Personally I do not understand why people do similations of circuits that you can solder together in five to ten minutes

On a sunny day (Sun, 24 Apr 2011 23:59:34 GMT) it happened snipped-for-privacy@puntnl.niks (Nico Coesel) wrote in :

Nope, you can do NOTHING with a simulator. Try listening to your mp3 simulator.

That is why NASA is still flying in circles around the earth. And they even simulate how galaxies collide. Not that anyone lived long enough to even verify a blimp of that crap. They do not even know what causes gravity. Simulations ..

Yes, just like real people.

Not really, but you have come to believe that because all you now know is simulations.

Just like your sig, endlessly repeating something has no value.

On a sunny day (Sun, 24 Apr 2011 17:04:30 -0700) it happened Jim Thompson wrote in :

If I have 10 V and a 1 Ohm 1/4 Watt resistor, I KNOW without pulling out the Casio what WILL happen.

On a sunny day (Mon, 25 Apr 2011 00:11:42 GMT) it happened snipped-for-privacy@puntnl.niks (Nico Coesel) wrote in :

I am just looking further ahead than you:

It will get colder. LOL

core material there are :-)

response is all different.

with real components.

well try it for real.

That looks familiar :-) I'd like it work for a 30kHz-ish PWM with an low/high side driver from IRF using cheap optos.

John Larkin expounded in news: snipped-for-privacy@4ax.com:

I think LTspice is simply wonderful for the [audio] hobbyist. It takes time searching through that treasure trove of parts to find all the resistors, caps, diodes, zeners etc. you need. Often you end up finding out you don't have exactly what you needed. Even if you do, you then either have to toss them out or re-file them when you're done. That's a waste of time.

LTspice allows you test out ideas with any part value (like fractional values). Not just using the std part values. This is good (as someone else posted) for "what if" explorations.

The graphic plots in LTspice are a great time saver as well. Especially currents. To measure current you end up having to break the circuit to read it.

Simulations aren't the final answer of course. For the hobbyist, they can sure save you a lot of time and grief in coming up with a starting design.

Warren

power.

Well, you gotta' use your brain a little too. I'm not going to do anything with mains power on it, but I surely have thrown together a lot a things just to test out. No more kids stuff than a piece of perfboard.

On a sunny day (Mon, 25 Apr 2011 13:54:34 -0400) it happened WangoTango wrote in :

with power.

I was actually referring not so much to 'mains', but to high currents. Those contacts are no good for that. You can probably put connections far enough apart for high voltage.

'perf' board rules :-)

that you can solder together in five to ten minutes

coefficients.

While i sympathize i also disagree. I have met too many "Engineers" that are a danger to themselves and others with so much as a screwdriver in their hands (let alone a soldering iron). Yet they do ok on other electrical engineering tasks. Moreover it is not like the old days where an average Dale could reasonably be expected to know enough to figure out how to use a = soldering iron, parts were big enough to handle without tweezers or such, and circuits to learn by were simple rather than software driven.

understand why people do simulations of circuits that

work?

coefficients.

Carlo

real

easily

the

of

Look up piece-wise linear voltage sources.

Someone suggested that and added PWL for a search term, which I found -- in the help there's no big table to help make it stand out as an option.

Plus, my brain wasn't working on the day, the straight voltage source can ramp from A to B over X time, more I learn about LTSpice, the more I like it! For seeing what happens over a range, it can save hours if one is in familiar territory -- knows that the chart looks 'real'.

Now I can isolate tricksy bits and watch how they interact, it's great for doing stuff I don't haven't got or forgot the math for.

Speaking of which, is there an easy way to get area under curve out of LTSpice?

Between cursors would be nice, but I don't see a pair of cursors, so I have specify from t1 to t2 on which curve, then??

Right-click the name of the waveform at the top of the waveform window. A pop-up box will appear in which there is an attached waveform drop-down from which you can choose either one or two cursors.

Cheers, John

Do you really want the area under the curve, or do you really want average or RMS? For either of the latter, hold down CTRL and left-click the name of the waveform at the top of the window.

There is a way to get the area under a curve using the .measure commands, but I don't think you are ready for that just yet. No offense intended, I just found those commands required a significant learning curve.

Cheers, John

Yeah, I found that, and in combination with an (A - B) trace I can now get a meaningful answer, for some things. For others I need a measure so that I can either count packets of energy transferred, or take RMS over time, or rather, to appear to take RMS over time.

Grant.

Gotcha, thanks.

By the way, you can click on the node of interest and hold, then drag to the reference node and release. That will show the node of interest with respect to the reference (dragged-to) node.

Do you mean you want joules? If so, then put the mouse on the load (or whatever), press the ALT key and left-click. You will then get a power waveform. Point to the name of the power waveform then left-click. You will now see a little box showing energy in joules.

If this not what you want, I will need a better description of your needs.

John

to do=20

a=20

good=20

flat cable:

very reliable.

Where do you get those cute little coaxial (smaller than SMA) push-on pull-off connectors?

Proof that you do not have the experience you claim.

A pretty good tell of lack of training, much less common sense.

"cute little coaxial..." Yes, idiot, you sound like and are a layman, of that I am sure.

If you're talking about the ones on, e.g., John's top board in ftp://jjlarkin.lmi.net/BreadBoards2.JPG , those are SMB connectors, available from DigiKey, Mouser, etc. -- although eBay is probably rather better on price, especially if you want pre-made cables.

Personally I like MMCX connectors, as they're even smaller and hence can often be soldered "right on top" of some little bit of circuitry you're testing, or an existing PCB trace to it. The male version of an MMCX connector (typically the cable end, as with SMAs and SMBs) does have a little retaining ring that actually secures the cable/connection together more tightly than you might like for testing, though -- I have a handful of cables around where that retaining ring has been removed, since usually there's still enough plain old friction to hold everything together.

Note that there are push-on/pull-off connectors (and adapters) for SMA, although the simplest versions tend to wear out more quickly than you'd like. (See, e.g. ,

---Joel

We buy really nice RG174 SMB cable assemblies from Lighthorse. In modest quantities, a 3-foot SMB-BNC cable is about $10.50.

Ebay typically has goodie-boxes of SMB, SMA, MCX, all sorts of connectors and cables and hardlines. I think lots of microwave people design boxes full of custom hardlines, change some dimension or something, and have to throw all the cables away. Suits me!

I don't like MMCXs as much because the retention force varies from big to huge. Hurts me tender little fingers. MCXs on the other hand are a little loose. SMB is about right.

I seed my breadboards with hardlines and SMBs.

ftp://jjlarkin.lmi.net/BreadBoards.jpg

It's great for plugging in sampling scopes, stuff that's too fast for a scope probe.

John