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New Rotax Oil Press Sensor
Posted: Sun Oct 16, 2022 3:47 am
by Geoff
I'm having difficulty getting RAD XF / EFIS to read the new Rotax OP sensor. The sender part no. is BRP456180 which Rotax calls 456-180. The red wire is connected on the RDAC to Oil P and the white wire is connected to GRD. The Setup in the EFIS is set for a 4-40mA signal, the dip switches on the RDAC are OilP PD is ON, OilP PU is off. I have connected the sender to a known pressure source but the EFIS reading remains 0 Bar.
Please could someone help with this .
Re: New Rotax Oil Press Sensor
Posted: Mon Oct 17, 2022 11:23 am
by rainier
Red should go to +12V and the while wire to the oil pressure input on the RDAC. Everything else seems fine.
This is a 4-20mA current sensor - this means it "creates" and electrical DC current between 4 and 20mA depending on oil pressure. At 1/2 the pressure range you would thus expect a current of 12mA.
The RDAC has a 100 ohm pull-down resistor (if switched on). 4mA would thus result in a voltage of 0.400V and 20mA would result in 2.0V. The RDAC measures this voltage. The current source is the 12V power supply. The current remains constant over a wide range of power supply voltages (provided oil pressure does not change).
BTW, you can use the RDAC Diagnostics in your EFIS as handy tool to measure the voltage at your oil pressure input.