Sunday, September 28, 2008

Motor/Battery Pictures

It finally stopped raining long enough for me to get a few pictures of the motor mount and the rear battery rack. The rear battery rack isn't finished yet, but the you can see five of the batteries installed for testing. I was pleasantly surprised how easily the batteries fit, and there is plenty of wiggle room on both sides for the stiff foam box I am going to build around it.

I haven't worked on the EV at all since last week, mainly because I was trying to figure out the controller deal. Now that I have decided to buy a controller, I can start to find the money for it and then get back to finishing the battery racks.

Saturday, September 27, 2008

Some Changes

I have decided to add a PayPal Donations button to my blog. I thought about doing it months ago, but had no real need until recently. My search for a decent temporary controller has been a bust, and my homemade controller is running into supply problems. That, and college classes take up most of my time and I have been draining away what cash I had left for the temporary controller to gas. :(

So I have decided to start to save up for a 96 volt controller that will meet my needs until my homemade controller is complete. I need about $600 for a Kelly KDH096400 96 Volt 400 AMP controller, so I am hoping anyone out there willing to spare a few bucks will.

I am also long overdue for come pictures of the rear battery rack and the front motor mount, so I will try and take some if the rain ever stops.

Friday, September 26, 2008

Quick Update

So I am feeling the pressure from my family to get this EV going soon, and my custom controller is taking way too long so I have started searching Craigslist for a cheap 48 volt controller just to get the EV moving. I have had a few hits, and the lastest sound promising so we will see.

As for my own controller design, I have my current sensors arriving today and I am still working out a few problems in my design. The design itself looks fine, but the 15 volt source I need doesn't. I was going to use a LM317T adjustable voltage regulator, but it is only 1.5 AMPs max and my math says I need at least 4.5 AMPS for the IGBT driver.

I have a computer gig to do this afternoon, so hopefully that will pay for the temporary controller.

Sunday, September 21, 2008

Controller Autopsy

After many hours or analyzing, the problem ended up being the flywheel diode. It was way undersized and because of that, a large voltage spike went through the controller, blasting parts away as it went.

The second generation controller has many new features and fixes, such as a microprocessor, 16KHz freguency, IGBT driver, Hall Effect current sensor and a large freewheel diode. Eventually I will hook up an LCD display to it and add some more feaures. This controller is still early in it's development, with parts being ordered this week. I have lots of work to do on this software for it, creating IDLE control, Performance/Range settings and what ever else I can thing of. I have gone through this particular design a few times, and showed to some professionals and it should work perfectly fine. Ideally I would want to make this as customizable as possible, and maybe make a small side business in the EV controller market, but that is probably a few years off.

Thursday, September 18, 2008

Zoom, Zoom, Zoom!

Well, I moved the car today! But not all went as planned. My basic controller had a problem with the driver for the IGBT and cooked it, so the motor went racing full on as I backed down the driveway. I was actually made aware of this the day before, but we were unsure how much of a problem it would be. Now we know.

But the car did move under it's own power! Tomorrow I am going to make sure nothing happend to the coupling because there were some loud sounds from that area when I jammed the car into park and shutdown the motor.

The second gen controller has a true IGBT driver, and should be ready to test this weekend. It will be getting a go over from a few professors and IGBT experts tomorrow.

Tuesday, September 16, 2008

Test Drive...Or Not

On Sunday I had everything ready to go for a test drive. That morning I had adjusted my current limit to a lower value for safety reasons, installed all the cabling, wired up the starting ciruit, contactors and put the rear battery pack in. Then went off to visit grandparents and came back that night for the test run.

So there I am, camera rolling, everything connected. I start up the car, contactors close, cooling fan comes on, put it into reverse and hit the pedal. NOTHING HAPPENS.

After 5 minutes of taking measurements, it hits me. I modified the current limiting wrong, so it forced on, prevent the car from moving. (Well at least that worked!)

It gets better. So I go to remove the controller, shut everything off, flick the breaker and proceed to remove the controller. In an act of complete stupidity, I drop the wrench across the B- and M- terminals, and it sparks blowing the logic board away. The capacitors were still charged, and found their way to there desitnation by toasting the controller.

I had breakers and fuses for every other part of the system except dropping a fraking wrench across the terminals. Now I have to repair it, which should be as simple as replacing the three chips and some bench testing. I also am almost done laying out the microprocessor controller and hope to have that is some sort of a testing phase in the next week or so. I just have to order a hall effect current sensor and plan on having it completed before it gets cold out. (It's water cooled, and that will provide my heat for the cabin.)

Friday, September 12, 2008


So yesterday I got the wheel unstuck but pushing the car down the driveway. It worked really well, but the brakes still stick a little. I also designed and cut out the front motor mount and it went to the welder this morning and I hope to get it back tonight.

