing variables in and only 1 equation.. I am thinking I am allowed to make a value for L or C and then use algebra to find the other
 
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  • #2
There are other designs for band-pass filters. But I do not think you are supposed to google them or invent them. You must have studied them in your course, so use the designs known to you.
 
  • #3
Yeah I missed the lecture on this topic so I had to refer to the internet but from what I've learned high pass frequency uses the combination of a resistor and capacitor and its purpose is to filter out the low frequency and a low pass frequency is just the opposite.
 
  • #4
I recommend that you still try to rely on the course material as much as you can. Talk to a fellow student who was there, they may have something to say and some lecture notes to borrow or to copy. You are very likely expected to design a circuit of the particular kind or kinds addressed at the lecture. Use the Internet as a supplement to that, not as a replacement.
 
  • #5
Yes I understand that and I will get caught up on the information I missed, but under my current situation I have to use my resources available to me as of right now. Which is just the internet and these forums. My classmate is busy so he can't help me at the moment and since this problem is the only thing I need to complete so I am just focusing my attention on what is in front of me. But yes in the long run I am sure that there will be more difficult circuits I will be facing, not to be rude or anything but for now I would just like to get feedback on what I've done so far.
 
  • #6
If there is no buffer between the 2 stages (LPF, HPF), then they will interact. You need to write the 2 KCL equations using the complex impedances (Zcap values are complex, Zr values are real, obviously), and solve for V3/V1 as a function of frequency.
 

FAQ: Building a RC circuit to pick up radio waves

1. How does a RC circuit pick up radio waves?

A RC (resistor-capacitor) circuit works by creating a resonant frequency that matches the frequency of the radio waves. This allows the circuit to amplify the radio waves and convert them into an electrical signal that can be detected by a receiver.

2. What components are needed to build a RC circuit for picking up radio waves?

To build a RC circuit for picking up radio waves, you will need a resistor, a capacitor, and an inductor. The values of these components will depend on the frequency of the radio waves you want to pick up. You may also need additional components such as a diode and antenna for better performance.

3. Can a RC circuit pick up all types of radio waves?

No, a RC circuit is designed to pick up specific frequencies of radio waves. The resonant frequency of the circuit must match the frequency of the radio waves for it to pick them up effectively. If the frequency of the radio waves is too different, the circuit will not be able to pick them up.

4. How can I adjust the sensitivity of a RC circuit for picking up radio waves?

The sensitivity of a RC circuit for picking up radio waves can be adjusted by changing the values of the components, such as the resistor, capacitor, and inductor. Increasing the values of these components can make the circuit more sensitive, while decreasing them can make it less sensitive.

5. Are there any safety precautions I should take when building a RC circuit for picking up radio waves?

Yes, it is important to follow safety precautions when building a RC circuit for picking up radio waves. Make sure to use components that are appropriate for the voltage and current of the circuit. Take proper precautions when handling and soldering components to avoid electric shocks. It is also recommended to have a fuse in the circuit to prevent damage in case of a short circuit.

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