inverter repair

Oh yes ! Forgot. Any tips on soldering in FETS, other than heat sink on the leg, that I should know ?

I dont mind my use of the word doodie being edited.... but replacing it with "doodie" ??

Yes, you get what you pay for.........but one DOES expect an item to function briefly before catching fire !

Didn't you know that "doodie" was a name for a part of the Doodie bird's body? Ah well here's where I get demoted yet again to "standard".

Oh, I'm not sure, anyone old enough to remember unbranded car audio from the early 70s?

No I was wrong, it was the legless Goollie bird, at least two of you will get that one.

Last chicken in the shop....turkey neck ?

Gollie Gosh! A plethora of notifications - read last "Last chicken in the shop....turkey neck ?". Oh no - war has broken out...!    Alas no. Why always expect the worst? I have several high-current MOSFETs I bought for $2-$3. I figure why not use them with their 80A - 120A ratings instead of relays, else to drive ordinary relays (ie, the high-impedance buffer device for any charge-signal to drive the UIBI battery isolator relay?). I lack the experience, but from what I understand, essentially a FET is a FET from a signal POV - ie, nano-Amps (if that!) into the Gate 5V above the Source (with a pull-down resistor to S to ensure turn-off when floating!), and the output is chosen to handle the Amperage... at least for simple switching applications like this. As to warranties on equipment - the owner has an onus of care and - as I found - things like "cleaning" are by the owner, not any vendor's maintenance contract. Hence if a server failed because WE did not clean the filters and remove the dust etc, WE were liable. (That made oft-logic sense, but it was an awakening at the time!) But I wonder... "laying in the cubby box for a few months..." - if smoking started at initial use, could there have been moisture, contaminants, dust, and the ever-present possum poo, etc. Alas contaminants in HV AC systems are usually fatal... to the components that is. (Not that fatalities cannot occur!) So bad storage & exposure may be a contributing factor..... But inverters are usually well sealed with a meshed cooling fan as the only unsealed area. (But yeah - I've seen possum-wiz cause enough electrical strife!) Except for larger inverters (say >600W), other than soft-drinks and spiders, I'd suspect moisture. But dust/dirt AND moisture - a bad combination!

Indeed.....moisture and dirt can be fatal to high power outputs.Back in my sound engineer days we had a particular problem caused by what was known (at the time) as "rave juice" and "gak". Rave juice was the moisture and grease given off by hundreds of sweating ravers,steam and condensation and the like that would condense when we took our ampliers out into the cold truck at the end of the show.    "Gak" in this instance was the dust,skin paricles and general airborne dirt kicked up by the said ravers and drawn through the amps by the cooling fans. These two lovely substances would coalesce and settle on the interior (and exterior) surfaces of all the equipment leaving a greasy,moist gritty paste that would cause shorts and untold damage if left. It had to be groken up with alcohol and/or switch cleaner and blown out with air lines between jobs.Which was nice. Yes,Spark,as you rightly say,storage in the cubby of a truck for months could well lead to a similar situation.However,in this case bearing in mind previous experience the unit had been dried out over the air blowers on hot and then blown dust free with a little in car compressor,for just this reason.    I dont expect any mileage from the shop as per refunds....the money wasnt much and is long gone.What I DO care about is some young kid having a fire in their car.....all I want to do is warn the manufacturers that there may be some problem.That way my conscience is clean.Ish. Anyway.....         I too lack the experience of designing and building electronic devices off my own back but can work to a plan. I am very interested in the use of FETS to control switching relays.....could this be the way to a low amperage switch for the alternator charge light when used to trigger other relays ?

Yes Oldie as you and Mr I. the Dragonslayer (in joke) well know I also can't design a circuit to save my life but I can follow them easily enough. About 10 years ago we were having a similar conversation about thyristors as a relay substitute, nowadays of course FETs. I think the only reason for t6he continued use of relays is ease of understanding (in theory) for the average mechanic.