TC-780 -- a different fan-speed question -- drop to zero?

Dunkin

Sorry for asking a similar question to my last, but this is different.

My previous question was about sudden fan rev-ups, but I've just noticed that when this machine is not working hard the fan actually stops spinning for short durations then starts back up again. So, when machine is not busy, fan essentially just cycles on and off at about 3-second intervals.

Question: Is it normal for fan speed to briefly drop to zero during operation?

Sorry if it's a bonehead question. I have two other Acer Desktops and both have just nice, steady, constant fan speeds.

Thanks, again, to anyone offering insight.

TC-780 Desktop - Core i5-7400 - 8GB RAM (Model: TC780UR1A - DT.B89AA.029) running Win-10

Dunkin

Billsey, thank you very much for the response, and for the information provided.

I'll add that I online-chatted with an Acer tech who says the ON-OFF Behavior is normal. I also downloaded a temperature read-out app that shows core temps well within limits at all times.

Since posting the first question I have noticed the fan actually staying off for long periods of time. Even so the core temps don't rise unless the CPU is really working -- anti-virus scans seem to be especially taxing. But after brief temp surges the readings drop right back down, fan or no fan. It will be interesting to see how it behaves come summer with ambient room temps of 80F-degrees.

Thank you.