Title: for us automobile technopihiles
Post by: massCougarxr7 on September 03, 2008, 08:36:29 PM
wow! looked like the cam was grooved or sumthing , to pull the valve closed....weird,,,,do they make them for all block sizes?
Title: for us automobile technopihiles
Post by: massCougarxr7 on September 03, 2008, 08:36:28 PM
wow! looked like the cam was grooved or sumthing , to pull the valve closed....weird,,,,do they make them for all block sizes?
Title: for us automobile technopihiles
Post by: Thunder Chicken on September 03, 2008, 09:14:47 PM
Interesting. Would be even more interesting to see it at high RPM, and to see how they'd deal with lash adjustment. A normal engine only needs to deal with lash adjustment for opening the valves; the valve springs themselves make up for any wear that might happen on the "closing" side. With that design you'd need to come up with a way to adjust for wear over the life of the engine, otherwise as the valve seats wore they wouldn't seal.
Title: for us automobile technopihiles
Post by: jcassity on September 04, 2008, 12:47:46 AM
im not sure about that. looking at the design, the valve spring is relocated to the bottom side of the head exposed to the lifter valley. It just relocates the spring to a different area basically putting the tension on the pushrod. as the seat wears, the spring will just pull in tighter.
I am having trouble absorbing the gain,, seems like the pushrod should still maintain the same tension but they are saying the valve spring is lighter in tension for some reason.
also,, cant figure out the connection part of the valve,, is that a standard valve there? with a clip on do hicky like thing a ma jig that bobs the valve up and down using the exising valve keeper knotches?
I think ill call them tomorrow
Title: for us automobile technopihiles
Post by: Haystack on September 04, 2008, 12:59:55 AM
+2. I was thinking the exact same thing. It really doesn't seem all that innovated, mostly just more complicated then it has to be. They just relocated the spring? I liked the rotary valve idea alot more.
Title: for us automobile technopihiles
Post by: Thunder Chicken on September 04, 2008, 08:13:33 AM
What spring are you guys talking about? I don't see any spring, all I see is a positive mechanical connection to the camshaft, so that the cam pulls the valve closed as well as pushes it open. I still don't see any means of pulling the valve closed so that it remains tight against the seat as the parts wear.
Title: for us automobile technopihiles
Post by: Chuck W on September 04, 2008, 08:29:05 AM
There is mention in the OHC video of a spring, but they make a point that it is to hold/seat the valve stem seals, and NOT to seat the valve.
They do show adjustments being made on the set-up, so perhaps the system would require fairly regular valve adjustments to keep the valve seated as things wear.
Looks interesting.
Title: for us automobile technopihiles
Post by: jcassity on September 04, 2008, 04:18:02 PM
Quote from: Thunder Chicken;234894
What spring are you guys talking about? I don't see any spring, all I see is a positive mechanical connection to the camshaft, so that the cam pulls the valve closed as well as pushes it open. I still don't see any means of pulling the valve closed so that it remains tight against the seat as the parts wear.
You need to drill into the page under "other inventions" and click on the true link system. In there you will see the plain jane pushrod motor application more clearly defined.
The premis is that since you have relocated a tension device more closely to the cam / lifter, the tenstion of the spring can be derated due to some engineering dynamic my piddly little brain cant comprehend at the moment...............see linky....... http://www.decuirenginetechnologies.com/trulink.php
Pete / Sam If you guys get this,, go to electrical tech and click on the sticky up at the top where you find 1987 EVTM,, all wiring diagrams for a fox 2.3/3.8/5.0.
Title: for us automobile technopihiles
Post by: jcassity on September 04, 2008, 04:24:05 PM
Somebody named "alex" will be calling me back today hopefully on these gems. Ill try to get pricing as well.
I think i like it!!
Title: for us automobile technopihiles
Post by: Innes on September 04, 2008, 04:49:17 PM
Looks very interesting this guy took one of those moments when I’m sitting around think of how to build/cheat/engineer more HP and did it. I wonder how much HP loss is compensated in the fact that the cam is now also pulling the valves not just pushing them. Does look neat though I’m sure it will be a few years to work out the kinks.
