Today's Message Index:
----------------------
1. 10:55 AM - pneumatic schematic (Doug Sapp)
2. 12:01 PM - Re: pneumatic schematic (Doug Sapp)
3. 08:22 PM - Re: White Paper on Russian Generator System (Rob Rowe)
Message 1
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| Subject: | pneumatic schematic |
My file which contained the schematic for the air system has been
corrupted and has been lost. Anyone out there have one they could email
me?? It was posted (I think) on the list a while back but I have had no
luck finding it. Any help would be appreciated.
Always Yakin,
Doug Sapp
Jill Gernetzke wrote
>
> Walt,
>
> Thanks for the follow up on my comments. The die we use is an
> Imperial Eastman Rolair Flaring Tool. It does not have any bevel on
> it for the 37 degree flare. We use the male 37 degree flare tool we
> bought from ATS. It works fine, but eventually we will machine a 37
> degree bevel in the die holes.
>
> I have plenty of rear brake cables in stock. The front sell out
> quick, as it is a longer cable and more prone to failures. If the
> outer sheathing on your brake cable is okay, we can repair it.
>
>
> Jill Gernetzke
> M-14P, Incorporated
> 4905 Flightline Drive
> Kingman, AZ 86401 -7417
> (928)-681-4400
> Fax(928)681-4404
> www.m-14p.com
>
>
Message 2
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| Subject: | Re: pneumatic schematic |
Thanks to everyone who came to my rescue with the schematic. This list
is great!!
Always yakin,
Doug
Message 3
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| Subject: | Re: White Paper on Russian Generator System |
Hi Mark,
Thanks for all this ... a very interesting discussion ... I've added some further
thoughts below.
Have also read your next edition of the white paper so will refer to some items
in that too rather than creating another long message.
Btw - I'm Rob Rowe ... Rob Kent (Russian Engineering) didn't write the differential
relay extract ... although he's a really helpful guy who's loaned various
docs to me so I can (try to) get my head around these systems ... so thanks again
Rob K from Rob R!
> Hi Rob,
>
> In the one day since I wrote that article, I have learned a lot more
> than what I knew just 24 hours ago, and some of that deals with what you
> have just brought up, so thank you for writing AS ALWAYS!
Mark ... we've both learned a lot over the last few days!
> The two short circuits to ground were both intermittant. To the best of
> my knowledge, neither of them caused the problem that I now have. Both
> shorts showed black arcing, but no wires were melted.... As in no wiring
> showed evidence of high current flow, instead it looked like a short
> "flash" and that was it. I did not write down the wire numbers, but on
> the Voltage Regulator, it was the first terminal (the one most aft) as
> you face forward in the aircraft, looking up and to the left (Yak-50).
> This terminal is on the right side of the regulator mounting bracket.
> It shorted to the mounting bracket mounting BOLT (right rear) as you
> tilted the shock mount in that direction. I did not even look for a
> marking on the wire that shorted against the airframe, but I can later
> if you like.
I posed these short circuit queries as I wasn't sure from your post whether you'd
yet found a definitive cause to your problems.
Now that you have (the eroded relay contacts), & from the nature of the flash over
described, there's not much to be gained from pursuing this ... but thanks
for offering to try!
> Here are some comments on your "comments" per se. My findings last night
> on the "polarization relay" were a big surprise.
> -------------------------
> You said:
> Quote:
> From the schematics ... a few points around the (western) DMD-200D
> "Complex Apparatus" for discussion from your description.
>
> ...
>
> So essentially the generator is voltage controlled to bring it online &
> (negative) current controlled to take it offline ... hence the differing
> engine / generator speeds related to these operations ... c.38% online &
> c.34% offline.
> ------------------------------
> My response:
>
> What you wrote above is exactly the same information I got from George
> Coy and it also matches some information I managed to get from a Russian
> manual translated to English. I also suspect that it is 100% accurate
> for SOME models of this unit. However, as we all know, Russian parts
> can sometimes have exactly the same make and part number, but what
> components we find inside are NOT the same.
> -----------------------------
RR Response #2:
My source comes from machine-translating extracts from my 1991 YAK-52 docs & and
some schematics from a Sukhoi 29 (Jan 92) that I'd been given ... to cross-reference
the discrepancies (in both!).
Btw - your Sukhoi schematic is different to mine in that its corrects a mistake
on the TKE1R2D contacts (NC, not NO), labels all the connections in English (except
the contactor "C" should be an English "S"), removes what appeared to be
a latch on the contactor & removed a "N" & "S" (North & South?) from the polarised
relay where the physically missing series coil should be ("S" on the bus
side) ... more on this latter on.
