Hercules Engines

"Scet" wrote in message
...

"Jim Yanik" wrote in message
...

There is a lot more info out their........or are you trying to be mates
with
Tarver?

Jim is not trying to be mates with me, Scet. It is only that you are being
an idiot.

"Scet" wrote in message
...

Wrong John, average on a T56

Are you narrowing your completely wrong statements about thermocouples down
to one engine now, Scet?

I suppose you do need to make some mad attempt to save some face.

Let us try again:

A URL can be made by anyone and has no guarantee of accuracy of any kind.

From: Jim Yanik
Date: 1/22/2004 5:11 PM Central Standard Time
Message-id:

(B2431) wrote in
:

Jim Yanik wrote:

"Well,then it violates basic physics.If you have two voltage sources
of
slightly different voltages,currents DO flow between them.That's a
basic principle. And bimetal TCs are simply millivolt voltage
sources."

Just picking a nit here. All thermocouples are bimetallic by
definition so the term "bimetal thermocouple" is redundant. It's kind
of like saying "8 am in the morning."

Dan, U.S. Air Force, retired


Well,I note you didn't have any argument with the first part of that post.
I apologize for my redundant statement.

BTW,how many of these TCs are paralleled together in one engine?

--
Jim Yanik
jyanik-at-kua.net

I think that depends on the engine. To be honest I no longer recall the number
as it never seemed important to me at the time.

I do know taver gets his jollies arguing and name calling. I do know the
systems I have worked on including TIT, EGT, EPR, IAS, TAS etc.

I know what it's like climbing up the exhaust pipe of an F-4E to connect the
jetcal tester to the EGT probes. I do know what a heat rise test does. I do
know when a thermocouple fails the indicator still reads since the
thermocouples are in parallel. I do know you can see each thermocouple has one
white wire and one green wire attached. The green and white colours are for
chromal-alumel systems.

Anyone who has been following what I have said in this newsgroup and who has
similar experiences can tell you I know pitot-static, engine etc instruments.

I do know if you do a google search on tarver in this and other NGs you will
find some rather outrageous statements and claims. If you confront him on these
and ask for proof you are subjected to personal and sometimes vulgar attacks
instead of independant citations that might back him up.

I choose not to debate him since he is obviously arguing for argument's sake.

BTW, I do not claim to be an expert on thermocouple systems, but I have worked
on recips and trubine engine systems.

Dan, U. S. Air Force, retired

Jim Yanik wrote:

(B2431) wrote in
:

Jim Yanik wrote:

"Well,then it violates basic physics.If you have two voltage sources
of
slightly different voltages,currents DO flow between them.That's a
basic principle. And bimetal TCs are simply millivolt voltage
sources."

Yes Jim, what you say is true but it's 'allowed' in this (and
other) cases because the voltage output, although in the
millivolt range, is 'soft'. so the current is extremely low, they
merely 'average' themselves.

You certainly couldn't parallel two different voltage sources IF
they were 'hard' because huge currents would flow. So on a T-56
engine they do indeed parallel many thermocouples. (I forget how
many now, but there's a bunch) Half are used for the FCU and half
for the Temperature Datum System.
--

-Gord.

"Gord Beaman" wrote in message
...
Jim Yanik wrote:


You certainly couldn't parallel two different voltage sources IF
they were 'hard' because huge currents would flow. So on a T-56
engine they do indeed parallel many thermocouples. (I forget how
many now, but there's a bunch) Half are used for the FCU and half
for the Temperature Datum System.

Did you know that the major failure mode for a theromocouple is a short?

Consider, Gord, that making your little friends look less foolish is only
making you look foolish.

Even if you were to make an "average", you would need a "total" first.

Jim Yanik wrote:


I fail to see how the separate thermocouples outputs will be
"averaged",because any individual TC cannot rise in output,as all the
others parallelled will prevent any rise in voltage.Or current would flow
from a higher V to a lower one,just as if you wired batteries of different
voltages together,you end up with circulating currents until all cells are
of equal voltage..
Seems to me that parallelling them is only for the possibility of an
individual thermocouple to be burned out or open.

Jim, as I mentioned before they do average. If you connected say
flashlight batteries of slightly different voltages in parallel
then quite high currents would flow because their internal
resistance is low but thermocouples have comparatively high
resistance therefore limiting the current that will flow.

Picture a slightly high voltage TC in parallel with a slightly
lower voltage TC. The high one will "pull" the voltage up
slightly. Now add another of the same voltage as the high voltage
one. This one will "pull" the voltage just slightly higher again
now add a lower voltage one, the voltage will drop slightly, as
this one pulls it down. The current BETWEEN these TC won't be
very much because the resistance is comparatively high...see?

Remember that you're right about high current flowing IF the
supplies have different voltages AND are HARD supplies (they have
low internal resistance)

An example of a very hard supply is a 'regulated power supply',
you cannot 'pull' them at all, large currents will flow and fuses
will pop. They have very low internal resistance.
--

-Gord.

"B2431" wrote in message
...

Looks like another peice of equipment Dan is incompetent to operate has been
found.

"Gord Beaman" wrote in message
news
Jim Yanik wrote:


I fail to see how the separate thermocouples outputs will be
"averaged",because any individual TC cannot rise in output,as all the
others parallelled will prevent any rise in voltage.Or current would flow
from a higher V to a lower one,just as if you wired batteries of
different
voltages together,you end up with circulating currents until all cells
are
of equal voltage..
Seems to me that parallelling them is only for the possibility of an
individual thermocouple to be burned out or open.

Jim, as I mentioned before they do average. If you connected say
flashlight batteries of slightly different voltages in parallel
then quite high currents would flow because their internal
resistance is low but thermocouples have comparatively high
resistance therefore limiting the current that will flow.

Which makes a higher voltage.

Quit while you are ahead, Gord, Danno has been hitting the bong.

"Tarver Engineering" wrote:


"Jonathan Stone" wrote in message
...
In article ,
Tarver Engineering wrote:

No, no, no. The Hercules engine is (as is well-known) a 14-cylinder
sleeve-valve radial.

(Lets see what Tarver makes of that.)

That is a lot of sparkplugs.

Hell John, not near as many as in a C-124...there's 216 in
that!...
--

-Gord.

(Jonathan Stone) wrote:

In article ,
Tarver Engineering wrote:

"Jonathan Stone" wrote in message
.. .
In article ,
Tarver Engineering wrote:

No, no, no. The Hercules engine is (as is well-known) a 14-cylinder
sleeve-valve radial.

(Lets see what Tarver makes of that.)

That is a lot of sparkplugs.

No, its completely true. Read carefully.

Quite correct...
--

-Gord.