Title: for us automobile technopihiles
Post by: jcassity on September 04, 2008, 05:26:54 PM
I spoke with alex, what a pleasure also to be able to talk with someone who started out working on cars at 18 and is heading to age 79 this coming sunday.
There really isnt too much that has happend in Nascar this guy does not know. He's worked for many of the greats in Nascar like Dick Trickle, Richard Petty ect.
He said that every so often he would run the dyno machine and observe/measure the nature of the three connection points a pushrod/ rocker has and its effects on valve float in order to solve it.
He said that he has ran engines to rpm's in the range of 7k and obverserved things you would have never thought posssible like the pushrod or rocker gap for a moment in time having a gap of nearly 3/8 of an inch ect. He said that at higher rpms, the parts will float naturally and that is amazing how it all stays together.
His idea makes the valve opening more contolled and also reduces the hp required to do so, which in turn frees up engine perfromance. The mods to the connection of the rocker to the valve is done by means of hand made parts to include the clip you see on the roller part of the rocker. That clip is a bike chain clip that he found suitable since it was already heat treated.
Alex went on to explain that a normal engine seat presure is in the range of 90-100psi and that it will require about double that presure to fully open the valve. locating the valve more to the center of the engine and its placement in range with the lifter reduces the amount of spring tension through trial and error, reduces the flopping of parts where the rocker touches the valve and the pushrod touches the rocker, and also controls float and eliminates 66% of crashing a valve. Actually, alex insisted that it nearly eliminates it. The formula he uses,he had to make up along the way but it has a lot to do with the ratio of the distance from the fulcrum of the rocker to the center of the valve stem and its relationship to the hp required by the cam lobe to open and close said valve.
I am to supply my cam/valve/spring/head specs to alex and proceed with getting a conversion set made and supply him with consumer test data as well as dyno / track info of before / after for his records. This guy is really neat. I like older generation types who dont mind teaching when they know there are open ears and closed mouths.:bowdown:
Title: for us automobile technopihiles
Post by: TurboCoupe50 on September 04, 2008, 05:32:48 PM
Quote from: Chuck W;234900
They do show adjustments being made on the set-up, so perhaps the system would require fairly regular valve adjustments to keep the valve seated as things wear.
Looks interesting.
Sounds to me like it already needed adjustment...
Was makin' more noise than two skeletons screwin' on a tin roof... :hick:
Title: for us automobile technopihiles
Post by: jcassity on September 04, 2008, 05:33:42 PM
Quote from: Innes;234954
Looks very interesting this guy took one of those moments when I’m sitting around think of how to build/cheat/engineer more HP and did it. I wonder how much HP loss is compensated in the fact that the cam is now also pulling the valves not just pushing them. Does look neat though I’m sure it will be a few years to work out the kinks.
take another look,, the cam is not pulling the valves closed, the spring is working the whole link. The pushrod is now under spring tension which is naturally following the profile of the cam lobe.
Title: for us automobile technopihiles
Post by: Thunder Chicken on September 04, 2008, 09:06:05 PM
Quote from: jcassity;234949
You need to drill into the page under "other inventions" and click on the true link system. In there you will see the plain jane pushrod motor application more clearly defined.
The premis is that since you have relocated a tension device more closely to the cam / lifter, the tenstion of the spring can be derated due to some engineering dynamic my piddly little brain cant comprehend at the moment...............see linky....... http://www.decuirenginetechnologies.com/trulink.php
Pete / Sam If you guys get this,, go to electrical tech and click on the sticky up at the top where you find 1987 EVTM,, all wiring diagrams for a fox 2.3/3.8/5.0.
