With the charger unplugged from the house outlet, there is no AC
power present to energize the high voltage winding with the
capacitor so not sure I follow how turning on DC power via the
disconnect would activate the capacitor. However if going to all the
trouble to pull out the charger, I'd replace the capacitor while I
was there so we agree in that respect. If replacing the capacitor,
be sure to identify which size: 4uF (smaller, less expensive) or
20uF (physically larger and a little more expensive).
I too am confused by the "solid state" reference. All diodes have
been solid state, that is silicon based, for decades. Okay, someone
may tell me of some specialty application, but any general purpose
diode/rectifier is solid state. And the terms are used
interchangeably - the bag of what I call "diodes" actually says
"industrial rectifiers" on it. And they never make noise. It sounds
like you are using option 2 in Davids list, diodes with a stud
mount/TO-220 type case which works fine. The original diodes
generally last a few decades and any replacement, press-fit or
stud-mount, should also last a few more decades with proper heat
sinking.
On 5/26/17 11:13 AM, bushman165s--- via
Elec-trak wrote:
Mike,
Been
following this post for a while and my thoughts were also that
a diode, both, or the cap had shorted. Since it had been
charging for a while before turning on the disconnect, I'm
betting the cap had heated up enough to short and when you
finally closed the disconnect, a surge of current caused the
diode/s to short. If you're going to buy an assembly from Jim,
make sure you also buy a capacitor.
I have been
using solid state rectifiers to replace the diodes for a while
now. They are much cheaper, don't have to remove the old
diodes or heat sink, and have lasted MUCH longer. I haven't
had a failure yet in the last 3 or 4 years. I have caps and
rectifiers available, if you want to go that route. With it
being a holiday weekend, might not be able to ship until
tuesday. Say $25 plus shipping? All that is required to
install the rectifier is a 1/4" hole (usually i drill between
the two diodes and a bit higher), a bit of heat sink compound
underneath it, and I'll send a #10 screw with it. I cut the
transformer wires right at the diodes, crimp on a 1/4" female
stab, and make a pigtail for the positive with a butt
connector to tie to the tractor wire #30. The rectifiers are
10x quieter, also.
Chad
On 25 May 2017 at 22:20, jlantonucci comcast net wrote:>> The charger is hard wired to the battery pack like Jim said. Turning off>> the power disconnect does not disconnect it>>David Roden wrote:>>Interesting. My HSM shows the E15 charger going through the main>disconnect. Dunno if my own E15 is wired that way thoug
h.>>Also, Michael didn't get his fireworks until he engaged the disco.Exactly what I was thinking David. I'm 99% positive the main disconnect disconnects the positive side of the battery from the charger (on mine). The tractor won't charge with that disconnect open, and if it was permanently connected, there's no reason closing the disconnect should have caused the fireworks - since it shouldn't have changed anything. >The symptoms described suggest at least one shorted diode in the charger,>though since it apparently sent out smoke signals, it might be open now.Ok, new diodes it is then. I haven't touched the charger in over 10 years - where exactly are those diodes? I don't suppose anyone has some pictures or a video showing there they are. Most of my tractor is clean and shiny and looks practically new - but I can't say that about the charger. It looks every bit of its 40+ year age. >Looks like you'll have to remove the heatsink, press or hammer the old>
diodes out, press in the new ones, and put it back. Jim mentions that the>aluminum may stretch so that the new diodes fit loosely, don't dissipate>heat well, and fail. He has a point.>>Jim conveniently offers a complete heatsink and diode assembly which is no>doubt the easy way to go. It is of course quite a bit more expensive.>>I tend to take such challenges as inspiration to my hacker side (the "make>it work" kind, not the "wreck someone's computer" kind). The nice thing>about this route is that if you can find diodes locally, you're back up and>running that much sooner.The hacker side of me also generally likes the challenge - but in this situation I just want to get it working again without too much time and frustration, since my plate is more than full (the whole reason for switching to a robotic mower - no time to mow, no time to fix tractor, etc.). So I like the quick and easy route - so I'll order the w
hole heatsink assembly. I should probably also clean up the charger while I"m in there - it's kind of nasty. Thanks everyone!Mike_______________________________________________Elec-trak mailing listElec-trak cosmos phy.tufts.eduhttps://cosmos.phy.tufts.edu/mailman/listinfo/elec-trak
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