Mofidying car computer to speed switch

[windbug]

Hi:

I have a windmill which requires a speed-switch for grid conection at 1200 rpm generator speed. Due to various wind conditions, a rapid on and off switch is required. Since commercial switches are very expensive, is it less expensive to modify a computer for the same task? From which cars would used computers be most suitable? Many features such as crank sensing and rpms for gear-shifting are already present in the micro controller.
Any help or advice would be greatly appreciated.

Windbug

 

[Skogsgurra]

How would you "modify" a car computer?

You will probably (surely) not get access to the chip. And if you do, you do not have the source. And if you, by any insanely incredible chance, ever find the source - do you have the development system for that chip? And last - if you have that, you would not ask a question like this.

Better buy a Basic Stamp or something similar and do it from scratch. Even better, one of the programmable relays - I have used Siemens LOGO! (yes the "!" is in the name). That will not cost you more than a couple of hundred USD.

Gunnar Englund

http://www.gke.org

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100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...

 

[VEBill]

Does one have to match phase before connecting to the grid? Or do you just stand back and make the connection and let it sort itself out?

 

[nbucska]

I have read somewhere that one car computer board cost $1600.- Getting documentation would be a nightmare, too.
I suggest for less than $100.

http://www.jkmicro.com>

or less than
$200.- <

http://www.bagotronics.com>

Both are PC compatible, small cards you can program in
FORTRAN, any flavor of interpreted or compiled BASIC,
PASCAL, several versions of "C" etc,,etc...

No computer can directly switch your generator -- you
need power relay which can be driven by smaller
relay or electronic driver.




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Please read FAQ240-1032
My WEB: <

http://geocities.com/nbucska/>

 

[davidbeach]

And people wonder why the utilities are so leery about the connection of small generators.

 

[Skogsgurra]

If it is an asynchronous induction motor being driven slightly overspeed, it can be switched without regards to phase angle. It does "sort itself out".

Still, thinking that a "car computer" (which one? motor control, cruise control, climate control, brake control, emission contro or any other?) can be modified is not very realistic.

I do a lot of onechipper programming and I would never dream of trying anything like that. I would buy a Propeller ProtoBoard from Parallax. It costs like 25 dollars and is a wonderful platform for any custom computer application, even has composite video and VGA output and also inputs for PS/2 mouse and PC keyboard. And fast - eight 32 bit processors running at 80 MHz each. A total of 160 MIPS (32 bit MIPS, that is) on that little dirt cheap board! Love it!

It is huge overkill for an application like this, a massacre really. But at that price, I use it for anything, even if it is only some "blinking lights".

Gunnar Englund

http://www.gke.org

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100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...

 

[OperaHouse]

You might want to post that on fieldlines.com but I am afraid they are about the most technically challenged group I have seen. If they can't beat something to work with a hammer they don't do it. I would think there would be a group of passionate people with a solid technical background creating really innovative solutions ahead of industry. What I have seen doesn't give me much hope for energy independence in the future.

 

[MikeHalloran]

The Ford EEC-IV uses a custom chip that's based on the Intel 8096. I think the differences are minor, amounting to a few added opcodes or modes that I'm not sure Ford even bothered to use. So a toolchain can be had, not real cheap because the 8096 wasn't real popular outside Ford. You can find disassembled source dumps of a few of the hundreds of EEC-IV variants, and schematics, on the Web.

But given the effort that's required to hack an EEC into doing what you want, it's easier to start from a deveopment board like Gunnar suggests. I.e., the EEC-IV does not have a connector that says 'grid here' and another that says 'windmill here'.



Mike Halloran
Pembroke Pines, FL, USA

 

[itsmoked]

I've torn my Ford's EEC apart. You don't want to go there....

Keith Cress
Flamin Systems, Inc.-

http://www.flaminsystems.com

 

[MacGyverS2000]

Is this for selling power back to the grid? If not, make sure you have a switch that separates the windmill form the grid, else you'll backpower it when something goes kablooey... next electrician that steps up to work on the line thinking it's dead will get a real nasty surprise.


