Share your DIY controllers

[madlabs]

Hi All,

I'm curious about what DIY control systems folks are making out there, so I started this thread to ask people to post a description of their systems.

My system is largely based on the Parallax Propeller uC, but I have a few PICs involved too. I don't want to start a war about which uC is the mightiest, they all have pro's and con's and none are perfect for every task. I like the propeller because the 8 independent cores make multitasking easy.

My system is divided into three basic subsystems:
1) a controller located next to the batteries and inverter which reads all the sensors and has a  keypad and a 4X40 VFD display.
2) A controller on my desk with a touchscreen. It is linked to the first controller with a rs232 connection.
3) A clock with a Nixie tube display that gets it's time via a GPS. It corrects for DST. Controller 2 queries this unit every night at 2 AM and then sets the time and date on controller 1.

Controller 1 is the heart of the system. It monitors: Battery voltage and temperature, load amps, solar charge, generator charge, windmill charge, windmill RPM, wind speed, well pump, water pressure pump. It also regulates my lawnmower- alternator rig to allow for a nice absorption charge and equalizing and then shuts it down. It has a keypad and display to allow changes in parameters. It's slowly getting pretty smart, for example the system keeps track of how many hours the well pump and pressure pump are used. Since I know how the flow rate of the well pump to the tank, I can track how many gallons I can pump from the well. The system has the ability  to lock out the water system if the pressure pump stays on for too long (tank dry, massive leak) or cycles too many times in an hour (hose left on, small leak). This is great because the pressure pump uses a lot of juice and could easily run the batteries low.

Controller two is essentially a UI, with a 4.5” touchscreen that can detect clicks, double clicks and slides. I can scroll through and set all the system parameters, see all the latest data. I can see everything from how many hours I've put on the generator, peak wattage of the PV panels today, wind speed over the last 5 minutes or hour, you name it.

Controller 3 is a glorified clock as described above. It is a hack I made from an old 18” rack mount HP frequency counter. I gutted all but the Nixie tubes and made it into a clock. I actually made this years ago just because I love Nixie tubes, but it is a great time base, always right, corrects for DST and never needs setting. It is so nice to have all 3 of the system time synched with no fiddling around. To save power the clock only fires up the GPS once a day around midnight and re-synchs. There is also a PIR sensor that only activates the nixie tubes when someone is in the room.

I showed you mine. Now show me yours!

Jonathan

[DamonHD]

The only part of my control system that is DIY (I have a combo of commercial charge controllers and black-box BMS and now a bit of GHurd-dump) is that the computer system powered by the off-grid stuff cranks itself up and does extra work when the batteries are full, to use some of the excess energy productively (eg runs a small AI project).  However right now my main server runs at ~4W normally and can only crank itself up to about double that at max; this software dump load idea worked better when I was using a laptop that could dump/use 60W!

Oh, I also have a NiMH dump-load charger that I can leave a few cells in to bleed off a tiny bit more when the main batteries are full, but that's occasional and tiny...

Rgds

Damon

[niall2]

hi Jonathan

i built (tried) a pwm 24v dumpcontroller a while back based on a 494 pc junked powersupply chip with help from the backshed/irc
really just an analogue controller ...not exactly pretty with my soldering though    



in hindsight it worked pretty good  (will probably need to use again) and would even work directly off the mill  for a time (no batteries)...though moving it to 48v later was  beyond me ....

the thing i was,nt prepared for was the amount of hidden inductive spikes caused by the dumpload and probably the mill itself
so the fets didnt really behave as the spec sheets would have  suggested....my board layout probably didn't help much either...builder at fault here

fun though trying the diy route ...i,m  all for that  .....pc power supplies can yield a lot of interesting free stuff

    

[frackers]

I'm curious about what DIY control systems folks are making out there, so I started this thread to ask people to post a description of their systems.

I've posted about my Linksys router based controller before but here it is again...
http://gilks.ath.cx/~g8ecj/Turbine/controller.html

It does control and it reports data back to the main server for processing into pretty graphs
http://gilks.ath.cx/cacti/graph_view.php?action=tree&tree_id=3

Its still going well, we'll see again this afternoon how well if the forecast gales arrive

[madlabs]

Cool to see other people's stuff.  Thanks for the posts. Frackers, nice router hack!

Niall, I haven't had much luck with high power fet switching on a perfboard. My holy grail of DIY is a 20 amp or better MPPT.

[fabricator]

I'm curious about what DIY control systems folks are making out there, so I started this thread to ask people to post a description of their systems.

I've posted about my Linksys router based controller before but here it is again...
http://gilks.ath.cx/~g8ecj/Turbine/controller.html

It does control and it reports data back to the main server for processing into pretty graphs
http://gilks.ath.cx/cacti/graph_view.php?action=tree&tree_id=3

Its still going well, we'll see again this afternoon how well if the forecast gales arrive

You cannot possibly imagine how awestruck a nuts and bolts mechanical person like me is by stuff like that, that is simply awesome.

