September, 2007

Hub is back but EE1SpeedoDiv is not there

Porsche 914 EV Conversion

Today had some ups and downs. I got the adapter hub from Electro Automotive back today. I installed it on the motor shaft and, to my delight, it had less than 1 mil of runout and wobble! That's how the hub is supposed to work.

2007 130

Someone videotaped me

Plugs and Cars

A few months ago I attended an eco-event in Fairfax, CA with my electric car. Someone seems to have videotaped me and posted it on youtube.

2007 130

Trending Sources

The Volvo Recharge

Plug In Partners

A nother major manufacturer is unveiling their PHEV at a car show. This time, it's Volvo. Here's the story from duemotori.com.

2007 130

Getting the Heater Relay and Sending Back the Hub

Porsche 914 EV Conversion

After putting the adapter hub from Electro Auto onto the motor shaft no less than twenty times, I'm pooped. I tried filing down several different faces of the hub to get the runout and wobble down and failed. It's going back to EA tomorrow morning for a new one.

2007 130

Keeping the Rain Out

Porsche 914 EV Conversion

Since I live in the Pacific Northwest, I get rather concerned that rain entering the engine compartment will cause problems with the electrical wiring. Many other 914 EV'ers have protected their wiring inside conduit boxes and other shields.

2007 130

Those (Not So) Good Vibrations

Porsche 914 EV Conversion

Well, it's time to bite the bullet again and see what I can do about the car vibrations. My friend graciously helped me remove the motor/tranny from the car again this morning and assisted with crude vibration measurements.

2007 130

DCDC Transistor Hack

Porsche 914 EV Conversion

After talking with various people and realizing that the over-current circuitry was making the FET gate pulses way too large, I decided to hack the DC-DC converter circuit. Here's the new circuit (click to enlarge).

2007 130

More Trending

I Blew it Again! Learning About Soft-Start.

Porsche 914 EV Conversion

After studying the oscilloscope waveforms, I believed that the current sense circuit was way too spikey. This is the "amp adjust" potentiometer output in the C400 schematic.

2007 130

Initial CCPower Schematic

Porsche 914 EV Conversion

In my efforts to debug the failures of the DC-DC converter, I tried to capture a schematic of the board. I didn't have time to create a component for the SG3525A controller, but all the pin numbers are listed.

2007 130

Doing Vibration Research

Porsche 914 EV Conversion

At the suggestion of Paul J, I started doing research on vibration analysis today. There are several online tutorials regarding vibration analysis.

2007 100

More Resonant Experiments

Porsche 914 EV Conversion

My friend Rick dropped by tonight to run the accelerator cable and monitor the RPM on the laptop while I put my hands on the motor/tranny to get a better feel for what's going on. We ran the motor with the transmission attached for weight without the clutch friction plate. I also put the transmission in first gear to guarantee that the input shaft was not turning and contributing to any vibration.

2007 100

Ethanol Boom Busting

Plugs and Cars

Check out today's NY Times story Ethanol’s Boom Stalling as Glut Depresses Price.the ethanol market is suddenly plagued by a glut, in part because the means to distribute it have not kept pace. The average national ethanol price on the spot market has plunged 30 percent since May.And if the bust becomes worse, candidates for president could be put on the spot to pledge even more federal support for the industry.

2007 100

Resonant Frequencies

Porsche 914 EV Conversion

After successfully spinning the flywheel and pressure plate at 9000 RPM, I felt confident that things were looking good with the motor. I re-installed the clutch friction disk and bolted on the transmission. After spinning up the system, it started rattling and skittering across the floor around 5500 RPM. This is a royal pain.

2007 100

Tesla - Longer Range, Later Delivery

Plugs and Cars

CNet is reporting some good and some not so welcome news about the Tesla Roadster. Seems the batteries are performing better than expected, and range is back up to about 250 mile per charge. But another delivery delay has been announced. Cars will not hit the road until early next year. Personally I'd trade range for earlier delivery, but of course it doesn't work that way. Simply getting on the waiting list for the car once cost $50,000.

