I chose Functional because it sounded most like "Eh, just get it working, don't worry about safety".
2 months ago
| 116
Your quizzes remind me that in fact no, I'm not an electrical engineer and that if it isn't a flashlight powered by two AA's then I probably should stay away.
2 months ago
| 76
Don't forget option number 4, a 9 volt battery to the tongue
2 months ago
| 34
Now you’re just pulling out random scrabble tiles to make me stupid. I’m on to you, sir. 😎
2 months ago
| 14
2 of them sound like they have some form of safety, and the other one sounds like it's just supposed to work. That's the only reason I guessed it right.
2 months ago (edited)
| 15
Choose 'functional' just because that sounded more like a 'eh, it works' kind of option.
2 months ago
| 3
I once had this as an exam question. Never forgot it, thanks for the memory Clive😄
2 months ago
| 4
I'm not inclined to cheat with a google search. I'd rather a "don't know"option.
2 months ago
| 24
I first misread it as 'least danger of shock' and started to write a comment about how the choice between SELV and PELV depends on what fault condition you're trying to address. Then I reread the question and the answer was obvious.
2 months ago
| 1
No Google needed for me I have seen enough mains voltage on a 5v output to drum that fact into me. I call them extra spicy ports. (240v here in wales) 120v is just spicy ports.
2 months ago (edited)
| 7
First one of these that I had not even the first inclining of the answer without looking it up. Usually even if I've never really learned it or forgotten your question reminds me I actually have heard of the topic in question, but this time...
2 months ago
| 0
A nurse in France was killed when she reached out for her phone to change the music. She was in the shower at the time and her hands were wet, and the phone was plugged into a non isolated charger...
2 months ago (edited)
| 9
GOT THIS ONE SIR! NOT FULLY ISOLATED SO YOU MIGHT GET THE BIG ONE BIG C!! 🤔❤❤❤💯💯💯👍👍👍👍
2 months ago
| 1
I well remember the first device I built with an FELV supply! It was a lighting controller. This was in the 1980s, before switched mode supplies, so it used two mains transformers; one for the PELV circuitry which was referenced to mains Earth, and one for the FELV circuitry which had its 0V tied to mains live. (None of that switching the neutral malarkey round here!) A bunch of opto-isolators sat between the two sections.
2 months ago
| 1
Used chatgpt instead... PELV, SELV, and FELV are classifications of low voltage electrical systems based on IEC standards (primarily IEC 60364). They define how electrical systems are isolated and protected to ensure safety, particularly from electric shock. 🔹 1. SELV — Separated Extra-Low Voltage Definition: A system that is electrically separated from earth and other systems to prevent electric shock. Max voltage: ≤ 50 V AC or ≤ 120 V DC (dry conditions) ≤ 25 V AC or ≤ 60 V DC (wet conditions) Features: No connection to earth (floating system) Power source is isolated (e.g., safety transformer, battery) All accessible parts are insulated or enclosed ✅ Best for: electronics, toys, medical equipment, bathroom lights 🔐 Very safe, because no conductive path to earth or other circuits 🔹 2. PELV — Protected Extra-Low Voltage Definition: Similar to SELV, but allows a connection to earth. Max voltage: Same as SELV Features: Protective earthing may be used Often used when a common reference (e.g., ground) is needed Same insulation and safety requirements as SELV ✅ Used in: industrial control panels, automation systems ⚠️ Slightly higher risk than SELV due to possible fault current via earth 🔹 3. FELV — Functional Extra-Low Voltage Definition: A system operating at extra-low voltage, but without the safety features of SELV or PELV. Features: Not isolated from higher voltage circuits May use conventional transformers without special isolation No guaranteed protection from electric shock ⚠️ Used when the low voltage is required for function, not safety ❌ Not inherently safe — must be treated like higher voltage systems regarding insulation and protec
2 months ago
| 1
I've seen lots of those crappy buck power supplies used in spots where they really should not, mostly plug in adapters up to 12v. When the final filter and zener go open suddenly you got full rectified maybe chopped maybe not mains volts across your device. 😳💀💀💀
2 months ago
| 0
bigclivedotcom
Of the three common extra low voltage systems, which one carries the most risk of a dangerous electric shock. (You're allowed to Google this one.)
2 months ago | [YT] | 663