Inductors for Colpitts Design AM Transmitter

  • Thread starter powzoom
  • Start date
  • Tags
    Inductors
In summary, the speaker is designing an AM transmitter using a colpitts design and is wondering which type of inductor to buy. They mention seeing different types available for sale and are aware of the differences in Q values and max current. They also mention their intention to broadcast over commercial AM and are not too concerned about FCC regulations. The expert advises choosing an inductor with a high SRF value and staying below the saturation current. They also mention that DCR (DC resistance) should be taken into consideration. Overall, the speaker should choose the cheapest and smallest inductor that meets these requirements.
  • #1
powzoom
3
0
I'm trying to design a AM transmitter using a colpitts design. I see many different types of inductors available for sale, smt, torrid, dip, ferrite core, iron core, etc... Which one should I buy? I know they have different Q values and max current. What do you think the max current would be for my transmitter if it only broadcasts over a 100ft or so?
 
Engineering news on Phys.org
  • #2
powzoom said:
I'm trying to design a AM transmitter using a colpitts design. I see many different types of inductors available for sale, smt, torrid, dip, ferrite core, iron core, etc... Which one should I buy? I know they have different Q values and max current. What do you think the max current would be for my transmitter if it only broadcasts over a 100ft or so?

What frequency is your transmitter? Be careful just broadcasting a signal -- The FCC has rules about how much power you can put out in different bands without a license...

You will choose inductors based on the frequency (hence the SRF makes a difference), the DCR, and Isat. Beyond those things, you will usually choose the cheapest and smallest that meets those requirements.
 
  • #3
I'd like to make it broadcast over commercial AM so that it can be picked up by a home radio. I'm not too concerned about FCC as it won't be broadcasting off my property and it's really only for learning purposes. So about 0.5Mhz to 1.6Mhz. If I understand correctly, I should pick a SRF value much greater than 1.6Mhz? What is DCR?

Thanks for the reply.
 
  • #4
powzoom said:
I'd like to make it broadcast over commercial AM so that it can be picked up by a home radio. I'm not too concerned about FCC as it won't be broadcasting off my property and it's really only for learning purposes. So about 0.5Mhz to 1.6Mhz. If I understand correctly, I should pick a SRF value much greater than 1.6Mhz? What is DCR?

Thanks for the reply.

DCR is DC resistance. Isat is the saturation current (which you want to stay below). Yes, just choose the SRF well above your operating frequency to be sure it's still an inductor.
 
  • #5
powzoom said:
If I understand correctly, I should pick a SRF value much greater than 1.6Mhz? ...
10X will do.
 

Related to Inductors for Colpitts Design AM Transmitter

1. What is the purpose of inductors in a Colpitts design AM transmitter?

Inductors are used in a Colpitts design AM transmitter to create a resonant circuit that determines the frequency of the transmitted signal. They also help to stabilize the frequency and provide voltage gain in the overall circuit.

2. How do I choose the right inductors for my Colpitts design AM transmitter?

The choice of inductors depends on the desired operating frequency and the specific requirements of the transmitter circuit. Factors such as inductance value, quality factor (Q), and self-resonant frequency (SRF) should be considered when selecting inductors for a Colpitts design AM transmitter.

3. Can I use any type of inductor in a Colpitts design AM transmitter?

No, not all types of inductors are suitable for use in a Colpitts design AM transmitter. Air core or ceramic core inductors are commonly used in this type of circuit due to their high Q and low parasitic capacitance. Ferrite core inductors may also be used in some cases.

4. How do I calculate the required inductance for my Colpitts design AM transmitter?

The required inductance can be calculated using the formula L=1/(4π²f²C), where L is the inductance in henries, f is the desired frequency in hertz, and C is the capacitance in farads. This formula assumes an ideal circuit and may need to be adjusted based on the specific components used.

5. Can I use multiple inductors in a single Colpitts design AM transmitter circuit?

Yes, multiple inductors can be used in a Colpitts design AM transmitter circuit to achieve desired frequency and voltage gain. These inductors can be connected in series or parallel, depending on the specific circuit requirements and component values.

Similar threads

Should a Big Inductor be Added to a Hartley Oscillator Design?
    • Electrical Engineering
2
Replies
36
Views
3K
COMSOL simulation of a 3D Ferrite Bar Numerical Model For Magnetic Flux
    • Electrical Engineering
Replies
4
Views
2K
Using an inductor choke as a receiving antenna for LW radio
    • Electrical Engineering
Replies
14
Views
2K
Role of the capacitor, coil and choke in this television receiver design
    • Electrical Engineering
Replies
26
Views
3K
Electronics Would This Setup for a Ball Bearing Accelerator Work?
    • DIY Projects
Replies
2
Views
2K
Winding a toroid inductor, is this calculation correct?
    • Electrical Engineering
Replies
4
Views
2K
Solving the operating point of a transformer with a nonlinear B-H curve
    • Electrical Engineering
Replies
4
Views
1K
Electronic circuit/inductor problems
    • Electrical Engineering
Replies
4
Views
2K
Electrically Variable Inductor
    • Electrical Engineering
Replies
4
Views
3K
Inductor Antenna for 125kHz NFMIC System: FCC Part 15
    • Electrical Engineering
Replies
9
Views
8K

Hot Threads

Recent Insights

Back
Top