Harvey - Solenoid Fault Checking ? - Page 2

Trevor · #16 04-09-2006, 05:37 PM

Harvey,

I give you full credit for spending a great deal of time at your easel, but in this regard please take note of that which appends my signature.

Trevor.

oab_au · #17 04-10-2006, 05:58 PM

Quote:

Originally Posted by b3lha

Harvey,

I'm not wishing to get in the line of fire here, but could you clarify further.

Suppose the solenoid starts off closed and is then activated at a 10% duty cycle as per your diagram above. One cycle being 1/50th second = 20ms.

From my reading of your description, the initial 2ms pulse is enough to open the solenoid slightly, opposing the spring and the oil damping. But the remaining 18ms is not enough time for the spring to even slightly close the solenoid because of the oil damping? And then the next pulse hits and keeps the solenoid in its current position, not opening it any further?

It sounds like the spring tension and the level of oil damping must be very very accurate for this to work. A 2ms pulse at 1A opening the solenoid by exactly 10%. A worn spring or thinner/thicker fluid could cause significant variations. Does the TCU self-calibrate in some way?

From my purely theoretical standpoint, I can understand the idea of the solenoid oscillating such that averaged over any given time period, it is fully open for 10% and fully closed for 90%. But I can't yet grasp how a duty cycle can maintain the solenoid at an exactly defined partially open position.

Phil.

Gid'ay Phil, I'll admit that it is not an easy concept to grasp, maybe I have been too technical. and you have taken me too literally.

You have to remember that the spring pressure is dependant on the armature position, the further up the coil, the higher the spring pressure. So the spring pressure at 10% open is not as strong as it is at 90% open.

As far as the spring pressure and the oil damping goes, the whole valve body operates under these conditions, so they can get it right.

Maybe a better way to explain it is to think of a solenoid that has an armature with a return spring in it. When we turn the current on, the armature is pulled up to the end, compressing the spring. When we turn the current off, the spring pushes the armature back. Now this movement is the result of the strength of the magnetic field, and the opposing pressure of the spring.

When we apply a Duty cycle feed to the coil, we are controlling the amount of current that flows through the coil, hence the strength, of the magnetic field.

Now if we start to apply a 10/90% cycle to it, we are only allowing 10% of the total magnetic strength to be developed, so the armature has enough strength to slightly compress the spring, but not enough to compress it fully, If we then apply a higher Duty cycle to it, say 50/50%, the magnetic field is increased, and is now strong enough to compress the spring further, to move the armature towards the centre of the solenoid, where the magnetic field is equalled by the rising pressure of the spring. While that Duty cycle is maintained, the armature will stay in that position.

Now I think you can see, that if we vary the Duty cycle, we can move the armature, to any position in the solenoid, and hold it there, for as long as we like.

To try to operate the valve by turning it on for 10% of the time, and turning it off for 90% of the time. Would produce peaks of high and low oil pressure that would be transmitted through the whole apply system. In the case of the C solenoid, the transfer clutch would respond at the same frequency, to produce serve drive line vibration. I know Trevor will say that " Pressure Modifier "

will smooth it out,

but there is none in the C solenoid circuit.

Getting back to the original. The aim is to find the way that the TCU can tell if the valve is stuck. If inductance is used to detect this then there has to be a recognisable difference, between the valve being open or closed. If the solenoid is driven by the Duty cycle to open for a timed period each time, as Trevor suggests, the inductance at each rise time, would be the same. If the valve stuck in the off position there would be no change in the inductance produced, so it would not know it was not moving.

With the valve operating as I say the position is known at any time, or position. As the different position gives a difference inductance, so a difference Rise Time. A valve stuck in any position is detectable.

Does this make it any clearer Phil.?

Harvey.

Trevor · #18 04-11-2006, 02:38 AM

Harvey Quote - Gid'ay Phil, I'll admit that it is not an easy concept to grasp, maybe I have been too technical. and you have taken me too literally.
-----------------------------------------

Reply by Trevor - As I am the instigator of this thread and I as am mentioned obliquely in this post, I have a right of reply. You may have included a great deal of alleged technical jargon by way of padding, but none of it makes sense. It was well understood I am sure and rejected for good reason. You insult Phil by inferring that he has been unable to grasp your “concept”. Your patronising attitude, I am confident will not be appreciated.
-----------------------------------------

Quote - You have to remember that the spring pressure is dependant on the armature position, the further up the coil, the higher the spring pressure. So the spring pressure at 10% open is not as strong as it is at 90% open.
-----------------------------------------

My Reply - As Phil and I have both pointed out the spring pressure will vary in manufacture and with age. You are suggesting the maintenance of a balance of forces in excess of knife edge conditions. This is impossible.
-----------------------------------------

