Duty cycle detector

Thread Starter

k1ng 1337

Joined Sep 11, 2020

The manual for my air compressor says it should not run for more than 50% of an hour. I have been thinking of building a circuit to compute this variable so please bear with me. I imagine the circuit working something like this:

Detector -> Bandpass filter -> Microcontroller -> Review memory on PC

The compressor is quite loud so testing will take place on site. Is this more complicated than it seems? The only issues I can see is the compressor frequency is variable and audible interference from a nail gun which is very loud if in close proximity. Suggestions for the detector and filter stages are appreciated.


Joined Mar 14, 2008
You might use a vibration detector mounted on the compressor to detect when it's running as it won't be affected as much by other sounds.
That shouldn't require much of a filter when detecting the vibration.

To monitor the duty-cycle, you could count time up when it is running and then count time down when it is not.
If it ever gets to 1/2 hour, then you shut off the compressor.
That may not strictly meet the manual's stated requirements, but it should be sufficient to keep the compressor from overheating.
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