Alarmingly stupid idea

[commanda]

Scenario........

Your auto-furling super-dooper multi-killerwatt (spelling miztake on purpoze) wind turbine doesn't auto-furl. As Murphy would have it, this is the first BBQ you've had since moving in, and all the neighbours were over, and you all drank too much, and you slept most of Sunday. It was just on dark when you awoke, and turned on the lights. Thought they were a bit dim, but put it down to too much of the good oil the night before. Shortly after, it's really dark as your expensive (and now cooked) battery bank gives it's last gasp.

Now imagine, the night before, when the auto-furling thing didn't, and an alarm went off to warn you of impending disaster. It's got a little button to silence the annoying noise, but 15 minutes later the noise starts again. Good oil or no good oil, you're soon gonna get the idea that there's a problem which requires your attention.

Imagine also that you've really over-designed the system. Lighting is all 12 volt, and individually fused & switched by zone in the house. Your multiple inverters are also individually fused. Each of your multiple wind turbines have individual tachos, with over-rev alarm outputs. The water heater you so painstakingly rigged as a dump load for all these solar generators has reached its maximum temperature,(haven't showered for days, but that's my problem) and there's nowhere else left to dump the excess generation capabilty.

Has anybody else considered such an alarm panel. Am I just paranoid that anything that can go wrong........Will. Or am I the only nutcase here stupid enough to conceive of such a thing, or even more improbable, the only one dumb enough, although capable, to actually do it.

If I do build it, anybody else want one?

[tecker]

     Everyone should have such a problem. Take look at some other animation, maybe freeze the beer cooler to interrupt flow of the sauce that caused distraction .Space heaters for winter fans and Ac in summer . Amp hogs everyone.

[TomW]

commanda;

This sounds very close to the kind of thing I am going to do using laptop serial and parallel ports and perl.

Make decisions on what to do based on voltages at different locations compared to loads and production.

Once the sensing and data logging is all in place you can modify the logic in software rather than reconfiguring a circuit. Also lends itself to network based monitoring and control plus additional parameters can be integrated as you go such as factoring in environmental conditions as well as predictive options for forecasting use, etc.

I just love cheap laptops for monitoring and control. Obviously not for everyone but I use them for monitoring 2 battery banks and can fire up my inverter from software based on voltage, time or a combination of parameters. With a Wireless LAN here I can monitor widely spaced components of my system without any wired connections for sensors at "remote" areas.

Just one rather geek way to accomplish this type control.

Any system that can self destruct if warning signals fail should have some automatic positive method to absolutely shut itself down should the operator fail to respond to critical warnings

Just my idea this day at this moment, subject to misinterpretation and change as needed.

T

[hiker]

just downloaded ie 6---testing...

[commanda]

I trust you're running this on Linux. I also hope you're going to release whatever you come up with as open source. Wish I could get my head around Perl; I've tried several times and I'm still convinced it was created by aliens. Maybe I'm just not smart enough.

Amanda Commanda

[TomW]

Well, pretty much anything I do is released for use by anyone when I feel it is ready. Linux of course since its got every tool I need for a free download.

JimU actually is the perl coder and his stuff is or will be freely open to use. Right now the stuff we have is all pretty much duct taped and wired together and not ready for prime time since there is no documentation and it takes a bit of customizing to your system and hardware you gather data with. Mostly proof of concept stuff thats been running here and at Jim's for quite some time. The biggest thing I would like to see is a simple "black box" that can convert analog voltage levels to data a serial port can read self powered would be nice too. We currently use digital meters with serial port output now since they are fairly cheap and most are supported in Linux.

[commanda]

http://www.picotech.com/data.html#hardware

I've used their stuff before with a laptop. Don't know if the protocol is published or not for writing your own interface.

There are others.

Amanda

[Chagrin]

The LabJack is $119 and USB (for better or worse). A perl module is available at the site but you'll probably need some C knowledge to get it figured out.

Haven't tried it myself, but intend to (some day...). Looks like the best deal out there to me.

[thunderhead]

I'm working on a battery charge monitor/controller that goes across each unit in your bank.  The idea is that it produces three isolated current loop outputs: an "OK to charge", an "OK to discharge" and a "not OK to charge".  

Also, an isolated enable can be used to switch in a resistor for a fixed current charge, switched by the "not OK to charge" sensor.  This should enable the batteries in a bank to be charged individually, by applying a fixed 2A current and waiting for them to all show "not OK to charge".  As each one shows "not OK to charge", the 2A is diverted through the resistor, so driving only the batteries in the bank that have not charged yet.

There will also be a dual LED - a red one for "OK to charge" and a green one for "OK to discharge", to give an instant visual indication of which battery in your bank is not pulling its weight.

The idea is to wire the outputs together so there are three outputs from the whole bank: "all OK to discharge", "all OK to charge" and "none OK to charge".  These should be what is needed to protect the bank and prolong its life, either with clever microprocessor controls or with something much simpler and more computer-free, like a couple of relays and a few transistors for the current regulation.

I'm aiming to keep the bill-of-materials below UK5 - call it $9 in today's money.  The monitor will consume a small parasitic current, which I'd like to keep below 5mA.  My 104Ah batteries should, by first approximation, supply 5mA for about 28 months - at a rate of 1kWh per unit every two years or so.  Of course the batteries will be long flat of self-discharge by then.

I have this in mind as part of my electric car ambitions, but it should be useful for any sort of electronic monitoring of a battery bank.  I'll post a circuit when I've finished prototyping it, and there should be a circuit board available in due course.

[nack]

Yes, Larry is an alien.

[TomW]

HaHa very funny. But, we are all aliens somewhere. I find some PERL to be semi understandable but usually only after its written!

T

[nack]

Oh, yes, I tend to draw looks that make me wonder if I sprouted antennae (I haven't, yet - usually it's just something I said)...