The rear battery rack has both coats of paint on it and is all dry and ready to be installed. I also made a test cable yesterday, and will make the rest up today. Before I mount the rear battery rack, I am going to do a test fit to make sure all 5 batteries fit.

I also have to adjust my controller battery current limiting from 500 amps to 250 amps for many reasons, but one is that if I don't, the controller can be called the EgoBuster. Set at 500 amps and you step on the pedal, the 250 amp breaker would blow before the current limiting kicked in, and that would make anyone's ego bust up. I can just picture going for my test run and stepping on the throttle to see what my controller can do, and blowing the breaker before I go anywhere!

So what's left:
-Install motor mount
-Make cables
-Install Rear Battery tray
-design and install front battery tray
-Make one last modification to my controller

Drive it. If I can get the front motor mount welded today, I can wire up the rear batteries and do a 60 volt street test!

Tuesday, September 9, 2008

More Batteries

OK, so now I have a total of 6 of my batteries. Yesterday I also did quite a bit of useful testing, and one of those test told me that I need the motor mount before I can even think of a road test. I had to jack the transmisson and motor up so that it was level, or else it wouldn't spin up at all. I then did some useful motor/controller tests and came to the conclusion that the transmission uses 480 watts to idle. I also painted my rear rack, and tomorrow I will put another coat of paint to finish it off.

Today is a wasted day because 1)- It's raining and 2)- I am in classes until 9:00 tonight.

Tomorrow I plan on painting the rear rack, buy the materials for the front motor mount, and mount two 12 volt fans to the controller. During my test, it got warm to the touch pulling 25-45 AMPs, so more cooling would be nice.

And on the topic of controllers, my second gen microproccessor controller is in the works with so many nice features. I have an IGBT driver on the way that is compatible with it, and I also am going to order an isolated current sensor. And I have also solve my heat problem in the EV. I have a water cooling system for my IGBT, and I am going to use it on the second gen controller, and route the water through the exsiting heating system. It should be up in the 90-150F range, so plenty of warmth for defrosting the windows. I also am trying to integrate the status display into this edition of the controller.

My hope is that I can build a successful, powerful controller that I could put into production in a few years, after gathering data and abusing it to the best of my ability. My hope is to eventually have a controller that can be programmed for specific motors and battery sizes, as to maximize range and performance.

Monday, September 8, 2008

The Motor is In!

It took most of the afternoon, but the motor is finally in! Everything appears to be aligned and I can spin the motor, so I think it is looking good. I have also bought 2 more batteries and hope to do a quick test spin up this afternoon after classes.
The motor looks so small in the compartment, but it should be able to move the car around since it's a 10 HP continuous motor and I don't plan on taking it past 55 at all. (30-45 MPH is the desired speed)

So here is what I have left:

-Paint rear battery rack and install it

-Design and build motor mount for extra strength

-Design and build front battery rack

-Wire everything up

I am really hoping for a short street test this week, up and down the road on the 36 volts I have.

Friday, September 5, 2008

Plates Drilled

So I have all the holes for the plates done, and all that is left is a few cuts for the transmission mount and one of the drive axles. The plates are bolted to my transmission template and I had an alignment problem, but I fix it by adjusting one of my spacer pieces.
Tomorrow it is supposed to rain and storm like crazy, so I am going to get my batteries and build my EPS grid (electric power system) that contains the starting relays, precharge resistor, circuit breaker and other low power + saftey features. And get the plates completely cut would be great so that part is done.
My rear battery rack has also been welded and I hope to mount it soon. This storm (Hanna) really ruins my installation weekend. I was hoping to get in a test drive on 60 volts on Sunday afternoon. (With the rear rack installed and 5 batteries)

Thursday, September 4, 2008

Controller Guts

A few people wanted to see the guts of my 555 timer controller, so here is a picture of it I took a while ago before I cased it all up.

As the plates go, I should have the spacer plate cut out and cleaned up tonight! I hope to have the motor and transmission assembled tonight and make the last cut outs for the drive shaft and the engine mounts because the plate covers them at the moment.

Tuesday, September 2, 2008

The Big One

So this is the last major cutting part of the project. And is a real pain. The hole is about 8 inches in diameter and the only thing that seems to work for a nice cut is the tiny jig saw. The real problem is that it is slow, and the battery runs out rather quickly. Tomorrow I have to buy some more blades and find all the good DeWalt batteries I can and charge them up. College starts up again tomorrow, but I have a goal of getting that motor in the car this weekend. Once it is in, I estimate a day for all the wiring and ignition system, and then another 2-3 days of finishing up the AC/PS bracket and the front battery rack.