REFLECTOR: Reflector Digest, Vol 85, Issue 4 N929X in Sport Aviation
Mark Riley
the_rileys1 at verizon.net
Tue Apr 3 19:48:15 CDT 2012
Our Velocity XL, N929X, finally made an appearance in this month's Sport Aviation magazine. Check it out at page 91 of the April issue. I dreamed about seeing this little article for years.
Mark
On Apr 2, 2012, at 10:50 PM, reflector-request at tvbf.org wrote:
> Send Reflector mailing list submissions to
> reflector at tvbf.org
>
> To subscribe or unsubscribe via the World Wide Web, visit
> http://www.tvbf.org/mailman/listinfo/reflector
> or, via email, send a message with subject or body 'help' to
> reflector-request at tvbf.org
>
> You can reach the person managing the list at
> reflector-owner at tvbf.org
>
> When replying, please edit your Subject line so it is more specific
> than "Re: Contents of Reflector digest..."
>
>
> Today's Topics:
>
> 1. Re: Dynon fuel pressure (Scott Derrick)
> 2. Re: Reflector Digest, Vol 85, Issue 3 interior pictures
> (Mark Riley)
> 3. Re: Dynon fuel pressure (Brian Michalk)
>
>
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Mon, 02 Apr 2012 16:42:17 -0600
> From: Scott Derrick <scott at tnstaafl.net>
> To: Velocity Aircraft Owners and Builders list <reflector at tvbf.org>
> Subject: Re: REFLECTOR: Dynon fuel pressure
> Message-ID: <4F7A2B49.9040903 at tnstaafl.net>
> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>
> I knew we had to be on the same track Brian! I'm not the electron
> pusher you but I venture into that realm on occasion.
>
> It looks like the Dynon supplied sensor is a VDO 360-003, 0-80PSI,
> 10-180 ohms and case ground
>
> I'm going to try a VDO 360-410, 0-80PSI, 10-180ohms, with a ground lug.
> separate connections for ground and signal.
>
> Scott
>
> -------- Original Message --------
> Subject: Re: REFLECTOR: Dynon fuel pressure
> From: Brian Michalk <michalk at awpi.com>
> To: Velocity Aircraft Owners and Builders list <reflector at tvbf.org>
> Date: 04/02/2012 03:59 PM
>
>> Oh. Actually we love the same thing.
>>
>> Yes. I agree. For any sensor you give me, it needs a minimum of two
>> wires. One for voltage reference (ground) the other for signal.
>>
>> Using the chassey for signal return is asking for trouble.
>>
>> On 4/2/2012 4:20 PM, Scott Derrick wrote:
>>> I love grounded sensors and have used them in instrumentation for
>>> years in avionics( Space3 Shuttle, B1-B, etc..) and commercial
>>> systems. But I expect that what ever I connect the sensor to, will
>>> provide me with the sensor ground along side the data wire(amp. volt,
>>> freq., etc).
>>>
>>> I completely agree that using power ground for sensors is B.A.D.
>>>
>>> Now Dynon actually provides the ground connections on the EFIS and EMS
>>> but then provides shitty cheap ungrounded(meaning the ground path is
>>> the bus(power) ground. Then when you tell them your having problems
>>> they say your ground path from the engine to the instrument is bad.
>>>
>>> I swapped out the crappy Dynon provided ungrounded oil temp sensor
>>> which was pathetically inaccurate, with a GRT grounded(ground lug on
>>> sensor run to EMS) and now I get a smooth acurte reading unaffected by
>>> voltage or amperage changes on the power bus.
>>>
>>> VDO is the manufacturer of the fuel sensor sold by Dynon. They make a
>>> grounded sensor in the same PSI range, I need to find out if the
>>> resistance is the same across its pressure range of 80 PSI. Or install
>>> a GRT grounded sensor, but that sensor is only rated to 30 PSI and my
>>> system is capable of producing 32 PSI. I think that would be OK but???
>>>
>>> Scott
>>>
>>> -------- Original Message --------
>>> Subject: Re: REFLECTOR: Dynon fuel pressure
>>> From: Brian Michalk <michalk at awpi.com>
>>> To: Velocity Aircraft Owners and Builders list <reflector at tvbf.org>
>>> Date: 04/02/2012 12:49 PM
>>>
>>>> Back in my instrumentation days, the classes taught that "grounding" is
>>>> really a misnomer. There are two type of common voltage, referred to as
>>>> "ground."