Dan - Owner

http://www.Hi-TecDesigns.com

 

[LionelHutz]

Well, the GM '7747 computer has been pretty much fully hacked. But, the code is written to run an engine, not switch a windmill on and off. It'd take a LOT of time to figure out that computer code enough to re-write it to do what you want.

Just go with a pic or stamp. I'm sure you can even find some code blocks that count pulses to start with.

Or try this;

http://www.scoraigwind.com/circuits/index.htm

I don't understand your rapid on-off switching statement. Wouldn't you just connect once you hit a certain minimum average wind speed??

 

[itsmoked]

Another case of the OP hitting and running??

Keith Cress
Flamin Systems, Inc.-

http://www.flaminsystems.com

 

[OperaHouse]

A few years back someone came up with an interesting product. It was a windmill that drove the alternator field coil with a computer generated waveform instead of DC or a permanent magnet. By changing the field frequency, the windmill could spin at a wide range of rpm and produce the same frequency and amplitude.

 

[MikeHalloran]

Looks that way.



Mike Halloran
Pembroke Pines, FL, USA

 

[itsmoked]

Opera I can't picture that working as the stator is fixed and nonadjustable.

I'd expect to see that being exploited all over..

Keith Cress
Flamin Systems, Inc.-

http://www.flaminsystems.com

 

[davidbeach]

The doubly fed induction generator. Use a wound rotor, apply a variable frequency field to the rotor to cause the stator to produce line frequency over varying shaft speeds. Rather clever, also patented I believe.

 

[ScottyUK]

I don't think it is patented, or at least the patent has probably expired. If you Google [blue]double fed induction generator[/blue] there numerous hits, mostly relating to wind energy conversion. There are some R&D papers in among the first few pages of hits.

The power electronics to drive the field is unusually large when compared to a standard synchronous machine: converters for double fed machines typically handle about a third of the overall machine rating.


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Sometimes I only open my mouth to swap feet...

 

[windbug]

Hi all:

Thanks for all the answers. As my initial question implies, you probably realize I am not an electronic technician. The idea of a car computer was only a thought. I will now engage in the various boards you mentioned. In the meantime some questions came from you which I can definitely answer.
1. Any ac motor driven over its design speed will turn into a generator and also will be in sync with the 60-cycle
system. The ac motor with a capacitor between L1 and L2 can then be used on a single-phase system either as a motor or a generator. In the motor mode, it will not self-start. Giving the shaft a push either left or right, it will then run as a regular motor.
Re: Injuring a lineman during a power loss is not possible because the stator needs to be energized from the line to produce power.
I need a speed switch because between motor and power production there are very few revolutions involved. I observed during a windspeed drop my mill went into a motor mode, resulting in the mill turning away from the wind and walking around its own axis. The mechanical switch I built
was not fast enough to rectify the situation.

Thanks again for you suggestions,
Windbug

 

[LionelHutz]

What size of windmill?

For anything below about 5kW (maybe even larger) I would consider using a PM generator with a battery bank and then use a grid-tied inverter to connect the utility.

For a direct connected unit I've often though that using back-to-back SCR's in the power connection with the gating circuit triggering the SCR's at the proper times should only allow power flow in one direction. Would make a good automatic switch that doesn't allow any motoring and catches all the generated power. However, you would have the extra losses of the constantly operating gating circuit...

 

[catserveng]

There are plently of electronic speed switches out on the market used for engine and electric machinery protection that ought to be able to do what you want for a reasonable price, some makers I know of,

Basler,
Woodward,
Altronic,
Crompton,
Dynalco,
Engineering Concepts Unlimited,

We have also used AB MicroLogix PLC's ( 1000's, 1100's and 1200's )on their high speed inputs with a hall effect speed transducer over a chopper wheel or gear.

I am sure there are other manufacturers of electronic speed switches, and other manufacturers of PLC's that can also do what you want. I'm not so sure for a device like a speed switch I would build my own, don't think the cost savings would be worth the potential problems.

Hope that helps.