Quote - As far as the spring pressure and the oil damping goes, the whole valve body operates under these conditions, so they can get it right.
_____________________________________

My Reply - Please Harvey stick to the technical language of which you pretend to be capable. Who or what are “they”. This sentence means and says nothing. What is this mystical adjusting force which can balance all the variables which Phil and I have pointed out?????
THIS IS THE FACTOR THAT YOU MUST EXACTLY AND PROPERLY EXPLAIN. YOUR THEORY FALLS APART UNLESS YOU CAN DO SO.
--------------------------------------------

Quote - Maybe a better way to explain it is to think of a solenoid that has an armature with a return spring in it. When we turn the current on, the armature is pulled up to the end, compressing the spring. When we turn the current off, the spring pushes the armature back. Now this movement is the result of the strength of the magnetic field, and the opposing pressure of the spring.

When we apply a Duty cycle feed to the coil, we are controlling the amount of current that flows through the coil, hence the strength, of the magnetic field.

Now if we start to apply a 10/90% cycle to it, we are only allowing 10% of the total magnetic strength to be developed, so the armature has enough strength to slightly compress the spring, but not enough to compress it fully, If we then apply a higher Duty cycle to it, say 50/50%, the magnetic field is increased, and is now strong enough to compress the spring further, to move the armature towards the centre of the solenoid, where the magnetic field is equalled by the rising pressure of the spring. While that Duty cycle is maintained, the armature will stay in that position.

Now I think you can see, that if we vary the Duty cycle, we can move the armature, to any position in the solenoid, and hold it there, for as long as we like.

------------------------------------
My Reply - You have repeated in a patronising manner, that which we already understand in respect of your impossible theory. You may “like” to hold the armature stationary, I would not attempt the impossible. What you suggest could be achieved ONLY if all the variables and the control signal could be MAINTAINED with EXTREME accuracy, much beyond that possible in a practical application of this sort. In the real world, these variable factors are continually adjusted by means of feed back loop, which definitely is not available in this case.

Please explain how the several following absolute variables, all of considerable magnitude, have no effect in respect of your theory.

Subaru, the undeniable authority, state that the solenoid has a tolerance of 1.5 to 4.5 ohms.
There is a circuit supplying current to the solenoid, quite independent of the modulated supply, via the famous resistor. Subaru give this resistor a tolerance of 9 to 15 Ohms.
Many reading this have either disconnected the resistor, changed its value, or fitted the “Shift Kit”.
Just why have none of these factors in relation to a parallel supply, not caused your alleged, armature in suspension, to shift ?????????
--------------------------------------

Quote - To try to operate the valve by turning it on for 10% of the time, and turning it off for 90% of the time. Would produce peaks of high and low oil pressure that would be transmitted through the whole apply system. In the case of the C solenoid, the transfer clutch would respond at the same frequency, to produce serve drive line vibration. I know Trevor will say that " Pressure Modifier " will smooth it out, but there is none in the C solenoid circuit.
---------------------------------------------

My Reply - The pressure modifier and pressure accumulator smooth the line pressure, i.e. the complete actuating portion of the system IS SMOOTHED as a result of this arrangement.
THE C SOLENOID CIRCUIT IS IN FACT SMOOTHED, as it is supplied from line pressure, therefore it DOES NOT provide an intermittent fluid supply to the transfer clutch.
----------------------------------------

Quote - Getting back to the original. The aim is to find the way that the TCU can tell if the valve is stuck. If inductance is used to detect this then there has to be a recognisable difference, between the valve being open or closed. If the solenoid is driven by the Duty cycle to open for a timed period each time, as Trevor suggests, the inductance at each rise time, would be the same. If the valve stuck in the off position there would be no change in the inductance produced, so it would not know it was not moving.
-----------------------------------

My Reply - Your intention is to endeavour to divert the base subject. In any event what you state makes no sense. e.g. “ so IT would not know it was not moving”.
There most certainly will be a measurable difference if the armature is open or closed. N.B. In the next paragraph you boldly state by way of confirmation, that a “different position gives a different inductance”. I pointed out that the inductance could be measured and compared with a known value by means of a bridge circuit. You have now made it clear that you do not understand the basic principals involved and are incapable of sound reasoning, or statement of fact.
----------------------------------------

Quote - With the valve operating as I say the position is known at any time, or position. As the different position gives a difference inductance, so a difference Rise Time. A valve stuck in any position is detectable.
------------------------------------------
My Reply - (“difference in” ?) Just how would you measure this infinitesimal value at a viable cost and why would not the variables pointed out upset measurements????? I recall that you mentioned a computer, where is it ???
------------------------------------------

Does this make it any clearer Phil.?
------------------------------------------

Trevor --- All that previously posted was I am sure perfectly clear to Phil, as it brought forth an exact reply. His answer will be awaited with interest.

b3lha · #19 04-11-2006, 11:33 AM

Thanks for clarifying that Harvey. I was taking your previous post too literally.