>
> I think you will find what comes next to be very interesting.
> ...
>
> Then we come to the "Polarized Relay". It did NOT have two windings on
> the same core. In fact it was instead a LATCHING relay with one coil
> only. This coil and the relay are built so that if you flow current in
> one direction it latches the relay in one position, and if you reverse
> the polarity you simply reverse the magnetic field and latch it in the
> opposite direction. Think of the internal design to be like a See-Saw
> .. I.E., a Lever Arm with a fulcrum in the middle. The coil winding
> SURROUNDS the lever arm at the fulcrum and has metal tabs to direct the
> mag field to two main points. If you energize the coil with PLUS
> voltage on one side, the magnetic field will pull the lever arm down to
> the left. If you reverse the voltage polarity, then the lever arm will
> pull down to the right. Once the lever arm is in EITHER position, when
> you remove voltage to it, it stays where it was last left at. That is
> what makes it a LATCHING relay.
>
> Even though this design is not the same as what you described (and I
> read in my own material), it never-the-less does indeed FUNCTION about
> the same way. If current from the battery start flowing into the
> generator, it will also flow through this coil backwards as well, and
> the magnetic field will reverse, the relay will OPEN and disconnect the
> main contactor just as we both described.
Excellent research Mark ... well done!
With the benefit of hindsight ... in as much as I've read the next version of your
YAK-50 white paper while still responding to this one ;-) ... maybe that's
foresight ... whatever ... it seems there might still be some credibility to
the differential relay theory.
As quoting from your next message about the polarised relay operation ... (Quote)
I could find no series winding per se, which does not necessarily mean it is
not there, just that I could not find it. The relay core in my unit had only
two wires coming out of it. (Unquote).
This is fair of you given there's nothing obvious to suggest anything other than
a single coil being present ... albeit the operation of the whole DMR-200D requires
a high current detection function to be present somewhere.
So to help figure this out one way or the other perhaps you could inspect the polarised
relay again (assuming you've still got it in bits ... a photograph would
be useful too!) for any signs of North or South markings on the structure
indicating the possibility of another polarised coil (and as hinted on my Sukhoi
schematic) ... in Cyrillic this would be a "C" & "IO" respectively [or YL:"S"
& YL:"Yu" ... this will make more sense when you've read the rest of this message!].
My guess is that because the series coil has to handle very high currents then
this might be physically embedded in the structure of the unit with no apparent
connections. So if you could check the continuity from Cyrillic "CETb" [YL:
"SETs"] across the structure of the polarised relay to find out what it's connected
to then this might give us some further insight ... similarly if you could
trace from the Contactor output contact back to the polarised relay structure
... thanks.
Again from your next message ;-) ... I've attached a PDF image file of the DMR-200D
in my 1991 YAK-52 (found a stock photo I had of the DC Power Box when the
loose connection was fixed) which I've marked up with various connections & screw
mounts you referenced (as best as I can make them out at the top of the image).
Could you confirm please if a/ it's the same unit as you have in your -50 & b/
whether I've got the labelling correct. I've also used the Cyrillic / Western
alphabet map discussed further below ... interested in your feedback. If we could
get a photograph of the polarised relay too then this could be added for future
reference by anyone trying to repeat this down the line.
> Next, this coil will operate with as little as 2 volts of voltage. This
> can be straight voltage with earth being 0 and input being 2 VDC, or..
> It can be DIFFERENTIAL voltage.
A few questions for you Mark please ...
- was this polarised coil operation at 2 volts tested with the (effectively in
parallel) TKE1R2D taken out of the circuit?
- did you have the opportunity to separately test the TKE1R2D operating voltage
characteristics?
- can you confirm that the TKE1R2D connections are as per the Sukhoi schematic
rather than the Yak schematics
i.e. TKE1R2D connection "6" goes to the DMR-200D terminal "6" (Sukhoi) & NOT to
the output connection of the Contactor contacts facing the Polarised relay (Yak)
The above will help confirm the correction to the Yak schematics (50 & 52) and
shed more light on the operations of both these relays, individually & collectively
... thanks.
> You said:
> ----------------------------
> 2 - the Cyrillic "6" terminal (western "B") will release Differential
> Relay II(a) on the bench with a ground (reverse bias), but this input is
> designed in situ to monitor the battery / generator output (depending on
> whether the generator is offline / online).
>
> ----------------------------
> My response:
> Putting a ground on this terminal (6) will cause a relay to close and
> open the electrical path to the "Differential Relay". I think we are
> both saying the same thing here. You are pointing out what it is used
> for (thanks!) but I believe I was suggesting how to check to make sure
> it was working (bench check). Bottom line here is that I need to add
> more to the explanation, thanks!
