12V car cig lighter adapters - safe?

Well the concept & the implementation are widely spaced in quite a few applications, the wikipedia entry provides a reasaonably sensible explanation of the basics, but PLLs have sod all to do with power line spike suppresion. ( Not that I doubt that DP knows how they work)

Serious cross purposes here. I obviously was not questioning for a second anything DP said, knows or has done. I don't doubt for a second his technical knowledge and it was not in question. I thought the posts earlier were perfectly clear on both sides, but there must be some ambiguity there I cannot see. Graham

You assume a great deal. I don't work in electronics anymore. Last related job was broadcast engineering in late 80's, but no actual hands on engineering anymore, beyond knowing how to set up equipment. As you rightly say, electronic engineers don't get paid very well. I worked that out in

1979, that is why I moved on and got a a job at ITN when I saw the money they paid.

BTW, I had a quick peek at uk.diy and seems you are an electrician by trade. Just a simple sparkes. No wonder you can't answer my simple question. What is the reactance of a 470uF capacitor at 50Hz.

Graham

Perhaps you need the answer for your homework.

You did get an answer. All you have to do is to enter the numbers into the formula using your calculator. Some calculators even have pi on a key so that you don't need to remember that.

The first time I did this was with a slide rule. Nowadays I would probably just drop the numbers into a javascript application on a web site.

Yawn. Another empty brain. A "Frank" must be a person of a certain age. This one obviously thinks that age has some superiority. I'm 50 mate so no spring chick myself.

I am really getting more and more disillusioned with humanity. If you don't know then say so. If you asked me an electronics question and I didn't know about that area, I'd say so or go and find out about it. What I wouldn't do is pretend or make wise remarks. Its so silly. How can any of us learn anything if we don't have an open and honest mind. Saying "i don't know" is the first step to understanding. Anything else if fooling ourselves.

Graham

This is a favourite of mine:-

Scroll down for links to all sorts of calculators.

Well, I say again, give the answer to your question. We could all do with a laugh on such a miserable day.

I never assume anything. Very dangerous. As they say, "assume" makes an "ass" out of "u" and "me".

OK.

Do they still?

Really? I have never worked in a trade in my life, let alone as an electrician.

I see. Just how many articles did you read in order to "deduce" that?

Did you actually ever *learn* how to research and deduce properly, or was this not part of your training syllabus?

Ah yes, very good.

It even has Ohm's Law for Graham.

Brilliant, we are getting close at last. But looks like its taking a web search and 3rd party tools to get the answer. This won't be as good as I thought, but we are getting close. I really want to see the answer. I honestly do. I would have been really happy to get an instant reply when this first started giving the answer, but sadly it didn't happen. It would be nice to see the full answer showing the calculation to show its understood, but the bare answer will do.

Graham

Two. It was an assumption. I am more than happy to be told I was wrong, but it seemed a reasonable guess with all the splurge about electrical regs.

Whats a training syllabus miss? I don't think we had anything called that in my day.

Graham

No it isn't. Assumptions are a dangerous thing. You are limiting the scope of your thinking to believing that because somebody provides a knowledgable answer on a topic that they must have been "trained" in it or do it for a living. This is almost as dangerous as the assumption that because somebody has been on a training course and has a certificate, that they are competent to answer questions or do a job of work.

When I interview people for some jobs, I am looking for those who are adaptable to new technologies and are self starting, showing initiative. These are usually people with degrees from one of the original universities. For other jobs I am looking for people who have had some kind of vocational education. In neither case do I hire people with certificated "qualifications" from trade organisations or from manufacturers. The electronics industry is bad enough for that, the IT and networking industry even worse.

Apparently

So why do you persist in them?

Use one of the web sites with answers and formulae for this. The learning experience will do you good. My consulting rates are very high.

Why's that then? Nobody's obliged to say anything on usenet.

Gosh.

So we're waiting. How about you demonstrate how you arrive at the answer using first principles and impress us with your prowess.

I'm still waiting for the answer. Why the childish comments? Its so dam silly. You can make those comments if you wish. Its water off a ducks back to me as I know what I am talking about. I suppose it helps to restore your position by attempting to make me look silly or small, but it really is so stupid.

Its now becomming pointless asking you for the answer as the online tool can provide it. But at least it owuld show some slight understanding of it now.

Lets make it more realistic and see how long it takes to find an online calculator for this:

What would be the resonant frequency for a 100pF capacitor and a 10uH coil?

That took me about a minute on the calculator once I got the (10 to the minus 12 and 10 to the minus 6 bits clear in my bonse). I am pretty dumb, but I learnt my skills well as it interested me greatly at the time and that is why I object to cowboys pretending to know my trade when they do not.

Graham

How's your IQ today Frank?

So there you have it. A statistical sample size of two.

OK tosser.

You are not worth the time, but here we are for the record.

Its ever so simple:

Xc (Capacitive reactance) = 1 divided by 2 x pi x F x C

So:

470uF = 470 x 10 to the minus 6 x 50 = 0.0235

2 x pi = 6.28

6.28 x 0.235 = 0.147

1 over 0.147 = 6.77

This is VERY, VERY basic electonics. Very basic.

I wasn't asking anyone to write it all out like this, just the answer would have been proof enough you knew what you were talking about. No point continuing now as you will just make childish comments of "As we already knew" etc. You didn't know, so in future be honest to yourself and then you might start to open your mind to learning agian.

Now you guys carry on with your bad selves. Try not to read the sun too much and be honest about what you do and do not know. Now feel free to slag me off to get your position ans status back again. Oh, and do try and widen those narrow minds a bit.

Graham