Wiring the UMA hall effect tach sensor question

mikehoover · #1 10-05-2011, 09:45 PM

Should the power wire from the UMA hall effect tach sensor be connected to the battery buss (always on), or the main buss? I would think the battery buss because you would want it to continue to work if you lose your master contactor. If that happened, the Dynon battery backup for the Skyview would continue to operate the Skyview system and the tach sensor would still operate (as long as the aircraft battery has juice). Will connecting it to the battery buss drain the battery when not flying because it is always on? Thanks!

az_gila · #2 10-06-2011, 12:39 AM

Quote:

Originally Posted by mikehoover

Should the power wire from the UMA hall effect tach sensor be connected to the battery buss (always on), or the main buss? I would think the battery buss because you would want it to continue to work if you lose your master contactor. If that happened, the Dynon battery backup for the Skyview would continue to operate the Skyview system and the tach sensor would still operate (as long as the aircraft battery has juice). Will connecting it to the battery buss drain the battery when not flying because it is always on? Thanks!

Why not just power it with pin 15 on the EMS unit, the 12v DC auxiliary power output?

mikehoover · #3 10-06-2011, 07:16 AM

Quote:

Originally Posted by az_gila

Why not just power it with pin 15 on the EMS unit, the 12v DC auxiliary power output?

I used Pin 15 for the Red Cube fuel flow transducer. Not sure if I can use pin 15 for both the Red Cube and the tach transducer. That would be convenient though.

az_gila · #4 10-06-2011, 09:30 AM

Quote:

Originally Posted by mikehoover

I used Pin 15 for the Red Cube fuel flow transducer. Not sure if I can use pin 15 for both the Red Cube and the tach transducer. That would be convenient though.

It's only a power source so it should be OK if it can source the current for both items.

Sounds like a simple question for Dynon...

mikehoover · #5 10-07-2011, 06:29 PM

I found out from UMA that the tach transducer "current draw is 10Ma @12VDC regulated." Haven't gotten a reply from EI about the Red Cube's current draw. Probably will work just fine wiring them both to the pin 15 12 v source on the Dynon EMS 37-pin connector. Waiting for more info from Dynon before I proceed.

az_gila · #6 10-07-2011, 09:42 PM

Quote:

Originally Posted by mikehoover

I found out from UMA that the tach transducer "current draw is 10Ma @12VDC regulated." Haven't gotten a reply from EI about the Red Cube's current draw. Probably will work just fine wiring them both to the pin 15 12 v source on the Dynon EMS 37-pin connector. Waiting for more info from Dynon before I proceed.

Looks like it's around 14 mA for the red cube -

http://www.fdatasystems.com/Manuals/...Manual_1.3.pdf

I'm sure Dynon will confirm that pin 15 is good for 24 mA, especially since pin 15 can drive two flow sensors and a FloScan sensor is 30-50 mA each.

Go for it...

mikehoover · #7 10-11-2011, 08:23 AM

UMA's reply to my question about their transducer:

"This is same probe, just MGL is supplying it with their system, that may be the reason for the price difference. PullUp resistor is not required, except is [if] mentioned in Manuals for certain systems (MGL need 22K resistor between white and orange-white wire). Current draw is 10Ma @12VDC regulated. And all pickups have white/blue, white/orange and white wires now."