[letERblow]

My DIY wind controller is built around a BasicX-35 from the Basic Stamp family of micro processors.
The LCDX from NetMedia (http://www.basicx.com/) has a 4x20 LCD display and built in keypad interface.
They are a little on the pricey side but I have used them in some other projects so was familiar with the
visual basic style programming and such. It has enough IO to monitor wind speed, RPMs, Volts, amps, two PWM
outputs (had to hack the circuit some to use the PWM, didn't realize they were using it to control display
brightness and contrast) and 8 relay outs. The salvaged key pad with display window worked out quite well.




Right now I am using it to control direct heat load for water and space heating only from my Dual rotor, 220 volt, IRP connected
PMA with PWM duty cycle from a RPM look up table and a bank of FETs. Would like to expand after we see what this genny will do.



I can monitor Wind speed, RPMs, TSR, Volts, amps, watts, %PWM, KWhr totalizer. High Wind, RPM, Amps and volt alarms can
shut the turbine down with a linear actuator connected to the spring loaded tail. Only been on line a couple of weeks
after several months fighting FET problems, dang, missed the good wind season. The display and key pad interface allows me to adjust the PWM lookup table and all shutdown parameters on the fly, it also has calibration routines built in. I now need to work on doing some data logging.

Been monitoring the board all through this project, gleaning info and ideas.
 Thanks to all who take the time to share.

[fabricator]

That is awesome.

[Rover]

Looks professional letERblow , really nice job

Fat chance I'll post any of mine now

besides mine are in a state of continuous change

[frackers]

You cannot possibly imagine how awestruck a nuts and bolts mechanical person like me is by stuff like that, that is simply awesome.

Now if I could weld as well as you, I wouldn't have to just tack things up and then pay to get them done 'properly' 

A bit embarrassing as my father was a sheet metal worker who could TIG two bits of stainless together so you couldn't see the join!!

[fabricator]

If we could just find a Vulcan to perform a mind meld we'd be all set. 

[madlabs]

Leterblow,

Nice pics! Great looking system! I'll go grab a camera and snap some pics of mine. Thanks for posting, love to see other folks stuff.

Jonathan

[Janne]

My small 12V system is also done with DIY electronic controls. The 3.2m diameter axial flux turbine is charging the 12V / 330Ah battery bank with an MPPT controller. There is also a separate analogue dump load controller, that is located next to the battery bank.

The MPPT controller I have works on the same principle as letERblow's heating controller. It adjusts the output power based on the rotor speed, and the output power level for a certain speed is just taken from a pre-generated lookup table. I have no fancy interface for changing the table on the fly, so it needs to be updated manually with a laptop, if needed. For testing, it also has a potentiometer, that can be used to adjust the output power manually. Maximum power it can handle is about 500W continuous , and the furling on the axial machine is adjusted a bit below that. As the turbine is wound for a quite slow cut in speed, below 130 rpm, and the blade design TSR is quite high at 7, the MPPT really helps with the efficiency at winds ranging from 4 to 7 m/s.
The processor on the controller is a PICAXE 40x1. It doesn't drive the switch mode converter directly, as the PWM generators on it are lacking in resolution. Instead, it drives a D/A converter to generate a current reference for the controller. The power stage is then based on a TL494 switch mode regulator, which drives the buck-topology at 100kHz. More of the MPPT on a separate diary entry, for anyone interested; http://fieldlines.com/board/index.php/topic,130334.0.html

The dump load controller works with a series of voltage comparators, utilized in the form of an LM3914 led bar driver. So, as the battery voltage raises from the set dumping point, it will gradually switch in more heating loads to dump the excess power.

[Treehouse]

There has been a lot of talk lately about building your own pwm dump load controller, so here is the new Dump load controller I have been working on. It's a c-40 like clone, holds the batt for an accumulated  1 hour at 14.4V  and then floats at 13.8V. The buttons adjust the set points up and down. I only have one FET on the power board so it's only good for 5-6 amps but I have more to put on it. I just tested it for 2 weeks on a 30W solar panel and a light that draws around 2amps. So far so good! now I have to add another FET's and take it up a step with more load and more solar. I am going to add one FET at a time and keep a close eye on temps and stuff.  Best of all I'm having fun ! and no magic smoke! (So far)

[zvizdic]

Looks good !
Can you post schematics and a parts list?

[Treehouse]

I would if I had one, lol. it's basically the same as elt's just with a bigger pic processor . It will also have a few output ports for controlling other things like a power vent fan, switched output for a second inverter for a small fridge when the batts are full.(too keep the beer cold lol)  I'm also thinking of adding a hall sensor for current sensing and I could make a remote display unit showing vbatt and accumulated amps dumped, some buttons to adjust the setpoints, and output functions. Like I said just like a c-40 but a little more modern. It's going to be a fun project, as I don't get a lot of time to work on it. It's going to be a slow work in progress. The wife and 3 kids come first.