>>>> The first is power grounds. This is for lights, motors, alternators and
>>>> that sort of stuff. The other type is for instrumentation. The sensor
>>>> either generates a small voltage potential, or somehow moderates a
>>>> voltage or current.
>>>>
>>>> I hate grounded sensors. They mix the power return path with my
>>>> sensitive acquisition system that I take great pains to keep noise free.
>>>> When the mfg. provides these, they contaminate all sorts of things
>>>> causing ground loops, induced voltage, and possibly injected RF noise.
>>>>
>>>> I don't consider temperature probes where the body is grounded to the
>>>> engine case for example to be a problem. In that case, the acquisition
>>>> sensor checks for a voltage drop across the temperature probe, which is
>>>> a high impedance sensor, and thus does not contaminate my sensitive
>>>> acquisition voltages. It is still a current loop and that make it
>>>> susceptible to noise because the current that went from the acquisition
>>>> system to the probe, and into the engine case has to magically find its
>>>> way back to the acquisition system somehow. The problem is that we don't
>>>> know the return path, and that's the problem.
>>>>
>>>> Okay off my sandbox. Can you put a voltmeter on the sensor? Do you get
>>>> the same results with everything turned off except the Dynon?
>>>>
>>>> On 4/2/2012 11:43 AM, Scott Derrick wrote:
>>>>> I'm having an issue of a false high fuel pressure readingon my Dynon
>>>>> EMS.
>>>>>
>>>>> I came within minutes of removing the fuel pump to see if the high
>>>>> pressure reg was dirty or the recirc outlet was clogged. A 5 hour job
>>>>> just to uncover the pump?
>>>>>
>>>>> I happened to be testing the installation of a replacement capacitive
>>>>> fuel probe and noticed the fuel pressure was reading 10 psi and the
>>>>> engine was off! I played around with re-grounding the sensor(Dynon has
>>>>> a serious Achilles heal because they use ungrounded sensors) to see if
>>>>> that would alleviate it but no joy.
>>>>>
>>>>> Anybody else have this issue?
>>>>>
>>>>> I'm thinking of switching to a GRT sensor as they are 1/2 to 1/4 the
>>>>> price of Dynon's and most are grounded.
>>>>>
>>>>> Scott
>>>>> _______________________________________________
>>>>> To change your email address, visit
>>>>> http://www.tvbf.org/mailman/listinfo/reflector
>>>>>
>>>>> Visit the gallery! www.tvbf.org/gallery
>>>>> user:pw = tvbf:jamaicangoose
>>>>> Check new archives: www.tvbf.org/pipermail
>>>>> Check old archives: http://www.tvbf.org/archives/velocity/maillist.html
>>>>
>>>> _______________________________________________
>>>> To change your email address, visit
>>>> http://www.tvbf.org/mailman/listinfo/reflector
>>>>
>>>> Visit the gallery! www.tvbf.org/gallery
>>>> user:pw = tvbf:jamaicangoose
>>>> Check new archives: www.tvbf.org/pipermail
>>>> Check old archives: http://www.tvbf.org/archives/velocity/maillist.html
>>>>
>>>
>>
>> _______________________________________________
>> To change your email address, visit
>> http://www.tvbf.org/mailman/listinfo/reflector
>>
>> Visit the gallery! www.tvbf.org/gallery
>> user:pw = tvbf:jamaicangoose
>> Check new archives: www.tvbf.org/pipermail
>> Check old archives: http://www.tvbf.org/archives/velocity/maillist.html
>>
>
> --
> No act of kindness, no matter how small, is ever wasted.
> Aesop
>
>
> ------------------------------
>
> Message: 2
> Date: Mon, 02 Apr 2012 22:31:04 -0400
> From: Mark Riley <the_rileys1 at verizon.net>
> To: reflector at tvbf.org
> Subject: Re: REFLECTOR: Reflector Digest, Vol 85, Issue 3 interior
> pictures
> Message-ID: <AD44B0E2-1339-416A-9E21-13E4260C8603 at verizon.net>
> Content-Type: text/plain; charset=us-ascii
>
> There are a bunch of interior pictures on my blog. Just check marksvelocity.blogspot.com
>
> Mark
> On Apr 2, 2012, at 5:54 PM, reflector-request at tvbf.org wrote:
>
>> Send Reflector mailing list submissions to
>> reflector at tvbf.org
>>
>> To subscribe or unsubscribe via the World Wide Web, visit
>> http://www.tvbf.org/mailman/listinfo/reflector
>> or, via email, send a message with subject or body 'help' to
>> reflector-request at tvbf.org
>>
>> You can reach the person managing the list at
>> reflector-owner at tvbf.org
>>
>> When replying, please edit your Subject line so it is more specific
>> than "Re: Contents of Reflector digest..."
