Aug 29, 2006 22:13
Of Smoke and MOSFETS ...
Today we enter yet the latest chapter in the ongoing saga of two companies and two people each separated by so many miles all trying to colaberate in a half assed sort of way to make a brake system that is something more than half baked.
THIS is the story, of what happens when there is no clear cut single entity responsible.
There is Dexter... the buyer... and the company ultimately in the drivers seat (from my own perspective)- though NOT REALLY! and you will see why....
There is Advanced Hydraulics Inc, which is not supposed to be much in the drivers seat from their own perspective, though I tend to believe that from Dexter's, they are..
There is a good friend who acts as a middle man between me and Advanced... who sometimes takes the wheel...
And there is ME ... and I dont _WANT_ the wheel!
Q: SO WHO THE HELLS DRIVING THIS G** DAMN THING ANYWAY????
A:NO ONE!!
And that brings us to now:
Today I was informed of a large number of units being returned to dexter... a good many of them are board related. Most of THOSE appear to have cooked MOSFETs.
I was asked to investigate, and I have done so..... My findings??? UNDER VOLTAGE!
And the root cause?? ..... welllllllll... there are two possible... and one underlying.
1) Bad wiring resulting in high voltage drop when 30 amps are drawn from the unit.
2) Low battery during a breakaway event.
The ever-so-laughable kicker? I had ORIGINALLY had code in the micro controller to prevent undervoltage events....because I was aware of the problems... BUT!
...BUTT!... Somewhere along the line I in a massive blast of cranial gas forgot about the need, and when I was asked to remove the limitation on input voltage (since it may shorten the duration of operation during a brakaway event)... I said "OKAY.. SUUuuuure!" failing to remember, or mention to dexter, "Oh, btw... that will probably result in a blown mosfet"
and FINALLY.....
ITS THEIR OWN FAULT (IMHO)....
Because..... THEY DIDNT TEST THE DANG THING!!!! ... morons!
Yes, thats right... through all of this, I have insisted that I not have any liability regarding it, as someone needs to test every aspect of it to make sure that it works CORRECTLY.... that's NOT me... I dont have trailers, and trucks to go driving and test every nuance of it, and since they are the ones wh slap their name on it, you'd think they'd be more careful. Yes I wish I had remembered at that point in time "hey, duhhhh... you cant do that!" but I didnt, and something should have caught that error.
At the time, I didnt even have a pump motor, or load that would sufficiently test the circuit. Ultimately to get more involved with analyzing it for them results in the risk of even more liability, that I dont want.
Anyway... they will eat the 40 or so returns now caused by this problem (but there are thousands out on the road now)... a simple request can have vast repercussions.