Westach Tach/Oil/Fuel Tranducers

[EchoCharlie1]

The Skyview installation manual appears to assume a 2-wire (+/-) setup for the digital tach transducer, but the Westach 303DH2T Hall Affect  transducer requires a 5-12V input, sensor (+) and ground (-).  I've used pin-1 of the EMS-37-pin connector since that is where 12V is coming into the system, used pin-32 for the sensor wire (+) and common ground (-) for the grnd wire.  No RPMs.

Additionally, with 12V supplied to pin-1 of the EMS connector, I get no voltage readings on the Skyview, yet all systems are up and running.

Last problem, with oil pressure reading 57 psi with engine off and over 160psi with engine running, I am assuming that the Westach 387-100KV is not supported, along with the fuel pressure transducer, Westach 387-30KV.

Thank you for your assistance.

R/
Frank

 

[EchoCharlie1]

UPDATE: Okay, I did some more digging and found that Dynon suggests that ONLY the type indicated for oil/fuel pressure, are supported. Therefore, I've ordered new oil/fuel pressure transducers and oil temperature probe.

Still, no info found on the Westach tachometer transducer. HELP!!! :'(

 

[dynonsupport]

First, on pin 1 on the EMS 37 pin: That's a voltage measurement pin, not a power supply. If you're saying that you're trying to get 12V out of that pin, you won't find it there.

Next, if you are putting ship's power into that pin, to create a voltmeter, you need to make sure that it's mapped in the pin mapping part of the EMS setup, and also that it has been enabled in the EMS page layout of your choosing.

As for the tach sender: SkyView ultimately needs a frequency input. You can use either pin 32 if it outputs 10+ VDC, or you can use pin 34 if it's peak is 2-10VDC. I can't say we're familiar enough with that sensor to know what it's output is, exactly.

 

[mmarien]

Try using EMS pin 15 which out puts 12V or pin 18 which outputs 5V. It looks like the hall effect sensor has the same pin out as a potentiometer where it needs a voltage input to create a pulse or output on the sensor wire. You could possible get the 12V straight from your power bus but in that case it should have a fuse to protect the wire.

If you use EMS pin 18 (5V) the sensor wire would be connected to EMS pin 34 or 35.

You could try it on the bench. Connect the 12V input and GND to a battery and see if there is a pulse on the sensor when you spin it.

 

[EchoCharlie1]

The Westach Tachmeter is expecting 5-12V DC, from which I acquire from Pin 15. The (+) side of the sensor is connected to in 32 (for std voltage) and the (-) side of the sensor is connected to a ground Pin on the EMS-37 connector. Still, no joy!

The 12V DC power, derived from a separate switch for the Dynon SV-1000, also applies power simultaneously to the EMS-37 connector, Pin 1. From what I see on the screen, it is setup to be the Voltmeter, as the default. Still, no joy!

As for the Oil Press/Temp and Fuel Pressure sensors, I've ordered the Dynon recommended units. That should take care of that problem.

I'm 99% there and have only 99% of the way to go!

R/

 

[dynonsupport]

So the core question is - what is the expected output of that tach sensor? Depending on it's output, you may need a pull up resistor in there (this would be the case if it only ever pulls the line down from open to ground, and doesn't actually output a positive voltage)

On the pin 1 input - you can take a look at EMS SETUP > SENSOR DEBUG DATA to see what's actually on that pin. Also, do you have Pin 1 mapped under the SENSOR INPUT MAPPING menu?

 

[EchoCharlie1]

I'm not electronically savvy enough to know what you said in your first statement.  All I know is that the tach transducer worked with the Blue Mountain One system, as did all the other sensors.  However, with the Dynon SV upgrade, I'm reinventing the wheel.  I've ordered replacement sensors for the other items, as recommended, but the tach is going to be more difficult to figure out.  A pull-up resistor?  How and where would you put one of those?  What is it?  If your eyes hurt from rolling, I apologize, but I didn't think I was actually going to need my one EE class from my undergraduate degree program as an engineer.  :

I'll check the settings for the voltmeter issue, but the last time I checked, it was set at default and the SENSOR DEBUG DATA read a big ZERO.  

 

[dynonsupport]

Back to basics for a second. If your engine has magnetos, you can forget about using ANY transducer, and instead use the Dynon-recommended method of running a wire from your magneto p-leads (the wire that goes to your ignition switches/key) through the included resistors, then to the SkyView L and R tachometer inputs. Is there a reason that wouldn't work in your installation? You could then forget about the problematic transducer AND having to buy another sensor.

 

[EchoCharlie1]

Yes, this would be an option.  I will investigate.

However, where are the "included" resistors?

For my particular setup, I have two separate switches for the mags, one for the left, one for the right.  Would I install a wire from each of the switches to the cooresponding EMS-37 pin, or would I have to run a separate wire directly from the mag to the correspond pin, thereby requiring the installation of a resistor inline?  And if so, would I just solder a resistor inline, as close to the mag, or buy a tiny circuit board and make such an assembly? OH, and I have Slick Mags...if that makes a difference.

