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> To Robert, that center-off may just cover it. Devils advocate: try > flipping that switch really fast and see if the Curtis picks up on the > brief "off" time. If so, good deal. I flipped it from fwd to off to rev fast enough that any faster i would have to use an amount of force that would break the switch. If the switch did break i would get a short, blowing the fuse killing the power. If it broke in the on position i could just step on the brake killing the main solenoid shutting down the controller. And it would not restart unless i reset the throttle. > Yes, my store does sell the Alltrax line, both the "special" ET version as > well as the "regular" versions. > But... I was answering from the perspective of an engineer who likes to > look for possible failure modes (what I think you asked for?), which makes > my wife think I'm a pessimist, but I'm not. Really. > I'd still be curious to see your diagram (e-mail address above) to try and > fully understand it. I had a offline conversation about possible failure and did indeed find a issue, which i was able to fix. Simply put in my design if a POS wire were to fall of the DPDT switch the relays would not energize and the controller would shut down. What i did not think of was what would happen if one of the NEG wires were to fall off the switch. In that case the field would loose it's NEG but the controller would stay on because i ran the NEG for the relays directly to a common ground. The fix for that was to run the relay NEG the same way i did the relay POS. That is branching off the switch. So now if any wire were to fall off the switch the controller would shut down. I consider that version 1.1. And it is a great example of why i consider it imperative for designs to be in the public domain. So people can critique and look for modes of failure. Guys like you are great... > Now to chew on what others have been saying about PM vs series type > controllers. Been doing that myself. The curtis is rated at 175a continuous. Considering that the power meter is scaled for 100A and i loose traction before hitting the limit i would think the controller is beefy enough to handle that issue. However i have put a craigslist alert out for any PM controller. Lots of people converting carts from 36 to 48v these days. |