inverter repair

meanwhile,on the subject of "wiz" and electronics...... ....many years ago I sold a high end VCR that my parents had passed on to me to a friend on the eve of leaving the country.Upon returning,years later,I saw said mate and was told the VCR worked for about a day and a half before giving up.Being a high end item he sent it for repair.The quote he got back listed damage across all the horizontal boards,seemingly caused by an "acrid corrosive substance" of unknown origin but exceptional destructive power.Oh dear ! What I hadnt considered was that at the time of the VCR use by my parents,my mother was a breeder of persian cats.And these pedigree things had an aversion to using normal toilet facilities....god forbid they would lower their grandiose backsides,outside.So they found the most novel places to go.On questioning the parent on this issue I was told that the then UK grand champion silver tabby would only do her business in two places.....the back of the TV or on the top of the VCR.Given the position and the effect of gravity,the prior would lead to the latter in any case.Thus,the acrid,corrosive substance.In your vernacular,'Sparks, "wiz".

Or the early days of CDs, about 1988, daughter then aged 8 discovered bless her that strawberry jam (jello to our US friends) and CD discs don't go together very well. Or last year spending about 1 hour stripping the Sat Nav disc drive from a Nissan Primera (again, Altima to our US friends) to discover the two £1 coins blocking the transport mech.

Howie, whereabouts do I look for a circuit design to achieve this kind of thing ? In another thread I was asking more opinions on split charge designs,specifically the use of a relay triggered by the charge light circuit to power a fusebox of supplies to split charge relays and other like stuff. From a previous comment by Oldspark I had developed a concern that the charge light circuit may not react well to powering the coil of a regular 12v split charge relay. And so proposed using a smaller relay as above. Then I began to worry that the circuit may not even take powering a normal 12v automotive relay of 20a or so rating.'Sparky suggested I use a relay with a very low coil current,such as below 500Ma but I am having trouble finding one.Generally I like to re-use parts from other items where I can but in this case cant even find one new....well,not for sensible money,anyway. Then   the subject of using a FET to trigger the coil of the first relay came up.I thought that it might be easier on the alternator charge light circuit to use the small current that a FET would need to initiate the next relay. Probably wrong,in my case,but its what I thought........     ....the alternator concerned is a magnetti marelli version of the lucas A127,a 100a unit as fitted to a LR discovery 300tdi in this case,and used in many other vehicles by other manufacturers.

Howie,with my transatlantic pedant hat on,my US born'n'bred wife,reading over my shoulder informs me that jam would be jell-y   whereas jell-o   would be our jell-y....... ....sorry mate,she made me do it! You know how it is.......

Oldspark is the man, it's beyond my knowledge.

We're out of synch here but.... I used to "commute" from Ft. Lauderdale to Houston Tx. to work, I always carried a bag of full strength UK sold Tetleys, catering size, I'm also bemused at hoods and bonnets, trunks and boots and wings and fenders; especially on this site.

Sorry Lads, if been missing out... Rave Juice. In all its flavors. Most destructive. Shirker - I didn't mean to scare you off with my warnings about over-stressing the charge lamp circuit, but whereas traditional electronic regulators would sink usually well over an Amp (they use to "test" up to 6 dash warning lights; 6x2W = 12V = 1A. 3W globes meant 6x3W = 18W = 1.5A. But newer models may only supply a small signal if they connect to ECUs etc which then control & power the charge light etc. I think it was about 6 months ago I wrote that 6 months earlier I had been intending to add a plain old $3 MOSFET as a buffer for the relay. (But why bother with a 30A or 60A relay? - these MOSFETs handle 120A. [Answer - like Howard said - relays are plain, simple, robust & proven. Besides, MOSFETs usually have a higher resistance than contacts (is it ~7 mOhm vs 2mOhm for contacts?), so for those extra milli-volts.... ]      Anyhow, I still haven't. FETs are perfect - almost infinite input impedance (ie, only takes nano-Amps; well under 1uA) so they don't load the source. Yet they can switch (and modulate) many tens of Amps. They used to be sensitive to static, but modern MOSFETs usually have internal spike quenching diodes so that spikes get shorted to the +ve or -ve (GND) supply. It's a simple noise (spike) limiting technique no different to those reverse-biased quenching diodes for relays - a diode with its Kathode (Line end - as per -|<- = Kathode end.... <--- that way} to #86, and the other (anode) end to #85. But it's worth being aware that they may be static sensitive. (Oh, the memories of CMOS go sailing past.... No Howard, that's not not a dyslexic UNIX command like CHMOS!) I can go into battery isolators separately. You may have read my rants about all the bullsh surrounding isolators, though it seems that false claims (like priority charging or charge sensing (ie, battery capacity)) are being cleaned up. The one advantage with a voltage sensing isolator is it independence from the alternator circuit. (But hence too its downfall - it is trying to determine what the alternator/system is doing. The UIBI gets its info from the alternator itself - no second guessing, no hysteresis or switching delays).    And if signal independence from the alternator was only to not load its regulator, why not use a FET - even a transistor - and eliminate all that voltage sensing with varying delays and adjustments and "non intelligent" behavior? I wonder if voltage sensing isolators were developed for marine use {ie, stator systems which have a permanent magnet rotor; hence no rotor regulation and no charge light}, and the auto market misinterpreted?   Nah - someone wanted to make money! Ooops - I said later... or separately... Remind me about "priority charging" - that's assuming you don't know why it's double-bovine-poo... The first cake for how are they sensing battery capacity? (Voltage? Bullsh - it's simply a time delay required for voltage-sensed switching) The second pattie is for the logic - why limit your output or TOTAL recharge rate? Valid cases rare - ie, where supplemental charging is required to keep the batteries in good health (ie, short trips or undersized alternators).

Got you Peter, I think I had an EDU on my Mits, = Electronic Destruct Unit rather than Electronic Control unit.