Any further consideration on the Pin 1 detail? I have a Dynon SV-1000 switch for powering up AFTER the engine is started, from which this switch routes 12V DC to the EMS-37 Pin 1. Although 12V DC reaches this point, it does not register on the VOLTMETER when the SV-1000 comes up. Should I supply 12V DC to Pin 1 from the Master Power Switch, rather than from the SV-1000 power-up switch?

Thanks for taking me to the basics.  I'm an ocean engineer, not much into electricity, but always interested in learning.  

Cheers!

 

[dynonsupport]

The resistors are in the small pack of little things (connectors, resistors, etc) that comes with the SV-EMS-220.

You can wire from anywhere on the p-leads, which means from either at the mag itself or where it connects to the ignition switch. Many people do it at the latter location because it's one less wire to run through the firewall. You do want the resistor as close to the mag as possible. Soldered inline is fine, and most people do that. If you're not familiar with good techniques for that, you might check-in with your local EAA chapter electronics whiz, or chat with an avionics shop.

You will connect both, per the Installation Guide's instructions. That lets you get a signal even during a mag check.

On pin 1 - you might give our tech support a call at 425-402-0433 so they can walk you through the setup menu and confirm that everything is set up correctly so that the unit can measure and display power.

 

[EchoCharlie1]

Excellent, thanks for walking me through this. My only concern with soldering a resistor inline is whether it can take the tensile load of the weight of the wire, or if I have to re-inforce the connection somehow. I'll take a look. It shouldn't be THAT hard. :-/

As for the voltmeter issue, I'll call tech support.

 

[mmarien]

I placed my resistors on the switch end and just used crimp on connects. I covered the whole thing with shrink wrap. See the two white wires with the black shrink wrap ends below. The resitors are in the shrink wrap.

 

[EchoCharlie1]

MMarien,

Thanks for the photo. I looked at the diagram in the install manual and did just that. I think I left about an inch from the crimped connector, but soldered the resistor inline and reinforced with shrink wrap, but left the resistor exposed (leaving no metal exposed) to permit identification.

Still perplexed about the voltmeter thingy...but hopefully will get a call to tech support today.

Cheers!!

 

[EchoCharlie1]

EUREKA!!! My setup for the EMS is to use two terminal blocks, one for the 25-pin and another for the 37-pin connectors. This way, I can attach the sensor wire to the terminal block and then have a connector attached to the terminal block to the EMS. This was all done by the builder to make it easier for maintenance when he installed a Blue Mountain One system.

Okay, so the EMS-37 connector pin-1 was for power input to the SV-1000, but I was getting 0.08V DC. Not good! After speaking with Mike from Tech Support, either I have a bad EMS, or something is amiss. I went with the latter since no else complained about EMS issues this bad. I did a continuity check from the pin-1 of the terminal block to the pin-1 outbound to the connector that leads to the EMS. Yep, you got it...there's a resistor in there that was preventing the voltages from getting to the EMS and ultimately the SV-1000. Work-around, I used pin-2 for voltmeter.

Life is good...even as a geek! A geek with a plane!

 

[EchoCharlie1]

First flight, all seemed good, BUT:

1. Using Dynon 0-30 psi sending unit, plugged into proper pin, reads only about 2.1 psi when in cruise at 2500', 18" MP and 2200 RPM.

2. "GPS ASSIST" reads across the PFD Screen, but I'm sure there's something in the install manual about that.

3. No airspeed! EEK! I suspect that one of the connectors is not seated and will investigate. Backup EFIS (BMA Lite) reads low, so there must be a leak/break in the tubing somewhere.

4. CHTs are all reading VERY low. Is there a polarity dependency on the CHTs as there is on the EGTs?

Otherwise, VERY cool system...I like it!

 

[dynonsupport]

1. If that's hooked up to oil pressure, that's not the right sensor. The 0-150psi is the oil pressure sensor. It's also not the fuel injected pressure sensor - that one's the 0-80psi one sensor.

2. Because of no airspeed.

3. Yep. Check your plumbing.

4. They are polarized, so do check that.

 

[EchoCharlie1]

1. It is hooked up to the fuel pressuse sending unit (0-30 psi) for the carb-powered O-320. Comes up to about 4.2 psi with fuel boost on. Oil pressure is reading fine.

2. But..but...there is airspeed, I was flying, really...I was.

3. I will be doing some digging tonight to find that rascal plumbing issue.

4. Great...thanks. I'll swap some around and do a ground test to verify.

Okay, quick question...with the cross-hairs on the horizon, does this mean that if I hook up a couple .50-cal guns on the wings of my RV-6, I can boresight and use that as my aiming point?

Have a great day!

 

[dynonsupport]

Not bullets (because they sink). But if you mounted lasers, it would work!

(For any lawyers / goverment types reading: The above is a joke. DO NOT SHOOT LASERS FROM YOUR AIRCRAFT)

 

[dynonsupport]

Actually, I take part of that back. They wouldn't line up with the flight path marker, but instead with the actual pitch marker.

 

[EchoCharlie1]

OR...photon torpedoes? :

On a serious note, I swapped around the wires on the CHTs, but during run-up, they only got up to about 98 degrees, even with the cowling in place. They are J-types, as recommended by the Dynon Installation Manual. The K-type EGT temps got up to about 1100 degrees during that same run-up. Thoughts?