The "True link" system is not the same system as the springless valve system you touted in your first post. The true link system uses two valve springs (one on the valve, one on the rocker arm) and actually looks to me like it could work. The "Springless Valve System" has no valve springs, it relies on grooves in the cam and those chain-link looking things to pull the valve closed. You can see the groove in the cam here (look at the side of the lobe - note how the lifter doesn't even seem to ride on the cam lobe. It's riding on a pin that fits in this groove): (http://www.foxthundercats.net/images/groovedcam.jpg)
The springless system still looks to me like it would not reliably work, at least on a street engine expected to last 100k+ miles. A race engine that will be rebuilt after every race (or could even have its valves adjusted during a pit stop), maybe. Still, even with adjustment, the problem I see is that the valves would have to be adjusted for less-than-zero lash when closed, otherwise the system would not pull them closed all the way and they'd leak compression (which would quickly lead to burned valves). Less-than-zero lash on a valve that is being pulled closed by what is essentially a crankshaft and connecting rod would result in the valve hitting the seat very hard and closing very tight, which would rapidly "tulip" the valve head or even stretch the stem or other valvetrain components. This tuliping or stretching would soon result in "more-than-zero" lash, which would cause compression leakage.
If it seems like I've put a lot of thought into this, it's because I've been thinking about alternatives to the current cam/lifter/valve setup since middle school (we're talking early 80's here). I would sit in class and daydream about ways to elimimate the cam and use solenoids. Solenoids would allow infinitely variable valve lift, duration, and overlap. It could be changed on the fly and cylinder-to-cylinder. The throttle blade could be eliminated entirely, since you could throttle the engine by only opening the valves enough to let enough air in to idle.
Strangely enough, in my mind I could never overcome the valve closing problem with solenoids, either. If I used springs in my imaginary cylinder head the solenoids would have to be extremely strong (meaning large, heavy, and really sucking down the current) in order to overcome spring pressure and open the valves. If I didn't use springs the solenoids could be smaller, but they would close the valves too hard (unlike a traditional cam, which closes the valve gently as the lifter rides down the back side of the lobe, a solenoid would whack it closed suddenly). This would lead to the "tuliping" problem I mentioned above.
Even stranger, though, is that after a few moments thought I think I may have come up with a solution for the Decuir springless valve system. Install a shock absorber on each valve. It would not have to be a big shock with a lot of range of motion, just something with a few thousandths of an inch that allows just a bit of "stretching" between the valve seat and the camshaft. Perhaps a solid rubber block inside the "shock absorber" that would compress ever so slightly when the valve closed, yet rebound (again, ever so slightly) when the valve is open again. This would allow the valves to be pulled fully closed without stressing metal components. Here's a quick drawing of my idea: (http://www.foxthundercats.net/images/valveshockabsorber.jpg)
Of course this idea opens itself to a whole new slew of problems. Aside from the extra weight (which would mean more inertia, which would make the engine more resistant to revving), I can't for the life of me see how you'd get this valve into the head. I drew it fully assembled, so just imagine trying to disassemble it :hick:
Title: for us automobile technopihiles
Post by: TurboCoupe50 on September 04, 2008, 10:22:10 PM
Quote from: jcassity;234952
Somebody named "alex" will be calling me back today hopefully on these gems. Ill try to get pricing as well.
I think i like it!!
I'm betting $5K won't touch it...
Title: for us automobile technopihiles
Post by: Haystack on September 04, 2008, 10:35:22 PM
Quote from: Thunder Chicken;234989
If it seems like I've put a lot of thought into this, it's because I've been thinking about alternatives to the current cam/lifter/valve setup since middle school (we're talking early 80's here). I would sit in class and daydream about ways to elimimate the cam and use solenoids. Solenoids would allow infinitely variable valve lift, duration, and overlap. It could be changed on the fly and cylinder-to-cylinder. The throttle blade could be eliminated entirely, since you could throttle the engine by only opening the valves enough to let enough air in to idle.