>>
>>
>> Today's Topics:
>>
>> 1. Re: finished interior pictures (nmflyer1 at aol.com)
>> 2. Dynon fuel pressure (Scott Derrick)
>> 3. Re: Dynon fuel pressure (Doug Kanczuzewski)
>> 4. Re: Dynon fuel pressure (Brian Michalk)
>> 5. Re: Dynon fuel pressure (Scott Derrick)
>> 6. Re: Dynon fuel pressure (Brian Michalk)
>>
>>
>> ----------------------------------------------------------------------
>>
>> Message: 1
>> Date: Mon, 2 Apr 2012 13:23:40 -0400 (EDT)
>> From: nmflyer1 at aol.com
>> To: reflector at tvbf.org
>> Subject: Re: REFLECTOR: finished interior pictures
>> Message-ID: <8CEDF0C7AC82C04-1FF4-54B7 at webmail-d159.sysops.aol.com>
>> Content-Type: text/plain; charset="us-ascii"
>>
>>
>> Doug,
>>
>> I can send you some this evening when I get home... If you still need them.
>>
>> Kurt
>>
>>
>>
>> -----Original Message-----
>> From: Douglas Holub <douglas.holub at gmail.com>
>> To: reflector <reflector at tvbf.org>
>> Sent: Mon, Apr 2, 2012 9:14 am
>> Subject: REFLECTOR: finished interior pictures
>>
>>
>> I'm looking for some pictures of finished interiors to show my upholstery guys. I found a few on Velocity's website in the "used planes for sale" area. Can somebody point me to some more?
>>
>> Douglas Holub
>> Flying since '09, finally putting the interior in
>>
>> _______________________________________________
>> o change your email address, visit http://www.tvbf.org/mailman/listinfo/reflector
>> Visit the gallery! www.tvbf.org/gallery
>> ser:pw = tvbf:jamaicangoose
>> heck new archives: www.tvbf.org/pipermail
>> heck old archives: http://www.tvbf.org/archives/velocity/maillist.html
>>
>> -------------- next part --------------
>> An HTML attachment was scrubbed...
>> URL: <http://www.tvbf.org/mailman/private/reflector/attachments/20120402/e1be48b4/attachment-0001.htm>
>>
>> ------------------------------
>>
>> Message: 2
>> Date: Mon, 02 Apr 2012 10:43:23 -0600
>> From: Scott Derrick <scott at tnstaafl.net>
>> To: Velocity Aircraft Owners and Builders list <reflector at tvbf.org>
>> Subject: REFLECTOR: Dynon fuel pressure
>> Message-ID: <4F79D72B.3030705 at tnstaafl.net>
>> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>>
>> I'm having an issue of a false high fuel pressure readingon my Dynon EMS.
>>
>> I came within minutes of removing the fuel pump to see if the high
>> pressure reg was dirty or the recirc outlet was clogged. A 5 hour job
>> just to uncover the pump?
>>
>> I happened to be testing the installation of a replacement capacitive
>> fuel probe and noticed the fuel pressure was reading 10 psi and the
>> engine was off! I played around with re-grounding the sensor(Dynon has a
>> serious Achilles heal because they use ungrounded sensors) to see if
>> that would alleviate it but no joy.
>>
>> Anybody else have this issue?
>>
>> I'm thinking of switching to a GRT sensor as they are 1/2 to 1/4 the
>> price of Dynon's and most are grounded.
>>
>> Scott
>>
>>
>> ------------------------------
>>
>> Message: 3
>> Date: Mon, 2 Apr 2012 17:46:39 +0000
>> From: Doug Kanczuzewski <doug at customstudio.com>
>> To: Velocity Aircraft Owners and Builders list <reflector at tvbf.org>
>> Subject: Re: REFLECTOR: Dynon fuel pressure
>> Message-ID:
>> <1965FCEAF15F5244BE6BA2516824A98A05EFE8F2 at fnf-ex-1.saxton.net>
>> Content-Type: text/plain; charset="us-ascii"
>>
>> NO put I have been having the problem with mine reading 20psi consistently too low.
