4-9-06 DC Controller Reliability vs AC Systems

Hello to All,

Michaela Merz wrote:

Hmm .. I think we all agree that a blown DC controller can cause some
problems. What about doing something about it? …a secondary system monitoring motor voltage and shut the system down if something seems to be wrong?….a way (for an electronic circuit) to know the difference
between a PCM signal and a constant DC on the motor? It could trigger the
mains before the driver knows that the controller went south….ways to detect this kind of dangerous conditions and to prevent a ‘runaway’ car :)

It’s already been done…it’s called a Zilla with Hairball.

All Zillas are controlled by the Hairball interface. First and foremost, Cafe Electric builds the most reliable DC power stage ever, period! His power stages simply don’t blow, that in itself is amazing, but when you consider the very high up-to 2000 amp currents (even the ‘small’ one kicks out 1000 amps!) and the industry leading up-to-348 volts and they still don’t blow, is incredible! Lesser controllers have a hard enough time managing 500 amps and 156 volts :-) The Zilla controllers power the worlds quickest electric drag cars, and don’t blow even under these extremes.

I’ve got credibility here and have ‘been there, done that’ in regards to blowing things up. The 5300 lb. Red Beastie electric Toyota truck Dick Finley and I put together was the ultimate test bed for seeing how robust controllers were. With a 2500 lb. battery pack capable of running the truck for hours on end at high average currents and at very high currents during hill climbing events, it ate 6, count ‘em, 6 controllers! Having been involved in too many conversions to list over my 26 years of EVing, I’ve blown up more controllers than most, believe me. I think my ‘We blow things up, so you don’t have to’ mantra was part of Otmar’s inspiration to make his Zilla line of controllers bullet proof (or would that be plasma proof?). The original Godzilla controller used to set world records in White Zombie never failed, ever. It lived through everything I threw at it, including the melt-down of the armature in the 11 inch Kostov under full power. It’s still in perfect condition and awaits its new owner (I’ll let him tell everyone when he’s ready).

In the very unlikely event of a Zilla power stage failure, the Hairball instantly drops out the contactors, and in many circumstances, it will sense a problem ‘before’ the power stage can blow and not allow any contactors to pull in.  Old fashioned Curtis controllers don’t have this feature, nor do many other old tech designs. I was at Oat’s side when he was first working on the Hairball interface, and even gave him my input on his ideas for its features and multitude of protection circuits…even threw some of my own ideas at him ;-)   The prototype interface was a mess of tangled wires strewn all over the place as he was first conceiving the idea, looking very much like what the cat coughs up…hence, Hairball.

DC controllers ‘can’ be every bit as safe and automatic in their control systems as any AC system, the Hairball/Zilla combo is proof.

See Ya…..John Wayland

Zilla biased (for good reasons) and sponsored by Cafe Electric

This entry was posted in EVDL Posts. Bookmark the permalink.

Comments are closed.