Strangely enough, in my mind I could never overcome the valve closing problem with solenoids, either. If I used springs in my imaginary cylinder head the solenoids would have to be extremely strong (meaning large, heavy, and really sucking down the current) in order to overcome spring pressure and open the valves. If I didn't use springs the solenoids could be smaller, but they would close the valves too hard (unlike a traditional cam, which closes the valve gently as the lifter rides down the back side of the lobe, a solenoid would whack it closed suddenly). This would lead to the "tuliping" problem I mentioned above.
Even stranger, though, is that after a few moments thought I think I may have come up with a solution for the Decuir springless valve system. Install a shock absorber on each valve. It would not have to be a big shock with a lot of range of motion, just something with a few thousandths of an inch that allows just a bit of "stretching" between the valve seat and the camshaft. Perhaps a solid rubber block inside the "shock absorber" that would compress ever so slightly when the valve closed, yet rebound (again, ever so slightly) when the valve is open again. This would allow the valves to be pulled fully closed without stressing metal components. Here's a quick drawing of my idea: (http://www.foxthundercats.com/images/valveshockabsorber.jpg)
Of course this idea opens itself to a whole new slew of problems. Aside from the extra weight (which would mean more inertia, which would make the engine more resistant to revving), I can't for the life of me see how you'd get this valve into the head. I drew it fully assembled, so just imagine trying to disassemble it :hick:
Why not use hydraulics like the hydralic lifters for the shock absorber?
Title: for us automobile technopihiles
Post by: jcassity on September 05, 2008, 02:43:09 AM
your right,, i jumped right to the true link system. That is what i thought the topic was about and did not notice the lifter to cam relationship as its designed.
I like your visio or whatever drawing, and i grasped the concept you needed to spend time on about absorbing the shock of the valve closing. We talked about this a couple of years ago and i asked you why not reverse the polarity of the solenoid to close it,,, of course this does not solve DC power consumption but it does close the valve without a spring. I cant computate what seat presure there would be but it would close the valve nonetheless. I really dont think a valve has to "look" like the cookie cutter valve we see everyday but something new and different such as a port / door / round flat disc moving in view and out of view allowing air/fuel in and closing on reverse polariity. basically the door or port would reside parallel with the the visible surface of the piston. There are many electrically activated check valves out there that are low current and used as safety cutoff valves for many industrial applications.
Title: for us automobile technopihiles
Post by: Thunder Chicken on September 05, 2008, 08:17:52 AM
Quote from: Haystack;235005
Why not use hydraulics like the hydralic lifters for the shock absorber?
Because hydraulics (liquids) are not compressible, so they cannot act as a shock absorber. You could use hydraulics using a "bleeder hole" similar to a suspension shock absorber, but then you'd be adding a whole lot of complication to the setup.
Quote from: jcassity;235022
your right,, i jumped right to the true link system. That is what i thought the topic was about and did not notice the lifter to cam relationship as its designed.
I like your visio or whatever drawing, and i grasped the concept you needed to spend time on about absorbing the shock of the valve closing. We talked about this a couple of years ago and i asked you why not reverse the polarity of the solenoid to close it,,, of course this does not solve DC power consumption but it does close the valve without a spring. I cant computate what seat presure there would be but it would close the valve nonetheless. I really dont think a valve has to "look" like the cookie cutter valve we see everyday but something new and different such as a port / door / round flat disc moving in view and out of view allowing air/fuel in and closing on reverse polariity. basically the door or port would reside parallel with the the visible surface of the piston. There are many electrically activated check valves out there that are low current and used as safety cutoff valves for many industrial applications.
The Coates engine uses a similar concept to the door you're talking about. That engine has been discussed here too, and once again durability came up: How do you keep the door (or, in the Coates engine, the rotary valves) sealing well over time? How do you deal with carbon deposits fouling up the contact surfaces?
I really should have been an engineer :hick: I spend way too much time finding reasons why things won't work
Title: for us automobile technopihiles
Post by: Innes on September 05, 2008, 04:00:40 PM
I also like to know what the life expectancy of this setup is. The valves look better off but the cam has a roller inside it, oiling carbon ect.
