Have you ever wondered how a very basic power supply from the mains to DC is so (almost) perfect?

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Good power supplies have a voltage regulator which makes an excellent filter as long as the ripple remains below the regulator's drop-out voltage.

I once built a power supply with a regulator and a capacitance multiplier. (It doesn't REALLY increase capacitance but it filters AC ripple similar to a bigger capacitor.

Switching power supplies operate at much higher frequencies which makes filtering easier. You can use a smaller capacitor and as a bonus the higher frequency means you can us a smaller, lighter, cheaper transformer. It's virtually impossible to build a switching power supply without regulation. And the switch-mode regulation is more energy efficient than linear (analog) regulation.

And if you're into audio, like me, power-line hum is obviously in the audio range, whereas switching power supplies normally operate above the audio spectrum so if any power supply noise leaks-into the audio circuitry, it's inaudible.

And of course, power supplies normally have a transformer to electrically-isolate the lethal voltages!!!

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...There's no need for me to pile-on, but there are two aspects of risk - If you know what you're doing, the odds of killing yourself may be low, but the consequences could be disastrous!

Or, imagine I offered you a bet on a coin-flip and I give you 10:1 odds, with me putting-up $100 to your $10. You'd be a fool NOT to take the chance. But if you had to put-up $1 million against my $10 million you'd be a fool to accept those very-good odds (assuming you're not a billionaire). I'd be a bigger fool, but that's not todays lesson on risk. :stuck_out_tongue:

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Yes, Jim, apparently it would be to you. I have dealt with someone like you recently, as I have in the past. It does not work on me. If you lack the experience, then you don't have any context to provide some insight as to my experience. You need to be "above" people, don't you Jim? Well you are not above me. The inquiring mind asks questions, regardless of how stupid they may seem. Scorn all you want, boy.

You want compliant subjects in this forum right? I am not one of them. You don't deceive me Jim. Try harder.

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Really? Your Troll-meter told you so? Did you consider yourself, and your ego to be the problem? Did you consider I am not an idiot, and that a lot of this stuff is really not that complicated to me? I asked for an opinion, you gave me attitude and BS.

Your lack of experience does not qualify you for this assumption. I do things based on my experience and knowledge. I connect a 240ac supply to a breadboard because I knew 100% that it would not be a problem. Did you?

240VAC is NOT high voltage. High voltage is 1000V! Low voltage like 240AC wont arc on a bread board, for crying out LOUD! I am a trained electrician!

If you need to tread carefully, then do so. I have handled voltages a little beyond 240 volts ac. We know what we are doing, and we did not blow ourselves up, mainly because 240 ac is not exactly a high voltage, is it? OR is it?? You tell me.

What it comes down to with forums like this is that you love to consider yourselves "gurus". I ask a question, feel free to answer, I did not require Steven Hawkings type responses. If you have an answer, give it. If not, then don't, I am sure I will get by without your genius. Check yourself, before you check me.

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Yes, I am an engineer because people have employed me to be one, for pretty high sums of money. They trusted me, and no I did not blow myself up because I didn't realize that a bit of prototype board with some strips of metal and plastic on it led me to be "afraid".

There is a bigger world beyond a little controller board with a few inputs and outputs on it. It is called industry. It is called employment. People paid me to KNOW things. People paid me to go beyond some scared assumption that putting a bit of conductor onto a piece of prototype material will blow up the universe.

I used "science" to justify my decisions. Some of us have those qualifications, regardless of what stupid questions we ask. Wind your neck in. Laugh at my stupid questions, that show I don't know the theory of the universe, and like to have a little banter sometimes. Oh sorry, I asked such a stupid question. What a complete a-hole I must be. I guess I picked the wrong forum, with a bunch of self righteous "gurus".

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I consider every word from "jim" and many, many others here to be truth-driven. THAT is how electricity and electronics is, and should be. Their delivery style is exactly what you want to help resolve your issue. If their message is rough, it is to get you to examine your data and your question. It isn't a beatdown, it is exacting instruction. If you feel hurt, that is your problem to fix on another forum. Take their word as the truth, ask what you need to move toward accepted standards, thank them, and don't cry about your project being strawman-stomped. You think you know more than you do know. Let that feeling pass. Absorbe every word.

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Then you maybe need to reconsider when it comes to someone who knows A LOT more. There are people on here who seem to think that 240vAC is going ARC on a breadboard! 240VAC is LOW VOLTAGE! I am an electrician. 240VAC is LOW VOLTAGE! LOW!!

I am sure you do consider every word Jim says. I DO NOT! I am an electrician, and I KNOW these details. Jim apparently, does NOT. This is not about being "hurt", it is about the scientific and engineering TRUTH. I go by TRUTH, and engineering principles. I have the experience and knowledge to back it up.

Just because people ask, what you might think are "stupid questions", does not deny the TRUTH of their knowledge. There are people way beyond the knowledge and experience of Jim. I am one of them. If you denigrate me due to what you perceive as a stupid question, then so be it. Nobody has the theory of everything. We are ALL learning. We do it all the time

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Why does your government require voltage potentials over 80vdc to be labeled as deadly?

Probably due to your lead-in.

I can do that with 8.4vdc.

Prove it... or hal'd'clappe. His demeanor is nothing less than concerned, and he has kind compassion for those learning.

Examine how you started and proceeded in a new environment. Introspection might solve all your arguments with empty walls and clouds.

