Author Topic: crystal oscillator breaks on EMF  (Read 402 times)

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Offline bullonwheels

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crystal oscillator breaks on EMF
« on: February 19, 2019, 05:54:45 am »
Hello all,
The external 32khz crystal is throwing garbage values when we move the AC light ballast closer to it. I guess 60hz frequency causing the issues.
Also, what are the sources which would break the crystal ?
What methods do i take to prevent. Not a metal can fix.
 

Offline Gyro

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Re: crystal oscillator breaks on EMF
« Reply #1 on: February 19, 2019, 07:53:04 am »
Very hard to say without seeing the PCB layout.

32kHz crystal drive levels are very low (= high impedance) so noise pickup is very likely on a non optimal layout. Grounding the crystal can (Aluminium) with a wire loop might help.
Chris

"Victor Meldrew, the Crimson Avenger!"
 

Offline tkamiya

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Re: crystal oscillator breaks on EMF
« Reply #2 on: February 23, 2019, 11:59:04 am »
32K piezo device is more like a tuning fork.  It is possible for a piece to break off or bonded wire to come off. 

I'm not sure if I know what "AC ballast" is....  but if that's the only time it misbehaves, can it be located elsewhere?  Did it happen suddenly or never worked right before?  It may be just shielding that is required.  Is there a reason you keep saying "no metal can"?? 

Can you take an image of the setup? 
 


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