Title: for us automobile technopihiles
Post by: jcassity on January 26, 2009, 08:04:06 PM
The shop is busy building the "MoTown express" but I expect a quote this week.
Title: for us automobile technopihiles
Post by: Cougar5.0 on January 26, 2009, 10:03:32 PM
I can't figure how the valve lash is controlled in the springless system either.
Looks like the other invention helps transfer the inertia of the lifter/pushrod away from the spring on the valve to the spring on the pushrod. Intuitively I can see how much less overall spring force would be needed in such a system. I can even imagine getting some heavy wall pushrods and machining them for the retainers & then mounting the backing plate for the springs. Seems like a good enough idea (assuming I understand it properly).
I'm interested in the results of your trial!
Title: for us automobile technopihiles
Post by: Quietleaf on January 27, 2009, 12:31:39 AM
Interesting idea, though the pin in the cam looks like a weak spot to me. I would expect it to bend over time as it clearly must be undergoing a torque parallel to the cam. The chain links also look to me like they might stretch, though they would have very little mass so perhaps it would happen extremely slowly. My feeling on the current spring setup is that the spring's expandability helps make up for shortening/stretching of parts over time, and so I wonder if a direct-connect setup using pushrods is ultimately self-defeating in the long run (presuming that the rods would change length over time, and at any rate they *certainly* would lengthen as they heat up (I have a M.A. in Physics and you'd be surprised at how much a metal rod can lengthen over the course of 50 degrees F -- though of course it depends on the composition).
As the rod heats and lengthens, it causes the valve to open more than it would when the engine is cold, but spring tension is linear with change in length, so a lengthened rod would cause the spring to work harder to keep it seated against the cam (just as it would if the rod stretched over its lifetime). This does nothing for the amount by which the valve opens, of course, but there's a key difference: with each reciprocation of the rod, something has to bear the load of the change in momentum of the entire system. A springless design puts all that load on the pin, whereas a spring system spreads it over the uncoiled length of the spring. It seems to me that a spring-valve system should be *far* more reliable.
The problem with pushrod engines is Newton's Third Law:
F=ma (force = mass * acceleration)
With each reciprocation of the valve, the entire valve and rod requires a linear force to accelerate them in the opposite direction, and an additional torque must be applied to the lifter. There are also frictional forces at work, which is of course why people buy roller rockers, but it seems to me that the major task needs to be to reduce the mass of the system (with an accompanying change in spring tension). Instead of spending money on this system, wouldn't it make more sense to try lighter materials, like Al or Ti, or a lighter steel alloy? That said, thermal expansion coefficients are really important when changing materials, and can't be ignored.
Title: for us automobile technopihiles
Post by: jncocowboyx on January 27, 2009, 12:47:01 AM
i always thought that was a good idea. imagine the performance possibilities...
and upon reading the entire thread, someone was thinking of this when i was a kid. i thought of it too in school, but my teacher told me that someone was already into it, just like bmw's electromagnetic brakes that i "thought of" a couple of semesters ago.
Title: for us automobile technopihiles
Post by: jcassity on January 27, 2009, 01:03:39 AM
I am only looking into the tru-link system. Not the springless system.
The idea offers the valve to follow the exact cam profile more precise without the losses absorbed by the lifter the typical high tension spring of today , not to mention the delay.
During my discussion, it was also explained that the spring in nothing more than your traditional stock spring with the center coil removed. Now your looking at just at half the force required to compress this part.
On a side not,, Alex said he has another "type of rocker arm" he is developing that eliminates valve float 100%. He described it but I couldnt get my head around it real well.
I sure hope you are wrong tom,, I will not see paying that much for this.
Title: for us automobile technopihiles
Post by: V8Demon on January 27, 2009, 11:34:34 AM
Magnets. Magnets will be the future IMHO.....
http://www.sae.org/technical/papers/2008-01-1360
Quote
VALEO Engine Management Systems has, since 1998, been working on an infinitely variable valve actuation system based on a linear spring-mass actuator. The VALEO electromagnetic variable valve actuation system replaces the intake camshaft with electromagnetic valve actuators that are driven by a Valve Control Unit (VCU).