Your new explanation makes more sense to me. If I understand correctly you are saying that the response time of the solenoid is significantly greater than the frequency of the duty cycle and therefore it cannot respond to each and every pulse. Instead it's effectively averageing out the signal.

Does the TCU decide that it wants the solenoid open by a given amount? This would surely necessite the spring in the solenoid to be calibrated to the duty cycle so that (for example) a 50% duty cycle corresponds with a 50% open valve. There is undoubtedly some tolerance, maybe it's not such a knife edge as Trevor suggests. Looking at how small the solenoid is, I can't see a couple of percent either way making a significant difference to the functioning of the transmission.

Or does the TCU just gradually increase the duty cycle, 10% at a time, until the trigger condition which caused it to open the solenoid is negated?

Coming back to the original point of the thread, none of this theory makes any real difference when it comes to repairing the transmission. The solenoid is a "black box" part and it doesn't really matter how it works internally. It either works within spec, or not.

The object of the error code is not to conclusively identify the problem, just to tell the mechanic where to start looking for the problem. In the event of a code 12, a mechanic will probably just check the wiring and fit a new solenoid as instructed in the service manual.
Phil.

oab_au · #20 04-11-2006, 05:44 PM

Quote:

Originally Posted by b3lha

Thanks for clarifying that Harvey. I was taking your previous post too literally.

Your new explanation makes more sense to me. If I understand correctly you are saying that the response time of the solenoid is significantly greater than the frequency of the duty cycle and therefore it cannot respond to each and every pulse. Instead it's effectively averageing out the signal.

Does the TCU decide that it wants the solenoid open by a given amount? This would surely necessite the spring in the solenoid to be calibrated to the duty cycle so that (for example) a 50% duty cycle corresponds with a 50% open valve. There is undoubtedly some tolerance, maybe it's not such a knife edge as Trevor suggests. Looking at how small the solenoid is, I can't see a couple of percent either way making a significant difference to the functioning of the transmission.

Or does the TCU just gradually increase the duty cycle, 10% at a time, until the trigger condition which caused it to open the solenoid is negated?

Coming back to the original point of the thread, none of this theory makes any real difference when it comes to repairing the transmission. The solenoid is a "black box" part and it doesn't really matter how it works internally. It either works within spec, or not.

The object of the error code is not to conclusively identify the problem, just to tell the mechanic where to start looking for the problem. In the event of a code 12, a mechanic will probably just check the wiring and fit a new solenoid as instructed in the service manual.
Phil.

Yes Phil the mass of the armature, spring pressure, and the oil resistance, will prevent the armature from responding to each pulse of the Duty cycle. The Duty cycle just averages the current applied to the solenoid, hence, the magnetic field, that the armature exerts on the spring.

Yes the TCU decides the position of the armature, with the percentage of Duty cycle it sends to it. I don't think it is necessary for the exact position to be fixed, for the percentage of duty cycle applied. For instance, a 50% Duty cycle applied to the C solenoid, may, or may not, provide 50% of the total pressure applied to the transfer clutch, you can't tell by the way the car drives, can you? but it will certainly provide the variation between 0 and 100%.

The Duty cycle has to suit the solenoid. If the Duty cycle frequency is slowed, the armature would start to pulse. If it is increased too far the armature won't respond at all.

I don't think that the TCU looks for a feedback on the armatures position. Though using the system that I suggested for finding its position, it would be possible. I built a machine for winding car springs back in the mid 70s that used a solenoid for this type to drive a ram. I just chose the Duty cycle frequency and percentage to produce the results, if it was a exact liner motion or not, did not matter, as long as the right action results.

It is a bit beside the point, if a code is posted, it is either a fault in the wiring or the solenoid is faulty. But it does help it troubleshooting, as we now that even if the wiring and solenoid resistance checks out OK, it still can be the solenoid.

Thanks for the feed back Phil.

Harvey.

oab_au · #21 04-11-2006, 06:59 PM

Quote:

Originally Posted by Trevor

Harvey Quote - Gid'ay Phil, I'll admit that it is not an easy concept to grasp, maybe I have been too technical. and you have taken me too literally.
-----------------------------------------

Reply by Trevor - As I am the instigator of this thread and I as am mentioned obliquely in this post, I have a right of reply. You may have included a great deal of alleged technical jargon by way of padding, but none of it makes sense. It was well understood I am sure and rejected for good reason. You insult Phil by inferring that he has been unable to grasp your “concept”. Your patronising attitude, I am confident will not be appreciated.
-----------------------------------------Not worth a comment