>>
>> Doug
>>
>> -----Original Message-----
>> From: reflector-bounces at tvbf.org [mailto:reflector-bounces at tvbf.org] On Behalf Of Scott Derrick
>> Sent: Monday, April 02, 2012 9:43 AM
>> To: Velocity Aircraft Owners and Builders list
>> Subject: REFLECTOR: Dynon fuel pressure
>>
>> I'm having an issue of a false high fuel pressure readingon my Dynon EMS.
>>
>> I came within minutes of removing the fuel pump to see if the high
>> pressure reg was dirty or the recirc outlet was clogged. A 5 hour job
>> just to uncover the pump?
>>
>> I happened to be testing the installation of a replacement capacitive
>> fuel probe and noticed the fuel pressure was reading 10 psi and the
>> engine was off! I played around with re-grounding the sensor(Dynon has a
>> serious Achilles heal because they use ungrounded sensors) to see if
>> that would alleviate it but no joy.
>>
>> Anybody else have this issue?
>>
>> I'm thinking of switching to a GRT sensor as they are 1/2 to 1/4 the
>> price of Dynon's and most are grounded.
>>
>> Scott
>> _______________________________________________
>> To change your email address, visit http://www.tvbf.org/mailman/listinfo/reflector
>>
>> Visit the gallery! www.tvbf.org/gallery
>> user:pw = tvbf:jamaicangoose
>> Check new archives: www.tvbf.org/pipermail
>> Check old archives: http://www.tvbf.org/archives/velocity/maillist.html
>>
>>
>> ------------------------------
>>
>> Message: 4
>> Date: Mon, 02 Apr 2012 13:49:21 -0500
>> From: Brian Michalk <michalk at awpi.com>
>> To: Velocity Aircraft Owners and Builders list <reflector at tvbf.org>
>> Subject: Re: REFLECTOR: Dynon fuel pressure
>> Message-ID: <4F79F4B1.4040009 at awpi.com>
>> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>>
>> Back in my instrumentation days, the classes taught that "grounding" is
>> really a misnomer. There are two type of common voltage, referred to as
>> "ground."
>> The first is power grounds. This is for lights, motors, alternators and
>> that sort of stuff. The other type is for instrumentation. The sensor
>> either generates a small voltage potential, or somehow moderates a
>> voltage or current.
>>
>> I hate grounded sensors. They mix the power return path with my
>> sensitive acquisition system that I take great pains to keep noise
>> free. When the mfg. provides these, they contaminate all sorts of
>> things causing ground loops, induced voltage, and possibly injected RF
>> noise.
>>
>> I don't consider temperature probes where the body is grounded to the
>> engine case for example to be a problem. In that case, the acquisition
>> sensor checks for a voltage drop across the temperature probe, which is
>> a high impedance sensor, and thus does not contaminate my sensitive
>> acquisition voltages. It is still a current loop and that make it
>> susceptible to noise because the current that went from the acquisition
>> system to the probe, and into the engine case has to magically find its
>> way back to the acquisition system somehow. The problem is that we
>> don't know the return path, and that's the problem.
>>
>> Okay off my sandbox. Can you put a voltmeter on the sensor? Do you get
>> the same results with everything turned off except the Dynon?
>>
>> On 4/2/2012 11:43 AM, Scott Derrick wrote:
>>> I'm having an issue of a false high fuel pressure readingon my Dynon EMS.
>>>
>>> I came within minutes of removing the fuel pump to see if the high
>>> pressure reg was dirty or the recirc outlet was clogged. A 5 hour job
>>> just to uncover the pump?
>>>
>>> I happened to be testing the installation of a replacement capacitive
>>> fuel probe and noticed the fuel pressure was reading 10 psi and the
>>> engine was off! I played around with re-grounding the sensor(Dynon has
>>> a serious Achilles heal because they use ungrounded sensors) to see if
>>> that would alleviate it but no joy.
>>>
>>> Anybody else have this issue?
>>>
>>> I'm thinking of switching to a GRT sensor as they are 1/2 to 1/4 the
>>> price of Dynon's and most are grounded.