The Valeo system uses electromagnetic actuation. Where a typical valvetrain uses a spring to hold the valve closed until the camshaft lobe overcomes the spring, the camless system uses a pair of springs, and the valves default to a partially open position. There's a pair of electromagnets above the valve assemblies with an armature in between. The armature is what the electromagnetic fields move to actuate the valve. The upper electromagnet pulls the valve shut, and the lower electromagnet fully opens the valve. This system eliminates entirely the camshaft and its associated drive system such as belts, tensioners and bearings. High performance engines with variable timing and lift valvetrains will be easy to accomplish with the Valeo system, as opposed to the complex mechanical systems currently used to accomplish those functions. Think of Valeo's system as operating much like a fuel-injection system. Each valve event can be discrete and optimized. Low end torque will be increased, and cylinder head design can use more radical valve and port angles without having to fit rotating machinery above and around the cylinder head. Depending on the size of the hardware, packaging could approach the compact size of pushrod engines.
http://autospeed.com/cms/article.html?&A=0910
It seems Valeo's original timetable has been whacked by a faltering global economy, however. No surprise in the age of procrastination and delays that we live in.
Title: for us automobile technopihiles
Post by: jcassity on January 27, 2009, 09:24:14 PM
.......
Title: for us automobile technopihiles
Post by: Cougar5.0 on January 27, 2009, 10:22:39 PM
That's an interesting twist on the "solenoid" actuated valve that's been in development for years. The systems have often been included with the introduction of the 42V battery that helps drive the electromagnets (V = L*di/dt) has been a long time in coming. I like how they suspend the valve partially open so when the inevitable failure occurs it wont destroy the engine. If injectors fail while driving a mere fraction of the mass of a valve, you can be sure the biggest issue with these systems is reliability. The 42V battery significantly reduces peak currents and would help increase speed and reliability.
I didn't realize until I read the article that noise from slamming valves is a huge issue with these systems. Apparently Siemens has a system to get the valve to near zero velocity (by carefully controlling current flow) as the valve closes - thus actually reducing noise and valve wear!!
I'll give it 5 more years. Then, by the time they're ready for prime-time, some amazing technological breakthrough will make them obsolete - lol!
Title: for us automobile technopihiles
Post by: jcassity on January 27, 2009, 10:49:07 PM
Quote from: Cougar5.0;254000
Siemens
you know what that is dont you,,? not being a smart a@@ or nothing, seriously.
Title: for us automobile technopihiles
Post by: Quietleaf on January 27, 2009, 11:34:28 PM
Quote from: Cougar5.0;254000
I didn't realize until I read the article that noise from slamming valves is a huge issue with these systems. Apparently Siemens has a system to get the valve to near zero velocity (by carefully controlling current flow) as the valve closes - thus actually reducing noise and valve wear!!
This part made me wonder if a coil ON the valve could be used to better regulate valve velocity...as the valve reaches its peak velocity, a nearby magnet would induce a current in the coil (the higher the velocity, the higher the current, Faraday's law and all that), which could perhaps be used to slow the valve down with a second (electro) magnet (reversed polarity). Just an off-the-wall thought.
Title: for us automobile technopihiles
Post by: Cougar5.0 on January 28, 2009, 02:04:33 PM
I also thought of using the valvestem directly when reading this. Today I've had a chance to think about it more and a sleeve of some sort would have to be put over the valve as the typical magnetic susceptibilty of stainless is relatively low and titanium, forget about it. Probably just as well from a service standpoint to have something that attaches to the stem in the normal fashion so that the electromagnetic (or otherwise) could be serviced separately from the valves themselves which could also be serviced/upgraded as needed.
No Scott, I know how to spell sp00ge. :rollin:
...and it's Hall-effect!!