Quote - You have to remember that the spring pressure is dependant on the armature position, the further up the coil, the higher the spring pressure. So the spring pressure at 10% open is not as strong as it is at 90% open.
-----------------------------------------

My Reply - As Phil and I have both pointed out the spring pressure will vary in manufacture and with age. You are suggesting the maintenance of a balance of forces in excess of knife edge conditions. This is impossible.
-----------------------------------------Some of the finest time pieces use a SPRING

Quote - As far as the spring pressure and the oil damping goes, the whole valve body operates under these conditions, so they can get it right.
_____________________________________

My Reply - Please Harvey stick to the technical language of which you pretend to be capable. Who or what are “they”. This sentence means and says nothing. What is this mystical adjusting force which can balance all the variables which Phil and I have pointed out?????
THIS IS THE FACTOR THAT YOU MUST EXACTLY AND PROPERLY EXPLAIN. YOUR THEORY FALLS APART UNLESS YOU CAN DO SO.
--------------------------------------------The MYSTICAL force is called magnetism

Quote - Maybe a better way to explain it is to think of a solenoid that has an armature with a return spring in it. When we turn the current on, the armature is pulled up to the end, compressing the spring. When we turn the current off, the spring pushes the armature back. Now this movement is the result of the strength of the magnetic field, and the opposing pressure of the spring.

When we apply a Duty cycle feed to the coil, we are controlling the amount of current that flows through the coil, hence the strength, of the magnetic field.

Now if we start to apply a 10/90% cycle to it, we are only allowing 10% of the total magnetic strength to be developed, so the armature has enough strength to slightly compress the spring, but not enough to compress it fully, If we then apply a higher Duty cycle to it, say 50/50%, the magnetic field is increased, and is now strong enough to compress the spring further, to move the armature towards the centre of the solenoid, where the magnetic field is equalled by the rising pressure of the spring. While that Duty cycle is maintained, the armature will stay in that position.

Now I think you can see, that if we vary the Duty cycle, we can move the armature, to any position in the solenoid, and hold it there, for as long as we like.

------------------------------------
My Reply - You have repeated in a patronising manner, that which we already understand in respect of your impossible theory. You may “like” to hold the armature stationary, I would not attempt the impossible. What you suggest could be achieved ONLY if all the variables and the control signal could be MAINTAINED with EXTREME accuracy, much beyond that possible in a practical application of this sort. In the real world, these variable factors are continually adjusted by means of feed back loop, which definitely is not available in this case.

Please explain how the several following absolute variables, all of considerable magnitude, have no effect in respect of your theory.

Subaru, the undeniable authority, state that the solenoid has a tolerance of 1.5 to 4.5 ohms.
There is a circuit supplying current to the solenoid, quite independent of the modulated supply, via the famous resistor. Subaru give this resistor a tolerance of 9 to 15 Ohms.
Many reading this have either disconnected the resistor, changed its value, or fitted the “Shift Kit”.
Just why have none of these factors in relation to a parallel supply, not caused your alleged, armature in suspension, to shift ?????????
--------------------------------------It does Trev, it reduces the magnetic field, to open the solenoid, to raise the line pressure, I thought you knew that.

Quote - To try to operate the valve by turning it on for 10% of the time, and turning it off for 90% of the time. Would produce peaks of high and low oil pressure that would be transmitted through the whole apply system. In the case of the C solenoid, the transfer clutch would respond at the same frequency, to produce serve drive line vibration. I know Trevor will say that " Pressure Modifier " will smooth it out, but there is none in the C solenoid circuit.
---------------------------------------------

My Reply - The pressure modifier and pressure accumulator smooth the line pressure, i.e. the complete actuating portion of the system IS SMOOTHED as a result of this arrangement.
THE C SOLENOID CIRCUIT IS IN FACT SMOOTHED, as it is supplied from line pressure, therefore it DOES NOT provide an intermittent fluid supply to the transfer clutch.
----------------------------------------Your are showing your lack of knowledge of auto trans. This is the circuit of the C Solenoid. show me where the pulsations are "SMOOTHED OUT"

Quote - Getting back to the original. The aim is to find the way that the TCU can tell if the valve is stuck. If inductance is used to detect this then there has to be a recognisable difference, between the valve being open or closed. If the solenoid is driven by the Duty cycle to open for a timed period each time, as Trevor suggests, the inductance at each rise time, would be the same. If the valve stuck in the off position there would be no change in the inductance produced, so it would not know it was not moving.
-----------------------------------

My Reply - Your intention is to endeavour to divert the base subject. In any event what you state makes no sense. e.g. “ so IT would not know it was not moving”.
There most certainly will be a measurable difference if the armature is open or closed. N.B. In the next paragraph you boldly state by way of confirmation, that a “different position gives a different inductance”. I pointed out that the inductance could be measured and compared with a known value by means of a bridge circuit. You have now made it clear that you do not understand the basic principals involved and are incapable of sound reasoning, or statement of fact.
----------------------------------------Now you are showing your lack of modern technology. Bridge circuits went out with the thermionic valve. We don't need to build hard wear to do this, a computer only needs a few lines of code, to measure the Rise Time of the Duty cycle, on time, to tell.

