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FM: Foster-Seeley discriminator

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transistor495

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This wikipedia explanation tells nothing. Anyone have a detailed explanation of the circuit. I didn't understand the underlined portion.
It uses a tuned RF transformer to convert frequency changes into amplitude changes. A transformer, tuned to the carrier frequency, is connected to two rectifier diodes. The circuit resembles a full-wave bridge rectifier. If the input equals the carrier frequency, the two halves of the tuned transformer circuit produce the same rectified voltage and the output is zero. As the frequency of the carrier changes, the balance between the two halves of the transformer secondary changes, and the result is a voltage proportional to the frequency deviation of the carrier.
 

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This wikipedia explanation tells nothing. Anyone have a detailed explanation of the circuit. I didn't understand the underlined portion.

hi BC,
The small voltage generated due being 'off tune' is used to correct the tuning, usually a varicap.
Is this what you mean.?
Or
Are you asking about the way the ratio detector demodulates a FM carrier.??

OK.?:)
This is a better description:
**broken link removed**
 
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Eric,
I didn't understand a single word u told. Please give me a detailed explanation.
When the input equals the carrier frequency and how the output become zero.
 
Eric,
I didn't understand a single word u told. Please give me a detailed explanation.
When the input equals the carrier frequency and how the output become zero.

hi,
Did you read the link I posted in my edit.:)
 
OK. That seems like a good link. I'll look on to that.
Do you think frequency modulation is possible below 2MHz?
 
OK. That seems like a good link. I'll look on to that.
Do you think frequency modulation is possible below 2MHz?

hi,
What are you modulating the FM carrier with,? audio, data etc..
 
Infrared headphones and speakers have the infrared FM modulated at 100kHz for one channel and at 200kHz for the other channel. Many of them use a CD4046 Phase-locked-loop IC to create the FM and to demodulate it.
 
Hi Eric,
I'm going to design a discrete fm detector circuit.
With minimum circuitry but acceptable performance.
For that I want to get a clear picture of the working principle of the available detectors.

It's on fm broadcast communication range only for audio.

I wonder there's no any clear information is available on net regarding the fm demodulation!
 
The internet shows many FM demodulator circuits. Enter it in Google.
Don't you know about the Google search engine?
 
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The internet shows many FM demodulator circuits. Enter it in Google.
Don't you know about the Google search engine?
Yes!
Lot of patent info is coming :D
Using the patent they've designed IC's and the technology is welldone;)

Guruji,
Please explain a highly detailed view of this thing:
**broken link removed**
What is happening on each section and what is the input of the transformer etc :)
 
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