Title: for us automobile technopihiles
Post by: V8Demon on January 28, 2009, 02:33:28 PM
Seamen :D
Title: for us automobile technopihiles
Post by: jcassity on January 28, 2009, 11:13:48 PM
Quote from: Cougar5.0;254123
No Scott, I know how to spell sp00ge. :rollin:
QUOTE]
whatever,, i just thought it was good triva and typical be typical, you dont answer the question. Ever wonder why you think the way you do,, you dont listen,,,,:flame:
all joking aside,,"Siemen" is a unit of measurement (s) which is the opposite of ohms. G=conductance Bc=Suseptance Y= Admittance
The perspective of the above measurements are like when you say,,"i think it will handle the power but I cant explain why" I use Admittance a lot with work when getting to the bottom of reactive to apparent power ratios when laying out genset work.
oh well.
Title: for us automobile technopihiles
Post by: Cougar5.0 on January 28, 2009, 11:28:29 PM
OK, I didn't get it, though I design switching power supplies for a living which use transformers/inductors (that I design) & MOSFETs etc, and never do I use the conductance or admittance term while designing. I do see the siemens unit (S) in MOSFET datasheets, but I generally ignore it as I'm most interested in Rdson & the various capacitive charges & gate threshold etc.
Title: for us automobile technopihiles
Post by: jcassity on January 28, 2009, 11:42:23 PM
Quote from: Cougar5.0;254222
OK, I didn't get it, though I design switching power supplies for a living .
humm...check pm
Title: for us automobile technopihiles
Post by: Cougar5.0 on January 30, 2009, 02:23:23 PM
OK, so a day after posting here, I'm reading a serial bus protocol for power management (not important), but at some point I came across (no jokes!) a command [COLOR="Red"]IOUT_CAL_GAIN[/COLOR] and the units it had listed were milliohms(?). I kept staring at it and thinking - that doesn't make sense, it should be the opposite of resitance.
Lo and behold, I was reading the "Errata And Change Proposals" for the next revision of the specification when I saw:
Quote
Linear Technology requests that the units of IOUT_CAL_GAIN be a conductance (siemens) rather than a resistance so that the need for division is minimized.
I'm surprised it wasn't Siemens that made this request! :punchballs:
Title: for us automobile technopihiles
Post by: JeremyB on January 30, 2009, 03:17:39 PM
Quote from: Cougar5.0;254222
I design switching power supplies for a living
...and here I was thinking you were an ME! :confused:
Title: for us automobile technopihiles
Post by: Cougar5.0 on January 30, 2009, 03:54:58 PM
Quote from: JeremyB;254524
...and here I was thinking you were an ME! :confused:
The I have to do to make a living these days!
I am a ME.
I design the connectors, heatsinks & specify thermal interface materials, design leadframes & printed circuit board using AutoCAD, Cadence Allegro (PCB) &/or PowerPCB & ProEngineer
I design the electrical circuit & magnetics using MathCAD, Excel, Magnetics Designer, PowerLogic &/or Cadence Concept HDL. This includes creating all the schematic symbols and part footprints if they are not already available :punchballs:
I also have to manually create the BOM, source low cost/high performance electrical parts, buy the parts (Digikey, Mouser) if not available in Asian factory & build the circuit board by hand here at home (I need to use a microscope to touch up the solder joints - oh, joy :mad:
Now I'm designing a "digital" version where I have to use Microsoft C++ & Code Composer (TI) to write and debug code, which I'm still learning :flame: This is why I was studying the Power Management Bus - so I will understand how the communication to the chip is done and learn the commands.
My head hurts! :mad:
Title: for us automobile technopihiles
Post by: jcassity on January 30, 2009, 08:45:11 PM
whats really sick,, all that work is done for you already........ "cordex cxc controller"
Title: for us automobile technopihiles
Post by: Cougar5.0 on January 30, 2009, 08:59:52 PM
Hmmm, will it fit in the 1 sq. in. of PCB space for the controller and bus connection and cost less than $2.50?