Quote - With the valve operating as I say the position is known at any time, or position. As the different position gives a difference inductance, so a difference Rise Time. A valve stuck in any position is detectable.
------------------------------------------
My Reply - (“difference in” ?) Just how would you measure this infinitesimal value at a viable cost and why would not the variables pointed out upset measurements????? I recall that you mentioned a computer, where is it ???
------------------------------------------Oh I see now, you don't even know that the TCU is a computer. Woo ho.

Does this make it any clearer Phil.?
------------------------------------------

Trevor --- All that previously posted was I am sure perfectly clear to Phil, as it brought forth an exact reply. His answer will be awaited with interest.

Well you got Phils answer, and you got mine.

Now I'll give you Subaru's.

This is a scan of the Air Conditioning Swash plate actuating solenoid (Section 4-7 page 9) that alters the compressor output, it works the same as all the solenoids, driven by a Duty cycle. If you can read it, it says that the armature that pushes the valve, is held in the middle position, and is moved back and forewords from there, to control the Swash plate.

As you can read, it uses the Duty cycle to regulate the current flow in the solenoid, hence, the magnetic field, to position the armature, and HOLD IT THERE, to keep the Swash plate, and the compressors output, at that setting.

You can now not deny that the armature is positioned and held stationary by the Duty cycle. It is plain for every body to see.

What else is plain for every body to see, is that your whole intension of this thread, and all your derogative comments to me in other threads, are designed to discredit and defame me.

Well mate I'll save you your time, give it up, get off my back.

Your not in the same class.

Harvey.

Trevor · #22 04-11-2006, 09:07 PM

Quote:

Originally Posted by b3lha

Thanks for clarifying that Harvey. I was taking your previous post too literally.

Your new explanation makes more sense to me. If I understand correctly you are saying that the response time of the solenoid is significantly greater than the frequency of the duty cycle and therefore it cannot respond to each and every pulse. Instead it's effectively averageing out the signal.

Trevor - The armature may not bottom as a result, as I have pointed out, but it most certainly wil not, does not and can not, remain stationary, as is Harvey's exactly stated theory. Furthermore the signal, in so far as current and therefore positional control of the solenoid, can not remain constant as would be required. This I have pointed out by giving several reasons in detail. N.B. including the presence of a variable parallel circuit involved.

Does the TCU decide that it wants the solenoid open by a given amount? This would surely necessite the spring in the solenoid to be calibrated to the duty cycle so that (for example) a 50% duty cycle corresponds with a 50% open valve. There is undoubtedly some tolerance, maybe it's not such a knife edge as Trevor suggests. Looking at how small the solenoid is, I can't see a couple of percent either way making a significant difference to the functioning of the transmission.

Trevor - Yes MOST surely the spring would have to be calibrated and most importantly remain so, to an impossible degree, along with other variables.. An exact balance IS required. There is NO force preventing the armature from moving either way. There is damping which is variable, in the form of the fluid, but this only introduces the element of time, not force or a continual fixed resistance. An error of .000000000001% either way will upset the suggested balance and the armature will move accordingly. The element of suggested balance is further made impossible, as a solenoid is hugely non linear, with force increasing at a hugely non linear rate, as the armature reaches the fully inwards position. At the near inwards position, the factors calling for balance are extreme.

Or does the TCU just gradually increase the duty cycle, 10% at a time, until the trigger condition which caused it to open the solenoid is negated?

Trevor - This is exacly what would be required and this action requires a balanced loop feed back system. Otherwise the "condition" required, can not be assesed or maintained. The "condition" can not be negated, or restored, so as to be kept in ACCURATE balance without such a system. A feed back loop could provide a means of continual adjustment in order to maintain a balance.

Coming back to the original point of the thread, none of this theory makes any real difference when it comes to repairing the transmission. The solenoid is a "black box" part and it doesn't really matter how it works internally. It either works within spec, or not.

The object of the error code is not to conclusively identify the problem, just to tell the mechanic where to start looking for the problem. In the event of a code 12, a mechanic will probably just check the wiring and fit a new solenoid as instructed in the service manual.
Phil.

Phil, in this regard the point is that Harvey has gone to a great deal of trouble in an effort to infer that what I have posted is wrong and I reserve the right to defend myself.

I trust that you will study my reply, as inserted above, without bias.

