wojtek

My Feedback: (73)

I have used both JetCat and the JetCentral air speed sensors for limiting air speed, and both work great. Xicoy also has one which i believe works with many other turbines including KingTech. Does anyone know if these are interchangeable ? It owuld seem like they all function off of the same ) or at least similar ) circuitry.

http://www.xicoy.com/catalog/shopping_cart.php

http://shopbvmjets.com/zencart/index...roducts_id=164

I also am most interested in if the signal type from something like this would be compatible.

http://www.robotshop.com/en/airspeed-sensor-kit.html


I am aware of the ASI unit, and its just not the direction I am looking to go in on a few projects right now .



Voy

roger.alli

Hi Voy,

I use an Eagle Tree Pitot tube connected to the Xicoy unit, with the output to a Weatronics telemetry system, so it is a bit of a “mix mash”..

I can tell you that the output of the Xicoy unit is a simple variable voltage, which the Wea system converts to airspeed.

I would guess that the others are similar..

Roger

seanreit

My Feedback: (60)

Take your voltmeter and see if the signal can be measured. Typically the sensor is going to be putting out 0 to "x" volts, or 4-20 Milliamps. (measured two ways, voltage, and inline respectively.) These are two different types of signals, and if you find two the same, they are interchangeable (at least in controls and building automation) which I would believe this tech is derived from. In building automation, the same sensor for temp can be purchased each way, 0-10v or 4-20ma depending on the brain (controls system) you are connecting to.

George

My Feedback: (57)

Welcome back Sean!

Voy,
What are the projects?

wojtek

My Feedback: (73)

Hey Sean! good to see you on here. How have you been ?

You make a good point. Since any of these sensors are definitely not digital, a voltage reading comparison should do. It should be a ground, and then one lead each for the static and dynamic pressure sensors. I ordered a xicoy unit, as well as one of the lower cost ones that are popular with the APM guys. I have a feeling these are one and the same. Ill report on here ..


I have too many George! lol ... I am putting a JetCentral Cheetah SP in my new Ultra Flash. Since the Simjet Nexus finally fried, a Rhino is going in my CAI Raptor. I really need to have a speed limiter on that one as i have a hard time telling 200 from 300 .. I'd also like to put a limiter on my MB339 with K180 to keep it at a steady scale speed, as well as a K210 getting fitted in a 1/6 SM F-16 G2 version... and that's about 1/2 of the projects right now.. a turboprop and turbine heli are also on the list .. too little time man !



Voy

GR7Racer

Does anybody have any experience with the Xicoy/Kingtech Ecu with regards to the speed limiter? I was wondering if the limiter can be turned on and off via the transmitter?

KennyMac

mr_matt

My Feedback: (10)

Hi Voy,

I can't speak to the Xicoy but I did look at the data sheet for the Robotzone one (I assume you were referring to the APM- Arduino Pilot guys). I believe this is the 3drobotics part.

That unit uses a freescale pressure sensing device (I used a similar part when it was still Motorola). It has a single analog voltage output and it measures differential pressure (the difference in pressure between the 2 ports).

For some reason, they use a device that has a range of -2 to 2 kpa. (the voltage range of 0.5 to 4.5v is a different issue, the pressure range is independent of that). Not sure why a speed sensor would need to measure vacuum?

Anyway, at 2 kpa full scale, that sensor would saturate at about 120-130 MPH (depending on atmospheric conditions)

My GUESS is that Xicoy is using a pressure sensor with 0-10 kpa range which saturates at more like 285mph .

I don't know for sure but I believe the JetCat sensor board uses an onboard device to perform an analog to digital conversion and sends digital data back to the ECU (but as I said I am not sure). The pixhawk (latest 32 bit open source flight controller) speed sensor is now digital.

tomsdk

Wojtek, still using Futaba?
I actually just finished designing a small Pitot/static IAS with barometric altimeter for SBUS-2 Size is 0.8 x 0.8 inches. It can be modified with a limiting function if needed. At the moment it has airspeed, altitude, vario and two digital output ports. Flight data is presented with real display values because it emulates an SBS-01G GPS sensor



Cheers, Thomas

wojtek

My Feedback: (73)

Matt, thanks for your post. You presented some great info. The Robotzone sensor is the same as the one The APM/Pixhawks use. I have always intended to play around with the Pixhawk on a fixed wing aircraft ( not jet of course ! lol ) to play around with what is possible, but looks like with the way things are, I'll be holding off. Its a great platform for multirotor camera ships however

I ended up just ordering up limiters/sensors from each respective manufacturer for their ECUs. This saves me time, and I will be able to compare the output of them as well. I really wish others besides JetCat had the speed control functionality as the JetCat ECU does. Cruise control mode is just awesome for scale routines , or even pattern aerobatics. ... I did lose a MB339 running a p200 once however because of it .. I loaded up on ordinance and never felt having to use more thrust, therefore more fuel ,, and well ... you know what happens .. lol lesson learned.


Thomas,

how much are these units ? I would not mind having a simple plug in option to also shoot over live info to my 18MZ. I could just Y off the pressure ports that I will have going to the ECU. What speed are these able to read up to? I intend to fly up in Canada a few times next year, and would love to be able to get acurate readings in the 350mph range .. Here in the USA however I we have the need to limit to under 200mph per the AMA.

best regards,

Voy

tomsdk

Hi Voy,

The sensor type only supports up to about 280mph. Generally you loose accuracy when looking for sensors capable of more pressure. Price will be about 80$.

Best regards
Thomas