>>>
>>> Scott
>>> _______________________________________________
>>> To change your email address, visit
>>> http://www.tvbf.org/mailman/listinfo/reflector
>>>
>>> Visit the gallery! www.tvbf.org/gallery
>>> user:pw = tvbf:jamaicangoose
>>> Check new archives: www.tvbf.org/pipermail
>>> Check old archives: http://www.tvbf.org/archives/velocity/maillist.html
>>
>>
>>
>> ------------------------------
>>
>> Message: 5
>> Date: Mon, 02 Apr 2012 15:20:32 -0600
>> From: Scott Derrick <scott at tnstaafl.net>
>> To: Velocity Aircraft Owners and Builders list <reflector at tvbf.org>
>> Subject: Re: REFLECTOR: Dynon fuel pressure
>> Message-ID: <4F7A1820.1030200 at tnstaafl.net>
>> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>>
>> I love grounded sensors and have used them in instrumentation for years
>> in avionics( Space3 Shuttle, B1-B, etc..) and commercial systems. But I
>> expect that what ever I connect the sensor to, will provide me with the
>> sensor ground along side the data wire(amp. volt, freq., etc).
>>
>> I completely agree that using power ground for sensors is B.A.D.
>>
>> Now Dynon actually provides the ground connections on the EFIS and EMS
>> but then provides shitty cheap ungrounded(meaning the ground path is the
>> bus(power) ground. Then when you tell them your having problems they say
>> your ground path from the engine to the instrument is bad.
>>
>> I swapped out the crappy Dynon provided ungrounded oil temp sensor which
>> was pathetically inaccurate, with a GRT grounded(ground lug on sensor
>> run to EMS) and now I get a smooth acurte reading unaffected by voltage
>> or amperage changes on the power bus.
>>
>> VDO is the manufacturer of the fuel sensor sold by Dynon. They make a
>> grounded sensor in the same PSI range, I need to find out if the
>> resistance is the same across its pressure range of 80 PSI. Or install
>> a GRT grounded sensor, but that sensor is only rated to 30 PSI and my
>> system is capable of producing 32 PSI. I think that would be OK but???
>>
>> Scott
>>
>> -------- Original Message --------
>> Subject: Re: REFLECTOR: Dynon fuel pressure
>> From: Brian Michalk <michalk at awpi.com>
>> To: Velocity Aircraft Owners and Builders list <reflector at tvbf.org>
>> Date: 04/02/2012 12:49 PM
>>
>>> Back in my instrumentation days, the classes taught that "grounding" is
>>> really a misnomer. There are two type of common voltage, referred to as
>>> "ground."
>>> The first is power grounds. This is for lights, motors, alternators and
>>> that sort of stuff. The other type is for instrumentation. The sensor
>>> either generates a small voltage potential, or somehow moderates a
>>> voltage or current.
>>>
>>> I hate grounded sensors. They mix the power return path with my
>>> sensitive acquisition system that I take great pains to keep noise free.
>>> When the mfg. provides these, they contaminate all sorts of things
>>> causing ground loops, induced voltage, and possibly injected RF noise.
>>>
>>> I don't consider temperature probes where the body is grounded to the
>>> engine case for example to be a problem. In that case, the acquisition
>>> sensor checks for a voltage drop across the temperature probe, which is
>>> a high impedance sensor, and thus does not contaminate my sensitive
>>> acquisition voltages. It is still a current loop and that make it
>>> susceptible to noise because the current that went from the acquisition
>>> system to the probe, and into the engine case has to magically find its
>>> way back to the acquisition system somehow. The problem is that we don't
>>> know the return path, and that's the problem.
>>>
>>> Okay off my sandbox. Can you put a voltmeter on the sensor? Do you get
>>> the same results with everything turned off except the Dynon?
>>>
>>> On 4/2/2012 11:43 AM, Scott Derrick wrote:
>>>> I'm having an issue of a false high fuel pressure readingon my Dynon EMS.
>>>>
>>>> I came within minutes of removing the fuel pump to see if the high
>>>> pressure reg was dirty or the recirc outlet was clogged. A 5 hour job
>>>> just to uncover the pump?
>>>>
>>>> I happened to be testing the installation of a replacement capacitive
>>>> fuel probe and noticed the fuel pressure was reading 10 psi and the
>>>> engine was off! I played around with re-grounding the sensor(Dynon has
>>>> a serious Achilles heal because they use ungrounded sensors) to see if
>>>> that would alleviate it but no joy.