Trevor.

b3lha · #23 04-12-2006, 03:53 AM

I'll happily read either of your posts without bias, however as a computer geek, I admit to being out of my depth in this discussion and relying on logic rather than knowledge.

I found the following article about electrohydraulic valves, which I believe contains some relevant information.

http://www.hydraulicspneumatics.com/...ue/6413/Valves

Quote:

Traditionally, the term servovalve describes valves that use closed-loop control. They monitor and feed back the main-stage spool position to a pilot stage or driver either mechanically or electronically. Proportional valves, on the other hand, move the main-stage spool in direct proportion to a command signal, but they usually do not have any means of automatic error correction (feedback) within the valve.
....
Typically, proportional valves use one or two proportional solenoids to move the spool by driving it against a set of balanced springs. The resultant spool displacement is proportional to the current driving the solenoids.

In the case of Solenoid B, surely the TCU can tell whether or not the TC is locked up. It has an engine RPM signal and a Speed Sensor within the transmission. Could it not just increase the duty cycle until the feedback from these sensors indicate that the TC is locked.

Phil.

Trevor · #24 04-12-2006, 05:00 AM

Quote:

Originally Posted by b3lha

I'll happily read either of your posts without bias, however as a computer geek, I admit to being out of my depth in this discussion and relying on logic rather than knowledge.

I found the following article about electrohydraulic valves, which I believe contains some relevant information.

http://www.hydraulicspneumatics.com/...ue/6413/Valves

In the case of Solenoid B, surely the TCU can tell whether or not the TC is locked up. It has an engine RPM signal and a Speed Sensor within the transmission. Could it not just increase the duty cycle until the feedback from these sensors indicate that the TC is locked.

Phil.

Thanks Phil, but unfortunately the site covers an entirely different animal.

The problem here is that the solenoid valves have to be monitored for faults as a separate identity. The fact that the controlled device does, or does not activate could be atributed to factors other than the control valve.

I do not agree that you are out of your depth. The debate is based on common logic. Your sensible comments are of value and are appreciated.

Cheers, Trevor.

b3lha · #25 04-12-2006, 05:18 AM

Quote:

Originally Posted by Trevor

Thanks Phil, but unfortunately this covers an entirely different animal.

Sorry for introducing a different animal into the discussion. Is this page any more relevant?

http://www.fas.ch/info_tech_prop.asp...Langue=english

The key to the operation of a proportional valve is a balance established between the forces in action on the plunger.

These balanced forces include a mechanical force provided by a spring specially developed for proportional valves and a magnetic force created by the current level passing through the coil.

The spring force is proportionaly opposed by the magnetic force.
.....
Control
Usually, a closed control loop circuit and a pressure (or flow) sensor are used with the power supply.
If high precision is not an issue, one can also use an open control loop

Quote:

Originally Posted by Trevor

I do not agree that you are out of your depth. The debate is based on common logic. Your sensible comments are of value and are appreciated.

Thank you.

Phil.

Trevor · #26 04-12-2006, 05:33 AM

Greetings once again Harvey,

Your extreme use of the network is presenting problems. I trust you have contributed to it’s upkeep as I have. I am forced to copy and paste in order to reply which is regrettable, as this is less than desirable. The thread is becoming much confused, in line with your intentions.

HARVEY ----Quote - You have to remember that the spring pressure is dependant on the armature position, the further up the coil, the higher the spring pressure. So the spring pressure at 10% open is not as strong as it is at 90% open.
--------------------------

As Phil and I have both pointed out the spring pressure will vary in manufacture and with age. You are suggesting the maintenance of a balance of forces in excess of knife edge conditions. This is impossible in this application.
---------------------------

HARVEY -----------Some of the finest time pieces use a SPRING
-----------------------------

TREVOR --------- This statement exactly records your lack of knowledge in respect of a simple wound spring. When I was six years old, I was given a second hand clockwork Meccano motor, which I found delivered instant power like a bomb. It did not take me long to discover that THE GOVERNOR WAS MISSING.
You on the other hand, appear not to not be aware that a time piece incorporates a pendulum or balance wheel etc. in order to regulate variable spring pressure -- amazing !
You should also note that your observation brings forth another important variable -- temperature. In a chronometer, this is taken care of mechanically with great ingenuity. N.B. The spring in question here, is located in a gearbox recording vast differences in temperature.
--------------------------------------------------------------------------

HARVEY ----- As far as the spring pressure and the oil damping goes, the whole valve body operates under these conditions, so they can get it right.
----------------------

Trevor ----- Please Harvey stick to the technical language of which you pretend to be capable. Who or what are “they”. This sentence means and says nothing. What is this mystical adjusting force which can balance all the variables which Phil and I have pointed out?????
THIS IS THE FACTOR THAT YOU MUST EXACTLY AND PROPERLY EXPLAIN. YOUR THEORY FALLS APART UNLESS YOU CAN DO SO.
----------------------

HARVEY ---- The MYSTICAL force is called magnetism.

