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Is anyone willing to step up to the plate?
- supertigrefan
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I've started trawling the interweb so I can teach myself but it would be good to use here as kind of a base to discuss questions and get some clarity. My weak point has always been Maths, I look at formulas and numbers and instantly skip past because to me it's a language I don't understand, a bit like looking at a page of Chinese, thing is I hold C&G qualifications in Electrical installation (15th Edition 236 part 1 & 2, Never used them though) so it's not as if I can't do it.
A couple of weeks ago I couldn't tell a diode from a transistor, now I can not only see them on a schematic but understand what they do, I now know about the 'Darlington' can find a Zenner and LEDs, know the differences and how a Capacitor works and why they're used, work out resistors in Parallel, what a bridge rectifier is......I can now even build a voltage compensated glow driver following a schematic, that's a milestone for me! Anyway, do we have any qualified Electronics engineers or competent hobbyists in our ranks that would act as tutors for us interested in taking up electronics?
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- Pylonuk
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Well another thing in common is holding C&G 15th edition !!
I am not much good at electronics although I will be watching this thread with interest to pick up tips.
B.
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- crash happy
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- Eric
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Also - circuit layout is important, too, to prevent unwanted interaction between components and circuit sections - especially on todays' extremely compact boards.
A lot of devices use integrated circuits, too, and unless you can identify exactly which one it is, and can obtain the circuit diagram of what is inside, you cannot easily tell what it does, never mind how.
if you are calm and collected when all about you are going berserk - you've missed something important!
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- supertigrefan
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I've been doing that and think I've got most of the symbols cracked, knowing what the components do is a massive help but there's a lot of head scratching when I see a part used that has a similar function to another and don't understand why it was used instead. I get that Zeners allow current flow only in one direction until a threshold is reached where they then allow flow in reverse and that Transistors act like a switch and amplify a signal but what is the purpose of a MOSFET above a standard field effect tranny? I also found out that if you open up a Transistor it acts similar to a photocell!crash happy wrote: From my limited experience I would suggest that learning to read a wiring diagram would be a good place to start. Knowing what a circuit does & how to build it, is far more important than knowing how it does it. Designing a circuit is a different ball game !
What's the difference between a variable resistor and a rheostat?
What's a Triac?
Why would you need 2 Zeners is series?
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- Eric
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With a cheap audio amp connected to a speaker, but with no input, turn the volume up to max, and you can hear the electrons hissing as they pass the 'junctions' and the next transistor amplifies that, and adds it's own, and the third one does the same, so you end up with a loud hiss and a weak signal
A MOSFET still hisses, (any 'active' component does) but does it more quietly, so are better for radio 'front ends' where the required signal is weak to start with.
if you are calm and collected when all about you are going berserk - you've missed something important!
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- supertigrefan
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SMC's are teeny and almost need surgical precision to work on but that's what magnifiers and electric 'scopes are for. I intend to stick with through hole components, Vero board and wire rather than all that stuff.Eric wrote: Although I have a Radio Amateur's license, and have an understanding of how things work, I wouldn't attempt to repair anything modern, because the sub-micro components in use now - I can't even SEE, never mind identify!
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- supertigrefan
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- Eric
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Both explain what happens and why, in a circuit, (and what to look for if it doesn't!)
if you are calm and collected when all about you are going berserk - you've missed something important!
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- Eric
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Back to the cheap amp, if you have a noisy power supply, you'll have an amplified noisy output!
if you are calm and collected when all about you are going berserk - you've missed something important!
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