Hi all,
I'm stuck. Is there a basic principle which can explain current flow between components in an amplifier. Does the flow come from the chassis or the B+, or is it a matter of equilibrium/potential difference between each component. I have some old radio books which I've been reading which start well enough in their explanations of basic principles but then they lose me.

I have a feeling that what I'm asking for cannot be answered in a brief statement so maybe someone could point me in the right direction.

PS I have watched hours of youtube and that has been really helpful but I'm just caught at this point. Also I know that I'm a bit thick in this area which doesn't help.

Cheers
Pat

This little bit of confusion was caused by the original assumption that current flowed from positive to negative & that's called "Conventional flow". Noting that it was not until around 1898 that Boyle discovered & described the electron they then worked out that electron flow was actually the reverse. The other under their nose revelation recently is that Electrons are promiscuous little devils & the flow of them is actually a case of them not being dedicated to one shell, they will actually jump ship.

I really don't think it matters too much as to which way its going in the amp. Most issues are caused when it stops going, or takes a short cut.

The easiest device to understand (mentioned before) is the FET. It has a Source; a Gate (or more); and a Drain So its: "Simplelness"

You apply a source, open the gate/s, & it all goes down the drain.

Marc

Yes, conventional current flow is from anode to cathode, actual flow of electrons is the opposite.

But in fact, it doesn't matter at all as long as you are consistent!

Yes, agree with the above .... however, if you want to understand valves, then I suggest you think in terms of electron flow.

Unfortunately, this is against the 'trend' .... as many textbooks use Conventional flow ... certainly 'exercises' the mind when beginning to learn electronics ...

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Cheers, Ian

Thanks all,

Yes I now get the FET thanks Mark. I think my problem is that I'm making it harder than I have to.

If there was this confusion at the beginning and circuits obviously worked then am I right in assuming that it doesn't really matter which way it goes? As long as there is movement of electrons, or current flow in a circuit it doesn't really matter where from or where to as long as the voltage/ current readings for a particular component align with circuit requirements.

Pat

Let us thank Benjamin Franklin for conventional current, after all, everyone must learn that electric fluid flows from positive to negative.

Just noted after reading the comments again, which I've done a few times now, that you Marc have already suggested that it doesn't really matter which direction the current is going as long as it stays going. So thanks again all for your help I'll just get on with it!

Cheers
Pat (permanently bewildered)

Marc's sarcasm is something we've all come to know and love.

I'd modify that statement to say that it doesn't matter which way the current flows, as long as its the correct way.

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A valve a day keeps the transistor away...

Yes, the correct way is the way that doesn't let the smoke out.

Electronics runs on smoke. If the smoke gets out, it's broken.

Benjamin Franklin didn't notice (or have any way of telling in fairness) that the sparks jumped UP from the ground wire to the key!
Many people were killed trying to replicate his famous kite flying experiment.

Some of us have a warped sense of humour & do not see a great need to complicate things. Being on a Farm & copping the crap we cop constantly, says one needs a sense of humour. Obviously, rarely are we the Pidgeon, usually its the statue.

This week appears to be statue week as the tractor started it off doing a rear tyre. So that's near enough to $700 & then there is a few hours of entertainment from the latest tree bombing of the boundary fence and for extra amusement The wipers on the ute are not working. It cannot be an electrical fault as they are not electric.

Of more concern: The Wax paper cap would be a classic example of where DC current should not flow. By now & based on random testing for provenance: Those Wax Paper caps, which couple from Plate to grid one in a valve amp. can do a lot of damage. These will cause the grid to be driven more positive and valves do not like the grid positive as it turns them into a diode.

The other thing to learn that is not often understood, is measurement. Not all meters are the same. Digital & Analogue can both lie when used wrongly So you need more so than worrying about electron flow, to know & interpret what the meter is actually showing you..

Marc

Ok thanks for all that. At this stage of my learning it is difficult weeding out the non factual from factual.

Cheers

Pat

One must be careful with online stuff, there are plenty of armchair experts & legends in their own lunchtime who are full of it and often a danger to humanity.

I can remember a clown on U-tube that was going to show how to repair an Oscilloscope. First thing: Turned it on & blew up the rectifier: Fail.

Several members of the Forum that had seen it & pointed it out.; Were onto U-tube to have it and the next one taken down, in the interest of public safety. If you rat some of the second hand book shops you may do well. Some of the school physics books may be a more accurate source and better put. Some of mine are from Library's tossing out reference books, containing valuable historic info.

Marc

Yep done that, I have a high school physics book and some great old books from the local antique shop including "Everybody's Radio Manual" and "Radio and Television Engineers' Reference Book" which is huge and not understandable for me yet, along with a few others. So as I said before it's a matter getting on with it, sitting down and taking the time to STUDY!! yuk...

Cheers
Pat

Patrick, you may get some reading/study tips from this thread:

https://vintage-radio.com.au/default.asp?f=2&th=736

QUOTE: many textbooks use Conventional flow

This error is much too deeply embedded in electronics theory for it ever to be corrected. Everyone ends up learning to live with it.

Similar things are found in mathematics. "Imaginary numbers". I hated that term, as "imaginary" meant to me "bogus" or "fake" And I heard that the first mathematicians that discovered these kinds of numbers felt sure that they were bogus, that they made some mistake that they could not find. Turns out imaginary and complex numbers happen to fit things in electronics, with caps and coils.