Pin 18 Power Rating???

[Dynon101]

I am considering using pin 18 of the EMS to power these items:

-MANIFOLD PRESSURE SENSOR PN 100434-000 PIN C (POWER SOURCE)
-GRAND RAPIDS CURRENT SENSOR CS-02 BLUE WIRE (POWER SOURCE)
-WESTBERG FUEL CAPACITANCE PROBES POWER SOURCE (2 PROBES)
-FUEL COLLECTOR TANK LOW DISPLAY ON THE DYNON SCREEN (SIMPLE FLOAT SWITCH)
-DOOR OPEN ANNUNCIATION DISPLAY ON THE DYNON SCREEN (2 DOORS)
-ALTERNATE AIR DOOR OPEN DISPLAY ON THE DYNON SCREEN (MICROSWITCH ON DOOR)

Would the pin 18 have sufficient capability for these items?

The only real current consumers on the list would be the Manifold Pressure, Grand Rapids CS-02, and the Fuel Capacitance Probes.

The fuel probes are Westberg 0-5 VDC probes and the manual dose not specify how much power the sending units draw.

I assume that EMS pins used to produce an annunciation icon on the Dynon screen itself are miniscule power consumers way down in the millivolt range...

For the doors open indicators, I plan on using simple spring loaded microswitches that have contacts that are open when compressed and closed when sprung outward.  The fuel float is a simple switch that is open when the float is up and closed when the float drops.

Thanks for your help!!!

 

[Dynon]

The manifold pressure sensor and GRT sensors both use pin 18, and you won't get close to the 300mA limit there.

However, most capacitance probes need 12V DC, which you can source from pin 15, provided that they don't draw more than 80mA in combination with whatever else you have connected to that line. Also, I think you mean Westach, not Westberg. If so, make sure the probes you source output a 0-5V variable DC voltage, and not a frequency (pulses). SkyView works with the former, not the latter. Many people that opt for capacitance probes use the princeton brand probes. See Aircraft Spruce for those.

For the bottom 3 - you don't want to use the 5V line at all. Use any of the general purpose EMS inputs, and when they're "open", they'll read 5V, and when grounded, close to 0V. See the section on "Contacts" in the EMS chapter of the Installation guide for more details on how to set up those inputs. Here's a partial excerpt...

"To configure them as contacts, use two voltage ranges in your sensor setup. Set one to 0-2V, and the other from 2-5V. SkyView will then report whether each input is open (no connection to ground, which is the 2-5V state) or closed (connection to ground, which is the 0-2V state). You must ensure that when closed, the contact connects to a ground common to the SV-EMS-220. Generally, the voltage on the general purpose inputs should not exceed 15 volts, but the inputs are protected against spikes up to 30V. Generally, it is safe to connect a general purpose input up to any 12V electrical signal (such as monitoring whether power is connected to a 12V fuel pump), but the same is not true for a 24V aircraft – connecting 24V (continuous) to a general purpose input will damage the input."