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sahrens
06-25-2016, 04:18 PM
I am installing a 5500 in my RV-7 panel connecting to Dynon SV-Network devices. The sum of the power demands for the Dynon devices connected to the SV-Network exceeds the 3.5 amp limitation of the TCWTech 6ah backup battery slightly. Total demand including the 5500 is 3.61 amps; 2.8 for the 5500 and 0.81 for SV devices. Not a significant overage but it does exceed the individual pin restriction of 3.5 amps.

TCWTech documentation does state the pins can be run in parallel which would provide greater amps (7.0) but there is no additional connection point within AFS/SV network. Just the one pin on the EFIS expansion cable.

Is there some other method of providing backup power to the SV-network devices that I have overlooked short of installing a second EFIS? The second EFIS would pick up half the load so the individual pin load would be 3.21 amps (2.8 for the EFIS and 0.41 for SV devices.)

Thanks for your time.

Scott

Shawn McGinnis
07-05-2016, 12:20 PM
My best guess is that you are including the SV-COM into your calculation. The power doesn't come through the SV-Network connection for this devices. Only the head unit is powered directly.

Additionally the EFIS rating includes the SV-network in its power requirements.

sahrens
07-07-2016, 08:15 AM
Just to make sure we are on the same page, the sum of the SV device's demand is 0.83A. The devices in my installation so far are:

These two always get power from the EFIS
GPS-2020 0.10A
WIFI 0.10A

These pull power from the SV-network
ADAHRS (primary and backup) 0.15A each or 030A total
AP-Panel 0.05A
Knob-Panel 0.07A
ARINC-429 0.10A
EMS 0.11A

Adding those to the 2.8 amps of the AFS EFIS is where I come up with 3.83 amps. In your post you state the EFIS rating includes all these devices? Or is it just the GPS and WIFI device included in the EFIS rating? I realize we are talking about a very small amount of amps, but I want to understand how the system operates to ensure my backup power design is robust enough.

Thanks for your time.

Shawn McGinnis
07-07-2016, 09:57 AM
All of those are already included in the 2.8A rating of the EFIS.

sahrens
07-08-2016, 04:34 PM
Thank you for that clarification.

Scott