SV-AP-Panel

[ljbuller]

Thank you Dynon for the AP-Panel.  Much appreciated.  I notice in the install manual that the trim system senses a ground condition to activate.

would it be possible to configure sensing a high to activate?
I suspect that you are pulling the pushbuttons up to 5vdc?

the reason for this is safety.  While proper installation would preclude a wire from chaffing on structure, it is much more likely that a wire will get shorted to ground rather than aircraft voltage.  If a switched hi line gets shorted to ground, it blows the circuit protection.  If it gets shorted to voltage, then the circuit is activated all the time, however shorting to ground is the most common occurrence.

I understand that you have the 3 second max run time, but a line could easily be vibrating and creating multiple activations.

It seems that even if you have the line pulled up, it could be configured to see voltage as activate.  It may mean putting a pull down resistor,  and a current limiting resistor and zener diode on the line to make that work.

Regardless, thanks again for the development work on the ap panel and the knob panel.  I am in line to get them as soon as they are released.

 

[dynonsupport]

Thank you for the feedback.

The timeout of a stuck button on the trim controller is actually 5 seconds - we'll be correcting that in our documentation.

Thank you Dynon for the AP-Panel.  Much appreciated.  I notice in the install manual that the trim system senses a ground condition to activate.

would it be possible to configure sensing a high to activate?
I suspect that you are pulling the pushbuttons up to 5vdc?

the reason for this is safety.  While proper installation would preclude a wire from chaffing on structure, it is much more likely that a wire will get shorted to ground rather than aircraft voltage.  If a switched hi line gets shorted to ground, it blows the circuit protection.  If it gets shorted to voltage, then the circuit is activated all the time, however shorting to ground is the most common occurrence.

I understand that you have the 3 second max run time, but a line could easily be vibrating and creating multiple activations.

It seems that even if you have the line pulled up, it could be configured to see voltage as activate.  It may mean putting a pull down resistor,  and a current limiting resistor and zener diode on the line to make that work.

Regardless, thanks again for the development work on the ap panel and the knob panel.  I am in line to get them as soon as they are released.

 

[JTD]

Just wanted to say: Great work on the autopilot and switch panel. They make the system so much more user friendly

 

[JTD]

I noticed today that the back lighting on the autopilot panel is on with the avionics master off ( no power to Skyview ) it extinguishes when I pull the trim CB. With skyview up and running it works and dims along with the D1000. Lighting must have a alternate internal source off of the trim circuit

 

[dynonsupport]

Tim,
The control panel will still control trim even when SkyView is off, which is why it also gets power from the Trim bus. However, with no SkyView online, it doesn't know what brightness to use so it defaults to on. Now that you mention it, you can't use the control panel buttons if SkyView is failed, so it's more logical for the lights to go off in this case, not on. We'll get that in a future software update.

 

[DBRV10]

As possibly the first customer flying with this function can I insist the TRIM timer is set to no more than 3 seconds not 5.

A runaway trim is not a good thing and 3 seconds is a lot as it is.

The SafeT-Trim controller was 3 seconds and is a happy medium between the annoying and run away disaster.

 

[Dynon]

You get to be the first vote, that's for sure! But we'll say it counts double

 

[DBRV10]

hehhehe

Actually the new system is working very well. We did some instrument approaches yesterday and the AP needed a few tweaks but it soon performed brilliantly.

Very pleased indeed

 

[ljbuller]

I suspect that the trim safety time will be different for different aircraft. 

A normal trim time for trimming when leveling out is about 1 1/2 sec on the RV7. 

For landing, I need the trim most of the way back which needs to be neutralized before take off.  I have not timed that, but that would probably be in that 3 second zone.  5 seconds would give about full travel on the trim, which when in flight would be the same as a runaway.

Any possibility of a user selected time and or a smaller time in flight?  or possibly a longer time with flaps extended?
I have not noticed a "TRIMMING" annunciation on the SV1000. Many aircraft have a beeper or buzzer to alert when trimming.

I appreciate your cautious approach to the trim system. I believe you have auto trim in the works which would also be great. You know all this already, but when the flaps are moved, the trim needs to move asap, not wait for the AP to sense an out of trim.

Just a comment, not a complaint, using the AP for approaches on the RV7A, I have to do them with flaps retracted and at least 100 kts to get an acceptable control response in pitch. That make it a bit tricky getting slowed down for flap speed when breaking out of the clouds.

Using the AP and knob panel make approaches very doable. Before that, there was just too much menu changes going on.
Thanks for the great work.

 

[dynonsupport]

The AP controller logic all runs internally to the AP control panel, and the purpose is to be pretty independent of SkyView. Because of this, we would prefer not to be sending the trim controller all sorts of configuration data, which may not be valid if SkyView is not yet booted.

Remember, in cruise, you have your trim slowed down, so 5 seconds is not a "runaway." Plus, after these 5 seconds the issue is correctable, which is different than a hard failure of going to the limit with no possibility of correction. In my plane with a Ray Allen servo,

We do not make any noises or indication when the user is manually trimming. If users really ask for this level of notification (annoyance?) then we can add it.

The auto trim will not move automatically when you move the flaps. That's way out of scope for our auto trim system. It will be reactive to the forces on the stick, not predictive.

If you are having issues with the AP at different speeds, I would suggest playing with pitch gain a bit to see if you can find the spot where it performs acceptably at 90 knots. It should be possible- most of our RV installs do not have an issue at approach speeds.