Capacitive fuel probes (VMS) to Skyview

[f5ftiger]

Hello everyone, I have found some information here in the forum but if people found a solution they did not post or send that as PM.
So let's se if we can clear up the mystery...

I have a Vision Microsystems (VMS) fuel probe that seems to have a frequenzy output. Dynon Skyviev needs a Voltage input from 0-5 volts to work with.
So I need a convertor that is able to transform the frequency information into a DC-voltage output.

Now I found 2 different converters, the first one is a complex unit made by Princeton electronics and has up to 11 set points (for calibration, more points are more accurate at irregular shaped tanks). The unit costs around 150 $
The model is: CP10A
Available at support@princeton-electronics.com
They have confirmed that the product was designed to use with VMS, EI, or similar probes.

The second nor is a Dynon unit and is called Capacitance to Voltage Converter (for Vans RV capacitive plates) 50 $ p/n: 100654-000.
Available at Dynon or Aircraftspruce.


The big question now is, does the Dynon Unit works with the VMS type probes?

I hope anyone has a idea to round this up. I'm sure there are other builders out who have the same problem since VMS is out of business...

Thanks

Christoph

 

[swatson999]

I didn't have very good luck with the Dynon converter. Others have had better luck. The Dynon converter outputs 0-5V nominally, but there's no way to calibrate it so that empty tanks = 0V and full = 5, so it ended up using a tiny, tiny range in the middle somewhere for the entire fuel curve. Consequently, it was extremely inaccurate...would show 15 gallons or so for ages, then suddenly drop to 8 or 9, etc. Bleah.

Switched to the Princeton converters, where you empty a tank completely, calibrate the converter to output 0V, fill the tank, calibrate it to output 5V, and now you have the full 0-5V range available.

The Princeton units I have only have the two setpoiints, IIRC. It's the *Dynon* that has measured points every 2 gallons (I can't imagine there is any need to have both the converter AND the SV with independent curves...?)

Do yourself a favor and skip the Dynon converters.

 

[dynonsupport]

The Dynon Avionics Capacitance to Voltage Converter for Van's Capacitive Plates will NOT work for this application.

Hello everyone, I have found some information here in the forum but if people found a solution they did not post or send that as PM.
So let's se if we can clear up the mystery...

I have a Vision Microsystems (VMS) fuel probe that seems to have a frequenzy output. Dynon Skyviev needs a Voltage input from 0-5 volts to work with.
So I need a convertor that is able to transform the frequency information into a DC-voltage output.

Now I found 2 different converters, the first one is a complex unit made by Princeton electronics and has up to 11 set points (for calibration, more points are more accurate at irregular shaped tanks). The unit costs around 150 $
The model is: CP10A
Available at  support@princeton-electronics.com
They have confirmed that the product was designed to use with VMS, EI, or similar probes.

The second nor is a Dynon unit and is called Capacitance to Voltage Converter (for Vans RV capacitive plates) 50 $ p/n: 100654-000.
Available at Dynon or Aircraftspruce.


The big question now is, does the Dynon Unit works with the VMS type probes?

I hope anyone has a idea to round this up. I'm sure there are other builders out who have the same problem since VMS is out of business...

Thanks

Christoph

 

[dynonsupport]

As the name implies :
Capacitance to Voltage Converter for Van's Capacitive Plates
this product was made specifically for the capacitive plates fuel level option for Van's Aircraft models. We don't recommend using it for other types of capacitive fuel level probes.

We're glad that the Princeton converters worked well for your application. We've heard similar good reports for the version designed for the Vision Microsystems fuel level probes.

I didn't have very good luck with the Dynon converter.  Others have had better luck.  The Dynon converter outputs 0-5V nominally, but there's no way to calibrate it so that empty tanks = 0V and full = 5, so it ended up using a tiny, tiny range in the middle somewhere for the entire fuel curve.  Consequently, it was extremely inaccurate...would show 15 gallons or so for ages, then suddenly drop to 8 or 9, etc.  Bleah.

Switched to the Princeton converters, where you empty a tank completely, calibrate the converter to output 0V, fill the tank, calibrate it to output 5V, and now you have the full 0-5V range available.

The Princeton units I have only have the two setpoiints, IIRC.  It's the *Dynon* that has measured points every 2 gallons (I can't imagine there is any need to have both the converter AND the SV with independent curves...?)

Do yourself a favor and skip the Dynon converters.

 

[swatson999]

As the name implies  :
Capacitance to Voltage Converter for Van's Capacitive Plates
this product was made specifically for the capacitive plates fuel level option for Van's Aircraft models. We don't recommend using it for other types of capacitive fuel level probes.

We're glad that the Princeton converters worked well for your application. We've heard similar good reports for the version designed for the Vision Microsystems fuel level probes.

I have a Van's RV-7A with their capacitive plates.

The change in voltage output at each 2-gallon increment was so small as to not register on the display, and each time I got the message about there being no change in voltage level, did I want to accept it anyway, etc.

If they were designed specifically for the Van's plates, you could have fooled me...