Fan Running?

[russdent]

I've noticed that when I power one of my Skyviews off, it's fan starts running. If ships power is not present, it will run on backup battery.

My plan was - if I lost my alternator, I would switch to essential bus with only one Skyview running at-a-time and stretch the time I have flight instruments. It appears that it would also cause the dark unit's backup battery to slowly run down during that same time. I have not done an endurance test to find out how long the fan will run.

Is it just my configuration or designed to be that way?

 

[dynonsupport]

The fans that run are powered off of the screen that is on. This is just the way the hardware works. It is not draining the battery on the off unit. It is the power that runs all the modules leaking into the SkyView and making the fans spin.

The current the fans draw is just a few mA, well less than 1% of the power of the SkyView that is on. If you are running the powered on screen off a battery, and have the other screen off, the fact the fans are running will only change the battery life by a few seconds.

You can prove it's not drawing power from the battery if you want: Unplug the battery and the behavior will be the same, so you know it's not the battery spinning the fans.

 

[skysailor]

In a situation where all ships power was down such that both Dynons are running off their own batteries, will shutting down one screen still allow the fans to run on on the Dynon which he switches off at this point?

 

[russdent]

Yes. My post was in error. The off unit's fan runs with power from the screen that is still on. I remember unplugging the backup battery and the fan kept running.

It only caught my attention because neither unit was hot enough to run the fan but as soon as one unit is powered down, it forces the fan to run on the downed screen.

Okay, thanks. I can deal with a few seconds less endurance. Thought maybe I had something wired or configured wrong.

 

[dynonsupport]

Skysailior,

Yes, if one screen is on and the other is off, the off screen will have it's fans spin. It doesn't matter via what power source the on screen is running.

Truth be told, newer units won't do this, as we did make a modification to prevent this. It's purely a customer perception issue, not a technical problem that affects the performance of the units in any way, so we aren't modifying older units to prevent it.