Why is it eGay links rarely work??? (LOL!)
Yep - that DMM is ok, but you can get cheaper (at least here in Oz).
I have a similar DMM but that includes a backlight for the display - very handy when broken down in shark infested deserts at night.
The hold is useful at some VERY rare times (for me). But it is probably more of a pain when I DO NOT realise it's on... (Why tf is it displaying that funny reading - low batteries? faulty leads? .... 5 minutes later "damned bluddy HOLD button. Again!" And that's ME - a clever dork with lots of experience!!)
May shops now have cheap $10 DMMs with much the same features (except the Hold, and backlighting).
They typically seem to be yellow, and unlike that eGay unit....
- include battery(s)
- include transistor testing (gains etc) (which I am yet to use - despite building a tranny tester eons ago).
I have several of those as spares and presents. I've seen them down to $3 each (without leads).
Apart from the usual features, the main one to look out for is the "continuity tester with buzzer" (audible continuity) - the "sound waves" as shown on your linked DMM on the RHS above "200" (Ohms) (at about the 2:30 position).
That might be trivial, but one of my cheap $10 DMMs has it as well as my (then $26, now ~$20) favorite backlit DMM with its bluddy $%#!&&*^! Hold button, and it comes in so handy when checking cables (don't look up, just keep looking at pins and listen).
But I wouldn't pay much extra for it.
BTW - try to get spare fuses. They are usually 250mA M205 (20x5mm) - but check. Eventually you will connect wrong and blow its fuse.
And NEVER connect an ammeter (current range) ACROSS anything (specially caps & batteries!) - always "insert" it in series with the load.
And NEVER take resistance measurements on a powered or charged circuit - the DMM's battery supplies power to test resistance - ot won't like getting power from outside. That includes continuity and diode testing.
And DON'T under-estimate test lights. Whilst perhaps of limited value for testing forward voltage drops, current etc, they can be much less complicated and even safer to use than a DMM.
And they can do some neat test things.... (Yes Howie!)
And they are cheap.
And you can have a buzzer in parallel....
And opening an electric circuit isn't like stopping water - there is no hammering effect - the electric current merely stops.
[At least for your circuit - it's different if we talk about inductive circuits like ignition coils (they're shocking!), or opening a circuit with several thousand DC amps (they explode!), but even opening a relay or switch to a 3,000 amplifier is no problem. And your circuit is what watts - 10W?]
Electricity must travel in a loop - ie, out battery+ through switch and circuit back to battery- & through the battery.
To stop a "circuit", just break that loop anywhere.
But make sure there are no bypasses or leaks.
EG - if you switch open one of your 3 or 4 LED strings, it will extinguish, but all the other strings will still be lit.
If you break the 12V to seat#1 but not seat#2, seat#2 will still be lit.
If you break the supply from battery+, none will light.
If you bypass that battery+ break with a resistor (aka, a "leak"), the the LEDs will get current & voltage, and maybe enough to light them (if the resistor is not too big, and assuming the relay or switch is closed).
I think you should have a search for some basic electric tuts.
They may have been too "urrghh!" before, But I reckon now, you will click the odd "arrr fudge - now I get it" etc.
Here on 12volt are some EXCELLENT tuts (tutorials) - eg - see "Basics" way up top-left under the12volt.com banner.
www.allaboutcircuits.com/ is another goodie - see Volume 1 - DC. (I must tell them that their "power factor" is wrong - but that's AC crap....)
And try to skim a lot and just read the easy bits rather than trying to understand each bit.
Do the easy, fun, or rewarding stuff first. The hard stuff eventually makes sense "without even trying".
The best way to learn is often tactical - learn only what you need to solve your problem. (Be aware of other vague things mentioned, but review them later.)
The solve your problem - ie, design or implement.
But then review (whether before building or after, or after it blows up) and the other vague things may then make sense, or tempt you....
Electrics & electronics is no different to most other disciplines, you need to understand everything before understanding anything....
Or am I thinking of microprocessors and programming LOL!
(Reminds me of "I want everything louder than everything else".)
But once you get an edge somewhere, you just keep expanding.
And making all the "common sense" mistakes we all do.
(Remember - common sense is what you have until you know better - and that's the new common sense, until next time!)
So forgive the ramble, but that's what you get when you say silly things like "
you have been a great help". LOL! (Thanks for that!).
But some of your questions & answers are VERY basic things.
Others are not - like LED voltages & effects. (You may have seen in one of the links I posted just how wrong an "experts" common sense can be! It was easily solved, but the usual ego saving techniques prevented any getting of wisdom. And that merely involved LEDs! Wait till you do batteries!)
The point is, after this you too may well be an expert in how to set up these LEDs - and know more than me about it.
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