TREVOR ----- Once again you come up with a silly reply. You must explain how the force of magnetism is held in balance by means of the MAGICAL MYSTIC ADJUSTING FORCE you state is available in this application.
Read carefully, understand that which is stated and try again. I called upon you to answer an exact question, sensibly and exactly. Your reply is as usual meaningless.
This IS THE IMPORTANT QUESTION YOU MUST ANSWER in order to validate your theory, otherwise it is not in fact proven.
----------------------------------------------------------------------

TREVOR ----- Please explain how the several following absolute variables, all of considerable magnitude, have no effect in respect of your theory.
Subaru, the undeniable authority, state that the solenoid has a tolerance of 1.5 to 4.5 ohms.
There is a circuit supplying current to the solenoid, quite independent of the modulated supply, via the famous resistor. Subaru give this resistor a tolerance of 9 to 15 Ohms.
Many reading this have either disconnected the resistor, changed its value, or fitted the “Shift Kit”.
Just why have none of these factors in relation to a parallel supply, not caused your alleged, armature in suspension, to shift ?????????
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HARVEY ------ It does Trev, it reduces the magnetic field, to open the solenoid, to raise the line pressure, I thought you knew that.

TREVOR ( In frustration.)-----Please read, and understand, as I am sure others can.
The operative words are, “ ------------ not caused your alleged ARMATURE IN SUSPENSION, TO SHIFT”; viz, the mystical balance will be continually completely upset.

Furthermore please reply to ALL questions, not just “it” and do not side step issues. I raised several.
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HARVEY ---- To try to operate the valve by turning it on for 10% of the time, and turning it off for 90% of the time. Would produce peaks of high and low oil pressure that would be transmitted through the whole apply system. In the case of the C solenoid, the transfer clutch would respond at the same frequency, to produce serve drive line vibration. I know Trevor will say that " Pressure Modifier " will smooth it out, but there is none in the C solenoid circuit.
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TREVOR ----- The pressure modifier and pressure accumulator smooth the line pressure, i.e. the complete actuating portion of the system IS SMOOTHED as a result of this arrangement.
THE C SOLENOID CIRCUIT IS IN FACT SMOOTHED, as it is supplied from line pressure, therefore it DOES NOT provide an intermittent fluid supply to the transfer clutch.
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HARVEY -----Your are showing your lack of knowledge of auto trans. This is the circuit of the C Solenoid. show me where the pulsations are "SMOOTHED OUT"

TREVOR (In disgust) ------ To the contrary it is YOU who now show a complete lack of knowledge and understanding of automatic transmission systems.
YES, I WILL SHOW YOU. Take up your illustration, there are several within the manual, following page 3-2-45.
The fluid circuit indicated in red/brown is in FACT clearly shown as line pressure, when the full drawing is on view. This, as is shown in this same schematic drawing, AS I HAVE STATED IS SMOOTHED at the point of supply. This and ALL the fluid in the circuit shown, is “SMOOTHED OUT” line pressure!!!
To doubly confirm, you and all those interested, should also refer to page 92, 3-2 [M22B8] of the Subaru manuals.
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HARVEY ---- Getting back to the original. The aim is to find the way that the TCU can tell if the valve is stuck. If inductance is used to detect this then there has to be a recognisable difference, between the valve being open or closed. If the solenoid is driven by the Duty cycle to open for a timed period each time, as Trevor suggests, the inductance at each rise time, would be the same. If the valve stuck in the off position there would be no change in the inductance produced, so it would not know it was not moving.
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TREVOR ------- What you state makes no sense. e.g. “ so IT would not know IT was not moving”. How could the armature be expected to, know it was not moving? I would certainly not expect it to know!
There most certainly will be a measurable difference if the armature is open or closed. N.B. In the next paragraph you boldly state, that a “different position gives a different inductance”, i.e. the exact opposite of what you state above! I pointed out that the inductance could be measured and compared with a known value by means of a bridge circuit. You have now made it clear that you do not understand the basic principals involved and are incapable of sound reasoning, or statement of fact.
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HARVEY (Sarcastic) ---- now you are showing your lack of modern technology. bridge circuits went out with the thermionic valve. we don't need to build hard wear to do this, a computer only needs a few lines of code, to measure the rise time of the duty cycle, on time, to tell.