>>>>
>>>> Anybody else have this issue?
>>>>
>>>> I'm thinking of switching to a GRT sensor as they are 1/2 to 1/4 the
>>>> price of Dynon's and most are grounded.
>>>>
>>>> Scott
>>>> _______________________________________________
>>>> To change your email address, visit
>>>> http://www.tvbf.org/mailman/listinfo/reflector
>>>>
>>>> Visit the gallery! www.tvbf.org/gallery
>>>> user:pw = tvbf:jamaicangoose
>>>> Check new archives: www.tvbf.org/pipermail
>>>> Check old archives: http://www.tvbf.org/archives/velocity/maillist.html
>>>
>>> _______________________________________________
>>> To change your email address, visit
>>> http://www.tvbf.org/mailman/listinfo/reflector
>>>
>>> Visit the gallery! www.tvbf.org/gallery
>>> user:pw = tvbf:jamaicangoose
>>> Check new archives: www.tvbf.org/pipermail
>>> Check old archives: http://www.tvbf.org/archives/velocity/maillist.html
>>>
>>
>> --
>> When one door of happiness closes, another opens; but often we look so
>> long at the closed door that we do not see the one which has been opened
>> for us.
>> Helen Keller
>>
>>
>> ------------------------------
>>
>> Message: 6
>> Date: Mon, 02 Apr 2012 16:59:38 -0500
>> From: Brian Michalk <michalk at awpi.com>
>> To: Velocity Aircraft Owners and Builders list <reflector at tvbf.org>
>> Subject: Re: REFLECTOR: Dynon fuel pressure
>> Message-ID: <4F7A214A.5010200 at awpi.com>
>> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>>
>> Oh. Actually we love the same thing.
>>
>> Yes. I agree. For any sensor you give me, it needs a minimum of two
>> wires. One for voltage reference (ground) the other for signal.
>>
>> Using the chassey for signal return is asking for trouble.
>>
>> On 4/2/2012 4:20 PM, Scott Derrick wrote:
>>> I love grounded sensors and have used them in instrumentation for
>>> years in avionics( Space3 Shuttle, B1-B, etc..) and commercial
>>> systems. But I expect that what ever I connect the sensor to, will
>>> provide me with the sensor ground along side the data wire(amp. volt,
>>> freq., etc).
>>>
>>> I completely agree that using power ground for sensors is B.A.D.
>>>
>>> Now Dynon actually provides the ground connections on the EFIS and EMS
>>> but then provides shitty cheap ungrounded(meaning the ground path is
>>> the bus(power) ground. Then when you tell them your having problems
>>> they say your ground path from the engine to the instrument is bad.
>>>
>>> I swapped out the crappy Dynon provided ungrounded oil temp sensor
>>> which was pathetically inaccurate, with a GRT grounded(ground lug on
>>> sensor run to EMS) and now I get a smooth acurte reading unaffected by
>>> voltage or amperage changes on the power bus.
>>>
>>> VDO is the manufacturer of the fuel sensor sold by Dynon. They make a
>>> grounded sensor in the same PSI range, I need to find out if the
>>> resistance is the same across its pressure range of 80 PSI. Or
>>> install a GRT grounded sensor, but that sensor is only rated to 30 PSI
>>> and my system is capable of producing 32 PSI. I think that would be
>>> OK but???
>>>
>>> Scott
>>>
>>> -------- Original Message --------
>>> Subject: Re: REFLECTOR: Dynon fuel pressure
>>> From: Brian Michalk <michalk at awpi.com>
>>> To: Velocity Aircraft Owners and Builders list <reflector at tvbf.org>
>>> Date: 04/02/2012 12:49 PM
>>>
>>>> Back in my instrumentation days, the classes taught that "grounding" is
>>>> really a misnomer. There are two type of common voltage, referred to as
>>>> "ground."
>>>> The first is power grounds. This is for lights, motors, alternators and
>>>> that sort of stuff. The other type is for instrumentation. The sensor
>>>> either generates a small voltage potential, or somehow moderates a
>>>> voltage or current.
>>>>
>>>> I hate grounded sensors. They mix the power return path with my
>>>> sensitive acquisition system that I take great pains to keep noise free.
>>>> When the mfg. provides these, they contaminate all sorts of things
>>>> causing ground loops, induced voltage, and possibly injected RF noise.
