Hello GMC Statpower owners, and interested bystanders.
Here's today's latest update. I just finished talking with Statpower's
Quality manager Mike Mui. Mike has been very helpful as this has unfolded.
First, Mike confirmed that the units are in fact UL and CSA listed which
means that they should not cause any thing to catch fire under any failure
mode. UL requires a "cheesecloth" test in which the unit is purposely
caused to fail. The cheesecloth is the "witness marker" for flames and the
like. I don't personally know all of the details of this test, but from my
past experience in consumer electronics I know that it is pretty rigorous
(nothing's 100% though).
Mike further confirmed that the electrolytic capacitors DID NOT fail (burst
or otherwise) but that circuitry including the MOSFET which is in a TO-220
package (that's a plastic package a bit smaller than a pencil eraser in
diameter) did fail. MOSFETs have a way of failing in a dramatic way though
(as Arch found out). Lots of light, sound etc. FWIW, if the electrolytic
caps had failed catastrophically too you'd have heard even more noise.
Statpower does not release failure rates or circuit schematics, but I asked
Mike if he had seen any unusual failure rates, clusters, or the like and he
said "no."
Mike indicated that they are very interested in the Dana compressor. Their
one lead is that somehow an inductively produced spike from the compressor
might have fooled the charger's control circuits or caused some other
circuit upset that led to the failure.
Statpower is interested in testing with a Dana compressor (anybody have one
to donate ;>).
That's what I know.
Henry
PS The TrueCharge 40+ is a redesigned 40, so what we learn here may not
apply to the straight 40. But, it's also UL listed.
Henry Davis Consulting, Inc / new product consulting
PO Box 1270 / product readiness reviews
Soquel, Ca 95073 / IP reviews
ph: (831) 462-5199 / full service marketing
fax: (831) 462-5198
http://www.henry-davis.com/ http://www.henry-davis.com
Here's today's latest update. I just finished talking with Statpower's
Quality manager Mike Mui. Mike has been very helpful as this has unfolded.
First, Mike confirmed that the units are in fact UL and CSA listed which
means that they should not cause any thing to catch fire under any failure
mode. UL requires a "cheesecloth" test in which the unit is purposely
caused to fail. The cheesecloth is the "witness marker" for flames and the
like. I don't personally know all of the details of this test, but from my
past experience in consumer electronics I know that it is pretty rigorous
(nothing's 100% though).
Mike further confirmed that the electrolytic capacitors DID NOT fail (burst
or otherwise) but that circuitry including the MOSFET which is in a TO-220
package (that's a plastic package a bit smaller than a pencil eraser in
diameter) did fail. MOSFETs have a way of failing in a dramatic way though
(as Arch found out). Lots of light, sound etc. FWIW, if the electrolytic
caps had failed catastrophically too you'd have heard even more noise.
Statpower does not release failure rates or circuit schematics, but I asked
Mike if he had seen any unusual failure rates, clusters, or the like and he
said "no."
Mike indicated that they are very interested in the Dana compressor. Their
one lead is that somehow an inductively produced spike from the compressor
might have fooled the charger's control circuits or caused some other
circuit upset that led to the failure.
Statpower is interested in testing with a Dana compressor (anybody have one
to donate ;>).
That's what I know.
Henry
PS The TrueCharge 40+ is a redesigned 40, so what we learn here may not
apply to the straight 40. But, it's also UL listed.
Henry Davis Consulting, Inc / new product consulting
PO Box 1270 / product readiness reviews
Soquel, Ca 95073 / IP reviews
ph: (831) 462-5199 / full service marketing
fax: (831) 462-5198
http://www.henry-davis.com/ http://www.henry-davis.com
