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Can somebody tell me how these circuits works ? Answered

these circuits are TX and RX 433MHz RF module.
Can somebody tell me how these circuit works ?
and can somebody show me its block diagram ?

5 Replies

electronicsengineer (author)2018-02-05

Hi Rendy,

you could go read the full article in Elektor Magazine (issue May 1998).
That's where these schematics have been copied (stolen) from (without even mentioning their source).

The Elektor engineers and editors have invested a lot of time to make a good article on this subject in that issue.

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orksecurity (author)2011-06-30

Uhm... A schematic is pretty close to a block diagram when it's as simple as these are. If you tried to abstract it much further, you'd wind up with just one or two blocks on each page.

The transmitter is a crystal-controlled single-transistor oscillator. It generates a signal at the frequency set by the crystal (X1). Serial data causes transmission or no-transmission transitions to be sent out over the antenna. Single-bit amplitude modulation.

The receiver appears to be a simple regenerative receiver which picks up the radio signal at that frequency and puts it through two stages of amplification (the triangles are op-amps) and filtering before presenting it to the output. All you're going to get out is "there was/wasn't a sufficiently strong signal at close to the right frequency" -- but that's enough to recover the data that was sent in.

If you want to send more than a one-bit on/off signal, you need hardware and/or software not shown here to encode that data in a self-clocking form before transmitting and to decode it from that form after receiving.

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iceng (author)orksecurity2011-06-30

+1 description.
Got to add, at 433Mhz the physical layout is critical.
Which Rendy is well aware judging by his previous questions.

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Nosphera (author)iceng2013-03-05

Can you tell me the T1 model, or some model to use. I´m searching for this schema a lot and want to build one, but i don´t know what transistor model use.


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Rendydevara (author)orksecurity2011-07-01

Thank you very much.
can you mark the image where is the filter, where is the envelope detector, etc, please

i want to make my own rf transmitter and receiver module for my microcontroller
and can you explain it more detail. i've search in google, but i still confuse.


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