HDX + VP-X + SV-AP-Panel

[#74430]

Hi all,

I’ve installed a Dynon Autopilot (SV-AP-PANEL). In order to access the auto trim function of the autopilot I’ve routed the trim servos (Ray Allen) input signal wires (up, down, left, right) and the trim motor wires to the SV-AP-PANEL, as per the Dynon instructions. I have left the trim position wire and +ve/-ve in the VP-X.

Do I need to still need to run power from the VP-X to the SV-AP-PANEL? My understanding is that the trim motor wires in the SV-AP- PANEL are just for signal and that the trim will get its power from the VP-X.

The Dynon manual mentions that the SV-AP-PANEL module is actually powered through the network cables.

I ask because I’m getting conflicting advice. Some believe I still need to run power from the VP-X to the SV-AP-PANEL to run the trim. This does’t make sense to me if the trim is being powered by the VP-X.

I understand that I may lose some features (5sec trim limit) but I will be able to monitor the trim motor circuits via the VP-X.

 

[DBRV10]

Two different topics, Trim Control and Trim Position

Trim position :You can have trim position via the VPX, but I would not do it. There is a serial link sending the position to the Dynon, and that has a delay in it.

The better way to do it is to use one of the EMS module inputs for each of the trim position sensors. Feed it 5v from the WHT/RED wire and away you go. Flap can be done via the VP-X if you want to use the flap control functions.

Trim Control: The AP module is powered by the SV network. The Trim motors are powered separately and you take a 12v 5A(or less) output from the VP-X and supply that to the AP module, which in turn powers the trim servos.

See attached. In this drawing there is a note about a relay between the VP-X output and the AP panel. I use several relays as a VP-X Bypass in case there is ever (highly unlikely) nuclear meltdown in the VPX. A few critical systems are bypassed and Trim is one of them. Thats up to you, but I figured someone would ask.