AC frequency on FreqMeasure

Magnethead494

Well-known member
When I use FrequencyMeasure on an LC, I am getting 60hz mains as a reading (LC powered by USB on a desktop pc) while testing the circuit. To me, this shows that any fluctuations on the power/ground line will be echoed upon the Teensy Freq Libraries.

In application, it will be powered by vehicle 12V (~14.4). Modern auto electronics I'm certain are much noisier than AC mains.

I'm using an LM1086 3v3 LDO with 10uF and 1000uF across the input, and 47uF across the output. Is there anything more that I can do to help filter out the noise?

Should I use a 5v LDO instead, and feed that to VIN to the Teensy's 3.3 regulator (double regulation)?
 
Last edited:
That sounds like ground loop or cheap psu somewhere on your pc,
Have you a battery powered laptop you can try with?
Chances are you wont get that 60hz mains loop in your car unless you maybe have a mains inverter in there.
 
Back
Top