Saturday, August 25, 2007

Talking with Mike at ElectroAuto

I just got off the phone with Mike at Electro Automotive. We chatted about the blown CCPower DC-DC converter and the engine vibrations. Since I fixed the DC-DC converter, we agreed that I would try to find out which conditions would cause it to blow again, if it does. It seems that Mike is more of a mechanical person than an electronics person. He graciously faxed me a circuit to generate a tach pulse from an ADC8" or 9" motor, but he didn't really understand the circuit. Unfortunately, the circuit relies on the fan inside the motor interrupting an optical emitter-receiver pair which doesn't exist on the AC24 motor in my vehicle.

He also agreed to provide a new motor to flywheel coupler if I still had engine vibrations. Mike commented that it was probably not the transmission, but probably had to do with the flywheel/clutch assembly. I'll have to do some more experiments to figure that out when I get the time and energy to take the motor/tranny back out.

I also said that I would look into the peak amps that the system draws if I could find a suitable ammeter. I still don't have the shunt or the console gauges since ElectroAuto is still waiting to see what peak amperage it has to deal with. When I told Mike that I easily pulled > 150 amps during acceleration, he seemed a bit surprised.

Apparently I'm the only person with an operational AC kit currently, although several other people are hot on the trail to finishing theirs. Mike doesn't have an AC kit 914 back at the ranch.

Regarding the 8V golf-cart batteries, Mike also mentioned that they tended to either last 3-4 years or die right away (infant mortality). I hope I don't have a batch that demonstrates the "infant mortality" behavior...

Okay, I'm going on a bike trip next weekend and need to get biking gear, so the 914 will have to wait for a bit.


Roger Daisley said...

Yeah ... Mike called me, too, regarding the DC/DC converter. He was very intent on correcting the problem. He said they have sold many of them and consider them a good solid unit. It might be that EA received a couple of bad units from the mfr. Who knows.

Steve said...

I have never gotten anything but the answering machine when I call there. The only time I've talked to Mike is when I drove 3+ hours to EA. Maybe he is getting more involved.

TimK said...

I chatted with the EV controller designer at SynkroMotive in Portland and he mentioned that the IRFP350 parts from International Rectifier are often bad and don't meet their stated specs. I suspect we got a bad batch of converters. I'll let y'all know if the IRFP460 FETs blow. I turned on all the accessories yesterday and drove around to see if that would cause the parts to blow, but they didn't. One way of determining if your DC-DC converter is working is watching the 12V voltmeter gauge. If it's at 14V without any accessories on, then it's working. The 12V battery normally floats around 12.5V. Cheers, Tim