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Probably because it has the capability to be harmful. It is not going to ARC across a breadboard though, is it?

Someone who didn't know a lot quizzed me, and tried to denigrate what I knew. If you have a serious connection to a small voltage like 240ac or 110, it can HARM you. It depends on how you get connected to it. It can literally be lethal!

If you got 2 mole grips, and connected them to both the incoming supply coming from the mains, and gripped them... it will HURT you! it is a nasty shock! This is to do with body area, and how much connection you have to the circuit. People wire an earth to metal sinks for a reason. If that metal sink is not earthed, and a live cable is touching it... it is DANGEROUS. Water is a factor too.

EDIT: you added a load of stuff to that post. Do it as a different post preferably. No one can prove beyond any shadow of a doubt what they know. It is a minefield.

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That would be me... I asked you to understand your knowlwdge. Why would you be asking questions if you have the answers? We both know why. Just absorbe the responses.

You keep referring to "stupid"... failing to define a question, and being asked to add data is neither condescending nor stupid, just use of unlike terms. Like a Frankfurter talking to a Schwabe. Be prepared, not offended.

You could probably complete your question/answer session if you adapt to the environment, rather that demanding the environment adapt to you.

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Sorry... you are right. I did not pay attention to activity.

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Yes, apparently in the UK, anyone can call themselves an engineer.

Helpers on this forum evaluate you based on what you have posted. Your feigned ignorance of much of basic electronics misled them. Today you post a suggestion for a circuit that if followed by someone , perhaps a young student, could get them killed. Then you justify it by proclaiming that you've been pranking everyone here and you are in fact a skilled engineer, scientist, a paid professional. Maybe you can understand the resultant skepticism.

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Knowledge versus respect: an anecdote. I was a competetive swimmwer from pre-teen to past-my-prime. I warmed up with two miles of various strokes and hinderances to increase strength. I could submerge for 100m... never did a day pass when I knew all water wanted me dead, and I must be swimming correctly, always, or die. "It's just water." I know... all too well. Danny Rocco didn't.

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No, it was not you who quizzed me. It was someone in the past, a couple of decades ago, who was completely devoid of knowledge of electrical principles, who was some DIY man. I think they were trying to "catch" me somehow. They were just pissing around because they thought they were some big shot, but they had literally no sense of anything. A lot of DIY people think they know something and yet they literally understand nothing, except the principle of putting wires into something.

They did not understand the principles of electrical engineering, but they were a DIY guy. I am a electrical engineer, so I know this stuff because it was my job. I pointed out that it is unlikely to get electrocuted by a house supply, because that is the truth. They just pretended to know something, but they clearly had no knowledge of anything, beyond the putting of wires into terminals lol. And yes, they ignored my advice on how to do things to IEE standards. They know all they need to know, apparently.

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Not sure what that post relates to but nvm :stuck_out_tongue:

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The heavies here are not this, they know their stuff. Stick with the forum. The perspectives here might give you what you want.

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In industry we had 2 groups of people, in basic terms. One of those groups were "operators". They operated the machines. They did what they were told. They did not innovate, and they were essentially banned from interfering with machines. Oh, they tried to interfere with machines, sometimes, because they often thought above their station. They were wrong.

And I am one of those people who dressed them down. If I found them going above their station, and doing things that were above their ability, or capability, I made sure that they did not. They were not paid to do that. I "checked" that to avoid them getting sacked for sabotage. I was really tactful, and I made them know where they stand.

The other group of people were "engineers". There was a difference in the amount they got paid. I was the engineer.

Would you like to take a wild guess as to which group you belong to, and which group I belonged to?

No Emily, 240vac is not going to arc on a breadboard. Would you like for me to go way back in my experience, and engineering training to describe why? Do you know the types of people who provide information as to not going above 50v, on a breadboard, for example. I will give you a hint... it is something to do with science, apprenticeships, and large amounts of money being funded to train people to be engineers, rather than operators.

Would you like to press this further? Or would you like to presume that you are just "correct"? Do you need me to supposedly "troll" any further, or should we maybe consider the idea that I do not actually fit that description?

Yes, Emily, I put 240vac on a breadboard. I did not blow up, and it did not smoke, and I am still alive (but I am wondering at this point whether you would have liked this fabled breadboard explosion, to have killed me??) It did not occur. And it won't. I thank you.

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Is this up for voting?

So, you understand.

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  • I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, I . . . . .

:grimacing:

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Then it would be a strong recommendation that they just stick to answering questions, and not trying to probe people's experience, and expertise. I can get info elsewhere. I was not desperate, and I am still not. I could just go somewhere else, and maybe that is what would be preferred (by you or others).

I can leave, and I can go elsewhere.

None of the responses, that questioned my experience as an engineer, were asked for. They simply materialized, without my request. They were not needed. I do not need recommendations on engineering. I can handle that myself. I do not need someone to warn me of the nonexistent threat of an arc from 240vac.

Keep testing my patience further, and my ego will probably require me to keep responding. I try to follow Eckhart Tolle's advice, and just stop. I guess I just have not got there yet. Tolle save me from my ego!

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No, it is not really up for voting. I can tell you now, to give you peace of mind... it ain't gonna happen. No a breadboard is not gonna explode because someone applies a low AC voltage to it, like 240vac. By all means step that voltage up to 10000 volts, and then try it.

240vac... nope.