TREVOR (In Anger) ----- “to tell” ? In the course of controlling my own businesses I took responsibility for the design of many industrial control systems, none of which utilised thermionic valves, even though I am well versed in their application. It is obvious that you intend sarcasm in relation to my age, but transistors were well in vogue during my term of participation in the field of design. Bridge circuits are a fundamental basis of electrical technology, both past and present and do not in require hardware as you stupidly suggest. Prove otherwise. Any one in doubt should Google the term.
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HARVEY---- With the valve operating as I say the position is known at any time, or position. As the different position gives a difference inductance, so a difference Rise Time. A valve stuck in any position is detectable.
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TREVOR ----- (“difference inductance, difference Rise Time” ?) Just how would you measure this strange infinitesimal value at a viable cost and why would not the variables pointed out upset measurements????? I recall that you mentioned a computer, where is it ???
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Harvey (Exulted and Excited) ----- Oh I see now, you don't even know that the TCU is a computer. Woo ho.

TREVOR,(LOL.) ----- Hook line and sinker is the term. There are many here who know the exact working and limitations regarding all the facilities provided by the TCU and the sophisticated task you suggest is not one of them. The necessary hardware does not exist and we are not talking about proportional spool type valves here.
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HARVEY ---- Does this make it any clearer Phil.?

Trevor --- All that previously posted was I am sure perfectly clear to Phil, as it brought forth an exact reply. His answer will be awaited with interest.

HARVEY ---- Well you got Phils answer, and you got mine.

TREVOR------ I have replied to Phil with the respect he deserves.
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HARVEY ( With gusto.) ----Now I'll give you Subaru's. This is a scan of the Air Conditioning Swash plate actuating solenoid (Section 4-7 page 9) that alters the compressor output, it works the same as all the solenoids, driven by a Duty cycle. If you can read it, it says that the armature that pushes the valve, is held in the middle position, and is moved back and forewords from there, to control the Swash plate.

TREVOR ---- I have the page open and can read, but I can see nowhere that is says “that the armature that pushes the valve is held in the middle position.”
The current flow varies as stated, because the pulse width of the supply, to what is a perfectly normal pulse modulated solenoid, is varied. The total current is the product of the total on time and will vary accordingly. There is no suggestion that the the solenoid is in any way continuously energised. The valve does not stay stationary in any position and is ramped on and off as is the usual practice.
It is reasonable to assume that the text has been limited to referring to current, rather than adding the complication of pulse width, but the description remains correct. The Manuals are obviously directed towards mechanical technicians with simplicity in mind. By the same token, nothing appears between the lines as you suggest.
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HARVEY ---- As you can read, it uses the Duty cycle to regulate the current flow in the solenoid, hence, the magnetic field, to position the armature, and HOLD IT THERE, to keep the Swash plate, and the compressors output, at that setting.

You can now not deny that the armature is positioned and held stationary by the Duty cycle. It is plain for every body to see.

TREVOR ---- There is nothing that anyone can read or see, plain or otherwise, which states that armature is held in any fixed position as this is impossible. It is only said that the valve controls the wobble chamber pressure. This is achieved by means of a normal PWMSV, pulse width modulated via the duty cycle.
Surely your theory must apply universally and be of common knowledge if correct. Google is available to you as well as the Subaru manual and your much quoted text books. Please try again.
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HARVEY ---- What else is plain for every body to see, is that your whole intension of this thread, and all your derogative comments to me in other threads, are designed to discredit and defame me.
Well mate I'll save you your time, give it up, get off my back.

TREVOR ---- You may be becoming inflamed, but my intention is to protect those here without technical knowledge, from your dogmatic and often incorrect statements. You often mislead people and this is not to their advantage and usurps their goodwill.
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HARVEY ----- Your not in the same class.

Trevor ------- A bold statement in bad English. Are you suggesting that we should trade credentials? If so, open the bidding.

Trevor · #27 04-16-2006, 04:19 AM

Harvey,

In this one you most certainly have driopped a clanger.

It would appear that reverberations have ceased, due to the lack an effective reflective body.

Trevor · #28 04-17-2006, 07:12 PM

Harvey,

It is important that members receive the correct information in respect of that being debated here, e.g. a current thread calling for assistance with problems involving solenoid C.

All will be aware, that you have recorded a personal insult against me within this thread, with the arrogant statement --- “You are not in the same class“ -- (as me).

In view of the fact that several simple questions remain on the blackboard, which remain unanswered, I am inclined to agree with you.

For the good of members will you please respond.

Trevor · #29 05-01-2006, 07:01 PM

Quote:

Originally Posted by Trevor

Harvey,

It is important that members receive the correct information in respect of that being debated here, e.g. a current thread calling for assistance with problems involving solenoid C.

All will be aware, that you have recorded a personal insult against me within this thread, with the arrogant statement --- “You are not in the same class“ -- (as me).

In view of the fact that several simple questions remain on the blackboard, which remain unanswered, I am inclined to agree with you.

For the good of members will you please respond.

???????????????????????????????????? !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

dannmarr · #30 05-01-2006, 08:47 PM

Is retirement that boring?