On Wednesday, October 18, 2017 at 3:33:01 PM UTC-4, wrote:

Note the interpolations. Again, your conception of things is massively flawed.

That tells me how the caps are connected internally, and although it's
"all or nothing", I do wonder if jiggling it (tapping it) can make that
connection make or break contact? This inverter is very simple, and I'm
pretty confident I can fix it. I'll start by replacing that cap. If that
dont do it, I may resolder every connection at least on that end of the
board.

Yes. A start.


This simple inverter does not completely shut down when the battery
voltage gets low. Instead it keeps shutting offn and on, till the
battery gets so low that it shuts off completely. It did leave me
stranded once, when it started to go off and on, in my car, when my
battery was weak to start with. The car would not start. Fortunately a
friend lived 2 blocks away, so I walked to his house and had him come
and jump my car.

The one is not directly related to the other.


b) The buzzer comes on when the input voltage approaches, then drops below
the trigger voltage for the inverter. So, if your battery voltage drops below wh
atever that is - first inverter will buzz, then AC-out will stop. \


The battery used to test that other inverter was purchased 2 months ago,
and was just charged, reading 14+ volts on my digital multimeter.

14V measures the availability of a chemical reaction. If all six cells have unconsumed electrolyte, you will get 14V (13.6). But that voltage will sag to as low as 8V (from six cells) under load. This is where the flaw in your understanding lies.


Although I could not find a schematic, I did find an owners manual for
that one. The red LED on that one does different things. Low battery
makes the red LED light up solid and the buzzer makes a steady sound.

What I am getting is flashing red, and beeping on-off alarm sound. The
manual says that means the LOAD is too large. The load I was using was
80W (AC).

No. The load *size* is a function of the input voltage *UNDER LOAD*. If you can do (for round figures) 120 watts (10 A @ 12 V) of AC load at full battery charge, your maximum load at say.... 8V will be about 75 watts. And that is assuming that the battery has a steady-state capacity of 10A @ 8V. It will not. So, your alarms will trigger. Further, if your load is a motor - the starting surge will be up to 3X the steady state load.

Far from too large. It was working until I shut off this
switch on the load. (ODD). Then that inverter went into that error mode
and has remained that way ever since, even with no load. According to
web articles, this is a common problem with this model.
The circuit in this thing is very complex, and without a schematic, near
impossible to trace. So, I think it belongs in my scrap box.

Most inverters, even cheap ones, will re-set if fed from a properly charged battery at full voltage and THIS DOES NOT MEAN from a battery feeding from the alternator at full voltage. The wave-form from an automotive alternator is chopped DC - there are no "smoothing caps". Inverters do not respond well to chopped DC. Nor do most alternators have the capacity to both run a car, run an inverter, and also charge a battery. Those would be highly specialized devices - our VW camper had such an alternator-and-inverter system, as well as a 200 AH deep-cycle marine battery as a second back-up to the regular battery in the engine compartment.

https://www.topmaq.co.nz/wp-content/...AVBA1580_a.jpg

One of these will tell you about your battery. A standard VOM will not. Not even my Fluke.

Again, you need to understand the entirety of your *SYSTEM* and what each piece of information means. So far, you have proven that you do not understand even the most basic concepts.

Peter Wieck
Melrose Park, PA