>>>>
>>>> I don't consider temperature probes where the body is grounded to the
>>>> engine case for example to be a problem. In that case, the acquisition
>>>> sensor checks for a voltage drop across the temperature probe, which is
>>>> a high impedance sensor, and thus does not contaminate my sensitive
>>>> acquisition voltages. It is still a current loop and that make it
>>>> susceptible to noise because the current that went from the acquisition
>>>> system to the probe, and into the engine case has to magically find its
>>>> way back to the acquisition system somehow. The problem is that we don't
>>>> know the return path, and that's the problem.
>>>>
>>>> Okay off my sandbox. Can you put a voltmeter on the sensor? Do you get
>>>> the same results with everything turned off except the Dynon?
>>>>
>>>> On 4/2/2012 11:43 AM, Scott Derrick wrote:
>>>>> I'm having an issue of a false high fuel pressure readingon my Dynon
>>>>> EMS.
>>>>>
>>>>> I came within minutes of removing the fuel pump to see if the high
>>>>> pressure reg was dirty or the recirc outlet was clogged. A 5 hour job
>>>>> just to uncover the pump?
>>>>>
>>>>> I happened to be testing the installation of a replacement capacitive
>>>>> fuel probe and noticed the fuel pressure was reading 10 psi and the
>>>>> engine was off! I played around with re-grounding the sensor(Dynon has
>>>>> a serious Achilles heal because they use ungrounded sensors) to see if
>>>>> that would alleviate it but no joy.
>>>>>
>>>>> Anybody else have this issue?
>>>>>
>>>>> I'm thinking of switching to a GRT sensor as they are 1/2 to 1/4 the
>>>>> price of Dynon's and most are grounded.
>>>>>
>>>>> Scott
>>>>> _______________________________________________
>>>>> To change your email address, visit
>>>>> http://www.tvbf.org/mailman/listinfo/reflector
>>>>>
>>>>> Visit the gallery! www.tvbf.org/gallery
>>>>> user:pw = tvbf:jamaicangoose
>>>>> Check new archives: www.tvbf.org/pipermail
>>>>> Check old archives: http://www.tvbf.org/archives/velocity/maillist.html
>>>>
>>>> _______________________________________________
>>>> To change your email address, visit
>>>> http://www.tvbf.org/mailman/listinfo/reflector
>>>>
>>>> Visit the gallery! www.tvbf.org/gallery
>>>> user:pw = tvbf:jamaicangoose
>>>> Check new archives: www.tvbf.org/pipermail
>>>> Check old archives: http://www.tvbf.org/archives/velocity/maillist.html
>>>>
>>>
>>
>>
>>
>> ------------------------------
>>
>> _______________________________________________
>> Visit the gallery! tvbf:jamaicangoose
>>
>> End of Reflector Digest, Vol 85, Issue 3
>> ****************************************
>
>
>
> ------------------------------
>
> Message: 3
> Date: Mon, 02 Apr 2012 21:52:36 -0500
> From: Brian Michalk <michalk at awpi.com>
> To: Velocity Aircraft Owners and Builders list <reflector at tvbf.org>
> Subject: Re: REFLECTOR: Dynon fuel pressure
> Message-ID: <4F7A65F4.4080503 at awpi.com>
> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>
> Yes, VDO makes I thought all of their sensors in ungrounded and grounded
> versions. I have a few of them on the plane for oil pressure and fuel
> pressure, which for me is 45PSI.
>
> None of mine are hard mounted to the engine. I've heard that the
> vibration can cause them to fail at the neck. The orifice is a few
> thousandths in diameter, really small, so if it does break off it won't
> flow very much.
>
> On 04/02/2012 05:42 PM, Scott Derrick wrote:
>> I knew we had to be on the same track Brian! I'm not the electron
>> pusher you but I venture into that realm on occasion.
>>
>> It looks like the Dynon supplied sensor is a VDO 360-003, 0-80PSI,
>> 10-180 ohms and case ground
>>
>> I'm going to try a VDO 360-410, 0-80PSI, 10-180ohms, with a ground
>> lug. separate connections for ground and signal.
>>
>> Scott
>
>
>
> ------------------------------
>
> _______________________________________________
> Visit the gallery! tvbf:jamaicangoose
>
> End of Reflector Digest, Vol 85, Issue 4
> ****************************************
More information about the Reflector
mailing list