EMI tester

A project log for Integrating RF LED Detector with ATtiny13

Using a given microcontroller system my question was: How can I make the simplest possible RF receiver.

bkainkab.kainka 04/25/2015 at 16:112 Comments

Tiny13-RX showing EMI noise from a switch mode charger. The old wall mounted transformer is clean.



b.kainka wrote 04/26/2015 at 10:54 point

I left it at 10 microseconds. The main emission of the switch mode charger is below 1 MHz. So it fits fine. Also some kinds of fluorescent lamps can be detected. But incandescent bulbs keep quiet.

It's a wideband receiver, mainly 10 kHz to 1MHz. It works up to 1 GHz but much less sensitive. One can add an LC circuit. But the software has to be changed to continuous pullup, otherwise it will ring …

By the way, 50 mV is not very sensitive. One has to go close to the source. Just ok to detect the origin of the fields.

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Elliot Williams wrote 04/25/2015 at 19:34 point

Great idea.  

Did you tweak the integration time to match whatever frequency the SM charger is running on?  Or did you just get lucky?

(And in the main example, did you broadcast 100kHz at the chip?  Or?)

How discriminant is this circuit?  How well can it be tuned?

So many questions!  (Apologies.)

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