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"Uneven" throttle signal ?

Posted: Sun 13. Mar 2016 6:50:29
by Dawiev
Hi, attached is the CC log from my 550x. Throttle curves are Normal = 0, 40, 79 ..... 79 IU1 = 84.....84 IU2 = 92.....92 (Governor is active and DSMX sats). After take-off I am in IU2 till I come in to land.

I would expect to see a flat and consistent throttle in signal for the majority of the flight that I am in IU2 ? Is there a problem somewhere with my sats, cables or setup ?

It is not the transmitter as I see flat lines in other configurations.

Re: "Uneven" throttle signal ?

Posted: Sun 13. Mar 2016 7:30:59
by Coco66
Not familiar with the CC log, but... if the Govenor you talk about is the Spirit one, then how else should it keep your headspeed constant, if not by changing the throttle request to the ESC?

Re: "Uneven" throttle signal ?

Posted: Sun 13. Mar 2016 7:48:27
by velocity90
What you see is a quite normal rpm plot. Look at the pwm plot if that is available. You can see there if everything is ok, if you have enough headroom.

Re: "Uneven" throttle signal ?

Posted: Sun 13. Mar 2016 7:53:40
by Dawiev
Hi, thanks for the replies !

RPM in green, Throttle in Black and Power Out in Blue.

Re: "Uneven" throttle signal ?

Posted: Sun 13. Mar 2016 8:10:13
by velocity90
Perfectly fine, pwm should not touch 100% a lot or even show straight lines there.

Re: "Uneven" throttle signal ?

Posted: Sun 27. Mar 2016 22:00:16
by curmudgeon
Dawiev wrote:Hi, attached is the CC log from my 550x. Throttle curves are Normal = 0, 40, 79 ..... 79 IU1 = 84.....84 IU2 = 92.....92
As I best understand it, the Spirit interprets your transmitter flat throttle IU curves (79-79-79, 84-84-84, and 92-92-92) as the desired set-point RPM. The Spirit then sends its own output throttle signal to the ESC to maintain that desired RPM. So the throttle signal from the Spirit to the ESC will change moment to moment depending on the conditions in an effort to maintain the desired head speed RPM. The Castle log only sees the throttle signal coming from the Spirit, not the throttle signal coming from the transmitter.

Re: "Uneven" throttle signal ?

Posted: Mon 28. Mar 2016 2:25:26
by kirby_
curmudgeon wrote:As I best understand it, the Spirit interprets your transmitter flat throttle IU curves (79-79-79, 84-84-84, and 92-92-92) as the desired set-point RPM. The Spirit then sends its own output throttle signal to the ESC to maintain that desired RPM. So the throttle signal from the Spirit to the ESC will change moment to moment depending on the conditions in an effort to maintain the desired head speed RPM. The Castle log only sees the throttle signal coming from the Spirit, not the throttle signal coming from the transmitter.
This is exactly how it works. Throttle into the Spirit is a command to achieve a specific RPM. Throttle out from Spirit to ESC does whatever it needs to do to achieve that specific RPM.

Re: "Uneven" throttle signal ?

Posted: Tue 29. Mar 2016 13:56:48
by ZeXx86
Yes, exactly this is correct.

Re: "Uneven" throttle signal ?

Posted: Tue 29. Mar 2016 15:15:08
by Dawiev
Hi, thank you for all the support !

All is well now.

I had a major "senior moment" ;) I compared the log from one of my other setups that had a very straight line and couldn't understand why this one doesn't. Needless to say, if you use the CC internal governor, you will see straight .... :oops: