Several eons ago, on the old forum, ListeroidsUSA1 was working on an inexpensive electric governor for listeroids (or anything else for that matter). The thread petered out and nothing else was heard.
I am wondering if anyone happens to know the status of this governor. Is it still being refined ? Did it turn out to not work ? Seemed like there was a LOT of interest at the time.
Jens
Jens, now this is a coincidence, I just navigated to this sub-forum to ask exactly the same question!
Just before the last "other forum crash", I tried to find more info on it by searching different keywords in Google, but had no luck :(
I hope someone can update us on this subject.
A good friend of mine has built a governer system - actually, a complete control system - for a diesel generator, which utilises an RC servo to control the throttle. The engine is an old Ford diesel unit, hooked up to an ex-army 6KVA alternator of unknown provenance. I'm not quite sure how he senses the RPM; I can find that out.
I know this system rather well, as it lives in the bus I carry my race car around in.... The control system does pretty much everything you'd want: I flick a switch in the bus cabin; the control system runs the glow plugs for a few seconds, starts the engine, lets it settle for a few seconds, then activates the alternator. It monitors for over-speed, under-speed, high temperature and low oil pressure (and maybe others, I will check). In fact, the only thing he did wrong is it doesn't turn the glow plugs off until after the engine is started - which means we keep burning glow plugs out... That, and after 10 years the throttle servo seems to have worn out, so the speed response isn't quite as rapid as it used to be.
I'll have a chat to him about making plans & software available. I'd imagine the system could be modified to start/stop a Lister or Changfa type engine with the greatest of ease.
some of the small import cars, for instance honda uses or used a servomotor controlled
cruise control unit, looks to be rock solid and dependable and can work with an H bridge
to contol it with a microcontroller,
nice aluminum case, no cheap plastic bits that are likely to melt
and they have the quick release to idle, should be a way to hold the setting
and drop to engine stop should the processor lose its way or a connection become
faulty
jose' research & development
Quote from: Jens on September 26, 2009, 01:12:33 PM
Several eons ago, on the old forum, ListeroidsUSA1 was working on an inexpensive electric governor for listeroids (or anything else for that matter).
Jens
ListeroidsUSA1 seems to be Mike Montieth.
Does anyone know him personally that might find out about an update? If the idea was abandoned, at least we'll know were we stand and can look elsewhere.
dubbleUJay
Update:
Apparently from:
Rutherfordton,
North Carolina
Quote from: Jens on September 27, 2009, 11:26:15 AM
My first thought was to use an RC servo but the ambient temperature around the engine is about 65C and the RC servos are heavy on plastic and are not likely to stand up to this for very long.
At what time should one switch off the glow plugs ???? I currently have the glow plugs activated until the engine is running at proper RPM.
I think we're seeing our first servo failure in progress, it doesn't seem to control the RPM quite as tightly as it used to. The servo is mounted quite close to the engine block, IIRC, so heat may well be its killer. It's lasted 10 years, albeit of fairly intermittent use.
As for the plugs: they should be turned off before you crank the engine... In a normal car, you'd see the plugs light go out about 10 seconds after you turn the ignition on; that means they're ready. With a big cast-iron blocked single, you may want to run them a little longer. Ultimately, you need to try it; if the engine won't start without the plugs a-glowin', then you'll have to continue using your current procedure.
I eventually got in contact with ListeroidsUSA1
He no longer manufacture these governors because of legal problems he encountered. :(
He does however claim that it worked!
So, now we know, back to the drawing board for a KISS system. ::)
He gave me an explanation of how it worked, but I'll have to ask him if I can share it Jens!
It's a little involved, but nothing over the top, simple electronics and it does make sense to me. (If that counts ::) )
I did ask him if he would give an update in this thread though, maybe he'll post some info.
I'll ask again, but maybe there's some "forum politics" involve, I don't know.
OK guys, ListeroidsUSA1 cannot give any info regarding his discontinued controller.
He gave me a very basic explanation regarding his setup at that time and I cannot take any credit for it.
That said, I've been having the following problems regarding my setup: (220Vac 50hz)
"Lazy Governor"
While set to 51hz with no load, it will drop to 50hz up to about 1/3 load (1000W). Over that up to full load it would drop to 46hz. I got this partly fixed by changing the governor spring assembly around as suggested elsewhere. (It made quit a unexpected difference)
Now its between 48-51hz, but with no load when the engine is hot, it will over-speed to 56hz occasionally.
"Hunting"
While running under any constant load, the frequency varies up and down, not much, I think less than 1hz either way. I can actually see the fuel rack moving in and out, this might be normal, but it seems a bit to much!
While tinkering with the spring tension with my finger while this is happening, I thought about using a secondary spring with less tension on the governor that counteract this problem automatically, with a solenoid applying and releasing the tension of this spring.
The solenoid must be connected/operated by/to something monitoring the speed of the engine. From there the electronic circuitry, which isn't difficult but not a simple solution (KISS) as well.
I suppose one can use a over/under frequency monitor of the shelf, one will just have to shop around for the right one, ie. quick response, auto resettable, range adjustable, exec.
I'm almost finish with my WVO heating project and will come back to this when I'm done.
In the meantime, I dont know if we should open a new thread on this idea, could get interesting? (Jens ???)
dubbleUJay
Hello men,
I had a neighbor that runs an auto repair business, he was always coming up with some project or other putting engines
from one thing in another etc.
He always swore by an aftermarket cruise control unit for speed control. I asked why didn't he use on of the add on belt drive
governors that were use on projects like the Farm Jeep, I saw one on a Chrysler slant six that powered a huge wood chipper,
one on a welder powered by a flathead four of some kind, any way you get the idea.
My neighbor told me that they are just too expensive, and hard to find so he would not budge from his electronic cruise control unit
he said just glue on a magnet (or two or three if the rpm range is low) stick your pickup coil on there and wire it up. The biggest
problem that I see is a source of vacuum for the servo.
JC Whitney sells a fully electronic unit (no vacuum), but I think it's a little pricey at $300. There has to be a solution out there
that's simple and cheap, for example, my son had a Camaro with an electric setup for the cruise control, transducers are available, I would think it's just a matter of reading wiring diagrams and doing a bunch of head scratching. I just wish I had a test bed of some kind.
Maybe someday!
Ron
Jens, I can probably build the electronic unit, its straight forward, but if you read my previous post, does it seem correct in the way I see things and the way you interpreted of what you read previously on the subject?
In a nutshell: (as I see it)
We will have a solenoid that is either on or off ("in or out", no in between setting), putting just a little extra tension to the existing governor to help it along if the RPM falls.
The solenoid will operate/release fast.
An electronic cct. will operate the solenoid, depending on the RPM it picks up.
If the RPM drops, the cct. will operate the low tension spring, bringing the RPM up, when it reaches the correct RPM, it will release the extra tension. This CAN happen a couple of time a second, but wont, 'cus the speed will take some time to stabilize. We could see some "hunting" with this setup, but I doubt it as the tolerances would be quit narrow.
I also think that if the cct goes faulty, it wouldn't cause runaway as the low-tension spring should only be allowed to add about 2-4hz to the overall governor. It would work like a "auto fine-tune" cct.
Now that I'm writing down my thoughts, it seems that my idea is a bit different from what I have read about the original idea.
For the pickup a speed-motor can be used, but also a magnetic pickup or a direct sensing cct from the AC gen-head.
I hope this all make sense guys, its been a long day ;-)
dubbleUJay
OK Jens, WJ, I hereby withdraw my electronic cruise control idea, Ya'll are "way above my paygrade! :-[
Jens, how big a universal motor would you need? Would one of the high end RC car permanent magnet ball bearing units work? If they would ,sometimes you can pick them up on E-bay for a song.
Ron
Hi vdubnut62, thanks for your input, it's just that we would like to keep it as simple as possible and to use regular available parts.
I'm sure a speed control can be implemented though, probably through various ways.
Regarding the motor, I recon that any continuous rated small DC motor will work. We just need it to generate a varying voltage in direct relation to the engine speed and a very small current, just to operate a op-amp or window comparator electronic cct.
Jens, the PWM idea is good, but I doubt it if one would get a readily available solenoid to do this, if one goes that way, you should use an actuator, (expensive), but I think in practice the on/off solenoid would actually work in a similar manner. It will be fully on or off, but because of the slow response of the mechanical governor and time it takes for the engine to adjust its revs, it should work by just giving it that extra "oomph" and taking it away when its up to speed. This is why I think we might get a bit of "hunting", but if we keep the frequency window narrow, it should not be a problem.
I can see why the DC motor is the best idea, to keep the electronics to a minimum.
Some more ideas on input sensors that I thought about were:
A contact on the injector pump tappet,
Some type of car points assembly on the camshaft collar by the camshaft end,
A acoustic pickup (peso-transducer or Xtal mic) for the combustion event (I think this might be an idea for a timing light conversion in the future ;))
but as you pointed out, all of these would need more electronic circuitry like frequency to voltage converters.
If possible, I would like to "hide" the "pickup" DC motor in the camshaft end cover, driving it of the camshaft, so I'll see if a flat stepper motor, like in a VCR machine or old stiffy drive might work. (These can be wired to give a DC voltage out)
I think those small AC motors in rotisseries and disco mirror balls are quit flat as well and they do have PM's in them.
It can just as well be driven of the flywheels or generator, I just don't want to see it ;D
I'm no electronic boffin, but I think we need an op-amp (741) and a FET or transistor to drive the solenoid. Maybe a duel op-amp to make a proper window comparator.
The op-amp must be adjustable in relation to its reference voltage and we can power the circuit via a 12v regulator or adj. one like LM317, keepin' it readily available.
Guess I'll have to dust off the ol' electronic project board soon ;)
On the mechanical side, I think that the important thing about the solenoid will be the travel of the armature and the way it mounts. If I remember correctly, the stiffy drives had a small one in it as well, but it might be to small.
We would need to have an adjustable spring, (something like the existing governor) as well to make up for the variations in different springs we might incorporate.
Once I have these in place, I can look at a mounting bracket of some sort to attach it to the existing governor linkages.
Does these ideas seem reasonably sane Jens? ::)
dubbleUJay
I've thought about this issue for some time and I think the simplest solution for a governor assist is an RC servo and a Picaxe 08M chip. It can sense the AC frequency via 1M ohm resistor a couple diodes to an input, and drive an RC servo. RC servos take temps well over 120F, as I used to fly them all summer in Phoenix. Failure just means the loss of fine tuning, so there's no need for complexity.
There's nothing wrong with PWM'ing a solenoid, but why suffer.
I do have a schematic for this, if anyone would like it. I haven't had time to work on it further.
Bruce M
Hi BruceM, after reading some of your other posts on your Automation Controller, you seem to be one of the top guys here on electronics and programming.
I've been looking for an automation controller myself, but although I can make all the boards and such, I always get to the problem of programming the code into a PIC or what ever micro used, 'cus I don't have the hardware to do it as I presume most of the guys here don't either. I can get them programmed & shipped from somewhere, but I would like to do it myself ;)
I think using an analog IC and a few parts, this cct should be plain and simple for the ordinary bloke like me to manufacture.
If you have the time, could you maybe draw a schematic for a basic cct to operate a 12v solenoid based on the varying input voltage from a small +/-12Vdc motor, driven from an engine?
I presume an op-amp, regulator and driver for the solenoid should do it, and a pre-set pot or two for adjusting the "input signal", if I might call it that.
I'll scratch around here as well, but I only do electronics as the need arises and a basic thing like a 741 will be a learning curve for me again.
I know the principles behind it, but implementing it is another thing. :(
It seems that a knowledgeable fellow like yourself could draw this up in his sleep ::) (The honey is dripping from my fingers as I type) ;)
Thanks,
dubbleUJay
Now this is nowhere near a working model, but just to give an idea of what I'm thinking and there IS flaws in the design as well, just before I get some "flack" for those ;)
I need to get the op-amp to work on a single rail supply, +12Vdc, not 12-0-12 as in the cct.
WJ,
I think there's going to be a lot more involved than just feeding the DC motor voltage to a comparator, then a mosfet to a solenoid. This is going to be unstable. Part of the problem is that the rpm is not constant due to compression and then ignition strokes. The real rpm looks like a hump. The DC motor output will have to be filtered, as this is hardly clean DC. The flywheels lag the engine response so much that an oscillatory situation is assured.
It might be possible to do this, using an op amp computed rpm velocity and acceleration terms for dampening. I have such a circuit that I designed for another application attached. A massively filtered alternator output is the "flywheel" in the circuit shown. A standard regulator would oscillate, because of the phase lag of the huge filter inductor.
I noted that the DC motor to solenoid device was promoted before it was developed, and then was not sold due to liability issues. Yet the design was not released, nor any performance data ever provided. Hmmm.
Learn to program, it's not hard. The Pixaxe chips are a perfect way to do so with very little expense.
Bruce
Hi BruceM,
I get what your saying about the oscillation, but is it not this oscillation of the cct that will make it work?
The lag of the flywheels and the small RPM difference the secondary spring will apply, is the key in this design I think.
I can see problems though if the voltage out from the DC motor is minute for say 650RPM & 655RPM, then this difference should be amplified to get a bigger "window" ???
I would think that some filtering would have to be incorporated, but maybe just a crude 10-100pF cap for high frequency spikes from the brushes and a 1-10uF for a "reservoir" on the input from the DC motor.
I'll have to wrap my head around this a bit more, like I said, I'm no expert with this stuff ;)
dubbleUJay
The oscillation is going to be caused by the slow response of the flywheel; the system as proposed has no dampening. The oscillation will only be limited by the authority of the solenoid. To make this abortion work, you'll have to add dampening of the applied correction based on the change in rpm, per the op amp circuit I provided.
There would be no CCT to the solenoid, a 12VDC solenoid was specified.
It seems insane to me to use a DC motor for an RPM signal, when the rpm signal is already present in the AC waveform. Why add a mechanical problem? AC signal frequency to analog voltage level could be done in some simple analog circuitry, but it is much easier and simpler to use a single chip computer like the Picaxe 08M or 14. Dampening of correction based on change in RPM is also easily done.
Best Wishes,
Bruce M
I can probably use my "copy" of National Instruments LabVIEW program and connect my Lister via a appropriate interface to my PC.
Their excellent tutorials will get me up and running in no time to control my speed with an actuator, but when my farmer brother over in Ireland sees this one day and he wants to make one, he'll have no clue of where to begin! ::)
Enough sarcasm from my side ;D, I think it boils down to simplicity for me and the ability for some ordinary Joe to reproduce it in the future. The latter being the main reason.
A micro controller would be better, but then I might as well do a total automation project and I'm just not up to it at this stage.
For now, my Lister CS has a "lazy governor" under maximum load and I just want to assist the mechanical governor with a little extra tension electro-mechanically.
dubbleUJay
PS(a)-I did say that a micro-controller would be better hey! ::)
PS(b)-My brother IS actually working over in Ireland, no offense intended ;)
As soon as you added one op amp, it's become a "black box" solution beyond the electronics ability of most. Even if you make a PCB, few will be able to build one. So any solution will be a "black box". ExpressPCB will make 3 fixed size "experimentors" boards for $53., cheap enough that I don't do as much hand wired prototypes now.
If I was the farmer, I'd rather have something that worked and was reliable. That would not include something with a DC motor driven off of a flywheel. If you really like having such a thing, well hell, have a ball. Just be prepared to add the op amp dampening circuit I provided.
A Picaxe chip is something developed for kids to use. Go to http://www.rev-ed.co.uk/picaxe/ A very good book with lots of well explained basic program examples for applications is "Programming and Customizing the PICAXE Microcontroller" by David Lincoln.
Alternately, governor performance can be improved by drilling out and re-bushing the sliding yoke piece in bronze; this seems to be where a lot of the bind in my machine was. The stock pieces didn't support the yolk fully, were roughly finished. The stock spring was too stiff for my machine, I found two softer springs that work better without hunting.
Bruce
Quote from: Jens on October 12, 2009, 09:27:06 AM
Quote from: BruceM on October 12, 2009, 09:23:08 AM
As soon as you added one op amp, it's become a "black box" solution beyond the electronics ability of most.
You have a point there ....
Jens
Definitely, but more people can go out and buy a 741 op-amp than a micro that's pre-programmed with dedicated code. This can go on & on & on...........
Guys, I do get what everyone is saying and I'm not even sure if my intentions is doable!
I'll start with the mechanical side first as soon as I get a change, ie. solenoid, then, if I see the op-amp "abortion" wont work, I can always change over to a more subtle way of controlling it.
Bruce, I've gone over all the mechanical side of thing on my governor 3x and cannot find anything more that I can see that's causing it.
It does not seem to bind, because when I apply a big load, the engine droops and do not come back to the set RPM, but even if I manually then open the rack by hand a bit, it easily picks up revs, but it then still falls back when I let go ???
So it seems that I'm not overloading the engine as it will "go" more and the rack is not binding as I'm overcoming that "spot" by hand and it still drops back upon release. (BTW, I'm applying pressure where the governor linkage come out of the engine, but it might be possible that I'm not "opening" the weights as such)
Now that I think of it, I've read somewhere that the weights of the governor might play a roll and I've seen photo's of the 6/1 & 8/1 weights being different.
There might be a possibility that my weights might be from the original 3/1 (if they were different), as my engine was build up of spare parts found all over.
I'll have to look into it further.
dubbleUJay
Quote from: Jens on October 12, 2009, 09:46:06 PM
I know what I am trying to say ... it just doesn't come out right. Anyway, point being that the governor can keep you in a certain range but can never keep the rpm constant over the entire load range.
Jens
I get it Jens, its no wonder I cannot find anything more mechanically wrong with my whole governor assembly! Obviously you did your homework much better than I did. ::)
So an extra "smaller" spring, released up to about half load (or wherever the frequency is still acceptable), but pulling upon full load (or wherever the frequency starts to be unacceptable), to bring the RPM up just a little bit, "should" do the trick and that is what we would like to achieve?
Somewhere in between there is going to be a point where the solenoid (op-amp) will slowly oscillate when the frequency is just about right, but due to the lag in the flywheel (actual frequency, not the frequency the "black box" is trying to achieve) this should only be a few revs either way. (And this is a big I THINK) ;)
Maybe something as crude as just the solenoid coming in at a 2hz drop might do the trick and be acceptable ???
I don't mind a slow oscillation of between 49 & 51hz with a constant load, but my UPS's start to complain round about 46-47hz.
If only I had some current sensing or frequency sensing relay or something just to test the theory :(
Anyway, I'll get there in the end!
dubbleUJay
a couple of thoughts if i may
has anyone tried to tailor the governor linkage to allow the flyweights to run either further out
or closer in at governed speed to see how they work against the spring? sometimes a bit of tweaking
here can make a huge difference in how the governor responds to load.
the old detroits had an airgap adjustment that had to be made very precisely at a specific rpm or all
bets were off on the engine power being what it should be, or governor responce would be sluggish etc.
failing that, how about this
a second spring to work in tandem with the stock governor spring to bias it as needed.
the second spring could be attached to a solenoid that instead of being a simple on/off affair
could have the coil replaced with one of fewer and heavier wound turns with the st head output running through
it.
then as the st head started to produce more amps for a heavier load the solenoid would start to pull increasingly harder
on the bias spring and help to maintain the proper rpm
it would take a bit of finigaling (tech term) to get it right, but out to be workable to some extent i would think
bob g
mobile_bob,
I've wondered about that solenoid tied to gen output idea too......
Wouldn't it be possible to just eliminate the mechanical linkage entirely and have the solenoid do the duty of the linkage? I suppose you would still need a spring, or would it be possible to replace it with a weight?
MK
i suppose anything is possible, i would hate to suggest anyone try it though
seems like if you got it wrong things could get really serious really quick
at least with the oem governor in place you got a failsafe control of the engine
and i think it might be prudent to keep that in place.
thats why i like biasing against the oem governor or its spring
anything fails electrically and you still have control over the rpm
i just don't think i am good enough to take the risk myself, and surely nowhere
near good enough to suggest anyone else try it.
maybe there are others that know more than me, which i am sure is the case
perhaps they got some idea's on how this might be done,, certainly a lot of interest
it appears.
bob g
It is technically appealing to me to just eliminate the mechanical governor, and directly control rack position via an RC servo. (A high end metal gear type unit.) Very little force is needed to move the rack in this manner. The software is not too challenging, either; it's a simple one axis autopilot. (And I've written a few of those.)
But it violates my own system rule- that all my electronics allow "manual reversion"; everything operates with the electronics off.
It would also require some serious secondary safety systems. I have this, but would also want something that would assure rack closure in case of 12VDC power failure. So decided that a mechanical governor augmenter would be the best compromise for me.
My mechanical governor can do 57-63Hz for full load range once it's warmed up. I have two springs in parallel, one is slack at rest. It's not great, but good enough as I have my homemade AVR on my ST3.
Quote from: mobile_bob on October 14, 2009, 07:06:13 AM
MK
i suppose anything is possible, i would hate to suggest anyone try it though
seems like if you got it wrong things could get really serious really quick
at least with the oem governor in place you got a failsafe control of the engine
and i think it might be prudent to keep that in place.
bob g
that's very true, and I've never tried an electrical only speed regulation. But take a look at the mechanical governor on the 'oid or changfa. All you have is a spring pulling the rack open and engine rpm working to close it. Why does the rpm-keeping-it-closed have to be mechanical? Would it be possible to do that electrically (not electronically) with just a small solenoid directly on the rack and a voltage source tied to rpm?
Keep in mind I've never tried this, it's just an idea that popped into my head in the middle of this discussion.
Here we go again. I know this has been rattled around a lot already but I blew up some more light bulbs and a battery charger .... Again. :-[
It was cold and we were running a small electric heater for the bathroom when the breaker on that circuit popped suddenly unloading the generator. Of course it over revved and ... :o
Based on the earlier posts on this thread, here is what I'm thinking.
Monitor either the voltage (E) or the frequency (Hz) of the output of the generator. Program something in such a way that if the E / Hz raises or drops a servo responds to the fuel rack.
However, if E or Hz goes over or under a certain set point, the fuel rack is closed and the engine shuts down. This would be for the times when there is a fuel or engine problem or a belt breaks or slips off.
Keeping the OME governor intact as an excessive over-rev safety would be important to protect the engine.
So my question is; Where can I go to find out what to use and how to program it for this. I'm willing to put the time and investment into such an idea.
Thanks
Ken Gardner
Quote from: akghound on October 20, 2009, 10:38:50 AM
Monitor either the voltage (E) or the frequency (Hz) of the output of the generator. Program something in such a way that if the E / Hz raises or drops a servo responds to the fuel rack.
So my question is; Where can I go to find out what to use and how to program it for this. I'm willing to put the time and investment into such an idea.
Thanks
Ken Gardner
Ken, stick around, I cannot promise anything, but I'm looking into it at the moment. I just want to get all my ducks in a row! ::)
This guy from the link below has done a lot of work on the subject with an electronic controller, but its quite involved and a lot of people (most) would not be able to do it, but if you read his pages, you get the general idea.
http://martin.nile.googlepages.com/automaticgeneratorcontroller (http://martin.nile.googlepages.com/automaticgeneratorcontroller)
I'm looking for something simpler (probably with less features) and readily available, that I can build up myself, otherwise one can just go out and buy one of these:
http://www.fwmurphy.co.uk/products/engine_controls/engmot_asm150.htm (http://www.fwmurphy.co.uk/products/engine_controls/engmot_asm150.htm)
but that wont be a proper DIY project! ;) and its functions would be limited.
So I was looking into using one of the regularly available experimental project boards for programmable micro-controllers, something that a lot of folks out there are using for other things and implementing it as a standalone automatic engine controller and also a data logger to PC.
Now, that said, I'm no programmer, but if I get the right board that has a big following all over the world, I'm 1/2way there I think. ;)
At the moment I'm looking at this board which seems to be very popular and available in most places:
http://www.arduino.cc/ (http://www.arduino.cc/)
Actually the USB version over here, but the 1st page explains more:
http://arduino.cc/en/Main/ArduinoBoardDuemilanove (http://arduino.cc/en/Main/ArduinoBoardDuemilanove)
and they seem to be very competitively priced to other products of the same nature at about $30 from Sparkfun:
http://www.sparkfun.com/commerce/product_info.php?products_id=666 (http://www.sparkfun.com/commerce/product_info.php?products_id=666)
Now, I'm not even sure that this board can do all the things I'm wishing for, but I'm asking around if it is capable of doing it in some of the forums and should have an answer soon, hopefully! ???
For one, the various sensors will have to be interfaced with the board first and I'm not sure if a program can be written to communicate the various conditions coming from it, to display and log it to PC!
The bottom line is, this is going to be a big and long project/exercise, for me anyway, but on the other hand, if I get the right guys to help with the PC interface/program it will help a lot. ::)
In the meantime I was looking into implementing a simpler semi-temporary device like this thread suggested that wont take so long to do.
If this thing can do data acquisition only for me, it will be worth my while. Think of all the nice graphs one can make if you have all the various temperature, voltage & amps to work out loads exec., while you are running the engine on different fuels! All in real time and logged!
We'll see what the future holds I suppose, I just have too many irons in the fire right now, 'cus this will need all my attention ;)
dubbleUJay
Hi Ken
Check out this thread in the Listeroid section. Topic is Overspeed Protection.
Romar points out a little relay that trips on high/low voltage.
http://www.microcogen.info/index.php?topic=156.15 (http://www.microcogen.info/index.php?topic=156.15)
Cheers,
Veggie
Ken, An AVR on your generator head would solve the overvoltage problem, and one of the smart voltage monitoring relays would also be good insurance.
I have the schematics (scanned hand drawn) for my prototype AVR that does timed voltage monitoring and shut down, and also allows "manual reversion" to harmonic operation. It is for a 240V head but is easily modified for 120. Let me know if that is something you want.
I have schematic and PCB layout for a 120V bare bones AVR. The board costs $53 for three ordered from expresspcb.com. Parts are about $50 for one.
As for a monitoring processor, I recommend a Picaxe 40X1 or 40X2. Very capable, least cost. Do a search on Picaxe for my previous discussion. I have scanned hand drawn schematics and Basic source code for a serious user. I do rpm monitoring via Cherry brand gear tooth sensor mounted next to the flywheel spokes.
Bruce M
Quote from: BruceM on October 20, 2009, 09:14:50 PM
Ken, An AVR on your generator head would solve the overvoltage problem, and one of the smart voltage monitoring relays would also be good insurance.
I found one that works for 220vac but I need one for 120vac.
I have the schematics (scanned hand drawn) for my prototype AVR that does timed voltage monitoring and shut down, and also allows "manual reversion" to harmonic operation. It is for a 240V head but is easily modified for 120. Let me know if that is something you want.
Yes Bruce I could really use your ideas. Thanks for the offer.
I have schematic and PCB layout for a 120V bare bones AVR. The board costs $53 for three ordered from expresspcb.com. Parts are about $50 for one.
As for a monitoring processor, I recommend a Picaxe 40X1 or 40X2. Very capable, least cost. Do a search on Picaxe for my previous discussion. I have scanned hand drawn schematics and Basic source code for a serious user. I do rpm monitoring via Cherry brand gear tooth sensor mounted next to the flywheel spokes.
Bruce M
I'll be gone until after the first of November. Will check in when I get back.
Thank you .... Ken Gardner akghound[at]gmail.com
I'm thinking more along the lines of controling the engine speed. I found this goodie on ebay.
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=290357196417&ssPageName=STRK:MEWAX:IT (http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=290357196417&ssPageName=STRK:MEWAX:IT)
Another option would be a Woodward APECS 500 but I'm having trouble finding out where to buy one.
http://www.traycana.com/catalogues/apecs/APECS500.PDF (http://www.traycana.com/catalogues/apecs/APECS500.PDF)
Of course I am in a hurry today and don't have much time to shop.
Ken Gardner
Hi Ken,
Some good finds in your post, Ken, thanks!
The Woodward unit looks like it has an ignition signal pickup for rpm- which wouldn't work for diesel. Woodward does seem to have a nice selection of high power solenoids.
The APECS500 looks suitable for replacing the mechanical governor and looks like a nice setup. It seems well suited to diesel since it has a magnetic rpm pickup. You'd have to buy the "calibration" software to keep it happy at 650Hz. The actuator appears to be a PWM modulated solenoid (burns a lot of power but is simple electro-mechanically). I'll bet the whole package is not cheap, but it looks like it would do the job.
My previous comment (10/10) on PWM was:
"There's nothing wrong with PWM'ing a solenoid, but why suffer."
I would still rather do it with an RC servo if designing it myself- it is cheaper and much lower power, and can be implemented as an augmenter instead of mechanical governor replacement.
But there is something to be said for buying off the shelf gear when possible- something like "Yes, thank God!"
No worries, Jens.
Solenoids have been used for "not so linear" actuators since long before I was born (with analog drive circuitry), so someone suggesting that they can't be used as such is at least confused.
The advent of PWM'ing from microprocessor gives them a new lease on life as non-linearity from return spring and position of slug within field coil can be easily compensated for, if need be, with a simple table look-up.
Getting back on track-
My thanks to Ken for finding an off the shelf option for electronic governor, please fill us in on any future info you find.
After reading this thread again, I have to change my view a little on some of the things I believed in at the time, mostly through ignorance on my side: ;)
BruceM, now that I'm busy with a micro-processor controller, I see that it would be much easier to implement it to do speed regulation.
My plan is still to use a Governor Assisting Solenoid with a weaker spring, but to control it with the ATmega board, seeing that I'm already going to use it for other things.
It will also ensure that the engine will still work if the electronics fail. I wanted to proof the concept before hand, but it looks like I'll have to implement it myself for the 1st time.
Once we know it does work, we can maybe look at easier ways to implement it as a dedicated standalone unit.
Almost every microcontroller with higher level language compiler or basic interpreter supports the PWM signal to RC servos, which makes using them very easy to use, just a resistor in hardware. For longer runs (over 3 feet) I use an opto-isolator just before the servo with a balanced current loop drive on twisted wire to have solid, noise free control. With the opto-isolated current loop drive, there's almost no limit on cable length.
They have excellent performance and are cheap and low power. One of the giant scale servos would be very lightly loaded for this application if the mechanics are done well.
If you insist on banging a solenoid, be careful to filter (LCLC) the solenoid supply, and put a inductive spike suppressing diode on the solenoid coil, or other noise suppression (zeiner or RC) if the diode causes too much response delay (it shouldn't for this application).
Found an Arduino based diesel engine governor project:
Michael McKGyver McKinley / Firewood Processor Governor (http://mckgyver.pbworks.com/Firewood_Processor_Governor)
Good find, NDavid79, Micheal has some very interesting projects.
He notes this governor code is poor, and if he thinks the other examples are not, then it would be "sporting" to try and use/adapt it. I didn't want to download the AVR program development environment just to look at his source code, which is not in a text format. (Grrr)
I'm baffled about the use of an optical encoder for rpm on an engine (grease and dirt will make it not work), and also the overkill use of a rotary encoder for "set point" adjustment (um, how about up/down buttons), but hey, it's cool, and he's obviously one sharp guy.
It didn't show now he maintained the manual mode, but it's a nice touch that he did.
Quote from: ndavid79 on November 19, 2009, 04:29:52 PM
Found an Arduino based diesel engine governor project:
Thanks David. 8)
Bruce, from your advice previously elsewhere on the forum, I'm going to use magnetic/Hall for RPM pickup on the Arduino, it just makes much more sense when I read your reasons.
I'll see if I can get the code "textified" (There's a new word for you ;) )
Although I haven't gone through the site yet to know exactly what your talking about, if its a Arduino/Processing sketch (PDE extension), one should be able to "read" it, but you guys know that.
dubbleUJay