> -----------------------------
RR Response #2:
Mark what I think we've both realised is that a narrative explanation of what a
given device does in a complex system goes a long way in helping to diagnose
a problem & then to create a testing regime ... these were the purpose of my comments,
nothing more.
> You said:
> ----------------------------
> 3 - note that the Cyrillic "B" (western "V") terminal connected to the
> Coupling Relay (I) is fed by 28V (not ground) from a 10A protection fuse
> via the Over Voltage Unit / External Power Disconnect Relay contacts /
> Generator Switch control line. None of these external devices are
> connected to the Cyrillic "6" terminal. The purpose of the Coupling
> Relay (I) is to isolate the generator / voltage control equipment from
> the power bus in the event of external power connection, over voltage,
> negative polarity or fault conditions.
> -----------------------------
> My Response:
> Again I believe we are saying the same thing Rob, and I did in fact
> point out that there was 28 volts on V and not gound. What I said in
> my article was: (Quote) "The Voltage Regulator (official name "R-27")
> has outputs that feed back to control the generator excitation field,
> but it also has another output that goes over to the over voltage box.
> If the voltage is normal, the over voltage box feeds this same voltage
> (28 volts) back to pin B on the Combined Device. (Note, it looks like a
> "B" to me, that is the SHAPE of the marking, but it is actually the
> Russian letter "V".)"
>
> I believe the confusion factor here centers on what the letters actually
> look like and what they actually are in Russian. It does no good to
> Americans to tell them that 28 volts goes to terminal "V" when they look
> for themselves and see no letter "V" marked on the unit! It's a problem
> to write about this kind of thing to be sure.
> -----------------------------
RR Response #2:
Guess there are two points here;
1 - while you correctly state the "how" function in the above quote Mark later
on in your text this was made ambiguous by (Quote) The ground on terminal "6"
is usually controlled by the Generator Switch in the cockpit.(Unquote) ... and
it was this quotation that I (literally) referenced in my feedback message. Based
on;
- Cyrillic "6" is not connected to the generator switch
- but Cyrillic "B" is
- neither uses a ground when operational
Again I'd added a narrative "what" explanation to help put this in context, not
to challenge your original (correct) "how" statement
2 - Mark we're in need of a Yak-List nomenclature to avoid confusion between Cyrillic
& Western alphabets. It's easily done in a long post and you've sometimes
used one or other or both ... so I've attempted to put together a standard
alphabet map between the two as per the attached PDF file. Given it's not really
practical to try & describe the Cyrillic characters (the backwards E, upside
down L, the one that looks like a 6 etc) nor can these characters be universally
posted on the Yak-List ... fine on the web site, but plain text email trashes
them. So prefixing descriptions with for example "YL: R-27" can be read from
the map as "Yak-List: P-27" in Cyrillic, also useful when some of the chars
look quite similar and a mug shot of the definitive version can act as a reference.
If this works Ok then perhaps it could be adopted by the list for general
use?
> -------------------------------
> You said:
>
> 4 - the Over Voltage Unit (western AZP-A2) does just that ... under
> voltage is controlled by the DMD-200D "Complex Apparatus", with reverse
> polarity protection from relay IV. The AZP-A2 operates above 31-32V
> although it has a time delay to it that's voltage dependent to prevent
> short term transients tripping the device. So it can take 0.5 sec to
> trip up to 37V & 0.12 sec up to 60V ... note that this device has no
> self-test capability so we have to assume it will work when needed! Once
> tripped it has an external button to reset it.
> --------------------------------
> My response:
> When I used an external variable power supply in place of the generator,
> I ran it up past 30 volts to indeed check the over-voltage protection
> circuit trip point. It works. I did not write about it simply because
> I am not so sure it is a good idea to recommend to anyone else to do
> that.
> -----------------------------
RR Response #2:
Mark my point was simply to highlight that a 10-20 year over-voltage unit with
no self-test capability might not be relied upon to work when it's most needed,
even if it does then the over voltage response might fry anything less than
DO160 tested avionics ... bus powered portable GPS users beware!
> I appreciate the additional info you sent me here Rob, and please keep
> it coming!
Don't worry I will ;-)
Take care & thanks for all the help,
Rob R
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p-621#95621
Attachments:
http://forums.matronics.com//files/yak_52_dmr_200d_connections_144.pdf
http://forums.matronics.com//files/yak_list_alphabet_mapping_739.pdf
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