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Feed multiple OAT inputs from one sensor?
- Thread starter QuixoteAg
- Start date
Not sure about others, but NO with GRT OAT probe. I suspect it the same for other manufacturers.
On GRT if you connect OAT probe to the EIS, that information will be shared with the EFIS'.
Last edited:
As Mel says, generally no. Most probes are thermistors - resistors of a sort that are fairly temperature dependent. Your device has to supply and measure a current to the probe. If you parallel them, each device only supplies a fraction of the current. If you can do gross re-calibration of each unit, then it might work.
Untainted123
Well Known Member
No
As stated above, they are basically calibrated resistors (thermistors, different temps give known resistance values). When splitting the feed 2 different places, you get half (or a portion) of the known value, and so end up with wacky numbers. Garmin solves this problem with a GAD 13, which is basically a small computer that reads the value, and then publishes it on the CANBUS for the other instruments to read. Dynon, GRT all do something similar, basically one device that converts the analog signal into a digital feed that can be consumed by the rest of the devices on the same “network”.
uAvionix AV-30’s have the ability to read the probe directly, but probably in an effort to save money or installation complexity, don’t share the info in any way, so on a retrofit I did in a Warrior, I ended up having 3 probes (2 AV-30’s and an AV-20) sticking out of an inspection plate, but buying 3 redundant probes was still cheaper for that install than ripping out an entire panel or buying all the necessary follow on pieces for a Garmin install.
As stated above, they are basically calibrated resistors (thermistors, different temps give known resistance values). When splitting the feed 2 different places, you get half (or a portion) of the known value, and so end up with wacky numbers. Garmin solves this problem with a GAD 13, which is basically a small computer that reads the value, and then publishes it on the CANBUS for the other instruments to read. Dynon, GRT all do something similar, basically one device that converts the analog signal into a digital feed that can be consumed by the rest of the devices on the same “network”.
uAvionix AV-30’s have the ability to read the probe directly, but probably in an effort to save money or installation complexity, don’t share the info in any way, so on a retrofit I did in a Warrior, I ended up having 3 probes (2 AV-30’s and an AV-20) sticking out of an inspection plate, but buying 3 redundant probes was still cheaper for that install than ripping out an entire panel or buying all the necessary follow on pieces for a Garmin install.