2007 100

An E-mail from Azure Dynamics about the DMOC445

Porsche 914 EV Conversion

I recently sent off an e-mail to Azure Dynamics, the maker of the DMOC445 AC motor controller in the 914 kit. I asked how I could tap into the motor encoder signals to create an RPM signal for the tachometer on the dashboard. It turns out that the DMOC controller already has a PWM (Pulse Width Modulated) output that can be used for this. There are also some LED signals that display system status without having to use the serial port.

2007 100

Balancing the Flywheel.Again

Porsche 914 EV Conversion

I took the flywheel/clutch to Dan Halls Machine Shop this morning and just picked it up half an hour ago. Dan basically said that it was fine. He spun it as fast as the machine would go and it was only out of balance by 2 grams on the flywheel and 2 grams on the clutch pressure plate. Apparently this really isn't a lot for flywheels. The motor adapter hub from Electro Auto still has 4 mils (thousands of an inch) runout, so I'll try to attack that next.

2007 100

Co-op America Really Gets It! - Plug-ins YES; Ethanol NO!

Plugs and Cars

Co-op America has cut through the hype and hyperbole about "clean" cars. They did an excellent issue of their magazine analysing the pros and cons of hybrids, plug-ins, electrics, bio-fuels of all types and hydrogen with a Consumer Reports type objectivity. They found "the truth is, not all of the "new" fuels are created equal. In fact, some are nearly as bad as gasoline in their environmental impacts, and others can't be scaled up in a meaningful way without creating other problems.

2007 100

Two Week Commuting Report

Porsche 914 EV Conversion

Since I don't work Fridays, this is the end of my second week commuting to work fifteen miles each way. Two things have definitely made the car more fun to drive. The batteries are broken in so I have more current to work with and more importantly 2. I've learned some of the tricks to driving the car. The biggest trick involves starting from a dead stop. Apparently, the AC motor feels like it has more torque at non-zero RPMs (perhaps just a false perception).

2007 100

Dissipating Doubt

Plugs and Cars

From the pricey ads in national magazines devoting serious space to the Volt to today's announcement about the plug-in hybrid Saturn Vue, GM is compelling me to take their expressed interest in plug-in cars seriously. As announced in Frankfort and reported in Detroit , GM hopes for a 2009 release of the first Saturn Vue plug-in hybrid SUV. Leaving wiggle room, "2009-ish" brand general manager Jill Lajdziak said Thursday.

2007 100

A Response from CC Power on the DC-DC

Porsche 914 EV Conversion

I just got an e-mail back from Electro Automotive from CC-Power regarding the failed DC-DC converter. I prefer not to comment on it but simply wish to pass it on to others who might have wondered what the manufacturer said. Here goes: "The converters have been manufactured for over 20 years and we have 10,000+ units operating in South Africa at 120 volts, all using the same build, without any problems.

2007 100

Worst Cars Ever: TIME and Dan Neil Trash EV1

Plugs and Cars

Along with a host of the filthy, the ugly and the dangerous, Time and Dan Neil declare the EV1 one of the 50 worst cars ever. Had they wanted to include a crappy electric car, they had plenty to choose from. But no, they picked what might have been the best electric car ever, and said even it sucked. Dan Neil, the LA Times writer who naively blames consumers for the lack of electric cars in the market in the film Who Killed the Electric Car? knows better now.

2007 100

DC-DC Seems to Work!

Porsche 914 EV Conversion

I just drove home from a meeting for half an hour with the headlights on. In the process of driving, the brake lights and turn-signals were also on. This is the first time I've arrived home with the DC-DC converter still working! I'm going to give it a week and see if anything else causes a failure. In the meantime, I'm going to report my findings to CCPower and Mike at ElectroAuto so perhaps they can modify the design.

2007 100